rc

[fork] interactive rc shell
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commit 26bb34cf036027dfa22dfae8d8fc2f6bfd6acb75
Author: Byron Rakitzis <byron@archone.tamu.edu>
Date:   Wed, 27 May 1992 00:00:01 +0100

release: rc-1.4

Diffstat:
A.gitignore | 0
ACHANGES | 171+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
ACOPYRIGHT | 26++++++++++++++++++++++++++
AEXAMPLES | 749+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
AMakefile | 65+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
AREADME | 100+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Aaddon.c | 22++++++++++++++++++++++
Aaddon.h | 38++++++++++++++++++++++++++++++++++++++
Abuiltins.c | 532+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Aconfig.h-dist | 204+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Acpp | 38++++++++++++++++++++++++++++++++++++++
Aexcept.c | 140+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Aexec.c | 119+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Aexecve.c | 61+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Afn.c | 266+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Afootobar.c | 368+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Agetopt.c | 50++++++++++++++++++++++++++++++++++++++++++++++++++
Aglob.c | 240+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Aglom.c | 420+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Ahash.c | 302++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Aheredoc.c | 156+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Ahistory/Makefile | 6++++++
Ahistory/history.1 | 234+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Ahistory/history.c | 333+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Ainput.c | 373+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Ajbwrap.h | 10++++++++++
Alex.c | 398+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Alist.c | 57+++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Amain.c | 115+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Amatch.c | 99+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Amksignal | 75+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Analloc.c | 137+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Aopen.c | 29+++++++++++++++++++++++++++++
Aparse.y | 174+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Aprint.c | 456+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Aproto.h | 81+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Arc.1 | 1880+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Arc.h | 380+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Aredir.c | 77+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Asignal.c | 75+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Astatus.c | 139+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Atree.c | 172+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Atrip.rc | 0
Autils.c | 125+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Avar.c | 226+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Aversion.c | 1+
Await.c | 124+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Awalk.c | 344+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Awhich.c | 114+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
49 files changed, 10301 insertions(+), 0 deletions(-)

diff --git a/.gitignore b/.gitignore diff --git a/CHANGES b/CHANGES @@ -0,0 +1,171 @@ +Changes since 1.2: (Too many to count!) + +A memory stomping bug was fixed (provoked by assigning a variable +to its old value plus something else). + +Better signal handling; a real signal handler which manages a queue +of pending signals was added. + +rc now ignores SIGQUIT and traps SIGINT even in non-interactive +mode. Thus, + + rc ed.sh + +will not do mysterious things if the shell script "ed.sh" calls a +command like "ed" and then you hit ^C. + +rc now opens 0, 1, 2 on /dev/null if they are inherited closed. +rc -o prevents this. + +A couple of stupid O(n^2) string appends were replaced with O(n) +loops. This should make foo=`{cat /etc/termcap} bar=$^foo a little +faster :-) + +Returning a list of signals from a function is now legal, so "return +$status" should always work. + +The code has been revised, new printing routines have been added. + +rc no longer uses redundant braces when exporting functions. + +A first stab at a verification suite has been added (trip.rc). +(someone, please help me make this comprehensive!) + +rc -p now does not initialize functions from the environment. This +should make it easier to write shell scripts that don't need to +assume anything about the environment. + +Inherited ignored signals are now ignored in the current shell and +passed on ignored to the child processes. whatis -s also reflects +this information. + +A file descriptor leak in the /dev/fd implementation of >{} was +fixed. + +A variable set to '' was not imported from the environment; this +has been fixed. + +Changes since 1.3beta: + +New Makefile/config.h setup. + +builtin echo may now be conditionally included out, to use a Goldwynism. + +builtin exit takes any legal exit status. If the status is not all zeros, +rc exits with 1. (having "exit sigiot" produce a core dump would be going +a little far, I think.) + +limit does not append a unit after a zero limit; 0g was too confusing. + +exec > /nonexistentfile does not cause rc to exit any more. + +If a noninteractive rc is started with sigint ignored, rc does not install +its own signal handler. + +error messages produced by rc in a subshell were cleaned up. (rc erroneously +reset the 'interactive' flag after a fork) + +print.c was cleaned up a little; no functionality was changed, but should +be more portable now. + +a bug in rc-1.3beta (not previous versions) was fixed: setting the first +element of $path to '' caused PATH to be exported as '':etc.. + +getopt's "illegal option" message was gratuitously changed to something +less abrupt. + +some dead code was removed from input.c + +%term was changed to %token in parse.y; apparently newer yacc's don't grok +%term any more. + +a race condition in the signal handler was fixed. + +the variable in for() was getting evaluated each time through the loop +(e.g., for (`{echo i;date>[1=2]} in 1 2 3)echo $i would print the date +three times). This was cleaned up. + +a redundant fork() was removed from walk.c; this showed up when running +a braced command with a redirection in the background. e.g., {a;b}>c& + +man pages for history and rc were cleaned up by david (thanks). + +rc set SIGQUIT and SIGTERM to SIG_DFL on background jobs---even when +trying to do old-style backgrounding (i.e., don't use process groups, +just ignore SIGINT & SIGQUIT & SIGTERM). + +$0 is now changed to the name of the signal when entering a signal +handler. Thus it's possible to write code like + + fn sigint sigterm sigquit { + switch ($0) { + case sigint + ... + case sigterm + ... + +wait with no arguments now prints the pid of any and all children +that died with a signal. e.g., + + ; wait + 25321: terminated + 25325: terminated + +as opposed to + + ; wait + terminated + +An error saving/restoring state in the input stream code would +cause rc to exit with the (erroneous) command: + + eval '|[a' + +FIFO's were not removed in a backgrounded command, e.g., + + cat <{echo hi}& + +Changes since rc-1.4beta: + +getopt was renamed to rc_getopt to avoid libc collisions. + +$cdpath with a / in it caused a cd to sometimes have two //'s at the +front of the path. This is reserved by POSIX, so I changed it to skip +one of the /'s. + +signal handling now emulates sh in the way I described in a previous +message: the race condition present in older rc's whereby some SIGINTs +got lost is now gone; any SIGINT received during a wait() is acted upon +at the end of the wait(), unless of course SIGINT is being deliberately +ignored. + +getopt was renamed to avoid naming conflicts with libc. Also a sound +move since rc_getopt is no longer quite libc-getopt compatible; I had +to add in a mechanism for resetting getopt. + +signal handler code in fn.c was cleaned up; there were several bugs +in rc-1.4beta, notably the shell sometimes spawned background jobs +with SIGTERM ignored. I took the opportunity to make things a little +cleaner here. + +a quasi-memory leak in the code for while() was fixed: a long-running +while that had rc commands allocating memory in it could cause the +shell to grow without bounds. I fixed this by placing the while loop +(*and* test!) inside a new allocation arena each time through the loop. + +A new configuration parameter, NOJOB, was added to allow you to force +v7-style backgrounding (no setpgrp, ignore SIGINT and SIGTERM). + +The FIFO code was reworked a little. It should be more robust now--- +FIFOs get removed at the end of the command of the argument list +that they were on: + + fn foo {echo $*; cat $*} + foo<{echo hi} + +now works as expected. Also FIFO names are pushed onto the exception +stack so that their removal occurs in the face of exceptions and so +on. + +A memory leak in treefree() was plugged up --- the root node of a +function was not getting freed. diff --git a/COPYRIGHT b/COPYRIGHT @@ -0,0 +1,26 @@ +/* + * Copyright 1991 Byron Rakitzis. All rights reserved. + * + * This software is not subject to any license of the American Telephone + * and Telegraph Company or of the Regents of the University of California. + * + * Permission is granted to anyone to use this software for any purpose on + * any computer system, and to alter it and redistribute it freely, subject + * to the following restrictions: + * + * 1. The author is not responsible for the consequences of use of this + * software, no matter how awful, even if they arise from flaws in it. + * + * 2. The origin of this software must not be misrepresented, either by + * explicit claim or by omission. Since few users ever read sources, + * credits must appear in the documentation. + * + * 3. Altered versions must be plainly marked as such, and must not be + * misrepresented as being the original software. Since few users + * ever read sources, credits must appear in the documentation. + * + * 4. This notice may not be removed or altered. + * + * [this copyright notice is adapted from Henry Spencer's + * "awf" copyright notice.] + */ diff --git a/EXAMPLES b/EXAMPLES @@ -0,0 +1,749 @@ +There is no repository for useful rc code snippets as yet, so I'm including +a (short) file in the distribution with some helpful/intriguing pieces of +rc code. + +A sample .rcrc +-------------- +Here is the .rcrc I use on archone: + +umask 022 +path=(/bin /usr/bin /usr/ucb) +ht=`/usr/arch/bin/hosttype +h=$home +history=$h/.history +bin=$h/bin/$ht +lib=$h/lib/$ht +sh=$h/bin/sh +include=$h/lib/include + +switch ($ht) { +case sun* + OBERON='. '$h/other/oberon + p=/usr/ucb + compiler='gcc -Wall -O -g' + MANPATH=$h/man:/usr/arch/man:/usr/man + if (! ~ $TERM ()) { + stty dec + /usr/arch/bin/msgs -q + } +case next + p=(/usr/ucb /usr/bin /NextApps) + compiler='cc -Wall -O -g -DNODIRENT' + MANPATH=$h/man:/usr/arch/man:/usr/man + if (! ~ $TERM ()) + stty dec +case sgi + p=(/usr/ucb /usr/sbin /usr/bin) + compiler='gcc -Wall -O -g -DNOSIGCLD' + MANPATH=$h/man:/usr/arch/man:/usr/catman + if (!{~ $TERM () || ~ $TERM *iris*}) + stty line 1 intr '' erase '' kill '' +case * + echo .rcrc not configured for this machine +} + +path=(. $sh $bin /usr/arch/bin $p /bin /usr/bin/X11 /etc /usr/etc) +cdpath=(. .. $h $h/src $h/misc $h/other $h/adm) +RNINIT=-d$h' -t -M -2400-h -2400+hfrom'; DOTDIR=$h/misc/news +PRINTER=lw + +fn s { + echo $status +} +fn cd { + builtin cd $1 && \ + switch ($1) { + case () + dir=$home + case * + dir=() + } +} +fn pwd { + if (~ $dir ()) + dir=`/bin/pwd + echo $dir +} +fn x { + if (~ `tty /dev/console) + clear_colormap + clear + exit +} +fn p { + if (~ $history ()) { + echo '$history not set' >[1=2] + return 1 + } + + if (! ~ $#* 0 1 2) { + echo usage: $0 '[egrep pattern] [sed command]' >[1=2] + return 1 + } + + command=`{ + egrep -v '^[ ]*p([ ]+|$)' $history | switch ($#*) { + case 0 + cat + case 1 + egrep $1 + case 2 + egrep $1 | sed $2 + } | tail -1 + } + + echo $command + eval $command +} + +if (~ $TERM dialup network) { + TERM=vt100 + biff y +} + +A front-end to NeXT's "openfile" +-------------------------------- + +Named after the sam "B" command for opening a file, this script was written +by Paul Haahr. (Assumes the "pick" command from Kernighan and Pike is also +in your path.) + +#!/bin/rc +if (~ $#* 0) + exec openfile +create = () +files = () +for (i in $*) + if (test -f $i) { + files = ($files $i) + } else { + create = ($create $i) + } +create = `{ pick $create } +files = ($files $create) +for (i in $create) + > $i +if (! ~ $#files 0) + openfile $files + +A read function +--------------- + +Unlike sh, rc doesn't have a read. This clever alternative returns an +exit status as well as fetch a variable. Use as + + read foo + +to set $foo to a single line from the terminal. + +(due to John Mackin <john@syd.dit.csiro.au>) + +fn read { + x=() { + x = `` ($nl) { awk '{print; print 0; exit}' ^ $nl ^ \ + 'END {print 1; print 1}' } + $1 = $x(1) + return $x(2) + } +} + +From cs.wisc.edu!dws Fri Aug 2 18:16:14 1991 + +#------- +# ls front end +#------- +fn ls \ +{ + test -t 1 && * = (-FCb $*) + builtin ls $* +} +#------- +# nl - holds a newline, useful in certain command substitutions +#------- +nl=' +' +#------- +# show - tell me about a name +# +# Runs possibly dangerous things through cat -v in order to protect +# me from the effects of control characters I might have in the +# environment. +#------- +fn show \ +{ + * = `` $nl {whatis -- $*} + for(itis) + { + switch($^itis) + { + case 'fn '* ; echo $itis | cat -v -t + case builtin* ; echo $itis + case /* ; file $itis; ls -ld $itis + case *'='* ; echo $itis | cat -v -t + case * ; echo $itis: UNKNOWN: update show + } + } + itis = () +} +#------- +# Tell me automatically when a command has a nonzero status. +#------- +fn prompt \ +{ + Status = $status + ~ $Status 0 || echo '[status '$Status']' +} + +#------- +# chop - echo the given list, less its final member +# +# e.g. chop (a b c) -> (a b) +#------- +fn chop { + ~ $#* 0 1 && return 0 + ans = '' { # local variable + ans = () + while(! ~ $#* 1) + { + ans = ($ans $1) + shift + } + echo $ans + } +} + +From arnold@audiofax.com Thu May 30 08:49:51 1991 + +# cd.rc --- souped up version of cd + +# this is designed to emulate the fancy version of cd in ksh, +# so if you're a purist, feel free to gag + +_cwd=$home +_oldcwd=$home + +fn cd { + if (~ $#* 0) { + if (~ $_cwd $home) { # do nothing + } else { + builtin cd && { _oldcwd=$_cwd ; _cwd=$home } + } + } else if (~ $#* 1) { + if (~ $1 -) { + _t=$_cwd + builtin cd $_oldcwd && { + _cwd=$_oldcwd + _oldcwd=$_t + echo $_cwd + } + _t=() + } else { + # if a cd happens through the cdpath, rc echos + # the directory on its own. all we have to do + # is track where we end up + _dopwd = 1 + { ~ $1 /* } && _dopwd = 0 # absolute path + builtin cd $1 && { + _oldcwd=$_cwd + _cwd=$1 + { ~ $_dopwd 1 } && _cwd=`/bin/pwd + } + _dopwd=() + } + } else if (~ $#* 2) { + _t=`{ echo $_cwd | sed 's<'$1'<'$2'<' } + builtin cd $_t && { + _oldcwd=$_cwd + _cwd=$_t + echo $_cwd + } + _t=() + } else { + echo cd: takes 0, 1, or 2 arguments >[1=2] + builtin cd $1 && { _oldcwd=$_cwd ; _cwd=`/bin/pwd ; echo $_cwd } + } +} + +fn pwd { echo $_cwd } + +From vlsi.cs.caltech.edu!drazen Tue Jan 21 16:03:14 1992 + +# A kill builtin. + +#ifdef B_KILL +#include <ctype.h> +static void b_kill(char **av) +{ + int signal = SIGTERM; + int n = 1; + pid_t pid; + boolean res; + + if (!av[1]) { + set(TRUE); + return; + } +#undef STRCMP +#define STRCMP strcmp + if ( '-' == av[1][0]) { + char *p = 1+av[1]; + if (0 == strcmp(av[1], "-l")){ + int r; const int nsig = NUMOFSIGNALS; + const int C = 4, R = 1 + (int)((nsig-2)/C); + for (r=1; r<=R; r++){ + int j; + for (j=r; j<nsig; j+=R){ + fprint(1, "%s%d. %s\t", j<10?" ":"", j, signals[j][0]); + } + fprint(1,"\n"); + } + set(TRUE); + return; + } + n++; + if ( (signal=a2u(p)) < 0){ + int i; + for (i = 1; i < NUMOFSIGNALS; i++){ + char UPPER[31], *u=UPPER, *q; + for (q=signals[i][0]; *q; q++, u++) *u = toupper(*q); + *u = '\0'; + + if (*signals[i][0] && + (!STRCMP(signals[i][0], p) || !STRCMP(3+signals[i][0],p) + || !STRCMP(UPPER, p) || !STRCMP(3+UPPER, p) ) ) + { + signal = i; + break; + } + } + if (signal < 0){ + fprint(2,"kill: bad signal %s\n", av[1]); + set(FALSE); + return; + } + } + } +#undef STRCMP + + for (res=TRUE; av[n]; n++){ + if( (pid = (pid_t) a2u(av[n])) < 0){ + fprint(2, "kill: bad process number %s\n", av[n]); + res = FALSE; + continue; + } + if (kill(pid,signal)){ + uerror("kill"); + res = FALSE; + continue; + } + } + set(res); +} +#endif +From acc.stolaf.edu!quanstro Thu Apr 2 02:51:10 1992 +Received: from thor.acc.stolaf.edu ([130.71.192.1]) by archone.tamu.edu with SMTP id <45339>; Thu, 2 Apr 1992 02:50:56 -0600 +Received: by thor.acc.stolaf.edu; Thu, 2 Apr 92 02:49:31 -0600 +Date: Thu, 2 Apr 1992 02:49:31 -0600 +From: quanstro@acc.stolaf.edu +Message-Id: <9204020849.AA26566@thor.acc.stolaf.edu> +To: byron@archone.tamu.edu +Subject: EXAMPLES in 1.4beta +Status: RO + + +I have a little bit of code which might be a little more general than +the souped-up version that is already there. Here it is, if you are +interested. + +# directory functions ################################################### +fn pwd { echo $PWD; } + +fn pushd { + dirs = ($PWD $dirs); + builtin cd $*; + PWD = `{builtin pwd}; +} + +fn popd { + switch ($#*) + { + case 0 + ; + case 1 + echo 'popd: argument '^$1^' ignored.' >[1=2]; + case * + echo 'popd: usage: popd [n].'; + } + + if (! ~ $dirs ()) + { + builtin cd $dirs(1); + PWD = $dirs(1); + echo $PWD; + * = $dirs; + shift + dirs = $*; + } +} + +fn cd { + ~ $* () && * = $home; + !~ $#* 1 && echo 'cd: too many arguments' >[1=2] && return 1; + + if (test -r $* ) { + pushd $*; + } else { + echo cd: $* does not exist. >[1=2] + return 1; + } +} + +fn back { popd $*; } + +fn Back { + cd $home; + PWD = $home; + dirs = (); +} + +fn dirs { + echo $dirs; +} + +PWD = `{builtin pwd} ; dirs = $PWD # kickstart + + + + + +From acc.stolaf.edu!quanstro Thu Apr 2 02:53:40 1992 +Received: from thor.acc.stolaf.edu ([130.71.192.1]) by archone.tamu.edu with SMTP id <45339>; Thu, 2 Apr 1992 02:53:38 -0600 +Received: by thor.acc.stolaf.edu; Thu, 2 Apr 92 02:51:46 -0600 +Date: Thu, 2 Apr 1992 02:51:46 -0600 +From: quanstro@acc.stolaf.edu +Message-Id: <9204020851.AA26573@thor.acc.stolaf.edu> +To: byron@archone.tamu.edu +Subject: EXAMPLES +Status: RO + + +Little yp hack which act's like ~ w/o syntatic sugar (for those who do +not have the luxury of seting up symbolic links to all user's homes + +# user function ######################################################### +fn u user { + info = () + info = `` (':') {ypmatch $1 passwd >[2] /dev/null } + + if (~ $info ()) { + echo user $1 unknown >[1=2]; + return 1; + } else { + echo $info(6) + if (~ $0 user) + cd $info(6) + } +} + + +From stolaf.edu!quanstro Sun Apr 5 04:53:34 1992 +Date: Sun, 5 Apr 1992 04:53:08 -0500 +From: quanstro@stolaf.edu (Erik Quanstrom) +To: byron@archone.tamu.edu +Subject: man written in rc +Status: RO + +I whipped this up because the NeXTs here insist on using MANPAGER +instead of PAGER and otherwise being obnoxious . . . + +Anyway ... I hope you approve + +#!/bin/rc +######################################################################### +# file: man # +# # +# object: display man pages # +# # +# bugs: * slow # +# * does not know about fmt files # +# # +# Erik Quanstrom # +# 11. Februar 1992 # +######################################################################### +PATH=/bin:/usr/bin:/usr/ucb:/usr/local/bin:$PATH ; +TROFF = (nroff -hq -Tcrt); +macros=an; +sections=(cat1 cat2 cat3 cat4 cat5 cat6 cat7 cat8 catl man1 man2 man3 man4 \ + man5 man6 man7 man8 manl) +$nl=' +' +fn sigint sighup sigquit sigalrm sigterm { rm -f $Bat; exit 2;} + +fn usage { + echo usage: $0 [-] [-t] [-M path] [-T macros] [[section] title] ...>[1=2]; + exit 1; +} + +n=(); +fn shiftn { + n=($n 1) +} + +~ $PAGER () && test -t 1 && PAGER=more; #default pager + +while (~ $1 -*) + { + switch ($1) + { + case - + if (~ $PAGER troff) + echo bad combination of flags >[1=2] && usage; + PAGER=cat; + case -t + ~ TROFF () && TROFF = (troff -t); + ~ TCAT () && PAGER=(lpr -t); + case -M + shift; + ~ $1 () && usage; + + MANPATH=$1; + case -T + shift; + ~ $1 () && usage; + macros=$1; + case -k + fflag=(); kflag=1; + shift; + break; + case -f + # locate related too filenames + kflag=(); fflag=1; + shift; + break; + case -* + echo bad flag '`'^$1^'''' >[1=2]; + usage; + } + shift; + } + +if (!~ $#* 1) { + ~ $1 [l1-8] && { sname=$1 ; sections=(cat man)^$1 ; shift } + #hack for sun-style man pages + ~ $1 [l1-8]? && { sname=$1 ; sections=(cat man)^`{echo $1| cut -c1} ; shift } +} + +if (~ 1 $fflag $kflag) { + dirlist=(); + for (d in ``(:$nl) {echo $MANPATH}) + test -s $d^/whatis && dirlist=($dirlist $d^/whatis); + + ~ $1 () && usage; + + if (~ $fflag 1) { + while (!~ $1 ()) { + cmd=`{echo $1 | sed 's/^.*\///g'} + egrep -h '^'^$cmd' ' $dirlist; + shift; + } + } else { + while (!~ $1 ()) { + grep -h $1 $dirlist; + shift; + } + } + exit 0; +} + +s=0; +while (!~ $1 ()) { + for (dir in ``(:$nl) {echo $MANPATH}) { + filelist=($filelist `{echo $dir/^$sections^/$1^.* |\ + tr ' ' '\12' | grep -v '*'}) + + # coment this out if you don't care about speed, but + # would rather find all the pages. + ~ $filelist () || break; + } + + if (~ $filelist ()) { + if (~ $#sections 2) { + echo no entry for $1 in section '`'$sname'''' of the manual >[1=2]; + } else { + echo no entry for '`'$1'''' found. >[1=2]; + } + s=1; + } else { + + echo $filelist '(' $#filelist ')' >[1=2]; + + for (file in $filelist) { + if (~ $file */cat[1-8l]/*) { + Cat = ($Cat $file); + } else { + # search for dups + dont=() + for (x in $Cat) { + if (~ `{echo $x | sed 's/\/[mc]a[nt][1-8l]//'} \ + `{echo $file | sed 's/\/[mc]a[nt][1-8l]//'}) { + dont=1; + break; + } + } + + if (~ $dont ()) { + cd `{echo $file | sed 's/man[1-8].*//'} + echo -n Formatting ... + $TROFF -m^$macros $file > /tmp/man^$pid^$#n && \ + Bat = ($Bat /tmp/man^$pid^$#n) + + shiftn; + echo ' 'done. + } + } + } + } + shift; +} + +{ !~ () $Cat || !~ () $Bat } && $PAGER $Cat $Bat; + +rm -f $Bat; +~ $s () || exit $s; + +exit 0; + + + +From osf.org!rsalz Thu Apr 23 16:22:32 1992 +Date: Thu, 23 Apr 1992 16:22:07 -0500 +From: rsalz@osf.org +To: byron@archone.tamu.edu +Subject: One for your EXAMPLES file +Status: RO + +Use + trimhist [-#lines] +trims your history file back; useful for folks with dis quota's :-) +fn trimhist { p1=-100 { + cp $history $history^'~' + ~ $#* 1 && p1=$1 + tail $p1 <$history^'~' >$history + rm $history^'~' +} } + +From Pa.dec.com!uucp Mon Apr 27 12:25:02 1992 +Date: Mon, 27 Apr 1992 12:15:18 -0500 +From: haahr@adobe.com +To: Byron Rakitzis <byron@archone.tamu.edu> +Subject: a neat little rc script + +what you have to know to understand this: + $md for me is usually obj.$machine + my mkfiles build *.o, *.a, and the a.outs in $md + this is my acc script, which i use for compiling adobe routines +--- +#! /user/haahr/bin/next/rc + +cc = cc +proto = '-DPROTOTYPES=1' + +switch ($md) { +case noproto.$machine; proto = '-DPROTOTYPES=0' +case gprof.$machine; cc = ($cc -pg) +case prof.$machine; cc = ($cc -p) +case lcomp.$machine; cc = lcomp +} +exec $cc $proto '-DPACKAGE_SPECS="package.h"' '-DISP=isp_mc68020' '-DOS=os_mach' $* + +From rc-owner Tue May 12 14:54:10 1992 +Received: from postman.osf.org ([130.105.1.152]) by archone.tamu.edu with SMTP id <45337>; Tue, 12 May 1992 14:38:16 -0500 +Received: from earth.osf.org by postman.osf.org (5.64+/OSF 1.0) + id AA14480; Tue, 12 May 92 13:25:03 -0400 +Received: by earth.osf.org (5.64/4.7) id AA03499; Tue, 12 May 92 13:25:02 -0400 +Date: Tue, 12 May 1992 12:25:02 -0500 +From: rsalz@osf.org +Message-Id: <9205121725.AA03499@earth.osf.org> +To: rc@archone.tamu.edu +Subject: Useful function +Status: R + +It looks like line noise, but it turns things like + /home/rsalz/foo/bar +into + ~/foo/bar + +Useful for when you put your current directory up in your icon title. +By duplicating the $home section you can make things like + /project/dce/build/dce1.0.1/src/rpc +become + $MYBT/src/rpc + +## If a pathname starts with $home, turn $home into ~. Uses all built-ins. +fn tildepath { p1=() i=() { + p1=$1 + switch ($p1) { + case $home $home/* + # Split arg into components + *=`` (/) { echo -n $p1 } + # Shift down by number of components in $home + for (i in `` (/) { echo -n $home } ) shift + # Glue back together + p1='~' + for (i) p1=$p1 ^ '/' ^ $i + echo $p1 + case * + echo $p1 + } + return 0 +} } + +From osf.org!rsalz Tue May 12 15:47:12 1992 +Received: from postman.osf.org ([130.105.1.152]) by archone.tamu.edu with SMTP id <45316>; Tue, 12 May 1992 15:47:06 -0500 +Received: from earth.osf.org by postman.osf.org (5.64+/OSF 1.0) + id AA21070; Tue, 12 May 92 16:46:58 -0400 +Received: by earth.osf.org (5.64/4.7) id AA09396; Tue, 12 May 92 16:46:56 -0400 +Date: Tue, 12 May 1992 15:46:56 -0500 +From: rsalz@osf.org +Message-Id: <9205122046.AA09396@earth.osf.org> +To: byron@archone.tamu.edu +Subject: Re: Useful function +Status: R + +>wow. thanks, i'll add it to EXAMPLES. +Glad you like. Getting something added to EXAMPLES has been a goal of mine... + +I've been thinking, a bit, about a more general way of doing it. I want +a "prefix-sub" function, like this + prefix $some_path var1 var2 var3 var4 var5 +That would take some_path and replace any leading $var1 (etc) values +with the variable name. Return on the first match. + +Hmm -- come to think of it, that's very easy to do: + +# Use pathprefix filename var1 var2 var3 +# returns filename, with leading prefixes (in $var1...) turned into the +# string $var1... +fn pathprefix { p1=() i=() j=() { + p1=$1 ; shift + for (i) { + ~ $p1 $$i $$i^/* && { + *=`` (/) { echo -n $p1 } + for (j in `` (/) { echo -n $$i } ) shift + p1='$'^$i + for (j) p1=$p1 ^ '/' ^ $j + echo $p1 + return 0 + } + } + echo $p1 + return 0 +} } + +home=/user/users/rsalz +z=/usr/users +pathprefix /usr/users/rsalz home usr # --> $home +pathprefix /usr/users/rsalz z # --> $z/rsalz +pathprefix /usr/users/rsalz/foo z home # --> $z/rsalz/foo +pathprefix /usr/users/rsalz/foo home # --> $home/foo + diff --git a/Makefile b/Makefile @@ -0,0 +1,65 @@ +# Makefile for rc. + +# Please check the configuration parameters in config.h (and if you want +# to make sure, the definitions in proto.h) to make sure they are correct +# for your system. + +SHELL=/bin/sh + +# Uncomment this line if you have defined the NOEXECVE macro in config.h +#EXECVE=execve.o + +# Define this macro if you wish to extend rc via locally-defined builtins. +# An interface is provided in addon.[ch]. Note that the author does not +# endorse any such extensions, rather hopes that this way rc will become +# useful to more people. +#ADDON=addon.o + +# Use an ANSI compiler (or at least one that groks prototypes and void *): +CC=gcc -g -O +CFLAGS= +LDFLAGS= + +# You may substitute "bison -y" for yacc. (You want to choose the one that +# makes a smaller y.tab.c.) +YACC=yacc + +OBJS=$(ADDON) builtins.o except.o exec.o $(EXECVE) fn.o footobar.o getopt.o \ + glob.o glom.o hash.o heredoc.o input.o lex.o list.o main.o match.o \ + nalloc.o open.o print.o redir.o sigmsgs.o signal.o status.o tree.o \ + utils.o var.o version.o wait.o walk.o which.o y.tab.o + +# If rc is compiled with READLINE defined, you must supply the correct +# arguments to ld on this line. Typically this would be something like: +# +# $(CC) -o $@ $(OBJS) -lreadline -ltermcap + +rc: $(OBJS) + $(CC) -o $@ $(OBJS) $(LDFLAGS) + +sigmsgs.c: mksignal + sh mksignal /usr/include/sys/signal.h + +y.tab.c: parse.y + $(YACC) -d parse.y + +config.h: config.h-dist + cp config.h-dist config.h + +trip: rc + ./rc -p < trip.rc + +clean: force + rm -f *.o *.tab.* sigmsgs.* + +history: force + cd history; make CC="$(CC)" $(HISTORYMAKEFLAGS) + +force: + +# dependencies: + +$(OBJS): config.h +sigmsgs.h: sigmsgs.c +lex.o y.tab.o: y.tab.c +builtins.c fn.c status.c hash.c: sigmsgs.h diff --git a/README b/README @@ -0,0 +1,100 @@ +This is release 1.4 of rc. + +Read COPYRIGHT for copying information. All files are + +Copyright 1991, Byron Rakitzis. + +COMPILING + +rc was written in portable ANSI C. If you don't have an ANSI compiler +like gcc or something close (e.g., sgi's cc) read further down on +how to convert rc's source to old C. + +Please read the Makefile, and copy config.h-dist to config.h and +examine the parameters in there; they let you customize rc to your +Unix. For example, some Unices support /dev/fd, or some have FIFOs. +If you do not perform this step then the Makefile will automatically +copy config.h-dist to config.h and proceed assuming that everything +is ok. Note that config.h-dist supplies default parameter configurations +for SunOS, NeXT-OS, Irix, Ultrix and some others. Finally, if you're +having trouble you may want to look at proto.h and see if everything +in there jibes with your system. + +After you've built rc, you may wish to run it through a test script +to see that everything is ok. Type "make trip" for this. This will +produce some output, and end with "trip is complete". If the trip +ends with "trip took a wrong turn..." then drop me a line. + +To compile the history program, go into the history subdirectory +and type "make". This will create a binary called "history". However, +in order for it to work as advertised it must be installed into +your bin as four files named -, --, -p and --p. (these can be soft +or hard links to the same file) + +rc may also be linked with either GNU readline (10,000+ lines of +code!) or a supplied readline-like system by Simmule Turner (1,000+ +lines of code). See the Makefile on how to do this. + +BUGS + +Send bug reports to byron@archone.tamu.edu. If a core dump is +generated, sending me a backtrace will help me out a great deal. You +can get a backtrace like this: + + ; gdb rc core + (gdb) where + <<<BACKTRACE INFO>>> + (gdb) + +Also, always report the machine, compiler and OS used to make rc. It's +possible I may have access to a machine of that type, in which case it +becomes much easier for me to track the bug down. + +If you are using gcc, please make sure that you have a recent version of +the compiler (1.39 and up) before you send me a note; I have found that +older versions of gcc choke over rc and generate bad code on several +architectures. (this is especially relevant for the the MIPS architecture) + +FEEPING CREATURISM + +See the end of the man page, under "INCOMPATABILITIES" for (known?) +differences from the "real" rc. Most of these changes were necessary +to get rc to work in a reasonable fashion on a real (i.e., commercial, +non-Labs) UNIX system; a few were changes motivated by concern +about some inadequacies in the original design. + +OLD C + +If you need to convert rc's source into K&R C, you need to run the +source through a filter called "unproto", posted in comp.sources.misc. +A sample "cpp" shell script that I used to run unproto under SunOS +is supplied with rc. + +CREDITS + +This shell was written by me, Byron Rakitzis, but kudos go to Paul +Haahr for letting me know what a shell should do and for contributing +certain bits and pieces to rc (notably the limits code, print.c, +most of which.c and the backquote redirection code), and to Hugh +Redelmeier for running rc through his fussy ANSI compiler and +thereby provoking interesting discussions about portability, and +also for providing many valuable suggestions for improving rc's +code in general. Finally, many thanks go to David Sanderson, for +reworking the man page to format well with troff, and for providing +many suggestions both for rc and its man page. + +Thanks to Boyd Roberts for the original history.c, and to Hugh +again for re-working parts of that code. + +Of course, without Tom Duff's design of the original rc, I could +not have written this shell (though I probably would have written +*a* shell). Almost of all of the features, with minor exceptions, +have been implemented as described in the Unix v10 manuals. Hats +off to td for designing a C-like, minimal but very useful shell. + +Tom Duff has kindly given permission for the paper he wrote for +UKUUG to be distributed with this version of rc (called "plan9.ps" +in the same ftp directory as the shell). Please read this paper +bearing in mind that it describes a program that was written at +AT&T and that the version of rc presented here differs in some +respects. diff --git a/addon.c b/addon.c @@ -0,0 +1,22 @@ +/* + This file contains the implementations of any locally defined + builtins. +*/ + +#ifdef DWS + +/* + This is what DaviD Sanderson (dws@cs.wisc.edu) uses. +*/ + +#include <sys/types.h> +#include <sys/file.h> +#include <sys/stat.h> + +#include "rc.h" /* for bool TRUE, FALSE */ +#include "addon.h" + +#include "addon/access.c" +#include "addon/test.c" + +#endif diff --git a/addon.h b/addon.h @@ -0,0 +1,38 @@ +/* + This file is the interface to the rest of rc for any locally + defined addon builtins. By default there are none. + The interface consists of the following macro. + + ADDONS A comma-separated list of pairs of function pointers + and string literals. + + The addon functions must also have proper prototypes in this file. + The builtins all have the form: + + void b_NAME(char **av); + + Builtins report their exit status using set(TRUE) or set(FALSE). + + Example: + + #define ADDONS { b_test, "test" }, + extern void b_test(char **av); +*/ + +#define ADDONS /* no addons by default */ + +#ifdef DWS + +/* + This is what DaviD Sanderson (dws@cs.wisc.edu) uses. +*/ + +#undef ADDONS +#define ADDONS { b_access, "access" },\ + { b_test, "test" },\ + { b_test, "[" }, + +extern void b_access(char **av); +extern void b_test(char **av); + +#endif diff --git a/builtins.c b/builtins.c @@ -0,0 +1,532 @@ +/* builtins.c: the collection of rc's builtin commands */ + +/* + NOTE: rc's builtins do not call "rc_error" because they are + commands, and rc errors usually arise from syntax errors. e.g., + you probably don't want interpretation of a shell script to stop + because of a bad umask. +*/ + +#include <sys/ioctl.h> +#include <setjmp.h> +#include <errno.h> +#include "rc.h" +#include "jbwrap.h" +#ifndef NOLIMITS +#include <sys/time.h> +#include <sys/resource.h> +#endif +#include "addon.h" + +extern int umask(int); + +static void b_break(char **), b_cd(char **), b_eval(char **), b_exit(char **), + b_newpgrp(char **), b_return(char **), b_shift(char **), b_umask(char **), + b_wait(char **), b_whatis(char **); + +#ifndef NOLIMITS +static void b_limit(char **); +#endif +#ifndef NOECHO +static void b_echo(char **); +#endif + +static struct { + builtin_t *p; + char *name; +} builtins[] = { + { b_break, "break" }, + { b_builtin, "builtin" }, + { b_cd, "cd" }, +#ifndef NOECHO + { b_echo, "echo" }, +#endif + { b_eval, "eval" }, + { b_exec, "exec" }, + { b_exit, "exit" }, +#ifndef NOLIMITS + { b_limit, "limit" }, +#endif + { b_newpgrp, "newpgrp" }, + { b_return, "return" }, + { b_shift, "shift" }, + { b_umask, "umask" }, + { b_wait, "wait" }, + { b_whatis, "whatis" }, + { b_dot, "." }, + ADDONS +}; + +extern builtin_t *isbuiltin(char *s) { + int i; + for (i = 0; i < arraysize(builtins); i++) + if (streq(builtins[i].name, s)) + return builtins[i].p; + return NULL; +} + +/* funcall() is the wrapper used to invoke shell functions. pushes $*, and "return" returns here. */ + +extern void funcall(char **av) { + Jbwrap j; + Estack e1, e2; + Edata jreturn, star; + if (setjmp(j.j)) + return; + starassign(*av, av+1, TRUE); + jreturn.jb = &j; + star.name = "*"; + except(eReturn, jreturn, &e1); + except(eVarstack, star, &e2); + walk(treecpy(fnlookup(*av), nalloc), TRUE); + varrm("*", TRUE); + unexcept(); /* eVarstack */ + unexcept(); /* eReturn */ +} + +static void arg_count(char *name) { + fprint(2, "too many arguments to %s\n", name); + set(FALSE); +} + +static void badnum(char *num) { + fprint(2, "%s is a bad number\n", num); + set(FALSE); +} + +/* a dummy command. (exec() performs "exec" simply by not forking) */ + +extern void b_exec(char **av) { +} + +#ifndef NOECHO +/* echo -n omits a newline. echo -- -n echos '-n' */ + +static void b_echo(char **av) { + char *format = "%A\n"; + if (*++av != NULL) { + if (streq(*av, "-n")) + format = "%A", av++; + else if (streq(*av, "--")) + av++; + } + fprint(1, format, av); + set(TRUE); +} +#endif + +/* cd. traverse $cdpath if the directory given is not an absolute pathname */ + +static void b_cd(char **av) { + List *s, nil; + char *path = NULL; + SIZE_T t, pathlen = 0; + if (*++av == NULL) { + s = varlookup("home"); + *av = (s == NULL) ? "/" : s->w; + } else if (av[1] != NULL) { + arg_count("cd"); + return; + } + if (isabsolute(*av) || streq(*av, ".") || streq(*av, "..")) { /* absolute pathname? */ + if (chdir(*av) < 0) { + set(FALSE); + uerror(*av); + } else + set(TRUE); + } else { + s = varlookup("cdpath"); + if (s == NULL) { + s = &nil; + nil.w = ""; + nil.n = NULL; + } + do { + if (s != &nil && *s->w != '\0') { + t = strlen(*av) + strlen(s->w) + 2; + if (t > pathlen) + path = nalloc(pathlen = t); + strcpy(path, s->w); + if (!streq(s->w, "/")) /* "//" is special to POSIX */ + strcat(path, "/"); + strcat(path, *av); + } else { + pathlen = 0; + path = *av; + } + if (chdir(path) >= 0) { + set(TRUE); + if (interactive && *s->w != '\0' && !streq(s->w, ".")) + fprint(1, "%s\n", path); + return; + } + s = s->n; + } while (s != NULL); + fprint(2, "couldn't cd to %s\n", *av); + set(FALSE); + } +} + +static void b_umask(char **av) { + int i; + if (*++av == NULL) { + set(TRUE); + i = umask(0); + umask(i); + fprint(1, "0%o\n", i); + } else if (av[1] == NULL) { + i = o2u(*av); + if ((unsigned int) i > 0777) { + fprint(2, "bad umask\n"); + set(FALSE); + } else { + umask(i); + set(TRUE); + } + } else { + arg_count("umask"); + return; + } +} + +static void b_exit(char **av) { + if (*++av != NULL) + ssetstatus(av); + rc_exit(getstatus()); +} + +/* raise a "return" exception, i.e., return from a function. if an integer argument is present, set $status to it */ + +static void b_return(char **av) { + if (*++av != NULL) + ssetstatus(av); + rc_raise(eReturn); +} + +/* raise a "break" exception for breaking out of for and while loops */ + +static void b_break(char **av) { + if (av[1] != NULL) { + arg_count("break"); + return; + } + rc_raise(eBreak); +} + +/* shift $* n places (default 1) */ + +static void b_shift(char **av) { + int shift = (av[1] == NULL ? 1 : a2u(av[1])); + List *s, *dollarzero; + if (av[1] != NULL && av[2] != NULL) { + arg_count("shift"); + return; + } + if (shift < 0) { + badnum(av[1]); + return; + } + s = varlookup("*")->n; + dollarzero = varlookup("0"); + while (s != NULL && shift != 0) { + s = s->n; + --shift; + } + if (s == NULL && shift != 0) { + fprint(2, "cannot shift\n"); + set(FALSE); + } else { + varassign("*", append(dollarzero, s), FALSE); + set(TRUE); + } +} + +/* dud function */ + +extern void b_builtin(char **av) { +} + +/* wait for a given process, or all outstanding processes */ + +static void b_wait(char **av) { + int stat, pid; + if (av[1] == NULL) { + waitforall(); + return; + } + if (av[2] != NULL) { + arg_count("wait"); + return; + } + if ((pid = a2u(av[1])) < 0) { + badnum(av[1]); + return; + } + if (rc_wait4(pid, &stat, FALSE) > 0) + setstatus(pid, stat); + else + set(FALSE); + SIGCHK; +} + +/* + whatis without arguments prints all variables and functions. Otherwise, check to see if a name + is defined as a variable, function or pathname. +*/ + +static void b_whatis(char **av) { + bool f, found; + bool ess = FALSE; + int i, ac, c; + List *s; + Node *n; + char *e; + for (rc_optind = ac = 0; av[ac] != NULL; ac++) + ; /* count the arguments for getopt */ + while ((c = rc_getopt(ac, av, "s")) == 's') + ess = TRUE; + if (c != -1) { + set(FALSE); + return; + } + av += rc_optind; + if (*av == NULL && !ess) { + whatare_all_vars(); + set(TRUE); + return; + } + if (ess) + whatare_all_signals(); + found = TRUE; + for (i = 0; av[i] != NULL; i++) { + f = FALSE; + errno = ENOENT; + if ((s = varlookup(av[i])) != NULL) { + f = TRUE; + prettyprint_var(1, av[i], s); + } + if ((n = fnlookup(av[i])) != NULL) { + f = TRUE; + prettyprint_fn(1, av[i], n); + } else if (isbuiltin(av[i]) != NULL) { + f = TRUE; + fprint(1, "builtin %s\n", av[i]); + } else if ((e = which(av[i], FALSE)) != NULL) { + f = TRUE; + fprint(1, "%s\n", e); + } + if (!f) { + found = FALSE; + if (errno != ENOENT) + uerror(av[i]); + else + fprint(2, "%s not found\n", av[i]); + } + } + set(found); +} + +/* push a string to be eval'ed onto the input stack. evaluate it */ + +static void b_eval(char **av) { + bool i = interactive; + if (av[1] == NULL) + return; + interactive = FALSE; + pushstring(av + 1, i); /* don't reset line numbers on noninteractive eval */ + doit(TRUE); + interactive = i; +} + +/* + push a file to be interpreted onto the input stack. with "-i" treat this as an interactive + input source. +*/ + +extern void b_dot(char **av) { + int fd; + bool old_i = interactive, i = FALSE; + Estack e; + Edata star; + av++; + if (*av == NULL) + return; + if (streq(*av, "-i")) { + av++; + i = TRUE; + } + if (dasheye) { /* rc -i file has to do the right thing. reset the dasheye state to FALSE, though. */ + dasheye = FALSE; + i = TRUE; + } + if (*av == NULL) + return; + fd = rc_open(*av, rFrom); + if (fd < 0) { + if (rcrc) /* on rc -l, don't flag nonexistence of .rcrc */ + rcrc = FALSE; + else { + uerror(*av); + set(FALSE); + } + return; + } + rcrc = FALSE; + starassign(*av, av+1, TRUE); + pushfd(fd); + interactive = i; + star.name = "*"; + except(eVarstack, star, &e); + doit(TRUE); + varrm("*", TRUE); + unexcept(); /* eVarstack */ + interactive = old_i; +} + +/* put rc into a new pgrp. Used on the NeXT where the Terminal program is broken (sigh) */ + +static void b_newpgrp(char **av) { + if (av[1] != NULL) { + arg_count("newpgrp"); + return; + } + setpgrp(rc_pid, rc_pid); +#ifdef TIOCSPGRP + ioctl(2, TIOCSPGRP, &rc_pid); +#endif +} + +/* Berkeley limit support was cleaned up by Paul Haahr. */ + +#ifndef NOLIMITS +typedef struct Suffix Suffix; +struct Suffix { + const Suffix *next; + long amount; + char *name; +}; + +static const Suffix + kbsuf = { NULL, 1024, "k" }, + mbsuf = { &kbsuf, 1024*1024, "m" }, + gbsuf = { &mbsuf, 1024*1024*1024, "g" }, + stsuf = { NULL, 1, "s" }, + mtsuf = { &stsuf, 60, "m" }, + htsuf = { &mtsuf, 60*60, "h" }; +#define SIZESUF &gbsuf +#define TIMESUF &htsuf +#define NOSUF ((Suffix *) NULL) /* for RLIMIT_NOFILE on SunOS 4.1 */ + +typedef struct { + char *name; + int flag; + const Suffix *suffix; +} Limit; +static const Limit limits[] = { + { "cputime", RLIMIT_CPU, TIMESUF }, + { "filesize", RLIMIT_FSIZE, SIZESUF }, + { "datasize", RLIMIT_DATA, SIZESUF }, + { "stacksize", RLIMIT_STACK, SIZESUF }, + { "coredumpsize", RLIMIT_CORE, SIZESUF }, +#ifdef RLIMIT_RSS /* SysVr4 does not have this */ + { "memoryuse", RLIMIT_RSS, SIZESUF }, +#endif +#ifdef RLIMIT_VMEM /* instead, they have this! */ + { "vmemory", RLIMIT_VMEM, SIZESUF }, +#endif +#ifdef RLIMIT_NOFILE /* SunOS 4.1 adds a limit on file descriptors */ + { "descriptors", RLIMIT_NOFILE, NOSUF }, +#endif + { NULL, 0, NULL } +}; + +extern int getrlimit(int, struct rlimit *); +extern int setrlimit(int, struct rlimit *); + +static void printlimit(const Limit *limit, bool hard) { + struct rlimit rlim; + long lim; + getrlimit(limit->flag, &rlim); + if (hard) + lim = rlim.rlim_max; + else + lim = rlim.rlim_cur; + if (lim == RLIM_INFINITY) + fprint(1, "%s \tunlimited\n", limit->name); + else { + const Suffix *suf; + for (suf = limit->suffix; suf != NULL; suf = suf->next) + if (lim % suf->amount == 0 && (lim != 0 || suf->amount > 1)) { + lim /= suf->amount; + break; + } + fprint(1, "%s \t%d%s\n", limit->name, lim, (suf == NULL || lim == 0) ? "" : suf->name); + } +} + +static long parselimit(const Limit *limit, char *s) { + char *t; + int len = strlen(s); + long lim = 1; + const Suffix *suf = limit->suffix; + if (streq(s, "unlimited")) + return RLIM_INFINITY; + if (suf == TIMESUF && (t = strchr(s, ':')) != NULL) { + *t++ = '\0'; + lim = 60 * a2u(s) + a2u(t); + } else { + for (; suf != NULL; suf = suf->next) + if (streq(suf->name, s + len - strlen(suf->name))) { + s[len - strlen(suf->name)] = '\0'; + lim *= suf->amount; + break; + } + lim *= a2u(s); + } + return lim; +} + +static void b_limit(char **av) { + const Limit *lp = limits; + bool hard = FALSE; + if (*++av != NULL && streq(*av, "-h")) { + av++; + hard = TRUE; + } + if (*av == NULL) { + for (; lp->name != NULL; lp++) + printlimit(lp, hard); + return; + } + for (;; lp++) { + if (lp->name == NULL) { + fprint(2, "no such limit\n"); + set(FALSE); + return; + } + if (streq(*av, lp->name)) + break; + } + if (*++av == NULL) + printlimit(lp, hard); + else { + struct rlimit rlim; + long pl; + getrlimit(lp->flag, &rlim); + if ((pl = parselimit(lp, *av)) < 0) { + fprint(2, "bad limit\n"); + set(FALSE); + return; + } + if (hard) + rlim.rlim_max = pl; + else + rlim.rlim_cur = pl; + if (setrlimit(lp->flag, &rlim) == -1) { + uerror("setrlimit"); + set(FALSE); + } else + set(TRUE); + } +} +#endif diff --git a/config.h-dist b/config.h-dist @@ -0,0 +1,204 @@ +/* Copy config.h-dist to config.h and edit config.h, don't edit this file */ + +/* + * Configuration parameters for rc. Suggested defaults are at the bottom + * of this file (you should probably look at those first to see if your + * system matches one of them; you can search for the beginning of the + * defaults section by looking for the string "#ifndef CUSTOM"). If you + * want to override the suggested defaults, define the macro CUSTOM. +#define CUSTOM + */ + +/* + * (Note that certain default settings redefine this macro) + * DEFAULTPATH the default search path that rc uses when it is started + * without either a $PATH or $path environment variable. You must pick + * something sensible for your system if you don't like the path shown + * below. + */ +#define DEFAULTPATH "/usr/ucb", "/usr/bin", "/bin", "." + +/* + * Define the macro NODIRENT if your system has <sys/dir.h> but not + * <dirent.h>. (e.g., NeXT-OS and RISCos) +#define NODIRENT + */ + +/* + * Define the macro SVSIGS if your system has System V signal semantics, + * i.e., if "slow" system calls are interrupted rather than resumed + * after returning from an interrupt handler. (If you are not sure what + * this means, see the man page for signal(2). In any case, it is probably + * safe to leave this macro undefined.) +#define SVSIGS + */ + +/* + * Define the macro NOCMDARG if you do not have /dev/fd or fifos on your + * system. You may also want to define this if you have broken fifos. +#define NOCMDARG + */ + +/* + * Define TMPDIR if you need to have rc create its fifos in a directory + * other than /tmp. For example, if you have a Sun with /tmp mounted + * as a ramdisk (type "tmpfs") then you cannot use fifos in /tmp (sigh). +#define TMPDIR "/var/tmp" + */ + +/* + * Define the macro DEVFD if your system supports /dev/fd. +#define DEVFD + */ + +/* + * Define the macro NOLIMITS if your system does not support Berkeley + * limits. +#define NOLIMITS + */ + +/* + * Define the macro NOSIGCLD if your system uses SIGCLD in the System + * V way. (e.g., sgi's Irix) +#define NOSIGCLD + */ + +/* + * Define the macro READLINE if you want rc to call GNU readline + * instead of read(2) on interactive shells. +#define READLINE + */ + +/* + * Define the macro NOEXECVE if your Unix does not interpret #! in the + * kernel, and uncomment the EXECVE variable in the Makefile. +#define NOEXECVE + */ + +/* + * If you want rc to default to some interpreter for files which don't + * have a legal #! on the first line, define the macro DEFAULTINTERP. +#define DEFAULTINTERP "/bin/sh" + */ + +/* + * If your /bin/sh (or another program you care about) rejects environment + * variables with special characters in them (such as ':' or '-'), rc can + * put out ugly variable names using [_0-9a-zA-Z] that encode the real name; + * define PROTECT_ENV for this hack. (Known offenders: every sh I have tried; + * SunOS (silently discards), NeXT (aborts with error), SGI (aborts with + * error), Ultrix (sh seems to work, sh5 aborts with error)) +#define PROTECT_ENV + */ + +/* + * Define the macro NOECHO if you wish to omit rc's echo builtin from the + * compile. +#define NOECHO + */ + +/* + * Define the NOJOB if you do *not* wish rc to perform backgrounding + * as if it were a job-control shell; that is, if you do *not* wish + * it to put a command spawned in the background into a new process + * group. Since most systems support job control and since there are + * many broken programs that do not behave correctly when backgrounded + * in a v7 non-job-control fashion, rc by default performs a job- + * control-like backgrounding. +#define NOJOB + */ + +/* Beginning of defaults section: */ + +#ifndef CUSTOM + +/* + * Suggested settings for Sun, NeXT and sgi (machines here at TAMU): + */ + +#ifdef NeXT /* Used on NextOS 2.1 */ +#define NODIRENT +#define PROTECT_ENV +#define NOCMDARG +#endif + +#ifdef sgi /* Used on Irix 3.3.[12] */ +#define SVSIGS +#define NOSIGCLD +#define PROTECT_ENV +#undef DEFAULTPATH +#define DEFAULTPATH "/usr/bsd", "/usr/sbin", "/usr/bin", "/bin", "." +#endif + +#ifdef sun /* Used on SunOS 4.1.1 */ +#define PROTECT_ENV +#undef DEFAULTPATH +#define DEFAULTPATH "/usr/ucb", "/usr/bin", "." +#endif + +/* + * Suggested settings for HP300 running 4.3BSD-utah (DWS): + */ + +#if defined(hp300) && !defined(hpux) +#define NODIRENT +#define NOCMDARG +#define DEFAULTINTERP "/bin/sh" +#define PROTECT_ENV +#endif + +/* + * Suggested settings for Ultrix + */ + +#ifdef ultrix +#define PROTECT_ENV +#define DEFAULTINTERP "/bin/sh" /* so /bin/true can work */ +#endif + +/* + * Suggested settings for RISCos 4.52 + */ + +/* + This doesn't work without interfering with other MIPS-based + systems' configuration. Please do it by hand. +*/ + +#if defined(host_mips) && defined(MIPSEB) && defined(SYSTYPE_BSD43) +#define NODIRENT +#define PROTECT_ENV +#endif + +/* + * Suggested settings for AIX + */ + +#ifdef _AIX +#define PROTECT_ENV +#endif + +/* + * Suggested settings for OSF/1 1.0 + */ + +#ifdef OSF1 +#define PROTECT_ENV +#endif + +/* + * Suggested settings for Unicos XXX + */ + +#ifdef cray +#define PROTECT_ENV +#define NOLIMITS +#define word _word +#define DEFAULTINTERP "/bin/sh" +#endif + +#endif /* CUSTOM */ + +#ifndef TMPDIR +#define TMPDIR "/tmp" +#endif diff --git a/cpp b/cpp @@ -0,0 +1,38 @@ +#!/bin/sh + +# @(#) cpp.sh 1.3 92/01/15 21:53:22 + +# Unprototypeing preprocessor for pre-ANSI C compilers. On some systems, +# this script can be as simple as: +# +# /lib/cpp "$@" | unproto +# +# However, some cc(1) drivers specify output file names on the +# preprocessor command line, so this shell script must be prepared to +# intercept them. Depending on the driver program, the cpp options may +# even go before or after the file name argument(s). The script below +# tries to tackle all these cases. +# +# You may want to add -Ipath_to_stdarg.h_file, -Dvoid=, -Dvolatile=, +# and even -D__STDC__. + +## (This is what I used while testing with the SunOS C compiler. +## Also, I added "-Qpath ." to CFLAGS so that cpp would be +## run out of the current directory. --- Byron) +cpp_args="-I/u/byron/lib/sun4 -Dconst= -Dvolatile=" + +while : +do + case $1 in + "") break;; + -*) cpp_args="$cpp_args $1";; + *) cpp_args="$cpp_args $1" + case $2 in + ""|-*) ;; + *) exec 1> $2 || exit 1; shift;; + esac;; + esac + shift +done + +/lib/cpp $cpp_args | unproto diff --git a/except.c b/except.c @@ -0,0 +1,140 @@ +#include <setjmp.h> +#include <signal.h> +#include "rc.h" +#include "jbwrap.h" + +/* + A return goes back stack frames to the last return. A break does + not. A signal goes to the last interactive level. (see below) +*/ + +bool nl_on_intr = TRUE; + +static Estack *estack; + +/* add an exception to the input stack. */ + +extern void except(ecodes e, Edata data, Estack *ex) { + ex->prev = estack; + estack = ex; + estack->e = e; + estack->data = data; + if (e == eError || e == eBreak || e == eReturn) + estack->interactive = interactive; +} + +/* remove an exception, restore last interactive value */ + +extern void unexcept() { + switch (estack->e) { + default: + break; + case eError: + interactive = estack->interactive; + break; + case eArena: + restoreblock(estack->data.b); + break; + case eFifo: + unlink(estack->data.name); + break; + case eFd: + close(estack->data.fd); + break; + } + estack = estack->prev; +} + +/* + Raise an exception. The rules are pretty complicated: you can return + from a loop inside a function, but you can't break from a function + inside of a loop. On errors, rc_raise() goes back to the LAST + INTERACTIVE stack frame. If no such frame exists, then rc_raise() + exits the shell. This is what happens, say, when there is a syntax + error in a noninteractive shell script. While traversing the + exception stack backwards, rc_raise() also removes input sources + (closing file-descriptors, etc.) and pops instances of variables + that have been pushed onto the variable stack (e.g., for a function + call (for $*) or a local assignment). +*/ + +extern void rc_raise(ecodes e) { + if (e == eError && rc_pid != getpid()) + exit(1); /* child processes exit on an error/signal */ + for (; estack != NULL; estack = estack->prev) + if (estack->e != e) { + if (e == eBreak && estack->e != eArena) + rc_error("break outside of loop"); + else if (e == eReturn && estack->e == eError) /* can return from loops inside functions */ + rc_error("return outside of function"); + switch (estack->e) { + default: + break; + case eVarstack: + varrm(estack->data.name, TRUE); + break; + case eArena: + restoreblock(estack->data.b); + break; + case eFifo: + unlink(estack->data.name); + break; + case eFd: + close(estack->data.fd); + break; + } + } else { + if (e == eError && !estack->interactive) { + popinput(); + } else { + Jbwrap *j = estack->data.jb; + + interactive = estack->interactive; + estack = estack->prev; + longjmp(j->j, 1); + } + } + rc_exit(1); /* top of exception stack */ +} + +extern bool outstanding_cmdarg() { + return estack->e == eFifo || estack->e == eFd; +} + +extern void pop_cmdarg(bool remove) { + for (; estack != NULL; estack = estack->prev) + switch (estack->e) { + case eFifo: + if (remove) + unlink(estack->data.name); + break; + case eFd: + if (remove) + close(estack->data.fd); + break; + default: + return; + } +} + +/* exception handlers */ + +extern void rc_error(char *s) { + pr_error(s); + set(FALSE); + redirq = NULL; + cond = FALSE; /* no longer inside conditional */ + rc_raise(eError); +} + +extern void sigint(int s) { + if (s != SIGINT) + panic("s != SIGINT in sigint catcher"); + /* this is the newline you see when you hit ^C while typing a command */ + if (nl_on_intr) + fprint(2, "\n"); + nl_on_intr = TRUE; + redirq = NULL; + cond = FALSE; + rc_raise(eError); +} diff --git a/exec.c b/exec.c @@ -0,0 +1,119 @@ +/* exec.c */ +#include <signal.h> +#include <errno.h> +#include <setjmp.h> +#include "rc.h" +#include "jbwrap.h" + +/* + Takes an argument list and does the appropriate thing (calls a + builtin, calls a function, etc.) +*/ + +extern void exec(List *s, bool parent) { + char **av, **ev = NULL; + int pid, stat; + builtin_t *b; + char *path = NULL; + bool didfork, returning, saw_exec, saw_builtin; + av = list2array(s, dashex); + saw_builtin = saw_exec = FALSE; + do { + if (*av == NULL || isabsolute(*av)) + b = NULL; + else if (!saw_builtin && fnlookup(*av) != NULL) + b = funcall; + else + b = isbuiltin(*av); + + /* + a builtin applies only to the immmediately following + command, e.g., builtin exec echo hi + */ + saw_builtin = FALSE; + + if (b == b_exec) { + av++; + saw_exec = TRUE; + parent = FALSE; + } else if (b == b_builtin) { + av++; + saw_builtin = TRUE; + } + } while (b == b_exec || b == b_builtin); + if (*av == NULL && saw_exec) { /* do redirs and return on a null exec */ + doredirs(); + return; + } + /* force an exit on exec with any rc_error, but not for null commands as above */ + if (saw_exec) + rc_pid = -1; + if (b == NULL) { + path = which(*av, TRUE); + if (path == NULL && *av != NULL) { /* perform null commands for redirections */ + set(FALSE); + redirq = NULL; + if (parent) + return; + rc_exit(1); + } + ev = makeenv(); /* environment only needs to be built for execve() */ + } + /* + If parent & the redirq is nonnull, builtin or not it has to fork. + If the fifoq is nonnull, then it must be emptied at the end so we + must fork no matter what. + */ + if ((parent && (b == NULL || redirq != NULL)) || outstanding_cmdarg()) { + pid = rc_fork(); + didfork = TRUE; + } else { + pid = 0; + didfork = FALSE; + } + returning = (!didfork && parent); + switch (pid) { + case -1: + uerror("fork"); + rc_error(NULL); + /* NOTREACHED */ + case 0: + if (!returning) + setsigdefaults(FALSE); + pop_cmdarg(FALSE); + doredirs(); + + /* null commands performed for redirections */ + if (*av == NULL || b != NULL) { + if (b != NULL) + (*b)(av); + if (returning) + return; + rc_exit(getstatus()); + } +#ifdef NOEXECVE + my_execve(path, (const char **) av, (const char **) ev); /* bogus, huh? */ +#else + execve(path, (const char **) av, (const char **) ev); +#endif +#ifdef DEFAULTINTERP + if (errno == ENOEXEC) { + *av = path; + *--av = DEFAULTINTERP; + execve(*av, (const char **) av, (const char **) ev); + } +#endif + uerror(*av); + rc_exit(1); + /* NOTREACHED */ + default: + redirq = NULL; + rc_wait4(pid, &stat, TRUE); + setstatus(-1, stat); + if ((stat & 0xff) == 0) + nl_on_intr = FALSE; + SIGCHK; + nl_on_intr = TRUE; + pop_cmdarg(TRUE); + } +} diff --git a/execve.c b/execve.c @@ -0,0 +1,61 @@ +/* execve.c: an execve() for geriatric unices without #! */ + +/* + NOTE: this file depends on a hack in footobar.c which places two free spots before + av[][] so that execve does not have to call malloc. +*/ + +#include <errno.h> +#include "rc.h" + +#define giveupif(x) { if (x) goto fail; } + +extern int my_execve(const char *path, const char **av, const char **ev) { + int fd, len, fst, snd, end; + bool noarg; + char pb[256]; /* arbitrary but generous limit */ + execve(path, av, ev); + if (errno != ENOEXEC) + return -1; + fd = rc_open(path, rFrom); + giveupif(fd < 0); + len = read(fd, pb, sizeof pb); + close(fd); + /* reject scripts which don't begin with #! */ + giveupif(len <= 0 || pb[0] != '#' || pb[1] != '!'); + for (fst = 2; fst < len && (pb[fst] == ' ' || pb[fst] == '\t'); fst++) + ; /* skip leading whitespace */ + giveupif(fst == len); + for (snd = fst; snd < len && pb[snd] != ' ' && pb[snd] != '\t' && pb[snd] != '\n'; snd++) + ; /* skip first arg */ + giveupif(snd == len); + noarg = (pb[snd] == '\n'); + pb[snd++] = '\0'; /* null terminate the first arg */ + if (!noarg) { + while (snd < len && (pb[snd] == ' ' || pb[snd] == '\t')) + snd++; /* skip whitespace to second arg */ + giveupif(snd == len); + noarg = (pb[snd] == '\n'); /* could have trailing whitespace after only one arg */ + if (!noarg) { + for (end = snd; end < len && pb[end] != ' ' && pb[end] != '\t' && pb[end] != '\n'; end++) + ; /* skip to the end of the second arg */ + giveupif(end == len); + if (pb[end] == '\n') { + pb[end] = '\0'; /* null terminate the first arg */ + } else { /* else check for a spurious third arg */ + pb[end++] = '\0'; + while (end < len && (pb[end] == ' ' || pb[end] == '\t')) + end++; + giveupif(end == len || pb[end] != '\n'); + } + } + } + *av = path; + if (!noarg) + *--av = pb + snd; + *--av = pb + fst; + execve(*av, av, ev); + return -1; +fail: errno = ENOEXEC; + return -1; +} diff --git a/fn.c b/fn.c @@ -0,0 +1,266 @@ +/* + fn.c: functions for adding and deleting functions from the symbol table. + Support for signal handlers is also found here. +*/ + +#include <signal.h> +#include <errno.h> +#include "rc.h" +#include "sigmsgs.h" + +static void fn_handler(int), dud_handler(int); + +static bool runexit = FALSE; +static Node *handlers[NUMOFSIGNALS], null; +static void (*def_sigint)(int) = SIG_DFL, + (*def_sigquit)(int) = SIG_DFL, + (*def_sigterm)(int) = SIG_DFL; + +/* + Set signals to default values for rc. This means that interactive + shells ignore SIGTERM, etc. +*/ + +extern void inithandler() { + int i; + null.type = nBody; + null.u[0].p = null.u[1].p = NULL; + for (i = 1; i < NUMOFSIGNALS; i++) +#ifdef NOSIGCLD + if (i != SIGCLD) +#endif + if (sighandlers[i] == SIG_IGN) + fnassign(signals[i].name, NULL); /* ignore incoming ignored signals */ + if (interactive || sighandlers[SIGINT] != SIG_IGN) { + def_sigint = sigint; + fnrm("sigint"); /* installs SIGINT catcher if not inherited ignored */ + } + if (!dashdee) { + if (interactive || sighandlers[SIGQUIT] != SIG_IGN) { + def_sigquit = dud_handler; + fnrm("sigquit"); /* "ignores" SIGQUIT unless inherited ignored */ + } + if (interactive) { + def_sigterm = dud_handler; + fnrm("sigterm"); /* ditto for SIGTERM */ + } + } +} + +/* only run this in a child process! resets signals to their default values */ + +extern void setsigdefaults(bool sysvbackground) { + int i; + /* + General housekeeping: setsigdefaults happens after fork(), + so it's a convenient place to clean up open file descriptors. + (history file, scripts, etc.) + */ + closefds(); + /* + Restore signals to SIG_DFL, paying close attention to + a few quirks: SIGINT, SIGQUIT and are treated specially + depending on whether we are doing v7-style backgrounding + or not; the default action for SIGINT, SIGQUIT and SIGTERM + must be set to the appropriate action; finally, care must + be taken not to set to SIG_DFL any signals which are being + ignored. + */ + for (i = 1; i < NUMOFSIGNALS; i++) + if (sighandlers[i] != SIG_IGN) { + handlers[i] = NULL; + switch (i) { + case SIGINT: + if (sysvbackground) { + def_sigint = SIG_IGN; + fnassign("sigint", NULL); /* ignore */ + } else { + def_sigint = SIG_DFL; + goto sigcommon; + } + break; + case SIGQUIT: + if (sysvbackground) { + def_sigquit = SIG_IGN; + fnassign("sigquit", NULL); /* ignore */ + } else { + def_sigquit = SIG_DFL; + goto sigcommon; + } + break; + case SIGTERM: + def_sigterm = SIG_DFL; + /* FALLTHROUGH */ + sigcommon: + default: + if (sighandlers[i] != SIG_DFL) { + rc_signal(i, SIG_DFL); + delete_fn(signals[i].name); + } + } + } + delete_fn("sigexit"); + runexit = FALSE; /* No sigexit on subshells */ +} + +/* rc's exit. if runexit is set, run the sigexit function. */ + +extern void rc_exit(int stat) { + static char *sigexit[2] = { + "sigexit", + NULL + }; + if (runexit) { + runexit = FALSE; + funcall(sigexit); + stat = getstatus(); + } + exit(stat); +} + +/* The signal handler for all functions. calls walk() */ + +static void fn_handler(int s) { + List *dollarzero; + Estack e; + Edata star; + int olderrno; + if (s < 1 || s >= NUMOFSIGNALS) + panic("unknown signal"); + olderrno = errno; + dollarzero = nnew(List); + dollarzero->w = signals[s].name; + dollarzero->n = NULL; + varassign("*", dollarzero, TRUE); + star.name = "*"; + except(eVarstack, star, &e); + walk(handlers[s], TRUE); + varrm("*", TRUE); + unexcept(); /* eVarstack */ + errno = olderrno; +} + +/* A dud signal handler for SIGQUIT and SIGTERM */ + +static void dud_handler(int s) { +} + +/* + Assign a function in Node form. Check to see if the function is also + a signal, and set the signal vectors appropriately. +*/ + +extern void fnassign(char *name, Node *def) { + Node *newdef = treecpy(def == NULL ? &null : def, ealloc); /* important to do the treecopy first */ + Function *new = get_fn_place(name); + int i; + new->def = newdef; + new->extdef = NULL; + if (strncmp(name, "sig", conststrlen("sig")) == 0) { /* slight optimization */ +#ifdef NOSIGCLD /* System V machines treat SIGCLD very specially */ + if (streq(name, "sigcld")) + rc_error("can't trap SIGCLD"); +#endif + if (streq(name, "sigexit")) + runexit = TRUE; + for (i = 1; i < NUMOFSIGNALS; i++) /* zero is a bogus signal */ + if (streq(signals[i].name, name)) { + handlers[i] = newdef; + if (def == NULL) + rc_signal(i, SIG_IGN); + else + rc_signal(i, fn_handler); + break; + } + } +} + +/* Assign a function from the environment. Store just the external representation */ + +extern void fnassign_string(char *extdef) { + char *name = get_name(extdef+3); /* +3 to skip over "fn_" */ + Function *new; + if (name == NULL) + return; + new = get_fn_place(name); + new->def = NULL; + new->extdef = ecpy(extdef); +} + +/* Return a function in Node form, evaluating an entry from the environment if necessary */ + +extern Node *fnlookup(char *name) { + Function *look = lookup_fn(name); + Node *ret; + if (look == NULL) + return NULL; /* not found */ + if (look->def != NULL) + return look->def; + if (look->extdef == NULL) /* function was set to null, e.g., fn foo {} */ + return &null; + ret = parse_fn(name, look->extdef); + if (ret == NULL) { + efree(look->extdef); + look->extdef = NULL; + return &null; + } else { + return look->def = treecpy(ret, ealloc); /* Need to take it out of nalloc space */ + } +} + +/* Return a function in string form (used by makeenv) */ + +extern char *fnlookup_string(char *name) { + Function *look = lookup_fn(name); + + if (look == NULL) + return NULL; + if (look->extdef != NULL) + return look->extdef; + return look->extdef = fun2str(name, look->def); +} + +/* + Remove a function from the symbol table. If it also defines a signal + handler, restore the signal handler to its default value. +*/ + +extern void fnrm(char *name) { + int i; + for (i = 1; i < NUMOFSIGNALS; i++) + if (streq(signals[i].name, name)) { + handlers[i] = NULL; + switch (i) { + case SIGINT: + rc_signal(i, def_sigint); + break; + case SIGQUIT: + rc_signal(i, def_sigquit); + break; + case SIGTERM: + rc_signal(i, def_sigterm); + break; + default: + rc_signal(i, SIG_DFL); + } + } + if (streq(name, "sigexit")) + runexit = FALSE; + delete_fn(name); +} + +extern void whatare_all_signals() { + int i; + for (i = 1; i < NUMOFSIGNALS; i++) + if (*signals[i].name != '\0') + if (sighandlers[i] == SIG_IGN) + fprint(1, "fn %s {}\n", signals[i].name); + else if (sighandlers[i] == fn_handler) + fprint(1, "fn %S {%T}\n", signals[i].name, handlers[i]); + else + fprint(1, "fn %s\n", signals[i].name); +} + +extern void prettyprint_fn(int fd, char *name, Node *n) { + fprint(fd, "fn %S {%T}\n", name, n); +} diff --git a/footobar.c b/footobar.c @@ -0,0 +1,368 @@ +/* + footobar.c: a collection of functions to convert internal representations of + variables and functions to external representations, and vice versa +*/ + +#include "rc.h" + +#define FSCHAR '\1' +#define FSSTRING "\1" + +static char *getenvw(char *, bool); + +#ifdef PROTECT_ENV +static bool Fconv(Format *f, int ignore) { /* protect an exported name from brain-dead shells */ + int c; + unsigned const char *s = va_arg(f->args, unsigned const char *); + + while ((c = *s++) != '\0') + if (dnw[c] || c == '*' || (c == '_' && *s == '_')) + fmtprint(f, "__%02x", c); + else + fmtputc(f, c); + return FALSE; +} +#endif + +/* used to turn a function in Node * form into something we can export to the environment */ + +extern char *fun2str(char *name, Node *n) { + return mprint("fn_%F={%T}", name, n); +} + +/* convert a redirection to a printable form */ + +static bool Dconv(Format *f, int ignore) { + const char *name = "?"; + int n = va_arg(f->args, int); + switch (n) { + case rCreate: name = ">"; break; + case rAppend: name = ">>"; break; + case rFrom: name = "<"; break; + case rHeredoc: name = "<<"; break; + case rHerestring: name = "<<<"; break; + } + fmtcat(f, name); + return FALSE; +} + +/* defaultfd -- return the default fd for a given redirection operation */ + +extern int defaultfd(int op) { + return (op == rCreate || op == rAppend) ? 1 : 0; +} + +/* convert a function in Node * form into something rc can parse (and humans can read?) */ + +static bool Tconv(Format *f, int ignore) { + Node *n = va_arg(f->args, Node *); + if (n == NULL) { + fmtprint(f, "()"); + return FALSE; + } + switch (n->type) { + case nWord: fmtprint(f, "%S", n->u[0].s); break; + case nQword: fmtprint(f, "%#S", n->u[0].s); break; + case nBang: fmtprint(f, "! %T", n->u[0].p); break; + case nCase: fmtprint(f, "case %T", n->u[0].p); break; + case nNowait: fmtprint(f, "%T&", n->u[0].p); break; + case nCount: fmtprint(f, "$#%T", n->u[0].p); break; + case nFlat: fmtprint(f, "$^%T", n->u[0].p); break; + case nRmfn: fmtprint(f, "fn %T", n->u[0].p); break; + case nSubshell: fmtprint(f, "@ %T", n->u[0].p); break; + case nVar: fmtprint(f, "$%T", n->u[0].p); break; + case nAndalso: fmtprint(f, "%T&&%T", n->u[0].p, n->u[1].p); break; + case nAssign: fmtprint(f, "%T=%T", n->u[0].p, n->u[1].p); break; + case nConcat: fmtprint(f, "%T^%T", n->u[0].p, n->u[1].p); break; + case nElse: fmtprint(f, "{%T}else %T", n->u[0].p, n->u[1].p); break; + case nNewfn: fmtprint(f, "fn %T {%T}", n->u[0].p, n->u[1].p); break; + case nIf: fmtprint(f, "if(%T)%T", n->u[0].p, n->u[1].p); break; + case nOrelse: fmtprint(f, "%T||%T", n->u[0].p, n->u[1].p); break; + case nArgs: fmtprint(f, "%T %T", n->u[0].p, n->u[1].p); break; + case nSwitch: fmtprint(f, "switch(%T){%T}", n->u[0].p, n->u[1].p); break; + case nMatch: fmtprint(f, "~ %T %T", n->u[0].p, n->u[1].p); break; + case nVarsub: fmtprint(f, "$%T(%T)", n->u[0].p, n->u[1].p); break; + case nWhile: fmtprint(f, "while(%T)%T", n->u[0].p, n->u[1].p); break; + case nLappend: fmtprint(f, "(%T %T)", n->u[0].p, n->u[1].p); break; + case nForin: fmtprint(f, "for(%T in %T)%T", n->u[0].p, n->u[1].p, n->u[2].p); break; + case nDup: + if (n->u[2].i != -1) + fmtprint(f, "%D[%d=%d]", n->u[0].i, n->u[1].i, n->u[2].i); + else + fmtprint(f, "%D[%d=]", n->u[0].i, n->u[1].i); + break; + case nBackq: { + Node *n0 = n->u[0].p, *n00; + if (n0 != NULL && n0->type == nVar + && (n00 = n0->u[0].p) != NULL && n00->type == nWord && streq(n00->u[0].s, "ifs")) + fmtprint(f, "`"); + else + fmtprint(f, "``%T", n0); + fmtprint(f, "{%T}", n->u[1].p); + break; + } + case nCbody: + case nBody: { + Node *n0 = n->u[0].p; + if (n0 != NULL) + fmtprint(f, "%T", n->u[0].p); + if (n->u[1].p != NULL) { + if (n0 != NULL && n0->type != nNowait) + fmtprint(f, ";"); + fmtprint(f, "%T", n->u[1].p); + } + break; + } + case nBrace: + fmtprint(f, "{%T}", n->u[0].p); + if (n->u[1].p != NULL) + fmtprint(f, "%T", n->u[1].p); + break; + case nEpilog: + case nPre: + fmtprint(f, "%T", n->u[0].p); + if (n->u[1].p != NULL) + fmtprint(f, " %T", n->u[1].p); + break; + case nPipe: { + int ofd = n->u[0].i, ifd = n->u[1].i; + fmtprint(f, "%T|", n->u[2].p); + if (ifd != 0) + fmtprint(f, "[%d=%d]", ofd, ifd); + else if (ofd != 1) + fmtprint(f, "[%d]", ofd); + fmtprint(f, "%T", n->u[3].p); + break; + } + case nRedir: { + int op = n->u[0].i; + fmtprint(f, "%D", op); + if (n->u[1].i != defaultfd(op)) + fmtprint(f, "[%d]", n->u[1].i); + fmtprint(f, "%T", n->u[2].p); + break; + } + case nNmpipe: { + int op = n->u[0].i; + fmtprint(f, "%D", op); + if (n->u[1].i != defaultfd(op)) + fmtprint(f, "[%d]", n->u[1].i); + fmtprint(f, "{%T}", n->u[2].p); + break; + } + } + return FALSE; +} + +/* convert a List to a string, separating it with ^A characters. Used for exporting variables to the environment */ + +extern char *list2str(char *name, List *s) { + SIZE_T size, step; + List *t; + char *w, *x; + name = nprint("%F", name); + size = strlen(name) + listlen(s); + w = ealloc(size + 2); + t = s; + x = w; + strcpy(x, name); + strcpy(x += strlen(name), "="); + strcpy(x += conststrlen("="), t->w); + for (x += strlen(t->w), s = s->n; s != NULL; s = s->n) { + memcpy(x, FSSTRING, step = conststrlen(FSSTRING)); + x += step; + memcpy(x, s->w, step = strlen(s->w)); + x += step; + } + *x = '\0'; + return w; +} + +/* convert a List to an array, for execve() */ + +extern char **list2array(List *s, bool print) { + char **av; + int i; + + /* 4 == 1 for the null terminator + 2 for the fake execve() + 1 for defaulting to sh */ + av = nalloc((listnel(s) + 4) * sizeof (char *)); + av += 3; /* hide the two free spots from rc (two for #! emulation, one for defaulting to sh) */ + if (print) + fprint(2, "%L\n", s, " "); + for (i = 0; s != NULL; i++) { + av[i] = s->w; + s = s->n; + } + av[i] = NULL; + return av; +} + +/* figure out the name of a variable given an environment string. copy this into malloc space */ + +extern char *get_name(char *s) { + int c; + SIZE_T i; + char *r, *namebuf; + for (i = 0; s[i] != '\0' && s[i] != '='; i++) + ; + if (s[i] == '\0') + return NULL; + r = namebuf = ealloc(i + 1); + while (1) + switch (c = *s++) { + case '=': + *r++ = '\0'; + return namebuf; +#ifdef PROTECT_ENV + case '_': + if (*s == '_') { + static const char hexchar[] = "0123456789abcdef"; + char *h1 = strchr(hexchar, s[1]); + char *h2 = strchr(hexchar, s[2]); + if (h1 != NULL && h2 != NULL) { + *r++ = ((h1 - hexchar) << 4) | (h2 - hexchar); + s += 3; + break; + } + } + /* FALLTHROUGH */ +#endif + default: + *r++ = c; + break; + } +} + +/* get the next word from a variable's value as represented in the environment. */ + +static char *getenvw(char *s, bool saw_alpha) { + SIZE_T i; + char *r; + for (i = 0; s[i] != '\0' && s[i] != FSCHAR; i++) + ; + if (i == 0) { + if (s[i] == '\0' && !saw_alpha) + return NULL; + else + return clear(enew(char), (SIZE_T) 1); + } + r = strncpy(ealloc(i + 1), s, i); + r[i] = '\0'; + return r; +} + +/* take an environment entry for a variable (elements ^A separated) and turn it into a List */ + +extern List *parse_var(char *name, char *extdef) { + List *r, *top; + char *f; + bool saw_alpha; + top = r = enew(List); + extdef = strchr(extdef, '=') + 1; + if ((f = getenvw(extdef, FALSE)) == NULL) { + r->w = ""; + r->m = NULL; + r->n = NULL; + } else { + while (1) { + r->w = f; + r->m = NULL; + extdef += strlen(f); + if (*extdef == FSCHAR) { + extdef++; + saw_alpha = TRUE; + } else { + saw_alpha = FALSE; + } + if ((f = getenvw(extdef, saw_alpha)) == NULL) { + r->n = NULL; + break; + } + r = r->n = enew(List); + } + } + return top; +} + +/* get an environment entry for a function and have rc parse it. */ + +#define PREFIX "fn x" +#define PRELEN conststrlen(PREFIX) +extern Node *parse_fn(char *name, char *extdef) { + Node *def; + char *s, old[PRELEN]; + if ((s = strchr(extdef, '=')) == NULL) + return NULL; + memcpy(old, s -= (PRELEN-1), PRELEN); + memcpy(s, PREFIX, PRELEN); + def = parseline(s); + memcpy(s, old, PRELEN); + return (def == NULL || def->type != nNewfn) ? NULL : def->u[1].p; +} + +static bool Aconv(Format *f, int c) { + char **a = va_arg(f->args, char **); + if (*a != NULL) { + fmtcat(f, *a); + while (*++a != NULL) + fmtprint(f, " %s", *a); + } + return FALSE; +} + +static bool Lconv(Format *f, int c) { + List *l = va_arg(f->args, List *); + char *sep = va_arg(f->args, char *); + char *fmt = (f->flags & FMT_leftside) ? "%s%s" : "%-S%s"; + if (l == NULL && (f->flags & FMT_leftside) == 0) + fmtprint(f, "()"); + else { + List *s; + for (s = l; s != NULL; s = s->n) + fmtprint(f, fmt, s->w, s->n == NULL ? "" : sep); + } + return FALSE; +} + +#define ISMETA(c) (c == '*' || c == '?' || c == '[') + +static bool Sconv(Format *f, int ignore) { + int c; + unsigned char *s = va_arg(f->args, unsigned char *), *t = s; + bool quoted = (f->flags & FMT_altform) != 0; /* '#' */ + bool metaquote = (f->flags & FMT_leftside) != 0; /* '-' */ + if (*s == '\0') { + fmtprint(f, "''"); + return FALSE; + } + if (!quoted) { + while ((c = *t++) != '\0') + if (nw[c] == 1 || (metaquote && ISMETA(c))) + goto quoteit; + fmtprint(f, "%s", s); + return FALSE; + } +quoteit: + fmtputc(f, '\''); + while ((c = *s++) != '\0') { + fmtputc(f, c); + if (c == '\'') + fmtputc(f, '\''); + + } + fmtputc(f, '\''); + return FALSE; +} + +void initprint(void) { + fmtinstall('A', Aconv); + fmtinstall('L', Lconv); + fmtinstall('S', Sconv); + fmtinstall('T', Tconv); + fmtinstall('D', Dconv); +#ifdef PROTECT_ENV + fmtinstall('F', Fconv); +#else + fmtinstall('F', fmtinstall('s', NULL)); +#endif +} diff --git a/getopt.c b/getopt.c @@ -0,0 +1,50 @@ +#include "rc.h" + +int rc_opterr = 1; +int rc_optind = 1; +int rc_optopt; +char *rc_optarg; + +/* getopt routine courtesy of David Sanderson */ + +extern int rc_getopt(int argc, char **argv, char *opts) { + static int sp = 1; + int c; + char *cp; + if (rc_optind == 0) /* reset rc_getopt() */ + rc_optind = sp = 1; + if (sp == 1) + if (rc_optind >= argc || argv[rc_optind][0] != '-' || argv[rc_optind][1] == '\0') { + return -1; + } else if (strcmp(argv[rc_optind], "--") == 0) { + rc_optind++; + return -1; + } + rc_optopt = c = argv[rc_optind][sp]; + if (c == ':' || (cp=strchr(opts, c)) == 0) { + fprint(2, "%s: bad option: -%c\n", argv[0], c); + if (argv[rc_optind][++sp] == '\0') { + rc_optind++; + sp = 1; + } + return '?'; + } + if (*++cp == ':') { + if (argv[rc_optind][sp+1] != '\0') { + rc_optarg = &argv[rc_optind++][sp+1]; + } else if (++rc_optind >= argc) { + fprint(2, "%s: option requires an argument -- %c\n", argv[0], c); + sp = 1; + return '?'; + } else + rc_optarg = argv[rc_optind++]; + sp = 1; + } else { + if (argv[rc_optind][++sp] == '\0') { + sp = 1; + rc_optind++; + } + rc_optarg = NULL; + } + return c; +} diff --git a/glob.c b/glob.c @@ -0,0 +1,240 @@ +/* glob.c: rc's (ugly) globber. This code is not elegant, but it works */ + +#include <sys/types.h> +#include <sys/stat.h> +#include "rc.h" +#ifdef NODIRENT +#include <sys/dir.h> +#define dirent direct /* need to get the struct declaraction right */ +#else +#include <dirent.h> +#endif + +static List *dmatch(char *, char *, char *); +static List *doglob(char *, char *); +static List *lglob(List *, char *, char *, SIZE_T); +static List *sort(List *); + +/* + Matches a list of words s against a list of patterns p. Returns true iff + a pattern in p matches a word in s. () matches (), but otherwise null + patterns match nothing. +*/ + +extern bool lmatch(List *s, List *p) { + List *q; + int i; + bool okay; + if (s == NULL) { + if (p == NULL) /* null matches null */ + return TRUE; + for (; p != NULL; p = p->n) { /* one or more stars match null */ + if (*p->w != '\0') { /* the null string is a special case; it does *not* match () */ + okay = TRUE; + for (i = 0; p->w[i] != '\0'; i++) + if (p->w[i] != '*' || p->m[i] != 1) { + okay = FALSE; + break; + } + if (okay) + return TRUE; + } + } + return FALSE; + } + for (; s != NULL; s = s->n) + for (q = p; q != NULL; q = q->n) + if (match(q->w, q->m, s->w)) + return TRUE; + return FALSE; +} + +/* + Globs a list; checks to see if each element in the list has a metacharacter. If it + does, it is globbed, and the output is sorted. +*/ + +extern List *glob(List *s) { + List *top, *r; + bool meta; + for (r = s, meta = FALSE; r != NULL; r = r->n) + if (r->m != NULL) + meta = TRUE; + if (!meta) + return s; /* don't copy lists with no metacharacters in them */ + for (top = r = NULL; s != NULL; s = s->n) { + if (s->m == NULL) { /* no metacharacters; just tack on to the return list */ + if (top == NULL) + top = r = nnew(List); + else + r = r->n = nnew(List); + r->w = s->w; + } else { + if (top == NULL) + top = r = sort(doglob(s->w, s->m)); + else + r->n = sort(doglob(s->w, s->m)); + while (r->n != NULL) + r = r->n; + } + } + r->n = NULL; + return top; +} + +/* Matches a pattern p against the contents of directory d */ + +static List *dmatch(char *d, char *p, char *m) { + bool matched = FALSE; + List *top, *r; + static DIR *dirp; + static struct dirent *dp; + static struct stat s; + /* prototypes for XXXdir functions. comment out if necessary */ + extern DIR *opendir(const char *); + extern struct dirent *readdir(DIR *); + /*extern int closedir(DIR *);*/ + + top = r = NULL; + /* opendir succeeds on regular files on some systems, so the stat() call is necessary (sigh) */ + if (stat(d, &s) < 0 || (s.st_mode & S_IFMT) != S_IFDIR || (dirp = opendir(d)) == NULL) + return NULL; + while ((dp = readdir(dirp)) != NULL) + if ((*dp->d_name != '.' || *p == '.') && match(p, m, dp->d_name)) { /* match ^. explicitly */ + matched = TRUE; + if (top == NULL) + top = r = nnew(List); + else + r = r->n = nnew(List); + r->w = ncpy(dp->d_name); + r->m = NULL; + } + closedir(dirp); + if (!matched) + return NULL; + r->n = NULL; + return top; +} + +/* + lglob() globs a pattern agains a list of directory roots. e.g., (/tmp /usr /bin) "*" + will return a list with all the files in /tmp, /usr, and /bin. NULL on no match. + slashcount indicates the number of slashes to stick between the directory and the + matched name. e.g., for matching ////tmp/////foo* +*/ + +static List *lglob(List *s, char *p, char *m, SIZE_T slashcount) { + List *q, *r, *top, foo; + static List slash; + static SIZE_T slashsize = 0; + if (slashcount + 1 > slashsize) { + slash.w = ealloc(slashcount + 1); + slashsize = slashcount; + } + slash.w[slashcount] = '\0'; + while (slashcount > 0) + slash.w[--slashcount] = '/'; + for (top = r = NULL; s != NULL; s = s->n) { + q = dmatch(s->w, p, m); + if (q != NULL) { + foo.w = s->w; + foo.m = NULL; + foo.n = NULL; + if (!(s->w[0] == '/' && s->w[1] == '\0')) /* need to separate */ + q = concat(&slash, q); /* dir/name with slash */ + q = concat(&foo, q); + if (r == NULL) + top = r = q; + else + r->n = q; + while (r->n != NULL) + r = r->n; + } + } + return top; +} + +/* + Doglob globs a pathname in pattern form against a unix path. Returns the original + pattern (cleaned of metacharacters) on failure, or the globbed string(s). +*/ + +static List *doglob(char *w, char *m) { + static char *dir = NULL, *pattern = NULL, *metadir = NULL, *metapattern = NULL; + static SIZE_T dsize = 0; + char *d, *p, *md, *mp; + SIZE_T psize; + char *s = w; + List firstdir; + List *matched; + if ((psize = strlen(w) + 1) > dsize || dir == NULL) { + efree(dir); efree(pattern); efree(metadir); efree(metapattern); + dir = ealloc(psize); + pattern = ealloc(psize); + metadir = ealloc(psize); + metapattern = ealloc(psize); + dsize = psize; + } + d = dir; + p = pattern; + md = metadir; + mp = metapattern; + if (*s == '/') + while (*s == '/') + *d++ = *s++, *md++ = *m++; + else + while (*s != '/' && *s != '\0') + *d++ = *s++, *md++ = *m++; /* get first directory component */ + *d = '\0'; + /* + Special case: no slashes in the pattern, i.e., open the current directory. + Remember that w cannot consist of slashes alone (the other way *s could be + zero) since doglob gets called iff there's a metacharacter to be matched + */ + if (*s == '\0') { + matched = dmatch(".", dir, metadir); + goto end; + } + if (*w == '/') { + firstdir.w = dir; + firstdir.m = metadir; + firstdir.n = NULL; + matched = &firstdir; + } else { + /* + we must glob against current directory, + since the first character is not a slash. + */ + matched = dmatch(".", dir, metadir); + } + do { + SIZE_T slashcount; + SIGCHK; + for (slashcount = 0; *s == '/'; s++, m++) + slashcount++; /* skip slashes */ + while (*s != '/' && *s != '\0') + *p++ = *s++, *mp++ = *m++; /* get pattern */ + *p = '\0'; + matched = lglob(matched, pattern, metapattern, slashcount); + p = pattern, mp = metapattern; + } while (*s != '\0'); +end: if (matched == NULL) { + matched = nnew(List); + matched->w = w; + matched->m = NULL; + matched->n = NULL; + } + return matched; +} + +static List *sort(List *s) { + SIZE_T nel = listnel(s); + if (nel > 1) { + char **a; + List *t; + qsort(a = list2array(s, FALSE), nel, sizeof(char *), starstrcmp); + for (t = s; t != NULL; t = t->n) + t->w = *a++; + } + return s; +} diff --git a/glom.c b/glom.c @@ -0,0 +1,420 @@ +/* glom.c: builds an argument list out of words, variables, etc. */ + +#include <sys/types.h> +#include <sys/stat.h> +#include <signal.h> +#include "rc.h" +#if !defined(S_IFIFO) && !defined(DEVFD) +#define NOCMDARG +#endif + +static List *backq(Node *, Node *); +static List *bqinput(List *, int); +static List *count(List *); +static List *mkcmdarg(Node *); + +Rq *redirq = NULL; + +extern List *word(char *w, char *m) { + List *s = NULL; + if (w != NULL) { + s = nnew(List); + s->w = w; + s->m = m; + s->n = NULL; + } + return s; +} + +/* + Append list s2 to list s1 by copying s1 and making the new copy + point at s2. +*/ + +extern List *append(List *s1, List *s2) { + List *r, *top; + if (s1 == NULL) + return s2; + if (s2 == NULL) + return s1; + for (r = top = nnew(List); 1; r = r->n = nnew(List)) { + r->w = s1->w; + r->m = s1->m; + if ((s1 = s1->n) == NULL) + break; + } + r->n = s2; + return top; +} + +extern List *concat(List *s1, List *s2) { + int n1, n2; + List *r, *top; + if (s1 == NULL) + return s2; + if (s2 == NULL) + return s1; + if ((n1 = listnel(s1)) != (n2 = listnel(s2)) && n1 != 1 && n2 != 1) + rc_error("bad concatenation"); + for (r = top = nnew(List); 1; r = r->n = nnew(List)) { + SIZE_T x = strlen(s1->w); + SIZE_T y = strlen(s2->w); + SIZE_T z = x + y + 1; + r->w = nalloc(z); + strcpy(r->w, s1->w); + strcat(r->w, s2->w); + if (s1->m == NULL && s2->m == NULL) { + r->m = NULL; + } else { + r->m = nalloc(z); + if (s1->m == NULL) + clear(r->m, x); + else + memcpy(r->m, s1->m, x); + if (s2->m == NULL) + clear(&r->m[x], y); + else + memcpy(&r->m[x], s2->m, y); + r->m[z] = 0; + } + if (n1 > 1) + s1 = s1->n; + if (n2 > 1) + s2 = s2->n; + if (s1 == NULL || s2 == NULL || (n1 == 1 && n2 == 1)) + break; + } + r->n = NULL; + return top; +} + +extern List *varsub(List *var, List *subs) { + List *r, *top; + int n = listnel(var); + for (top = r = NULL; subs != NULL; subs = subs->n) { + int i = a2u(subs->w); + if (i < 1) + rc_error("bad subscript"); + if (i <= n) { + List *sub = var; + while (--i) + sub = sub->n; /* loop until sub == var(i) */ + if (top == NULL) + top = r = nnew(List); + else + r = r->n = nnew(List); + r->w = sub->w; + r->m = sub->m; + } + } + if (top != NULL) + r->n = NULL; + return top; +} + +extern List *flatten(List *s) { + List *r; + SIZE_T step; + char *f; + if (s == NULL || s->n == NULL) + return s; + r = nnew(List); + f = r->w = nalloc(listlen(s) + 1); + r->m = NULL; /* flattened lists come from variables, so no meta */ + r->n = NULL; + strcpy(f, s->w); + f += strlen(s->w); + do { + *f++ = ' '; + s = s->n; + step = strlen(s->w); + memcpy(f, s->w, step); + f += step; + } while (s->n != NULL); + *f = '\0'; + return r; +} + +static List *count(List *l) { + List *s = nnew(List); + s->w = nprint("%d", listnel(l)); + s->n = NULL; + s->m = NULL; + return s; +} + +extern void assign(List *s1, List *s2, bool stack) { + List *val = s2; + if (s1 == NULL) + rc_error("null variable name"); + if (s1->n != NULL) + rc_error("multi-word variable name"); + if (*s1->w == '\0') + rc_error("zero-length variable name"); + if (a2u(s1->w) != -1) + rc_error("numeric variable name"); + if (strchr(s1->w, '=') != NULL) + rc_error("'=' in variable name"); + if (*s1->w == '*' && s1->w[1] == '\0') + val = append(varlookup("0"), s2); /* preserve $0 when * is assigned explicitly */ + if (s2 != NULL || stack) { + if (dashex) + prettyprint_var(2, s1->w, val); + varassign(s1->w, val, stack); + alias(s1->w, varlookup(s1->w), stack); + } else { + if (dashex) + prettyprint_var(2, s1->w, NULL); + varrm(s1->w, stack); + } +} + +/* + The following two functions are by the courtesy of Paul Haahr, + who could not stand the incompetence of my own backquote implementation. +*/ + +#define BUFSIZE ((SIZE_T) 1000) + +static List *bqinput(List *ifs, int fd) { + char *end, *bufend, *s; + List *r, *top, *prev; + SIZE_T remain, bufsize; + char isifs[256]; + int n, state; /* a simple FSA is used to read in data */ + + clear(isifs, sizeof isifs); + for (isifs['\0'] = TRUE; ifs != NULL; ifs = ifs->n) + for (s = ifs->w; *s != '\0'; s++) + isifs[*(unsigned char *)s] = TRUE; + remain = bufsize = BUFSIZE; + top = r = nnew(List); + r->w = end = nalloc(bufsize + 1); + r->m = NULL; + state = 0; + prev = NULL; + + while (1) { + if (remain == 0) { /* is the string bigger than the buffer? */ + SIZE_T m = end - r->w; + char *buf; + while (bufsize < m + BUFSIZE) + bufsize *= 2; + buf = nalloc(bufsize + 1); + memcpy(buf, r->w, m); + r->w = buf; + end = &buf[m]; + remain = bufsize - m; + } + if ((n = rc_read(fd, end, remain)) <= 0) { + if (n == 0) + /* break */ break; + uerror("backquote read"); + rc_error(NULL); + } + remain -= n; + for (bufend = &end[n]; end < bufend; end++) + if (state == 0) { + if (!isifs[*(unsigned char *)end]) { + state = 1; + r->w = end; + } + } else { + if (isifs[*(unsigned char *)end]) { + state = 0; + *end = '\0'; + prev = r; + r = r->n = nnew(List); + r->w = end+1; + r->m = NULL; + } + } + } + if (state == 1) { /* terminate last string */ + *end = '\0'; + r->n = NULL; + } else { + if (prev == NULL) /* no input at all? */ + top = NULL; + else + prev->n = NULL; /* else terminate list */ + } + return top; +} + +static List *backq(Node *ifs, Node *n) { + int p[2], pid, sp; + List *bq; + if (n == NULL) + return NULL; + if (pipe(p) < 0) { + uerror("pipe"); + rc_error(NULL); + } + if ((pid = rc_fork()) == 0) { + setsigdefaults(FALSE); + mvfd(p[1], 1); + close(p[0]); + redirq = NULL; + walk(n, FALSE); + exit(getstatus()); + } + close(p[1]); + bq = bqinput(glom(ifs), p[0]); + close(p[0]); + rc_wait4(pid, &sp, TRUE); + statprint(-1, sp); + SIGCHK; + return bq; +} + +extern void qredir(Node *n) { + Rq *next; + if (redirq == NULL) { + next = redirq = nnew(Rq); + } else { + for (next = redirq; next->n != NULL; next = next->n) + ; + next->n = nnew(Rq); + next = next->n; + } + next->r = n; + next->n = NULL; +} + +#ifdef NOCMDARG +static List *mkcmdarg(Node *n) { + rc_error("named pipes are not supported"); + return NULL; +} +#else +#ifndef DEVFD +static List *mkcmdarg(Node *n) { + int fd; + char *name; + Edata efifo; + Estack *e = enew(Estack); + List *ret = nnew(List); + static int fifonumber = 0; + name = nprint("%s/rc%d.%d", TMPDIR, getpid(), fifonumber++); + if (mknod(name, S_IFIFO | 0666, 0) < 0) { + uerror("mknod"); + return NULL; + } + if (rc_fork() == 0) { + setsigdefaults(FALSE); + fd = rc_open(name, (n->u[0].i != rFrom) ? rFrom : rCreate); /* stupid hack */ + if (fd < 0) { + uerror("open"); + exit(1); + } + if (mvfd(fd, (n->u[0].i == rFrom)) < 0) /* same stupid hack */ + exit(1); + redirq = NULL; + walk(n->u[2].p, FALSE); + exit(getstatus()); + } + efifo.name = name; + except(eFifo, efifo, e); + ret->w = name; + ret->m = NULL; + ret->n = NULL; + return ret; +} +#else +static List *mkcmdarg(Node *n) { + char *name; + List *ret = nnew(List); + Estack *e = nnew(Estack); + Edata efd; + int p[2]; + if (pipe(p) < 0) { + uerror("pipe"); + return NULL; + } + if (rc_fork() == 0) { + setsigdefaults(FALSE); + if (mvfd(p[n->u[0].i == rFrom], n->u[0].i == rFrom) < 0) /* stupid hack */ + exit(1); + close(p[n->u[0].i != rFrom]); + redirq = NULL; + walk(n->u[2].p, FALSE); + exit(getstatus()); + } + name = nprint("/dev/fd/%d", p[n->u[0].i != rFrom]); + efd.fd = p[n->u[0].i != rFrom]; + except(eFd, efd, e); + close(p[n->u[0].i == rFrom]); + ret->w = name; + ret->m = NULL; + ret->n = NULL; + return ret; +} +#endif /* DEVFD */ +#endif /* !NOCMDARG */ + +extern List *glom(Node *n) { + List *v, *head, *tail; + Node *words; + if (n == NULL) + return NULL; + switch (n->type) { + case nArgs: + case nLappend: + words = n->u[0].p; + tail = NULL; + while (words != NULL && (words->type == nArgs || words->type == nLappend)) { + if (words->u[1].p != NULL && words->u[1].p->type != nWord && words->u[1].p->type != nQword) + break; + head = glom(words->u[1].p); + if (head != NULL) { + head->n = tail; + tail = head; + } + words = words->u[0].p; + } + v = append(glom(words), tail); /* force left to right evaluation */ + return append(v, glom(n->u[1].p)); + case nBackq: + return backq(n->u[0].p, n->u[1].p); + case nConcat: + head = glom(n->u[0].p); /* force left-to-right evaluation */ + return concat(head, glom(n->u[1].p)); + case nDup: + case nRedir: + qredir(n); + return NULL; + case nWord: + case nQword: + return word(n->u[0].s, n->u[1].s); + case nNmpipe: + return mkcmdarg(n); + default: + /* + The next four operations depend on the left-child of glom + to be a variable name. Therefore the variable is looked up + here. + */ + if ((v = glom(n->u[0].p)) == NULL) + rc_error("null variable name"); + if (v->n != NULL) + rc_error("multi-word variable name"); + if (*v->w == '\0') + rc_error("zero-length variable name"); + v = (*v->w == '*' && v->w[1] == '\0') ? varlookup(v->w)->n : varlookup(v->w); + switch (n->type) { + default: + panic("unexpected node in glom"); + exit(1); + /* NOTREACHED */ + case nCount: + return count(v); + case nFlat: + return flatten(v); + case nVar: + return v; + case nVarsub: + return varsub(v, glom(n->u[1].p)); + } + } +} diff --git a/hash.c b/hash.c @@ -0,0 +1,302 @@ +/* hash.c: hash table support for functions and variables. */ + +/* + Functions and variables are cached in both internal and external + form for performance. Thus a variable which is never "dereferenced" + with a $ is passed on to rc's children untouched. This is not so + important for variables, but is a big win for functions, where a call + to yyparse() is involved. +*/ + +#include "rc.h" +#include "sigmsgs.h" + +static bool var_exportable(char *); +static bool fn_exportable(char *); +static int hash(char *, int); +static int find(char *, Htab *, int); +static void free_fn(Function *); + +Htab *fp; +Htab *vp; +static int fused, fsize, vused, vsize; +static char **env; +static int bozosize; +static int envsize; +static bool env_dirty = TRUE; +static char *dead = ""; + +#define HASHSIZE 64 /* rc was debugged with HASHSIZE == 2; 64 is about right for normal use */ + +extern void inithash() { + Htab *fpp, *vpp; + int i; + fp = ealloc(sizeof(Htab) * HASHSIZE); + vp = ealloc(sizeof(Htab) * HASHSIZE); + fused = vused = 0; + fsize = vsize = HASHSIZE; + for (vpp = vp, fpp = fp, i = 0; i < HASHSIZE; i++, vpp++, fpp++) + vpp->name = fpp->name = NULL; +} + +#define ADV() {if ((c = *s++) == '\0') break;} + +/* hash function courtesy of paul haahr */ + +static int hash(char *s, int size) { + int c, n = 0; + while (1) { + ADV(); + n += (c << 17) ^ (c << 11) ^ (c << 5) ^ (c >> 1); + ADV(); + n ^= (c << 14) + (c << 7) + (c << 4) + c; + ADV(); + n ^= (~c << 11) | ((c << 3) ^ (c >> 1)); + ADV(); + n -= (c << 16) | (c << 9) | (c << 2) | (c & 3); + } + if (n < 0) + n = ~n; + return n & (size - 1); /* need power of 2 size */ +} + +static bool rehash(Htab *ht) { + int i, j, size; + int newsize, newused; + Htab *newhtab; + if (ht == fp) { + if (fsize > 2 * fused) + return FALSE; + size = fsize; + } else { + if (vsize > 2 * vused) + return FALSE; + size = vsize; + } + newsize = 2 * size; + newhtab = ealloc(newsize * sizeof(Htab)); + for (i = 0; i < newsize; i++) + newhtab[i].name = NULL; + for (i = newused = 0; i < size; i++) + if (ht[i].name != NULL && ht[i].name != dead) { + newused++; + j = hash(ht[i].name, newsize); + while (newhtab[j].name != NULL) { + j++; + j &= (newsize - 1); + } + newhtab[j].name = ht[i].name; + newhtab[j].p = ht[i].p; + } + if (ht == fp) { + fused = newused; + fp = newhtab; + fsize = newsize; + } else { + vused = newused; + vp = newhtab; + vsize = newsize; + } + efree(ht); + return TRUE; +} + +#define varfind(s) find(s, vp, vsize) +#define fnfind(s) find(s, fp, fsize) + +static int find(char *s, Htab *ht, int size) { + int h = hash(s, size); + while (ht[h].name != NULL && !streq(ht[h].name, s)) { + h++; + h &= size - 1; + } + return h; +} + +extern void *lookup(char *s, Htab *ht) { + int h = find(s, ht, ht == fp ? fsize : vsize); + return (ht[h].name == NULL) ? NULL : ht[h].p; +} + +extern Function *get_fn_place(char *s) { + int h = fnfind(s); + env_dirty = TRUE; + if (fp[h].name == NULL) { + if (rehash(fp)) + h = fnfind(s); + fused++; + fp[h].name = ecpy(s); + fp[h].p = enew(Function); + } else + free_fn(fp[h].p); + return fp[h].p; +} + +extern Variable *get_var_place(char *s, bool stack) { + Variable *new; + int h = varfind(s); + + env_dirty = TRUE; + + if (vp[h].name == NULL) { + if (rehash(vp)) + h = varfind(s); + vused++; + vp[h].name = ecpy(s); + vp[h].p = enew(Variable); + ((Variable *)vp[h].p)->n = NULL; + return vp[h].p; + } else { + if (stack) { /* increase the stack by 1 */ + new = enew(Variable); + new->n = vp[h].p; + return vp[h].p = new; + } else { /* trample the top of the stack */ + new = vp[h].p; + efree(new->extdef); + listfree(new->def); + return new; + } + } +} + +extern void delete_fn(char *s) { + int h = fnfind(s); + if (fp[h].name == NULL) + return; /* not found */ + env_dirty = TRUE; + free_fn(fp[h].p); + efree(fp[h].p); + efree(fp[h].name); + if (fp[(h+1)&(fsize-1)].name == NULL) { + --fused; + fp[h].name = NULL; + } else { + fp[h].name = dead; + } +} + +extern void delete_var(char *s, bool stack) { + int h = varfind(s); + Variable *v; + if (vp[h].name == NULL) + return; /* not found */ + env_dirty = TRUE; + v = vp[h].p; + efree(v->extdef); + listfree(v->def); + if (v->n != NULL) { /* This is the top of a stack */ + if (stack) { /* pop */ + vp[h].p = v->n; + efree(v); + } else { /* else just empty */ + v->extdef = NULL; + v->def = NULL; + } + } else { /* needs to be removed from the hash table */ + efree(v); + efree(vp[h].name); + if (vp[(h+1)&(vsize-1)].name == NULL) { + --vused; + vp[h].name = NULL; + } else { + vp[h].name = dead; + } + } +} + +static void free_fn(Function *f) { + treefree(f->def); + efree(f->extdef); +} + +extern void initenv(char **envp) { + int n; + for (n = 0; envp[n] != NULL; n++) + ; + n++; /* one for the null terminator */ + if (n < HASHSIZE) + n = HASHSIZE; + env = ealloc((envsize = 2 * n) * sizeof (char *)); + for (; *envp != NULL; envp++) + if (strncmp(*envp, "fn_", conststrlen("fn_")) == 0) { + if (!dashpee) + fnassign_string(*envp); + } else { + if (!varassign_string(*envp)) /* add to bozo env */ + env[bozosize++] = *envp; + } +} + +static bool var_exportable(char *s) { + static char *notforexport[] = { + "apid", "pid", "apids", "*", "ifs" + }; + int i; + for (i = 0; i < arraysize(notforexport); i++) + if (streq(s, notforexport[i])) + return FALSE; + return TRUE; +} + +static bool fn_exportable(char *s) { + int i; + if (strncmp(s, "sig", conststrlen("sig")) == 0) { /* small speed hack */ + for (i = 0; i < NUMOFSIGNALS; i++) + if (streq(s, signals[i].name)) + return FALSE; + if (streq(s, "sigexit")) + return FALSE; + } + return TRUE; +} + +extern char **makeenv() { + int ep, i; + char *v; + if (!env_dirty) + return env; + env_dirty = FALSE; + ep = bozosize; + if (vsize + fsize + 1 + bozosize > envsize) { + envsize = 2 * (bozosize + vsize + fsize + 1); + env = erealloc(env, envsize * sizeof(char *)); + } + for (i = 0; i < vsize; i++) { + if (vp[i].name == NULL || vp[i].name == dead || !var_exportable(vp[i].name)) + continue; + v = varlookup_string(vp[i].name); + if (v != NULL) + env[ep++] = v; + } + for (i = 0; i < fsize; i++) { + if (fp[i].name == NULL || fp[i].name == dead || !fn_exportable(fp[i].name)) + continue; + env[ep++] = fnlookup_string(fp[i].name); + } + env[ep] = NULL; + qsort(env, (SIZE_T) ep, sizeof(char *), starstrcmp); + return env; +} + +extern void whatare_all_vars() { + int i; + List *s; + for (i = 0; i < vsize; i++) + if (vp[i].name != NULL && (s = varlookup(vp[i].name)) != NULL) + prettyprint_var(1, vp[i].name, s); + for (i = 0; i < fsize; i++) + if (fp[i].name != NULL && fp[i].name != dead) + prettyprint_fn(1, fp[i].name, fnlookup(fp[i].name)); +} + +/* fake getenv() for readline() follows: */ + +#ifdef READLINE +extern char *getenv(const char *name) { + List *s; + if (name == NULL || vp == NULL || (s = varlookup((char *) name)) == NULL) + return NULL; + return s->w; +} +#endif diff --git a/heredoc.c b/heredoc.c @@ -0,0 +1,156 @@ +/* heredoc.c: heredoc slurping is done here */ + +#include "rc.h" + +struct Hq { + Node *doc; + char *name; + Hq *n; + bool quoted; +} *hq; + +static bool dead = FALSE; + +/* + * read in a heredocument. A clever trick: skip over any partially matched end-of-file + * marker storing only the number of characters matched. If the whole marker is matched, + * return from readheredoc(). If only part of the marker is matched, copy that part into + * the heredocument. + * + * BUG: if the eof string contains a newline, the state can get confused, and the + * heredoc may continue past where it should. on the other hand, /bin/sh seems to + * never get out of its readheredoc() when the heredoc string contains a newline + */ + +static char *readheredoc(char *eof) { + int c; + char *t, *buf, *bufend; + unsigned char *s; + SIZE_T bufsize; + t = buf = nalloc(bufsize = 512); + bufend = &buf[bufsize]; + dead = FALSE; +#define RESIZE(extra) { \ + char *nbuf; \ + bufsize = bufsize * 2 + extra; \ + nbuf = nalloc(bufsize); \ + memcpy(nbuf, buf, (SIZE_T) (t - buf)); \ + t = nbuf + (t - buf); \ + buf = nbuf; \ + bufend = &buf[bufsize]; \ + } + for (;;) { + print_prompt2(); + for (s = (unsigned char *) eof; (c = gchar()) == *s; s++) + ; + if (*s == '\0' && (c == '\n' || c == EOF)) { + *t++ = '\0'; + return buf; + } + if (s != (unsigned char *) eof) { + SIZE_T len = s - (unsigned char *) eof; + if (t + len >= bufend) + RESIZE(len); + memcpy(t, eof, len); + t += len; + } + for (;; c = gchar()) { + if (c == EOF) { + yyerror("heredoc incomplete"); + dead = TRUE; + return NULL; + } + if (t + 1 >= bufend) + RESIZE(0); + *t++ = c; + if (c == '\n') + break; + } + } +} + +/* parseheredoc -- turn a heredoc with variable references into a node chain */ + +static Node *parseheredoc(char *s) { + int c = *s; + Node *result = NULL; + while (TRUE) { + Node *node; + switch (c) { + default: { + char *begin = s; + while ((c = *s++) != '\0' && c != '$') + ; + *--s = '\0'; + node = mk(nQword, begin, NULL); + break; + } + case '$': { + char *begin = ++s, *var; + c = *s++; + if (c == '$') { + node = mk(nQword, "$", NULL); + c = *s; + } else { + SIZE_T len = 0; + do + len++; + while (!dnw[c = *(unsigned char *) s++]); + if (c == '^') + c = *s; + else + s--; + var = nalloc(len + 1); + var[len] = '\0'; + memcpy(var, begin, len); + node = mk(nFlat, mk(nWord, var, NULL)); + } + break; + } + case '\0': + return result; + } + result = (result == NULL) ? node : mk(nConcat, result, node); + } +} + +/* read in heredocs when yyparse hits a newline. called from yyparse */ + +extern int heredoc(int end) { + Hq *here; + if ((here = hq) != NULL) { + hq = NULL; + if (end) { + yyerror("heredoc incomplete"); + return FALSE; + } + do { + Node *n = here->doc; + char *s = readheredoc(here->name); + if (dead) + return FALSE; + n->u[2].p = here->quoted ? mk(nQword, s, NULL) : parseheredoc(s); + n->u[0].i = rHerestring; + } while ((here = here->n) != NULL); + } + return TRUE; +} + +/* queue pending heredocs into a queue. called from yyparse */ + +extern int qdoc(Node *name, Node *n) { + Hq *new, **prev; + if (name->type != nWord && name->type != nQword) { + yyerror("eof-marker not a single literal word"); + flushu(); + return FALSE; + } + for (prev = &hq; (new = *prev) != NULL; prev = &new->n) + ; + *prev = new = nnew(Hq); + new->name = name->u[0].s; + new->quoted = (name->type == nQword); + new->doc = n; + new->n = NULL; + return TRUE; +} diff --git a/history/Makefile b/history/Makefile @@ -0,0 +1,6 @@ +CC=gcc -g -O + +history: history.c + $(CC) -o history history.c + @echo 'Now install "history" as -, --, -p and --p in your bin directory' + @echo '(for example, by making them links to the same file)' diff --git a/history/history.1 b/history/history.1 @@ -0,0 +1,234 @@ +.\" history.1 +.\"------- +.\" See rc.1 for man page portability notes. +.\"------- +.\" Dd distance to space vertically before a "display" +.\" These are what n/troff use for interparagraph distance +.\"------- +.if t .nr Dd .4v +.if n .nr Dd 1v +.\"------- +.\" Ds begin a display, indented .5 inches from the surrounding text. +.\" +.\" Note that uses of Ds and De may NOT be nested. +.\"------- +.de Ds +.\" .RS \\$1 +.sp \\n(Ddu +.in +0.5i +.nf +.. +.\"------- +.\" De end a display (no trailing vertical spacing) +.\"------- +.de De +.fi +.in +.\" .RE +.. +.\"------- +.\" I stole the Xf macro from the -man macros on my machine (originally +.\" "}S", I renamed it so that it won't conflict). +.\"------- +.\" Set Cf to the name of the constant width font. +.\" It will be "C" or "(CW", typically. +.\" NOTEZ BIEN the lines defining Cf must have no trailing white space: +.\"------- +.if t .ds Cf C +.if n .ds Cf R +.\"------- +.\" Rc - Alternate Roman and Courier +.\"------- +.de Rc +.Xf R \\*(Cf \& "\\$1" "\\$2" "\\$3" "\\$4" "\\$5" "\\$6" +.. +.\"------- +.\" Ic - Alternate Italic and Courier +.\"------- +.de Ic +.Xf I \\*(Cf \& "\\$1" "\\$2" "\\$3" "\\$4" "\\$5" "\\$6" +.. +.\"------- +.\" Bc - Alternate Bold and Courier +.\"------- +.de Bc +.Xf B \\*(Cf \& "\\$1" "\\$2" "\\$3" "\\$4" "\\$5" "\\$6" +.. +.\"------- +.\" Cr - Alternate Courier and Roman +.\"------- +.de Cr +.Xf \\*(Cf R \& "\\$1" "\\$2" "\\$3" "\\$4" "\\$5" "\\$6" +.. +.\"------- +.\" Ci - Alternate Courier and Italic +.\"------- +.de Ci +.Xf \\*(Cf I \& "\\$1" "\\$2" "\\$3" "\\$4" "\\$5" "\\$6" +.. +.\"------- +.\" Cb - Alternate Courier and Bold +.\"------- +.de Cb +.Xf \\*(Cf B \& "\\$1" "\\$2" "\\$3" "\\$4" "\\$5" "\\$6" +.. +.\"------- +.\" Xf - Alternate fonts +.\" +.\" \$1 - first font +.\" \$2 - second font +.\" \$3 - desired word with embedded font changes, built up by recursion +.\" \$4 - text for first font +.\" \$5 - \$9 - remaining args +.\" +.\" Every time we are called: +.\" +.\" If there is something in \$4 +.\" then Call ourself with the fonts switched, +.\" with a new word made of the current word (\$3) and \$4 +.\" rendered in the first font, +.\" and with the remaining args following \$4. +.\" else We are done recursing. \$3 holds the desired output +.\" word. We emit \$3, change to Roman font, and restore +.\" the point size to the default. +.\" fi +.\" +.\" Use Xi to add a little bit of space after italic text. +.\"------- +.de Xf +.ds Xi +.\"------- +.\" I used to test for the italic font both by its font position +.\" and its name. Now just test by its name. +.\" +.\" .if "\\$1"2" .if !"\\$5"" .ds Xi \^ +.\"------- +.if "\\$1"I" .if !"\\$5"" .ds Xi \^ +.\"------- +.\" This is my original code to deal with the recursion. +.\" Evidently some nroffs can't deal with it. +.\"------- +.\" .ie !"\\$4"" \{\ +.\" . Xf \\$2 \\$1 "\\$3\\f\\$1\\$4\\*(Xi" "\\$5" "\\$6" "\\$7" "\\$8" "\\$9" +.\" .\} +.\" .el \{\\$3 +.\" . ft R \" Restore the default font, since we don't know +.\" . \" what the last font change was. +.\" . ps 10 \" Restore the default point size, since it might +.\" . \" have been changed by an argument to this macro. +.\" .\} +.\"------- +.\" Here is more portable (though less pretty) code to deal with +.\" the recursion. +.\"------- +.if !"\\$4"" .Xf \\$2 \\$1 "\\$3\\f\\$1\\$4\\*(Xi" "\\$5" "\\$6" "\\$7" "\\$8" "\\$9" +.if "\\$4"" \\$3\fR\s10 +.. +.TH HISTORY 1 "30 July 1991" +.SH NAME +\-, \-\|\-, \-p, \-\|\-p \- shell history programs +.SH SYNOPSIS +.B \- +.RI [ pattern ...] +.RI [ substitution ...] +.SH DESCRIPTION +This set of programs provides a crude history mechanism for the shell +.IR rc (1). +It is based on the v8 UNIX programs +.IR = , +.IR == , +etc. +.PP +The program +.RI `` \- '' +runs the shell on the command it is requested to find. +The program +.RI `` \-\|\- '' +edits that command first. +The programs +.RI `` \-p '' +and +.RI `` \-\|\-p '' +are similar, except that they print the final command on their standard +output instead of running the shell. +.PP +The commands work by looking for a file +named by the environment variable +.Cr $history , +and by searching for previous commands in this file. +Old commands can be edited, +or simply re-executed according to the rules below: +.PP +A command is searched for by examining the lines in +.Cr $history +in reverse order. +Lines which contain a previous invocation of the history +program itself are ignored. +If one or more +.I pattern +is supplied on the command line, +then the patterns are used as a means of +limiting the search. +Patterns match any substring of a previous command, +and if more than one pattern is present then all patterns must be +matched before a command is selected. +.PP +Substitutions may also be specified on the command line. +These have the syntax: +.Ds +.Ic old : new +.De +.PP +(Note that the +.I old +pattern is used as a search-limiting pattern also.) +Substitutions happen on the first match. +.PP +Finally, a command may be edited in a crude line-mode fashion: +The line to be edited is printed out, and below it the user +supplies modifications to the command: +.TP +.B any character +Replaces the character above. +.TP +.B space or tab +Skips over the above character(s). +.TP +.B # +Deletes one character. +.TP +.B % +Replaces one character with a space. +.TP +.B ^ +Inserts the rest of the typed line just before the character. +.TP +.B $ +Deletes the rest of the line from that character on, and replaces +it with the rest of the typed line. +.TP +.B + +Appends the rest of the typed line. +.TP +.B \- +Backs up to a previous command satisfying the same matching +constraints. +.TP +.B end of file +If an end-of-file is read from the keyboard by the editor, +it aborts with exit status 1 and does not produce any output. +.SH EXAMPLES +The history programs work best when their output is reinterpreted by +the shell using an +.Cr eval +command. +This can be achieved by writing a shell function to perform the +reinterpretation: +.Ds +.Cr "fn - -- {" +.Cr " comm = \`{$0^p $*}" +.Cr " if (! ~ $#comm 0) {" +.Cr " echo $comm >[1=2]" +.Cr " eval $comm" +.Cr " }" +.Cr "}" diff --git a/history/history.c b/history/history.c @@ -0,0 +1,333 @@ +/* + history.c -- primitive history mechanism + + Paul Haahr & Byron Rakitzis, July 1991. + + This program mimics the att v8 = and == history programs. + The edit() algorithm was adapted from a similar program + that Boyd Roberts wrote, but otherwise all the code has + been written from scratch. + + edit() was subsequently redone by Hugh Redelmeier in order + to correctly deal with tab characters in the source line. + + BUGS: + There is an implicit assumption that commands are no + more than 1k characters long. +*/ + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +static char *id = "@(#) history.c 8/91"; + +#undef FALSE +#undef TRUE +typedef enum { FALSE, TRUE } bool; + +#define CHUNKSIZE 65536 + +static struct { + char *old, *new; +} *replace; + +static char **search, *progname, *history; +static char me; /* typically ':' or '-' */ +static bool editit = FALSE, printit = FALSE; +static int nreplace = 0, nsearch = 0; +static FILE *fp; + +static void *ealloc(size_t n) { + void *p = (void *) malloc(n); + if (p == NULL) { + perror("malloc"); + exit(1); + } + return p; +} + +static void *erealloc(void *p, size_t n) { + p = (void *) realloc(p, n); + if (p == NULL) { + perror("realloc"); + exit(1); + } + return p; +} + +static char *newstr() { + return ealloc((size_t)1024); +} + +static char *basename(char *s) { + char *t = strrchr(s, '/'); + return (t == NULL) ? s : t + 1; +} + +/* stupid O(n^2) substring matching routine */ + +static char *isin(char *target, char *pattern) { + size_t plen = strlen(pattern); + size_t tlen = strlen(target); + for (; tlen >= plen; target++, --tlen) + if (strncmp(target, pattern, plen) == 0) + return target; + return NULL; +} + +/* replace the first match in the string with "new" */ +static char *sub(char *s, char *old, char *new) { + char *t, *u; + + t = isin(s, old); + u = newstr(); + + *t = '\0'; + while (*old != '\0') + old++, t++; + strcpy(u, s); + strcat(u, new); + strcat(u, t); + return u; +} + +static char *edit(char *s) { + char *final, *f, *end; + int col; + bool ins; + +start: + fprintf(stderr, "%s\n", s); + f = final = newstr(); + end = s + strlen(s); + col = 0; + ins = FALSE; + + for (;; col++) { + int c = getchar(); + + if (c == me && col == 0) { + int peekc = getchar(); + if (peekc == '\n') + return NULL; + ungetc(peekc, stdin); + } + if (c == '\n') { + if (col == 0) + return s; + + while (s < end) /* copy remainder of string */ + *f++ = *s++; + *f = '\0'; + s = final; + goto start; + } else if (ins || s>=end) { + /* col need not be accurate -- tabs need not be interpreted */ + *f++ = c; + } else { + switch (c) { + case '+': + while (s < end) + *f++ = *s++; + *f = '\0'; + continue; + case '%': + c = ' '; + /* FALLTHROUGH */ + default: + *f++ = c; + break; + case EOF: + exit(1); + /* NOTREACHED */ + case ' ': + if (*s == '\t') { + int oldcol = col; + + for (;; col++) { + int peekc; + + if ((col&07) == 07) { + *f++ = '\t'; /* we spaced past a tab */ + break; + } + peekc = getchar(); + if (peekc != ' ') { + ungetc(peekc, stdin); + if (peekc != '\n') { + /* we spaced partially into a tab */ + do { + *f++ = ' '; + oldcol++; + } while (oldcol <= col); + } + break; + } + } + } else { + *f++ = *s; + } + break; + case '#': + break; + case '$': + end = s; /* truncate s */ + continue; /* skip incrementing s */ + case '^': + ins = TRUE; + continue; /* skip incrementing s */ + case '\t': + for (;; col++) { + if ((*f++ = s<end? *s++ : '\t') == '\t') { + col = col | 07; /* advance to before next tabstop */ + } + if ((col&07) == 07) /* stop before tabstop */ + break; + } + continue; /* skip incrementing s */ + } + if (s<end && (*s!='\t' || (col&07)==07)) + s++; + } + } +} + +static char *readhistoryfile(char **last) { + char *buf; + size_t count, size; + long nread; + + if ((history = getenv("history")) == NULL) { + fprintf(stderr, "$history not set\n"); + exit(1); + } + fp = fopen(history, "r+"); + if (fp == NULL) { + perror(history); + exit(1); + } + + size = 0; + count = 0; + buf = ealloc(size = CHUNKSIZE); + while ((nread = fread(buf + count, sizeof (char), size - count, fp)) > 0) { + count += nread; + if (size - count == 0) + buf = erealloc(buf, size *= 4); + } + if (nread == -1) { + perror(history); + exit(1); + } + *last = buf + count; + return buf; +} + +static char *getcommand() { + char *s, *t; + static char *hist = NULL, *last; + + if (hist == NULL) { + hist = readhistoryfile(&last); + *--last = '\0'; /* trim final newline */ + } + +again: s = last; + if (s < hist) + return NULL; + while (*--s != '\n') + if (s <= hist) { + last = hist - 1; + return hist; + } + *s = '\0'; + last = s++; + + /* + * if the command contains the "me" character at the start of the line + * or after any of [`{|()] then try again + */ + + for (t = s; *t != '\0'; t++) + if (*t == me) { + char *u = t - 1; + while (u >= s && (*u == ' ' || *u == '\t')) + --u; + if (u < s || *u == '`' || *u == '{' || *u == '|' || *u == '(' || *u == ')') + goto again; + } + return s; +} + +int main(int argc, char **argv) { + int i; + char *s; + + s = progname = basename(argv[0]); + me = *s++; + if (*s == me) { + s++; + editit = TRUE; + } + if (*s == 'p') { + s++; + printit = TRUE; + } +/* Nahh... + if (*s != '\0') { + fprintf(stderr, "\"%s\": bad name for history program\n", progname); + exit(1); + } +*/ + + if (argc > 1) { + replace = ealloc((argc - 1) * sizeof *replace); + search = ealloc((argc - 1) * sizeof *search); + } + for (i = 1; i < argc; i++) + if ((s = strchr(argv[i], ':')) == NULL) + search[nsearch++] = argv[i]; + else { + *(char *)s = '\0'; /* do we confuse ps too much? */ + replace[nreplace].old = argv[i]; + replace[nreplace].new = s + 1; + nreplace++; + } + +next: s = getcommand(); + if (s == NULL) { + fprintf(stderr, "command not matched\n"); + return 1; + } + for (i = 0; i < nsearch; i++) + if (!isin(s, search[i])) + goto next; + for (i = 0; i < nreplace; i++) + if (!isin(s, replace[i].old)) + goto next; + else + s = sub(s, replace[i].old, replace[i].new); + if (editit) { + s = edit(s); + if (s == NULL) + goto next; + } + fseek(fp, 0, 2); /* 2 == end of file. i.e., append command to $history */ + fprintf(fp, "%s\n", s); + fclose(fp); + if (printit) + printf("%s\n", s); + else { + char *shell = getenv("SHELL"); + + if (!editit) + fprintf(stderr, "%s\n", s); + if (shell == NULL) + shell = "/bin/sh"; + execl(shell, basename(shell), "-c", s, NULL); + perror(shell); + exit(1); + } + return 0; +} diff --git a/input.c b/input.c @@ -0,0 +1,373 @@ +/* input.c: i/o routines for files and pseudo-files (strings) */ + +#include <errno.h> +#include <setjmp.h> +#include "rc.h" +#include "jbwrap.h" + +/* + NB: character unget is supported for up to two characters, but NOT + in the case of EOF. Since EOF does not fit in a char, it is easiest + to support only one unget of EOF. +*/ + +typedef struct Input { + inputtype t; + char *ibuf; + int fd, index, read, lineno, last; + bool saved, eofread; +} Input; + +#define BUFSIZE ((SIZE_T) 256) + +#ifdef READLINE +extern char *readline(char *); +extern void add_history(char *); +static char *rlinebuf; +#endif + +char *prompt, *prompt2; +bool rcrc; + +static int dead(void); +static int fdgchar(void); +static int stringgchar(void); +static void history(void); +static void ugdead(int); +static void pushcommon(void); + +static char *inbuf; +static SIZE_T istacksize, chars_out, chars_in; +static bool eofread = FALSE, save_lineno = TRUE; +static Input *istack, *itop; +static char *histstr; +static int histfd; + +static int (*realgchar)(void); +static void (*realugchar)(int); + +int last; + +extern int gchar() { + if (eofread) { + eofread = FALSE; + return last = EOF; + } + return (*realgchar)(); +} + +extern void ugchar(int c) { + (*realugchar)(c); +} + +static int dead() { + return last = EOF; +} + +static void ugdead(int c) { + return; +} + +static void ugalive(int c) { + if (c == EOF) + eofread = TRUE; + else + inbuf[--chars_out] = c; +} + +/* get the next character from a string. */ + +static int stringgchar() { + return last = (inbuf[chars_out] == '\0' ? EOF : inbuf[chars_out++]); +} + +/* signal-safe readline wrapper */ + +#ifdef READLINE +#ifndef SVSIGS +static char *rc_readline(char *prompt) { + char *r; + interrupt_happened = FALSE; + if (!setjmp(slowbuf.j)) { + slow = TRUE; + if (!interrupt_happened) + r = readline(prompt); + else + r = NULL; + } else + r = NULL; + slow = FALSE; + if (r == NULL) + errno = EINTR; + SIGCHK; + return r; +} +#else +#define rc_readline readline +#endif /* SVSIGS */ +#endif /* READLINE */ + +/* + read a character from a file-descriptor. If GNU readline is defined, add a newline and doctor + the buffer to look like a regular fdgchar buffer. +*/ + +static int fdgchar() { + if (chars_out >= chars_in + 2) { /* has the buffer been exhausted? if so, replenish it */ + while (1) { +#ifdef READLINE + if (interactive && istack->fd == 0) { + rlinebuf = readline(prompt); + if (rlinebuf == NULL) { + chars_in = 0; + } else { + if (*rlinebuf != '\0') + add_history(rlinebuf); + chars_in = strlen(rlinebuf) + 1; + efree(inbuf); + inbuf = ealloc(chars_in + 3); + strcpy(inbuf+2, rlinebuf); + strcat(inbuf+2, "\n"); + } + } else +#endif + { + long /*ssize_t*/ r = rc_read(istack->fd, inbuf + 2, BUFSIZE); + if (r < 0) { + if (errno == EINTR) + continue; /* Suppose it was interrupted by a signal */ + uerror("read"); + rc_exit(1); + } + chars_in = (SIZE_T) r; + } + break; + } + if (chars_in == 0) + return last = EOF; + chars_out = 2; + if (dashvee) + writeall(2, inbuf + 2, chars_in); + history(); + } + return last = inbuf[chars_out++]; +} + +/* set up the input stack, and put a "dead" input at the bottom, so that yyparse will always read eof */ + +extern void initinput() { + istack = itop = ealloc(istacksize = 256 * sizeof (Input)); + istack->t = iFd; + istack->fd = -1; + realugchar = ugalive; +} + +/* push an input source onto the stack. set up a new input buffer, and set gchar() */ + +static void pushcommon() { + SIZE_T idiff; + istack->index = chars_out; + istack->read = chars_in; + istack->ibuf = inbuf; + istack->lineno = lineno; + istack->saved = save_lineno; + istack->last = last; + istack->eofread = eofread; + istack++; + idiff = istack - itop; + if (idiff >= istacksize / sizeof (Input)) { + itop = erealloc(itop, istacksize *= 2); + istack = itop + idiff; + } + realugchar = ugalive; + chars_out = 2; + chars_in = 0; +} + +extern void pushfd(int fd) { + pushcommon(); + istack->t = iFd; + save_lineno = TRUE; + istack->fd = fd; + realgchar = fdgchar; + inbuf = ealloc(BUFSIZE + 2); + lineno = 1; +} + +extern void pushstring(char **a, bool save) { + pushcommon(); + istack->t = iString; + save_lineno = save; + inbuf = mprint("..%A", a); + realgchar = stringgchar; + if (save_lineno) + lineno = 1; + else + --lineno; +} + +/* remove an input source from the stack. restore the right kind of getchar (string,fd) etc. */ + +extern void popinput() { + if (istack->t == iFd) + close(istack->fd); + efree(inbuf); + --istack; + realgchar = (istack->t == iString ? stringgchar : fdgchar); + if (istack->fd == -1) { /* top of input stack */ + realgchar = dead; + realugchar = ugdead; + } + last = istack->last; + eofread = istack->eofread; + inbuf = istack->ibuf; + chars_out = istack->index; + chars_in = istack->read; + if (save_lineno) + lineno = istack->lineno; + else + lineno++; + save_lineno = istack->saved; +} + +/* flush input characters upto newline. Used by scanerror() */ + +extern void flushu() { + int c; + if (last == '\n' || last == EOF) + return; + while ((c = gchar()) != '\n' && c != EOF) + ; /* skip to newline */ + if (c == EOF) + ugchar(c); +} + +/* the wrapper loop in rc: prompt for commands until EOF, calling yyparse and walk() */ + +extern Node *doit(bool execit) { + bool eof; + Jbwrap j; + Estack e1, e2; + Edata jerror; + if (dashen) + execit = FALSE; + setjmp(j.j); + jerror.jb = &j; + except(eError, jerror, &e1); + for (eof = FALSE; !eof;) { + Edata block; + block.b = newblock(); + except(eArena, block, &e2); + SIGCHK; + if (dashell) { + char *fname[3]; + fname[1] = concat(varlookup("home"), word("/.rcrc", NULL))->w; + fname[2] = NULL; + rcrc = TRUE; + dashell = FALSE; + b_dot(fname); + } + if (interactive) { + List *s; + if (!dashen && fnlookup("prompt") != NULL) { + static char *arglist[] = { "prompt", NULL }; + funcall(arglist); + } + if ((s = varlookup("prompt")) != NULL) { +#ifdef READLINE + prompt = s->w; +#else + fprint(2, "%s", s->w); +#endif + prompt2 = (s->n == NULL ? "" : s->n->w); + } + } + inityy(); + if (yyparse() == 1 && execit) + rc_raise(eError); + eof = (last == EOF); /* "last" can be clobbered during a walk() */ + if (parsetree != NULL) { + if (execit) + walk(parsetree, TRUE); + else if (dashex && dashen) + fprint(2, "%T\n", parsetree); + } + unexcept(); /* eArena */ + } + popinput(); + unexcept(); /* eError */ + return parsetree; +} + +/* parse a function imported from the environment */ + +extern Node *parseline(char *extdef) { + int i = interactive; + char *in[2]; + Node *fun; + in[0] = extdef; + in[1] = NULL; + interactive = FALSE; + pushstring(in, TRUE); + fun = doit(FALSE); + interactive = i; + return fun; +} + +/* write last command out to a file. Check to see if $history has changed, also */ + +static void history() { + List *histlist; + SIZE_T a; + if (!interactive) + return; + if ((histlist = varlookup("history")) == NULL) { + if (histstr != NULL) { + efree(histstr); + close(histfd); + histstr = NULL; + } + return; + } + if (histstr == NULL || !streq(histstr, histlist->w)) { /* open new file */ + if (histstr != NULL) { + efree(histstr); + close(histfd); + } + histstr = ecpy(histlist->w); + histfd = rc_open(histstr, rAppend); + if (histfd < 0) { + uerror(histstr); + efree(histstr); + histstr = NULL; + varrm("history", FALSE); + } + } + /* + Small unix hack: since read() reads only up to a newline + from a terminal, then presumably this write() will write at + most only one input line at a time. + */ + for (a = 2; a < chars_in + 2; a++) { /* skip empty lines and comments in history. */ + if (inbuf[a] == '#' || inbuf[a] == '\n') + return; + if (inbuf[a] != ' ' && inbuf[a] != '\t') + break; + } + writeall(histfd, inbuf + 2, chars_in); +} + +/* close file descriptors after a fork() */ + +extern void closefds() { + Input *i; + if (histstr != NULL) { /* Close an open history file */ + close(histfd); + histstr = NULL; /* But prevent re-closing of the same file-descriptor */ + } + for (i = istack; i != itop; --i) /* close open scripts */ + if (i->t == iFd && i->fd > 2) { + close(i->fd); + i->fd = -1; + } +} diff --git a/jbwrap.h b/jbwrap.h @@ -0,0 +1,10 @@ +/* certain braindamaged environments don't define jmp_buf as an array, so... */ + +struct Jbwrap { + jmp_buf j; +}; + +extern Jbwrap slowbuf; /* for getting out of interrupts while performing slow i/o on BSD */ + +extern int setjmp(jmp_buf); +extern void longjmp(jmp_buf, int); diff --git a/lex.c b/lex.c @@ -0,0 +1,398 @@ +/* lex.c: rc's lexical analyzer */ + +#include "rc.h" +#include "y.tab.h" + +/* + Special characters (i.e., "non-word") in rc: + \t \n # ; & | ^ $ = ~ ` ' { } @ ! ( ) < > \ + + The lexical analyzer is fairly straightforward. The only really + unclean part concerns backslash continuation and "double + backslashes". A backslash followed by a newline is treated as a + space, otherwise backslash is not a special characeter (i.e., + it can be part of a word). This introduces a host of unwanted + special cases. In our case, \ cannot be a word character, since + we wish to read in all word characters in a tight loop. + + Note: to save the trouble of declaring these arrays with TRUEs + and FALSEs, I am assuming that FALSE = 0, TRUE = 1. (and so is + it declared in rc.h) +*/ + +#define BUFSIZE ((SIZE_T) 1000) /* malloc hates power of 2 buffers? */ +#define BUFMAX (8 * BUFSIZE) /* How big the buffer can get before we re-allocate the + space at BUFSIZE again. Premature optimization? Maybe. + */ + +typedef enum wordstates { + NW, RW, KW /* "nonword", "realword", "keyword" */ +} wordstates; + +static void getpair(int); + +int lineno; + +const char nw[] = { + 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 1, 1, 0, 1, 1, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 0, + 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, + 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 +}; + +const char dnw[] = { + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, + 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 0, + 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 +}; + +static SIZE_T bufsize = BUFSIZE; +static char *realbuf = NULL; +static bool newline = FALSE; +static bool errset = FALSE; +static bool prerror = FALSE; +static wordstates w = NW; +static int fd_left, fd_right; + +#define checkfreecaret {if (w != NW) { w = NW; ugchar(c); return '^'; }} + +enum filedescriptors { + UNSET = -9, CLOSED = -1 +}; + +extern int yylex() { + static bool dollar = FALSE; + bool saw_meta = FALSE; + int c; + SIZE_T i; /* The purpose of all these local assignments is to */ + const char *meta; /* allow optimizing compilers like gcc to load these */ + char *buf = realbuf; /* values into registers. On a sparc this is a */ + YYSTYPE *y = &yylval; /* win, in code size *and* execution time */ + if (errset) { + errset = FALSE; + return '\n'; + } + /* rc variable-names may contain only alnum, '*' and '_', so use dnw if we are scanning one. */ + meta = (dollar ? dnw : nw); + dollar = FALSE; + if (newline) { + --lineno; /* slight space optimization; print_prompt2() always increments lineno */ + print_prompt2(); + newline = FALSE; + } +top: while ((c = gchar()) == ' ' || c == '\t') + w = NW; + if (c == EOF) + return END; + if (!meta[(unsigned char) c]) { /* it's a word or keyword. */ + checkfreecaret; + w = RW; + i = 0; + read: do { + buf[i++] = c; + if (c == '?' || c == '[' || c == '*') + saw_meta = TRUE; + if (i >= bufsize) + buf = realbuf = erealloc(buf, bufsize *= 2); + } while ((c = gchar()) != EOF && !meta[(unsigned char) c]); + while (c == '\\') { + if ((c = gchar()) == '\n') { + print_prompt2(); + c = ' '; /* Pretend a space was read */ + break; + } else { + bs: if (meta != dnw) { /* all words but varnames may have a bslash */ + buf[i++] = '\\'; + if (i >= bufsize) + buf = realbuf = erealloc(buf, bufsize *= 2); + if (!meta[(unsigned char) c]) + goto read; + } else { + ugchar(c); + c = '\\'; + break; + } + } + } + ugchar(c); + buf[i] = '\0'; + w = KW; + if (i == 2) { + if (*buf == 'i' && buf[1] == 'f') return IF; + if (*buf == 'f' && buf[1] == 'n') return FN; + if (*buf == 'i' && buf[1] == 'n') return IN; + } + if (streq(buf, "for")) return FOR; + if (streq(buf, "else")) return ELSE; + if (streq(buf, "switch")) return SWITCH; + if (streq(buf, "while")) return WHILE; + if (streq(buf, "case")) return CASE; + w = RW; + y->word.w = ncpy(buf); + if (saw_meta) { + char *r, *s; + + y->word.m = nalloc(strlen(buf) + 1); + for (r = buf, s = y->word.m; *r != '\0'; r++, s++) + *s = (*r == '?' || *r == '[' || *r == '*'); + } else { + y->word.m = NULL; + } + return WORD; + } + if (c == '`' || c == '!' || c == '@' || c == '~' || c == '$' || c == '\'') { + checkfreecaret; + if (c == '!' || c == '@' || c == '~') + w = KW; + } + switch (c) { + case '\0': + pr_error("warning: null character ignored"); + goto top; + case '!': + return BANG; + case '@': + return SUBSHELL; + case '~': + return TWIDDLE; + case '`': + c = gchar(); + if (c == '`') + return BACKBACK; + ugchar(c); + return '`'; + case '$': + dollar = TRUE; + c = gchar(); + if (c == '#') + return COUNT; + if (c == '^') + return FLAT; + ugchar(c); + return '$'; + case '\'': + w = RW; + i = 0; + do { + buf[i++] = c; + if (c == '\n') + print_prompt2(); + if (c == EOF) { + w = NW; + scanerror("eof in quoted string"); + return HUH; + } + if (i >= bufsize) + buf = realbuf = erealloc(buf, bufsize *= 2); + } while ((c = gchar()) != '\'' || (c = gchar()) == '\''); /* quote "'" thus: 'how''s it going?' */ + ugchar(c); + buf[i] = '\0'; + y->word.w = ncpy(buf); + y->word.m = NULL; + return WORD; + case '\\': + if ((c = gchar()) == '\n') { + print_prompt2(); + goto top; /* Pretend it was just another space. */ + } + ugchar(c); + c = '\\'; + checkfreecaret; + c = gchar(); + i = 0; + goto bs; + case '(': + if (w == RW) /* SUB's happen only after real words, not keyowrds, so if () and while () work */ + c = SUB; + w = NW; + return c; + case '#': + while ((c = gchar()) != '\n') /* skip comment until newline */ + if (c == EOF) + return END; + /* FALLTHROUGH */ + case '\n': + lineno++; + newline = TRUE; + /* FALLTHROUGH */ + case ';': + case '^': + case ')': + case '=': + case '{': case '}': + w = NW; + return c; + case '&': + w = NW; + c = gchar(); + if (c == '&') + return ANDAND; + ugchar(c); + return '&'; + case '|': + w = NW; + c = gchar(); + if (c == '|') + return OROR; + getpair(c); + if (errset) + return HUH; + if ((y->pipe.left = fd_left) == UNSET) + y->pipe.left = 1; /* default to fd 1 */ + if ((y->pipe.right = fd_right) == UNSET) + y->pipe.right = 0; /* default to fd 0 */ + if (y->pipe.right == CLOSED) { + scanerror("expected digit after '='"); /* can't close a pipe */ + return HUH; + } + return PIPE; + case '>': + c = gchar(); + if (c == '>') { + c = gchar(); + y->redir.type = rAppend; + } else + y->redir.type = rCreate; + y->redir.fd = 1; + goto common; + case '<': + c = gchar(); + if (c == '<') { + c = gchar(); + if (c == '<') { + c = gchar(); + y->redir.type = rHerestring; + } else { + y->redir.type = rHeredoc; + } + } else + y->redir.type = rFrom; + y->redir.fd = 0; + common: + w = NW; + getpair(c); + if (errset) + return HUH; + if (fd_right == UNSET) { /* redirection, not dup */ + if (fd_left != UNSET) { + y->redir.fd = fd_left; + return SREDIR; + } + return (y->redir.type == rFrom || y->redir.type == rCreate) ? REDIR : SREDIR; + } else { /* dup; recast yylval */ + y->dup.type = y->redir.type; + y->dup.left = fd_left; + y->dup.right = fd_right; + return DUP; + } + default: + w = NW; + return c; /* don't know what it is, let yacc barf on it */ + } +} + +extern void yyerror(const char *s) { + char *tok; + if (prerror) { /* don't print "syntax error" if there's a more informative scanerror */ + prerror = FALSE; + return; + } + if (!interactive) { + if (w != NW) + tok = realbuf; + else if (last == EOF) + tok = "eof"; + else if (last == '\n') + tok = "end of line"; + else + tok = nprint((last < 32 || last > 126) ? "(decimal %d)" : "'%c'", last); + fprint(2, "line %d: %s near %s\n", lineno - (last == '\n'), s, tok); + } else + fprint(2, "%s\n", s); +} + +extern void scanerror(char *s) { + flushu(); /* flush upto newline */ + yyerror(s); + errset = prerror = TRUE; +} + +extern void inityy() { + newline = FALSE; + w = NW; + hq = NULL; + /* return memory to the system if the buffer got too large */ + if (bufsize > BUFMAX && realbuf != NULL) { + efree(realbuf); + bufsize = BUFSIZE; + realbuf = ealloc(bufsize); + } else if (realbuf == NULL) + realbuf = ealloc(bufsize); +} + +extern void print_prompt2() { + lineno++; +#ifdef READLINE + prompt = prompt2; +#else + if (interactive) + fprint(2, "%s", prompt2); +#endif +} + +/* + Scan in a pair of integers for redirections like >[2=1]. CLOSED represents a closed file + descriptor (i.e., >[2=]) and UNSET represents an undesignated file descriptor (e.g., + >[2] is represented as (2,UNSET). + + This function makes use of unsigned compares to make range tests in one compare operation. +*/ + +static void getpair(int c) { + int n; + fd_left = fd_right = UNSET; + if (c != '[') { + ugchar(c); + return; + } + if ((unsigned int) (n = gchar() - '0') > 9) { + scanerror("expected digit after '['"); + return; + } + while ((unsigned int) (c = gchar() - '0') <= 9) + n = n * 10 + c; + fd_left = n; + c += '0'; + switch (c) { + default: + scanerror("expected '=' or ']' after digit"); + return; + case ']': + return; + case '=': + if ((unsigned int) (n = gchar() - '0') > 9) { + if (n != ']' - '0') { + scanerror("expected digit or ']' after '='"); + return; + } + fd_right = CLOSED; + } else { + while ((unsigned int) (c = gchar() - '0') <= 9) + n = n * 10 + c; + if (c != ']' - '0') { + scanerror("expected ']' after digit"); + return; + } + fd_right = n; + } + } +} diff --git a/list.c b/list.c @@ -0,0 +1,57 @@ +/* list.c: routines for manipulating the List type */ + +#include "rc.h" + +/* + These list routines assign meta values of null to the resulting lists; + it is impossible to glob with the value of a variable unless this value + is rescanned with eval---therefore it is safe to throw away the meta-ness + of the list. +*/ + +/* free a list from malloc space */ + +extern void listfree(List *p) { + while (p != NULL) { + List *n = p->n; + efree(p->w); + efree(p); + p = n; + } +} + +/* Copy list into malloc space (for storing a variable) */ + +extern List *listcpy(List *s, void *(*alloc)(SIZE_T)) { + List *top, *r; + for (top = r = NULL; s != NULL; s = s->n) { + if (top == NULL) + r = top = (*alloc)(sizeof (List)); + else + r = r->n = (*alloc)(sizeof (List)); + r->w = (*alloc)(strlen(s->w) + 1); + strcpy(r->w, s->w); + r->m = NULL; + } + if (r != NULL) + r->n = NULL; + return top; +} + +/* Length of list */ + +extern SIZE_T listlen(List *s) { + SIZE_T size; + for (size = 0; s != NULL; s = s->n) + size += strlen(s->w) + 1; + return size; +} + +/* Number of elements in list */ + +extern int listnel(List *s) { + int nel; + for (nel = 0; s != NULL; s = s->n) + nel++; + return nel; +} diff --git a/main.c b/main.c @@ -0,0 +1,115 @@ +/* main.c: handles initialization of rc and command line options */ + +#include "rc.h" + +bool dashdee, dashee, dashvee, dashex, dashell, dasheye, + dashen, dashpee, interactive; +int rc_pid; + +static bool dashoh; + +static void assigndefault(char *,...); +static void checkfd(int, enum redirtype); + +extern void main(int argc, char *argv[], char *envp[]) { + char *dashsee[2], *dollarzero, *null[1]; + int c; + initprint(); + dashsee[0] = dashsee[1] = NULL; + dollarzero = argv[0]; + rc_pid = getpid(); + dashell = (*argv[0] == '-'); /* Unix tradition */ + while ((c = rc_getopt(argc, argv, "nolpeivdxc:")) != -1) + switch (c) { + case 'l': + dashell = TRUE; + break; + case 'e': + dashee = TRUE; + break; + case 'i': + dasheye = interactive = TRUE; + break; + case 'v': + dashvee = TRUE; + break; + case 'x': + dashex = TRUE; + break; + case 'd': + dashdee = TRUE; + break; + case 'c': + dashsee[0] = rc_optarg; + goto quitopts; + case 'n': + dashen = TRUE; + break; + case 'p': + dashpee = TRUE; + break; + case 'o': + dashoh = TRUE; + break; + case '?': + exit(1); + } +quitopts: + argv += rc_optind; + /* use isatty() iff -i is not set, and iff the input is not from a script or -c flag */ + if (!dasheye && dashsee[0] == NULL && *argv == NULL) + interactive = isatty(0); + if (!dashoh) { + checkfd(0, rFrom); + checkfd(1, rCreate); + checkfd(2, rCreate); + } + initsignal(); + inithash(); + initparse(); + assigndefault("prompt", "; ", "", (void *)0); +#ifdef DEFAULTPATH + assigndefault("path", DEFAULTPATH, (void *)0); +#endif + assigndefault("ifs", " ", "\t", "\n", (void *)0); + assigndefault("pid", nprint("%d", rc_pid), (void *)0); + initenv(envp); + initinput(); + null[0] = NULL; + starassign(dollarzero, null, FALSE); /* assign $0 to $* */ + inithandler(); + if (dashsee[0] != NULL) { /* input from the -c flag? */ + if (*argv != NULL) + starassign(dollarzero, argv, FALSE); + pushstring(dashsee, TRUE); + } else if (*argv != NULL) { /* else from a file? */ + b_dot(--argv); + rc_exit(getstatus()); + } else { /* else stdin */ + pushfd(0); + } + dasheye = FALSE; + doit(TRUE); + rc_exit(getstatus()); +} + +static void assigndefault(char *name,...) { + va_list ap; + List *l; + char *v; + va_start(ap, name); + for (l = NULL; (v = va_arg(ap, char *)) != NULL;) + l = append(l, word(v, NULL)); + varassign(name, l, FALSE); + if (streq(name, "path")) + alias(name, l, FALSE); + va_end(ap); +} + +/* open an fd on /dev/null if it is inherited closed */ + +static void checkfd(int fd, enum redirtype r) { + int new = rc_open("/dev/null", r); + if (new != fd && new != -1) + close(new); +} diff --git a/match.c b/match.c @@ -0,0 +1,99 @@ +/* match.c: pattern matching routines */ + +#include "rc.h" + +static int rangematch(char *, char); + +enum { RANGE_FAIL = -1, RANGE_ERROR = -2 }; + +/* match() matches a single pattern against a single string. */ + +extern bool match(char *p, char *m, char *s) { + int i, j; + if (m == NULL) + return streq(p, s); + i = 0; + while (1) { + if (p[i] == '\0') + return *s == '\0'; + else if (m[i]) { + switch (p[i++]) { + case '?': + if (*s++ == '\0') + return FALSE; + break; + case '*': + while (p[i] == '*' && m[i] == 1) /* collapse multiple stars */ + i++; + if (p[i] == '\0') /* star at end of pattern? */ + return TRUE; + while (*s != '\0') + if (match(p + i, m + i, s++)) + return TRUE; + return FALSE; + case '[': + if (*s == '\0') + return FALSE; + switch (j = rangematch(p + i, *s)) { + default: + i += j; + break; + case RANGE_FAIL: + return FALSE; + case RANGE_ERROR: + if (*s != '[') + return FALSE; + } + s++; + break; + default: + panic("bad metacharacter in match"); + /* NOTREACHED */ + return FALSE; /* hush up gcc -Wall */ + } + } else if (p[i++] != *s++) + return FALSE; + } +} + +/* + From the ed(1) man pages (on ranges): + + The `-' is treated as an ordinary character if it occurs first + (or first after an initial ^) or last in the string. + + The right square bracket does not terminate the enclosed string + if it is the first character (after an initial `^', if any), in + the bracketed string. + + rangematch() matches a single character against a class, and returns + an integer offset to the end of the range on success, or -1 on + failure. +*/ + +static int rangematch(char *p, char c) { + char *orig = p; + bool neg = (*p == '~'); + bool matched = FALSE; + if (neg) + p++; + if (*p == ']') { + p++; + matched = (c == ']'); + } + for (; *p != ']'; p++) { + if (*p == '\0') + return RANGE_ERROR; /* bad syntax */ + if (p[1] == '-' && p[2] != ']') { /* check for [..-..] but ignore [..-] */ + if (c >= *p) + matched |= (c <= p[2]); + p += 2; + } else { + matched |= (*p == c); + } + } + if (matched ^ neg) + return p - orig + 1; /* skip the right-bracket */ + else + return RANGE_FAIL; +} diff --git a/mksignal b/mksignal @@ -0,0 +1,75 @@ +#!/bin/sh +# generate rc's internal signal table from signal.h + +exec > sigmsgs.c + +echo '#include "sigmsgs.h"' +echo +echo 'Sigmsgs signals[] = {' + +sed ' s/\/\*[ ]*// + s/[ ]*\*\/// + s/([@*+!]) // + s/[ ]*([a-zA-Z,->& ]*)[ ]*// + s/^[ ]*\#[ ]*define/\#define/ + s/[ ]*signal$//' $1 | +awk ' + BEGIN { + # assign to nomesg["SIGNAME"] to suppress a long message + nomesg["SIGINT"] = 1 + nomesg["SIGPIPE"] = 1 + # assign to mesg["SIGNAME"] to override a message + mesg["SIGHUP"] = "hangup" + mesg["SIGKILL"] = "killed" + mesg["SIGQUIT"] = "quit" + mesg["SIGTERM"] = "terminated" + mesg["SIGURG"] = "urgent condition on i/o channel" + mesg["SIGSTOP"] = "stop signal not from tty" + mesg["SIGTSTP"] = "stopped" + mesg["SIGCONT"] = "continue" + mesg["SIGCHLD"] = "child stop or exit" + mesg["SIGTTIN"] = "background tty read" + mesg["SIGTTOU"] = "background tty write" + # assign to ignore["SIGNAME"] to explicitly ignore a named signal + ignore["SIGMAX"] = 1 + } + $1 == "#define" && $2 == "NSIG" && $3 ~ /^[0-9]+$/ { nsig = $3 } + $1 == "#define" && $2 ~ /^SIG/ && $3 ~ /^[0-9]+$/ && sig[$3] == "" && ignore[$2] == 0 { + sig[$3] = $2 + if ($3 > max) + max = $3 + if (mesg[$2] == "" && nomesg[$2] == 0) { + str = $4 + for (i = 5; i <= NF; i++) + str = str " " $i + mesg[$2] = str + } + } + END { + if (nsig == 0) + nsig = max + 1 + printf " {!!, !!},\n" + for (i = 1; i < nsig; i++) { + if (sig[i] == "") + printf " {!!, !!},\n" + else + printf " {!%s!, !%s!},\n", sig[i], mesg[sig[i]] + } + } +' | +tr 'ABCDEFGHIJKLMNOPQRSTUVWXYZ!' 'abcdefghijklmnopqrstuvwxyz"' + +echo '};' + +exec > sigmsgs.h + +echo 'typedef struct {' +echo ' char *name, *msg;' +echo '} Sigmsgs;' +echo 'extern Sigmsgs signals[];' + +grep '^ ' sigmsgs.c | # the thing in quotes is ^<tab> +awk ' + { sum = sum + 1; } + END { print "#define NUMOFSIGNALS", sum } +' diff --git a/nalloc.c b/nalloc.c @@ -0,0 +1,137 @@ +/* nalloc.c: a simple single-arena allocator for command-line-lifetime allocation */ +#include "rc.h" + +static struct Block { + SIZE_T used, size; + char *mem; + Block *n; +} *fl, *ul; + +/* alignto() works only with power of 2 blocks and assumes 2's complement arithmetic */ +#define alignto(m, n) ((m + n - 1) & ~(n - 1)) +#define BLOCKSIZE ((SIZE_T) 4096) + +/* Allocate a block from the free list or malloc one if none in the fl fit */ + +static void getblock(SIZE_T n) { + Block *r, *p; + for (r = fl, p = NULL; r != NULL; p = r, r = r->n) + if (n <= r->size) + break; /* look for a block which fits the request */ + if (r != NULL) { /* if one is found, take it off the free list */ + if (p != NULL) + p->n = r->n; + else + fl = r->n; + } else { /* else allocate a new block */ + r = enew(Block); + r->mem = ealloc(r->size = alignto(n, BLOCKSIZE)); + } + r->used = 0; + r->n = ul; + ul = r; +} + +/* + A fast single-arena allocator. Looks at the current block, and if + there is not enough room, it goes to getblock() for more. "ul" + stands for "used list", and the head of the list is the current + block. "ulp" is a register cache for "ul"; this routine is hacked + for speed. (sigh, optimizing RISC compilers still can't cache the + address of a global in a register) +*/ + +extern void *nalloc(SIZE_T n) { + SIZE_T base; + Block *ulp; + n = alignto(n, sizeof (ALIGN_T)); + ulp = ul; + if (ulp != NULL && n + (base = ulp->used) < ulp->size) { + ulp->used = base + n; + return &ulp->mem[base]; + } else { + getblock(n); /* assert(ul->used) == 0 */ + (ulp = ul)->used = n; + return &ulp->mem[0]; + } +} + +/* + Frees memory from nalloc space by putting it on the free list. + Returns free blocks to the system, retaining at least MAXMEM bytes + worth of blocks for nalloc. +*/ + +#define MAXMEM 500000 + +extern void nfree() { + SIZE_T count; + Block *r; + if (ul == NULL) + return; + for (r = ul; r->n != NULL; r = r->n) + ; /* get to end of used list */ + r->n = fl; /* tack free list onto it */ + fl = ul; /* and make it the free list */ + ul = NULL; /* finally, zero out the used list */ + for (r = fl, count = r->size; r->n != NULL; r = r->n, count += r->size) { + if (count >= MAXMEM) { + Block *tmp = r; + r = r->n; + tmp->n = NULL; /* terminate the free list */ + while (r != NULL) { /* free memory off the tail of the free list */ + tmp = r->n; + efree(r->mem); + efree(r); + r = tmp; + } + return; + } + } +} + +/* + "Allocates" a new arena by zeroing out the old one. Up to the + calling routine to keep the old value of the block around. +*/ + +extern Block *newblock() { + Block *old = ul; + ul = NULL; + return old; +} + +/* "Restores" an arena to its saved value. */ + +extern void restoreblock(Block *old) { + nfree(); + ul = old; +} + +/* generic memory allocation functions */ + +extern void *ealloc(SIZE_T n) { + extern void *malloc(SIZE_T); + void *p = malloc(n); + if (p == NULL) { + uerror("malloc"); + rc_exit(1); + } + return p; +} + +extern void *erealloc(void *p, SIZE_T n) { + extern void *realloc(void *, SIZE_T); + if ((p = realloc(p, n)) == NULL) { + uerror("realloc"); + rc_exit(1); + } + return p; +} + +extern void efree(void *p) { + extern void free(void *); + if (p != NULL) + free(p); +} + diff --git a/open.c b/open.c @@ -0,0 +1,29 @@ +/* open.c: to insulate <fcntl.h> from the rest of rc. */ + +#include <fcntl.h> +#include "rc.h" + +/* prototype for open() follows. comment out if necessary */ + +/*extern int open(const char *, int,...);*/ + +/* + Opens a file with the necessary flags. Assumes the following + declaration for redirtype: + + enum redirtype { + rFrom, rCreate, rAppend, rHeredoc, rHerestring + }; +*/ + +static const int mode_masks[] = { + /* rFrom */ O_RDONLY, + /* rCreate */ O_TRUNC | O_CREAT | O_WRONLY, + /* rAppend */ O_APPEND | O_CREAT | O_WRONLY +}; + +extern int rc_open(const char *name, redirtype m) { + if ((unsigned) m >= arraysize(mode_masks)) + panic("bad mode passed to rc_open"); + return open(name, mode_masks[m], 0666); +} diff --git a/parse.y b/parse.y @@ -0,0 +1,174 @@ +/* parse.y */ + +/* + * Adapted from rc grammar, v10 manuals, volume 2. + */ + +%{ +#include "rc.h" +#ifndef lint +#define lint /* hush up gcc -Wall, leave out the dumb sccsid's. */ +#endif +static Node *star, *nolist; +Node *parsetree; /* not using yylval because bison declares it as an auto */ +%} + +%token ANDAND BACKBACK BANG CASE COUNT DUP ELSE END FLAT FN FOR IF IN +%token OROR PIPE REDIR SREDIR SUB SUBSHELL SWITCH TWIDDLE WHILE WORD HUH + +%left WHILE ')' ELSE +%left ANDAND OROR '\n' +%left BANG SUBSHELL +%left PIPE +%right '$' +%left SUB +/* +*/ + +%union { + struct Node *node; + struct Redir redir; + struct Pipe pipe; + struct Dup dup; + struct Word word; + char *keyword; +} + +%type <redir> REDIR SREDIR +%type <pipe> PIPE +%type <dup> DUP +%type <word> WORD +%type <keyword> keyword +%type <node> assign body brace case cbody cmd cmdsa cmdsan comword epilog + first line nlwords paren redir sword simple iftail word words + +%start rc + +%% + +rc : line end { parsetree = $1; YYACCEPT; } + | error end { yyerrok; parsetree = NULL; YYABORT; } + +/* an rc line may end in end-of-file as well as newline, e.g., rc -c 'ls' */ +end : END /* EOF */ { if (!heredoc(1)) YYABORT; } /* flag error if there is a heredoc in the queue */ + | '\n' { if (!heredoc(0)) YYABORT; } /* get heredoc on \n */ + +/* a cmdsa is a command followed by ampersand or newline (used in "line" and "body") */ +cmdsa : cmd ';' + | cmd '&' { $$ = ($1 != NULL ? mk(nNowait,$1) : $1); } + +/* a line is a single command, or a command terminated by ; or & followed by a line (recursive) */ +line : cmd + | cmdsa line { $$ = ($1 != NULL ? mk(nBody,$1,$2) : $2); } + +/* a body is like a line, only commands may also be terminated by newline */ +body : cmd + | cmdsan body { $$ = ($1 == NULL ? $2 : $2 == NULL ? $1 : mk(nBody,$1,$2)); } + +cmdsan : cmdsa + | cmd '\n' { $$ = $1; if (!heredoc(0)) YYABORT; } /* get h.d. on \n */ + +brace : '{' body '}' { $$ = $2; } + +paren : '(' body ')' { $$ = $2; } + +assign : first '=' word { $$ = mk(nAssign,$1,$3); } + +epilog : { $$ = NULL; } + | redir epilog { $$ = mk(nEpilog,$1,$2); } + +/* a redirection is a dup (e.g., >[1=2]) or a file redirection. (e.g., > /dev/null) */ +redir : DUP { $$ = mk(nDup,$1.type,$1.left,$1.right); } + | REDIR word { $$ = mk(nRedir,$1.type,$1.fd,$2); + if ($1.type == rHeredoc && !qdoc($2, $$)) YYABORT; /* queue heredocs up */ + } + | SREDIR word { $$ = mk(nRedir,$1.type,$1.fd,$2); + if ($1.type == rHeredoc && !qdoc($2, $$)) YYABORT; /* queue heredocs up */ + } + +case : CASE words ';' { $$ = mk(nCase, $2); } + | CASE words '\n' { $$ = mk(nCase, $2); } + +cbody : cmd { $$ = mk(nCbody, $1, NULL); } + | case cbody { $$ = mk(nCbody, $1, $2); } + | cmdsan cbody { $$ = mk(nCbody, $1, $2); } + +iftail : cmd %prec ELSE + | brace ELSE optnl cmd { $$ = mk(nElse,$1,$4); } + +cmd : /* empty */ %prec WHILE { $$ = NULL; } + | simple + | brace epilog { $$ = mk(nBrace,$1,$2); } + | IF paren optnl iftail { $$ = mk(nIf,$2,$4); } + | FOR '(' word IN words ')' optnl cmd { $$ = mk(nForin,$3,$5,$8); } + | FOR '(' word ')' optnl cmd { $$ = mk(nForin,$3,star,$6); } + | WHILE paren optnl cmd { $$ = mk(nWhile,$2,$4); } + | SWITCH '(' word ')' optnl '{' cbody '}' { $$ = mk(nSwitch,$3,$7); } + | TWIDDLE optcaret word words { $$ = mk(nMatch,$3,$4); } + | cmd ANDAND optnl cmd { $$ = mk(nAndalso,$1,$4); } + | cmd OROR optnl cmd { $$ = mk(nOrelse,$1,$4); } + | cmd PIPE optnl cmd { $$ = mk(nPipe,$2.left,$2.right,$1,$4); } + | redir cmd %prec BANG { $$ = ($2 != NULL ? mk(nPre,$1,$2) : $1); } + | assign cmd %prec BANG { $$ = ($2 != NULL ? mk(nPre,$1,$2) : $1); } + | BANG optcaret cmd { $$ = mk(nBang,$3); } + | SUBSHELL optcaret cmd { $$ = mk(nSubshell,$3); } + | FN words brace { $$ = mk(nNewfn,$2,$3); } + | FN words { $$ = mk(nRmfn,$2); } + +optcaret : /* empty */ + | '^' + +simple : first + | simple word { $$ = ($2 != NULL ? mk(nArgs,$1,$2) : $1); } + | simple redir { $$ = mk(nArgs,$1,$2); } + +first : comword + | first '^' sword { $$ = mk(nConcat,$1,$3); } + +sword : comword + | keyword { $$ = mk(nWord,$1, NULL); } + +word : sword + | word '^' sword { $$ = mk(nConcat,$1,$3); } + +comword : '$' sword { $$ = mk(nVar,$2); } + | '$' sword SUB words ')' { $$ = mk(nVarsub,$2,$4); } + | COUNT sword { $$ = mk(nCount,$2); } + | FLAT sword { $$ = mk(nFlat, $2); } + | '`' sword { $$ = mk(nBackq,nolist,$2); } + | '`' brace { $$ = mk(nBackq,nolist,$2); } + | BACKBACK word brace { $$ = mk(nBackq,$2,$3); } + | BACKBACK word sword { $$ = mk(nBackq,$2,$3); } + | '(' nlwords ')' { $$ = $2; } + | REDIR brace { $$ = mk(nNmpipe,$1.type,$1.fd,$2); } + | WORD { $$ = ($1.w[0] == '\'') ? mk(nQword, $1.w+1, NULL) : mk(nWord,$1.w, $1.m); } + +keyword : FOR { $$ = "for"; } + | IN { $$ = "in"; } + | WHILE { $$ = "while"; } + | IF { $$ = "if"; } + | SWITCH { $$ = "switch"; } + | FN { $$ = "fn"; } + | ELSE { $$ = "else"; } + | CASE { $$ = "case"; } + | TWIDDLE { $$ = "~"; } + | BANG { $$ = "!"; } + | SUBSHELL { $$ = "@"; } + +words : { $$ = NULL; } + | words word { $$ = ($1 != NULL ? ($2 != NULL ? mk(nLappend,$1,$2) : $1) : $2); } + +nlwords : { $$ = NULL; } + | nlwords '\n' + | nlwords word { $$ = ($1 != NULL ? ($2 != NULL ? mk(nLappend,$1,$2) : $1) : $2); } + +optnl : /* empty */ + | optnl '\n' + +%% + +void initparse() { + star = treecpy(mk(nVar,mk(nWord,"*",NULL)), ealloc); + nolist = treecpy(mk(nVar,mk(nWord,"ifs",NULL)), ealloc); +} + diff --git a/print.c b/print.c @@ -0,0 +1,456 @@ +/* print.c -- formatted printing routines (Paul Haahr, 12/91) */ + +#include "rc.h" +#include <setjmp.h> + +#define PRINT_ALLOCSIZE ((SIZE_T)64) +#define SPRINT_BUFSIZ ((SIZE_T)1024) + +#define MAXCONV 256 + +/* + * conversion functions + * true return -> flag changes only, not a conversion + */ + +#define Flag(name, flag) \ +static bool name(Format *format, int c) { \ + format->flags |= flag; \ + return TRUE; \ +} + +Flag(uconv, FMT_unsigned) +Flag(hconv, FMT_short) +Flag(lconv, FMT_long) +Flag(altconv, FMT_altform) +Flag(leftconv, FMT_leftside) +Flag(dotconv, FMT_f2set) + +static bool digitconv(Format *format, int c) { + if (format->flags & FMT_f2set) + format->f2 = 10 * format->f2 + c - '0'; + else { + format->flags |= FMT_f1set; + format->f1 = 10 * format->f1 + c - '0'; + } + return TRUE; +} + +static bool zeroconv(Format *format, int c) { + if (format->flags & (FMT_f1set | FMT_f2set)) + return digitconv(format, '0'); + format->flags |= FMT_zeropad; + return TRUE; +} + +static void pad(Format *format, SIZE_T len, int c) { + while (len-- != 0) + fmtputc(format, c); +} + +static bool sconv(Format *format, int c) { + char *s = va_arg(format->args, char *); + if ((format->flags & FMT_f1set) == 0) + fmtcat(format, s); + else { + SIZE_T len = strlen(s), width = format->f1 - len; + if (format->flags & FMT_leftside) { + fmtappend(format, s, len); + pad(format, width, ' '); + } else { + pad(format, width, ' '); + fmtappend(format, s, len); + } + } + return FALSE; +} + +static char *utoa(unsigned long u, char *t, unsigned int radix, const char *digit) { + if (u >= radix) { + t = utoa(u / radix, t, radix, digit); + u %= radix; + } + *t++ = digit[u]; + return t; +} + +static void intconv(Format *format, unsigned int radix, int upper, const char *altform) { + static const char * const table[] = { + "0123456789abcdefghijklmnopqrstuvwxyz", + "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ", + }; + char padchar; + SIZE_T len, pre, zeroes, padding, width; + long n, flags; + unsigned long u; + char number[64], prefix[20]; + + if (radix > 36) + return; + + flags = format->flags; + if (flags & FMT_long) + n = va_arg(format->args, long); + else if (flags & FMT_short) + n = va_arg(format->args, short); + else + n = va_arg(format->args, int); + + pre = 0; + if ((flags & FMT_unsigned) || n >= 0) + u = n; + else { + prefix[pre++] = '-'; + u = -n; + } + + if (flags & FMT_altform) + while (*altform != '\0') + prefix[pre++] = *altform++; + + len = utoa(u, number, radix, table[upper]) - number; + if ((flags & FMT_f2set) && (SIZE_T) format->f2 > len) + zeroes = format->f2 - len; + else + zeroes = 0; + + width = pre + zeroes + len; + if ((flags & FMT_f1set) && (SIZE_T) format->f1 > width) { + padding = format->f1 - width; + } else + padding = 0; + + padchar = ' '; + if (padding > 0 && flags & FMT_zeropad) { + padchar = '0'; + if ((flags & FMT_leftside) == 0) { + zeroes += padding; + padding = 0; + } + } + + + if ((flags & FMT_leftside) == 0) + pad(format, padding, padchar); + fmtappend(format, prefix, pre); + pad(format, zeroes, '0'); + fmtappend(format, number, len); + if (flags & FMT_leftside) + pad(format, padding, padchar); +} + +static bool cconv(Format *format, int c) { + fmtputc(format, va_arg(format->args, int)); + return FALSE; +} + +static bool dconv(Format *format, int c) { + intconv(format, 10, 0, ""); + return FALSE; +} + +static bool oconv(Format *format, int c) { + intconv(format, 8, 0, "0"); + return FALSE; +} + +static bool xconv(Format *format, int c) { + intconv(format, 16, 0, "0x"); + return FALSE; +} + +static bool pctconv(Format *format, int c) { + fmtputc(format, '%'); + return FALSE; +} + +static bool badconv(Format *format, int c) { + panic("bad conversion character in printfmt"); + /* NOTREACHED */ + return FALSE; /* hush up gcc -Wall */ +} + + +/* + * conversion table management + */ + +static Conv fmttab[MAXCONV]; + +static void inittab(void) { + int i; + for (i = 0; i < MAXCONV; i++) + fmttab[i] = badconv; + + fmttab['s'] = sconv; + fmttab['c'] = cconv; + fmttab['d'] = dconv; + fmttab['o'] = oconv; + fmttab['x'] = xconv; + fmttab['%'] = pctconv; + + fmttab['u'] = uconv; + fmttab['h'] = hconv; + fmttab['l'] = lconv; + fmttab['#'] = altconv; + fmttab['-'] = leftconv; + fmttab['.'] = dotconv; + + fmttab['0'] = zeroconv; + for (i = '1'; i <= '9'; i++) + fmttab[i] = digitconv; +} + +extern bool (*fmtinstall(int c, bool (*f)(Format *, int)))(Format *, int) { +/*Conv fmtinstall(int c, Conv f) {*/ + Conv oldf; + if (fmttab[0] == NULL) + inittab(); + c &= MAXCONV - 1; + oldf = fmttab[c]; + if (f != NULL) + fmttab[c] = f; + return oldf; +} + + +/* + * functions for inserting strings in the format buffer + */ + +extern void fmtappend(Format *format, const char *s, SIZE_T len) { + while (format->buf + len > format->bufend) { + SIZE_T split = format->bufend - format->buf; + memcpy(format->buf, s, split); + format->buf += split; + s += split; + len -= split; + (*format->grow)(format, len); + } + memcpy(format->buf, s, len); + format->buf += len; +} + +extern void fmtcat(Format *format, const char *s) { + fmtappend(format, s, strlen(s)); +} + +/* + * printfmt -- the driver routine + */ + +extern int printfmt(Format *format, const char *fmt) { + unsigned const char *s = (unsigned const char *) fmt; + + if (fmttab[0] == NULL) + inittab(); + + for (;;) { + int c = *s++; + switch (c) { + case '%': + format->flags = format->f1 = format->f2 = 0; + do + c = *s++; + while ((*fmttab[c])(format, c)); + break; + case '\0': + return format->buf - format->bufbegin + format->flushed; + default: + fmtputc(format, c); + break; + } + } +} + + +/* + * the public entry points + */ + +extern int fmtprint(Format *format, const char *fmt,...) { + int n = -format->flushed; + va_list saveargs = format->args; + + va_start(format->args, fmt); + n += printfmt(format, fmt); + va_end(format->args); + format->args = saveargs; + + return n + format->flushed; +} + +static void fprint_flush(Format *format, SIZE_T more) { + SIZE_T n = format->buf - format->bufbegin; + char *buf = format->bufbegin; + + format->flushed += n; + format->buf = format->bufbegin; + writeall(format->u.n, buf, n); +} + +extern int fprint(int fd, const char *fmt,...) { + char buf[1024]; + Format format; + + format.buf = buf; + format.bufbegin = buf; + format.bufend = buf + sizeof buf; + format.grow = fprint_flush; + format.flushed = 0; + format.u.n = fd; + + va_start(format.args, fmt); + printfmt(&format, fmt); + va_end(format.args); + + fprint_flush(&format, (SIZE_T) 0); + return format.flushed; +} + +static void memprint_grow(Format *format, SIZE_T more) { + char *buf; + SIZE_T len = format->bufend - format->bufbegin + 1; + len = (len >= more) + ? len * 2 + : ((len + more) + PRINT_ALLOCSIZE) &~ (PRINT_ALLOCSIZE - 1); + if (format->u.n) + buf = erealloc(format->bufbegin, len); + else { + SIZE_T used = format->buf - format->bufbegin; + buf = nalloc(len); + memcpy(buf, format->bufbegin, used); + } + format->buf = buf + (format->buf - format->bufbegin); + format->bufbegin = buf; + format->bufend = buf + len - 1; +} + +static char *memprint(Format *format, const char *fmt, char *buf, SIZE_T len) { + format->buf = buf; + format->bufbegin = buf; + format->bufend = buf + len - 1; + format->grow = memprint_grow; + format->flushed = 0; + printfmt(format, fmt); + *format->buf = '\0'; + return format->bufbegin; +} + +extern char *mprint(const char *fmt,...) { + Format format; + char *result; + format.u.n = 1; + va_start(format.args, fmt); + result = memprint(&format, fmt, ealloc(PRINT_ALLOCSIZE), PRINT_ALLOCSIZE); + va_end(format.args); + return result; +} + +extern char *nprint(const char *fmt,...) { + Format format; + char *result; + format.u.n = 0; + va_start(format.args, fmt); + result = memprint(&format, fmt, nalloc(PRINT_ALLOCSIZE), PRINT_ALLOCSIZE); + va_end(format.args); + return result; +} + + +/* THESE ARE UNUSED IN rc */ + +#if 0 + +extern int print(const char *fmt,...) { + char buf[1024]; + Format format; + + format.buf = buf; + format.bufbegin = buf; + format.bufend = buf + sizeof buf; + format.grow = fprint_flush; + format.flushed = 0; + format.u.n = 1; + + va_start(format.args, fmt); + printfmt(&format, fmt); + va_end(format.args); + + fprint_flush(&format, 0); + return format.flushed; +} + +extern int eprint(const char *fmt,...) { + char buf[1024]; + Format format; + + format.buf = buf; + format.bufbegin = buf; + format.bufend = buf + sizeof buf; + format.grow = fprint_flush; + format.flushed = 0; + format.u.n = 2; + + va_start(format.args, fmt); + printfmt(&format, fmt); + va_end(format.args); + + fprint_flush(&format, 0); + return format.flushed; +} + +static void snprint_grow(Format *format, SIZE_T more) { + longjmp(format->u.p, 1); +} + +extern int snprint(char *buf, int buflen, const char *fmt,...) { + int n; + jmp_buf jbuf; + Format format; + + if (setjmp(jbuf)) { + *format.buf = '\0'; + return format.buf - format.bufbegin; + } + + format.buf = buf; + format.bufbegin = buf; + format.bufend = buf + buflen - 1; + format.grow = snprint_grow; + format.flushed = 0; + format.u.p = jbuf; + + va_start(format.args, fmt); + n = printfmt(&format, fmt); + va_end(format.args); + + *format.buf = '\0'; + return n; +} + +extern int sprint(char *buf, const char *fmt,...) { + int n; + jmp_buf jbuf; + Format format; + + if (setjmp(jbuf)) { + *format.buf = '\0'; + return format.buf - format.bufbegin; + } + + format.buf = buf; + format.bufbegin = buf; + format.bufend = buf + SPRINT_BUFSIZ - 1; + format.grow = snprint_grow; + format.flushed = 0; + format.u.p = jbuf; + + va_start(format.args, fmt); + n = printfmt(&format, fmt); + va_end(format.args); + + *format.buf = '\0'; + return n; +} +#endif diff --git a/proto.h b/proto.h @@ -0,0 +1,81 @@ +/* proto.h + This file provides a definition for size_t and align_t that + should work for your system. If it does not, it is up to you to + make it the right thing. The problem is that I cannot rely upon + <sys/params.h> to do the right thing on machines which don't + yet have ansi header files. Note that on many RISC machines, + align_t must be at least 32 bits wide, and sparc doubles are + aligned on 64 bit boundaries, but of course rc does not use + doubles in its code, so the "typedef long ALIGN_T" is good + enough in the sparc's case. Also for performance reasons on a + VAX one would probably want align_t to be 32 bits wide. + + You can override these definitions with compile-line definitions + of the same macros. +*/ + +#ifndef ALIGN_T +typedef long ALIGN_T; +#endif +#ifndef SIZE_T +typedef unsigned int SIZE_T; +#endif +#ifndef MODE_T +typedef short int MODE_T; +#endif +#ifndef PID_T +typedef int PID_T; +#endif +#ifndef SIG_ATOMIC_T +typedef int SIG_ATOMIC_T; +#endif + +/* fake stdlib.h */ + +extern void exit(int); +extern void qsort(void *, SIZE_T, SIZE_T, int (*)(const void *, const void *)); + +/* fake string.h */ + +extern int strncmp(const char *, const char *, SIZE_T); +extern int strcmp(const char *, const char *); +extern SIZE_T strlen(const char *); +extern char *strchr(const char *, int); +extern char *strrchr(const char *, int); +extern char *strcpy(char *, const char *); +extern char *strncpy(char *, const char *, SIZE_T); +extern char *strcat(char *, const char *); +extern char *strncat(char *, const char *, SIZE_T); +extern void *memcpy(void *, const void *, SIZE_T); + +/* fake unistd.h */ + +extern PID_T fork(void); +extern PID_T getpid(void); +extern char *getenv(const char *); +extern int chdir(const char *); +extern int close(int); +extern int dup(int); +extern int dup2(int, int); +extern int execve(const char *, const char **, const char **); +extern int execl(const char *,...); +extern int getegid(void); +extern int geteuid(void); +extern int getgroups(int, int *); +/*extern int ioctl(int, long,...);*/ /* too much trouble leaving this uncommented */ +extern int isatty(int); +#ifndef SYSVR4 /* declares AND defines this in sys/stat.h!! */ +extern int mknod(const char *, int, int); +#endif +extern int pipe(int *); +extern int read(int, void *, unsigned int); +extern int setpgrp(int, PID_T); +extern int unlink(const char *); +extern int wait(int *); +extern int write(int, const void *, unsigned int); + +/* fake errno.h for mips (which doesn't declare errno in errno.h!?!?) */ + +#ifdef host_mips +extern int errno; +#endif diff --git a/rc.1 b/rc.1 @@ -0,0 +1,1880 @@ +.\" rc.1 +.\"------- +.\" Man page portability notes +.\" +.\" These are some notes on conventions to maintain for greatest +.\" portability of this man page to various other versions of +.\" nroff. +.\" +.\" When you want a \ to appear in the output, use \e in the man page. +.\" (NOTE this comes up in the rc grammar, where to print out '\n' the +.\" man page must contain '\en'.) +.\" +.\" Evidently not all versions of nroff allow the omission of the +.\" terminal " on a macro argument. Thus what could be written +.\" +.\" .Cr "exec >[2] err.out +.\" +.\" in true nroffs must be written +.\" +.\" .Cr "exec >[2] err.out" +.\" +.\" instead. +.\" +.\" Use symbolic font names (e.g. R, I, B) instead of the standard +.\" font positions 1, 2, 3. Note that for Xf to work the standard +.\" font names must be single characters. +.\" +.\" Not all man macros have the RS and RE requests (I altered the Ds +.\" and De macros and the calls to Ds accordingly). +.\" +.\" Thanks to Michael Haardt (u31b3hs@cip-s01.informatik.rwth-aachen.de) +.\" for pointing out these problems. +.\" +.\" Note that sentences should end at the end of a line. nroff and +.\" troff will supply the correct intersentence spacing, but only if +.\" the sentences end at the end of a line. Explicit spaces, if given, +.\" are apparently honored and the normal intersentence spacing is +.\" supressed. +.\" +.\" DaviD W. Sanderson +.\"------- +.\" Dd distance to space vertically before a "display" +.\" These are what n/troff use for interparagraph distance +.\"------- +.if t .nr Dd .4v +.if n .nr Dd 1v +.\"------- +.\" Ds begin a display, indented .5 inches from the surrounding text. +.\" +.\" Note that uses of Ds and De may NOT be nested. +.\"------- +.de Ds +.\" .RS \\$1 +.sp \\n(Ddu +.in +0.5i +.nf +.. +.\"------- +.\" De end a display (no trailing vertical spacing) +.\"------- +.de De +.fi +.in +.\" .RE +.. +.\"------- +.\" I stole the Xf macro from the -man macros on my machine (originally +.\" "}S", I renamed it so that it won't conflict). +.\"------- +.\" Set Cf to the name of the constant width font. +.\" It will be "C" or "(CW", typically. +.\" NOTEZ BIEN the lines defining Cf must have no trailing white space: +.\"------- +.if t .ds Cf C +.if n .ds Cf R +.\"------- +.\" Rc - Alternate Roman and Courier +.\"------- +.de Rc +.Xf R \\*(Cf \& "\\$1" "\\$2" "\\$3" "\\$4" "\\$5" "\\$6" +.. +.\"------- +.\" Ic - Alternate Italic and Courier +.\"------- +.de Ic +.Xf I \\*(Cf \& "\\$1" "\\$2" "\\$3" "\\$4" "\\$5" "\\$6" +.. +.\"------- +.\" Bc - Alternate Bold and Courier +.\"------- +.de Bc +.Xf B \\*(Cf \& "\\$1" "\\$2" "\\$3" "\\$4" "\\$5" "\\$6" +.. +.\"------- +.\" Cr - Alternate Courier and Roman +.\"------- +.de Cr +.Xf \\*(Cf R \& "\\$1" "\\$2" "\\$3" "\\$4" "\\$5" "\\$6" +.. +.\"------- +.\" Ci - Alternate Courier and Italic +.\"------- +.de Ci +.Xf \\*(Cf I \& "\\$1" "\\$2" "\\$3" "\\$4" "\\$5" "\\$6" +.. +.\"------- +.\" Cb - Alternate Courier and Bold +.\"------- +.de Cb +.Xf \\*(Cf B \& "\\$1" "\\$2" "\\$3" "\\$4" "\\$5" "\\$6" +.. +.\"------- +.\" Xf - Alternate fonts +.\" +.\" \$1 - first font +.\" \$2 - second font +.\" \$3 - desired word with embedded font changes, built up by recursion +.\" \$4 - text for first font +.\" \$5 - \$9 - remaining args +.\" +.\" Every time we are called: +.\" +.\" If there is something in \$4 +.\" then Call ourself with the fonts switched, +.\" with a new word made of the current word (\$3) and \$4 +.\" rendered in the first font, +.\" and with the remaining args following \$4. +.\" else We are done recursing. \$3 holds the desired output +.\" word. We emit \$3, change to Roman font, and restore +.\" the point size to the default. +.\" fi +.\" +.\" Use Xi to add a little bit of space after italic text. +.\"------- +.de Xf +.ds Xi +.\"------- +.\" I used to test for the italic font both by its font position +.\" and its name. Now just test by its name. +.\" +.\" .if "\\$1"2" .if !"\\$5"" .ds Xi \^ +.\"------- +.if "\\$1"I" .if !"\\$5"" .ds Xi \^ +.\"------- +.\" This is my original code to deal with the recursion. +.\" Evidently some nroffs can't deal with it. +.\"------- +.\" .ie !"\\$4"" \{\ +.\" . Xf \\$2 \\$1 "\\$3\\f\\$1\\$4\\*(Xi" "\\$5" "\\$6" "\\$7" "\\$8" "\\$9" +.\" .\} +.\" .el \{\\$3 +.\" . ft R \" Restore the default font, since we don't know +.\" . \" what the last font change was. +.\" . ps 10 \" Restore the default point size, since it might +.\" . \" have been changed by an argument to this macro. +.\" .\} +.\"------- +.\" Here is more portable (though less pretty) code to deal with +.\" the recursion. +.\"------- +.if !"\\$4"" .Xf \\$2 \\$1 "\\$3\\f\\$1\\$4\\*(Xi" "\\$5" "\\$6" "\\$7" "\\$8" "\\$9" +.if "\\$4"" \\$3\fR\s10 +.. +.TH RC 1 "28 April 1991" +.SH NAME +rc \- shell +.SH SYNOPSIS +.B rc +.RB [ \-eixvldnpo ] +.RB [ \-c +.IR command ] +.RI [ arguments ] +.SH DESCRIPTION +.I rc +is a command interpreter and programming language similar to +.IR sh (1). +It is based on the AT&T Plan 9 shell of the same name. +The shell offers a C-like syntax (much more so than the C shell), +and a powerful mechanism for manipulating variables. +It is reasonably small and reasonably fast, +especially when compared to contemporary shells. +Its use is intended to be interactive, +but the language lends itself well to scripts. +.SH OPTIONS +.TP +.Cr \-e +If the +.Cr \-e +option is present, then +.I rc +will exit if the exit status of a command is false (nonzero). +.I rc +will not exit, however, if a conditional fails, e.g., an +.Cr if() +command. +.TP +.Cr \-i +If the +.Cr \-i +option is present or if the input to +.I rc +is from a terminal (as determined by +.IR isatty (3)) +then +.I rc +will be in +.I interactive +mode. +That is, a prompt (from +.Cr $prompt(1)\^ ) +will be printed before an +input line is taken, and +.I rc +will ignore the signals +.Cr SIGINT +and +.Cr SIGQUIT . +.TP +.Cr \-x +This option will make +.I rc +print every command on standard error before it is executed. +It can be useful for debugging +.I rc +scripts. +.TP +.Cr \-v +This option will echo input to +.I rc +on standard error as it is read. +.TP +.Cr \-l +If the +.Cr \-l +option is present, or if +.IR rc 's +.Cr argv[0][0] +is a dash +.Rc ( \- ), +then +.I rc +will behave as a login shell. +That is, it will try to run commands present in +.Cr $home/.rcrc , +if this file exists, before reading any other input. +.TP +.Cr \-d +This flag causes +.I rc +not to ignore +.Cr SIGQUIT +or +.Cr SIGTERM . +Thus +.I rc +can be made to dump core if sent +.Cr SIGQUIT . +This option is only useful for debugging +.IR rc . +.TP +.Cr \-n +This flag causes +.I rc +to read its input and parse it, but not to execute any commands. +This is useful for syntax checking on scripts. +If used in combination with the +.Cr \-x +option, +.I rc +will print each command as it is parsed in a form similar to the one +used for exporting functions into the environment. +.TP +.Cr \-p +This flag prevents +.I rc +from initializing shell functions from the environment. +This allows +.I rc +to run in a protected mode, whereby it becomes more difficult for +an +.I rc +script to be subverted by placing false commands in the environment. +(Note that this presence of this option does NOT mean that it is safe to +run setuid +.I rc +scripts; the usual caveats about the setuid bit still apply.) +.TP +.Cr \-o +This flag prevents the usual practice of trying to open +.Cr /dev/null +on file descriptors 0, 1, and 2, if any of those descriptors +are inherited closed. +.TP +.Cr \-c +If +.Cr \-c +is present, commands are executed from the immediately following +argument. +Any further arguments to +.I rc +are placed in +.Cr $* . +.PP +.SH COMMANDS +A simple command is a sequence of words, separated by white space +(space and tab) characters that ends with a newline, semicolon +.Rc ( ; ), +or ampersand +.Rc ( & ). +The first word of a command is the name of that command. +If the name begins with +.Cr / , +.Cr ./ , +or +.Cr ../ , +then the name is used as an absolute path +name referring to an executable file. +Otherwise, the name of the command is looked up in a table +of shell functions, builtin commands, +or as a file in the directories named by +.Cr $path . +.SS "Background Tasks" +A command ending with a +.Cr & +is run in the background; that is, +the shell returns immediately rather than waiting for the command to +complete. +Background commands have +.Cr /dev/null +connected to their standard input unless an explicit redirection for +standard input is used. +.SS "Subshells" +A command prefixed with an at-sign +.Rc ( @ ) +is executed in a subshell. +This insulates the parent shell from the effects +of state changing operations such as a +.B cd +or a variable assignment. +For example: +.Ds +.Cr "@ {cd ..; make}" +.De +.PP +will run +.IR make (1) +in the parent directory +.Rc ( .. ), +but leaves the shell running in the current directory. +.SS "Line continuation" +A long logical line may be continued over several physical lines by +terminating each line (except the last) with a backslash +.Rc ( \e ). +The backslash-newline sequence is treated as a space. +A backslash is not otherwise special to +.IR rc . +(In addition, +inside quotes a backslash loses its special meaning +even when it is followed by a newline.) +.SS Quoting +.IR rc +interprets several characters specially; special characters +automatically terminate words. +The following characters are special: +.Ds +.Cr "# ; & | ^ $ = \` ' { } ( ) < >" +.De +.PP +The single quote +.Rc ( ' ) +prevents special treatment of any character other than itself. +All characters, including control characters, newlines, +and backslashes between two quote characters are treated as an +uninterpreted string. +A quote character itself may be quoted by placing two quotes in a row. +The minimal sequence needed to enter the quote character is +.Cr '''' . +The empty string is represented by +.Cr '' . +Thus: +.Ds +.Cr "echo 'What''s the plan, Stan?'" +.De +.PP +prints out +.Ds +.Cr "What's the plan, Stan?" +.De +.PP +The number sign +.Rc ( # ) +begins a comment in +.IR rc . +All characters up to but not including the next newline are ignored. +Note that backslash continuation does not work inside a comment, +i.e., +the backslash is ignored along with everything else. +.SS Grouping +Zero or more commands may be grouped within braces +.Rc (`` { '' +and +.Rc `` } ''), +and are then treated as one command. +Braces do not otherwise define scope; +they are used only for command grouping. +In particular, be wary of the command: +.Ds +.Cr "for (i) {" +.Cr " command" +.Cr "} | command" +.De +.PP +Since pipe binds tighter than +.Cr for , +this command does not perform what the user expects it to. +Instead, enclose the whole +.Cr for +statement in braces: +.Ds +.Cr "{for (i) command} | command" +.De +.PP +Fortunately, +.IR rc 's +grammar is simple enough that a (confident) user can +understand it by examining the skeletal +.IR yacc (1) +grammar +at the end of this man page (see the section entitled +.BR GRAMMAR ). +.SS "Input and output" +.PP +The standard output may be redirected to a file with +.Ds +.Cr "command > file" +.De +.PP +and the standard input may be taken from a file with +.Ds +.Cr "command < file" +.De +.PP +File descriptors other than 0 and 1 may be specified also. +For example, to redirect standard error to a file, use: +.Ds +.Cr "command >[2] file" +.De +.PP +In order to duplicate a file descriptor, use +.Ci >[ n = m ]\fR. +Thus to redirect both standard output and standard error +to the same file, use +.Ds +.Cr "command > file >[2=1]" +.De +.PP +To close a file descriptor that may be open, use +.Ci >[ n =]\fR. +For example, to +close file descriptor 7: +.Ds +.Cr "command >[7=]" +.De +.PP +In order to place the output of a command at the end of an already +existing file, use: +.Ds +.Cr "command >> file" +.De +.PP +If the file does not exist, then it is created. +.PP +``Here documents'' are supported as in +.I sh +with the use of +.Ds +.Cr "command << 'eof-marker'" +.De +.PP +If the end-of-file marker is enclosed in quotes, +then no variable substitution occurs inside the here document. +Otherwise, every variable is substituted +by its space-separated-list value (see +.BR "Flat Lists" , +below), +and if a +.Cr ^ +character follows a variable name, it is deleted. +This allows the unambiguous use of variables adjacent to text, as in +.Ds +.Cr $variable^follow +.De +To include a literal +.Cr $ +in a here document when an unquoted end-of-file marker is being used, +enter it as +.Cr $$ . +.PP +Additionally, +.I rc +supports ``here strings'', which are like here documents, +except that input is taken directly from a string on the command line. +Its use is illustrated here: +.Ds +.Cr "cat <<< 'this is a here string' | wc" +.De +.PP +(This feature enables +.I rc +to export functions using here documents into the environment; +the author does not expect users to find this feature useful.) +.SS Pipes +Two or more commands may be combined in a pipeline by placing the +vertical bar +.Rc ( \||\| ) +between them. +The standard output (file descriptor 1) +of the command on the left is tied to the standard input (file +descriptor 0) of the command on the right. +The notation +.Ci |[ n = m ] +indicates that file descriptor +.I n +of the left process is connected to +file descriptor +.I m +of the right process. +.Ci |[ n ] +is a shorthand for +.Ci |[ n =0]\fR. +As an example, to pipe the standard error of a command to +.IR wc (1), +use: +.Ds +.Cr "command |[2] wc" +.De +.PP +The exit status of a pipeline is considered true if and only if every +command in the pipeline exits true. +.SS "Commands as Arguments" +Some commands, like +.IR cmp (1) +or +.IR diff (1), +take their arguments on the command +line, and do not read input from standard input. +It is convenient +sometimes to build nonlinear pipelines so that a command like +.I cmp +can read the output of two other commands at once. +.I rc +does it like this: +.Ds +.Cr "cmp <{command} <{command}" +.De +.PP +compares the output of the two commands in braces. +A note: since this form of +redirection is implemented with some kind of pipe, and since one cannot +.IR lseek (2) +on a pipe, commands that use +.IR lseek (2) +will hang. +For example, +most versions of +.IR diff (1) +use +.IR lseek (2) +on their inputs. +.PP +Data can be sent down a pipe to several commands using +.IR tee (1) +and the output version of this notation: +.Ds +.Cr "echo hi there | tee >{sed 's/^/p1 /'} >{sed 's/^/p2 /'}" +.De +.SH "CONTROL STRUCTURES" +The following may be used for control flow in +.IR rc : +.SS "If-else Statements" +.PD 0 +.sp +.Ci "if (" test ") {" +.br +.I " cmd" +.br +.TP +.Ci "} else " cmd +The +.I test +is executed, and if its return status is zero, the first +command is executed, otherwise the second is. +Braces are not mandatory around the commands. +However, an +.Cr else +statement is valid only if it +follows a close-brace on the same line. +Otherwise, the +.Cr if +is taken to be a simple-if: +.Ds +.Cr "if (test)" +.Cr " command" +.De +.PD +.SS "While and For Loops" +.TP +.Ci "while (" test ) " cmd" +.I rc +executes the +.I test +and performs the command as long as the +.I test +is true. +.TP +.Ci "for (" var " in" " list" ) " cmd" +.I rc +sets +.I var +to each element of +.I list +(which may contain variables and backquote substitutions) and runs +.IR cmd . +If +.Rc `` in +.IR list '' +is omitted, then +.I rc +will set +.I var +to each element of +.Cr $* +(excluding +.Cr $0 ). +For example: +.Ds +.Cr "for (i in \`{ls -F | grep '\e*$' | sed 's/\e*$//'}) { commands }" +.De +.TP +\& +will set +.Cr $i +to the name of each file in the current directory that is +executable. +.SS "Switch" +.TP +.Ci "switch (" list ") { case" " ..." " }" +.I rc +looks inside the braces after a +.Cr switch +for statements beginning with the word +.Cr case . +If any of the patterns following +.Cr case +match the list supplied to +.Cr switch , +then the commands up until the next +.Cr case +statement are executed. +The metacharacters +.Cr "*" , +.Cr [ +or +.Cr ? +should not be quoted; +matching is performed only against the strings in +.IR list , +not against file names. +(Matching for case statements is the same as for the +.Cr ~ +command.) +.SS "Logical Operators" +There are a number of operators in +.I rc +which depend on the exit status of a command. +.Ds +.Cr "command && command" +.De +.PP +executes the first command and then executes the second command if and only if +the first command exits with a zero exit status (``true'' in Unix). +.Ds +.Cr "command || command" +.De +.PP +executes the first command executing the second command if and only if +the second command exits with a nonzero exit status (``false'' in Unix). +.Ds +.Cr "! command" +.De +.PP +negates the exit status of a command. +.SH "PATTERN MATCHING" +There are two forms of pattern matching in +.IR rc . +One is traditional shell globbing. +This occurs in matching for file names in argument lists: +.Ds +.Cr "command argument argument ..." +.De +.PP +When the characters +.Cr "*" , +.Cr [ +or +.Cr ? +occur in an argument or command, +.I rc +looks at the +argument as a pattern for matching against files. +(Contrary to the behavior other shells exhibit, +.I rc +will only perform pattern matching if a metacharacter occurs unquoted and +literally in the input. +Thus, +.Ds +.Cr "foo='*'" +.Cr "echo $foo" +.De +.PP +will always echo just a star. +In order for non-literal metacharacters to be expanded, an +.Cr eval +statement must be used in order to rescan the input.) +Pattern matching occurs according to the following rules: a +.Cr * +matches any number (including zero) of +characters. +A +.Cr ? +matches any single character, and a +.Cr [ +followed by a +number of characters followed by a +.Cr ] +matches a single character in that +class. +The rules for character class matching are the same as those for +.IR ed (1), +with the exception that character class negation is achieved +with the tilde +.Rc ( ~ ), +not the caret +.Rc ( ^ ), +since the caret already means +something else in +.IR rc . +.PP +.I rc +also matches patterns against strings with the +.Cr ~ +command: +.Ds +.Cr "~ subject pattern pattern ..." +.De +.PP +.Cr ~ +sets +.Cr $status +to zero if and only if a supplied pattern matches any +single element of the subject list. +Thus +.Ds +.Cr "~ foo f*" +.De +.PP +sets status to zero, while +.Ds +.Cr "~ (bar baz) f*" +.De +.PP +sets status to one. +The null list is matched by the null list, so +.Ds +.Cr "~ $foo ()" +.De +.PP +checks to see whether +.Cr $foo +is empty or not. +This may also be achieved +by the test +.Ds +.Cr "~ $#foo 0" +.De +.PP +Note that inside a +.Cr ~ +command +.I rc +does not match patterns against file +names, so it is not necessary to quote the characters +.Cr "*" , +.Cr [ +and +.Cr "?" . +However, +.I rc +does expand the glob the subject against filenames if it contains +metacharacters. +Thus, the command +.Ds +.Cr "~ * ?" +.De +.PP +returns true if any of the files in the current directory have a +single-character name. +(Note that if the +.Cr ~ +command is given a list as its first +argument, then a successful match against any of the elements of that +list will cause +.Cr ~ +to return true. +For example: +.Ds +.Cr "~ (foo goo zoo) z*" +.De +.PP +is true.) +.SH "LISTS AND VARIABLES" +The primary data structure in +.IR rc +is the list, which is a sequence of words. +Parentheses are used to group lists. +The empty list is represented by +.Cr "()" . +Lists have no hierarchical structure; +a list inside another list is expanded so the +outer list contains all the elements of the inner list. +Thus, the following are all equivalent +.Ds +.Cr "one two three" + +.Cr "(one two three)" + +.Cr "((one) () ((two three)))" +.De +.PP +Note that the null string, +.Cr "''" , +and the null list, +.Cr "()" , +are two very +different things. +Assigning the null string to variable is a valid +operation, but it does not remove its definition. +For example, +if +.Cr $a +is set to +.Cr "''" , +then +.Cr "$#a" , +returns a 1. +.SS "List Concatenation" +Two lists may be joined by the concatenation operator +.Rc ( ^ ). +A single word is treated as a list of length one, so +.Ds +.Cr "echo foo^bar" +.De +.PP +produces the output +.Ds +.Cr foobar +.De +.PP +For lists of more than one element, +concatenation works according to the following rules: +if the two lists have the same number of elements, +then concatenation is pairwise: +.Ds +.Cr "echo (a\- b\- c\-)^(1 2 3)" +.De +.PP +produces the output +.Ds +.Cr "a\-1 b\-2 c\-3" +.De +.PP +Otherwise, one of the lists must have a single element, +and then the concatenation is distributive: +.Ds +.Cr "cc \-^(O g c) (malloc alloca)^.c" +.De +.PP +has the effect of performing the command +.Ds +.Cr "cc \-O \-g \-c malloc.c alloca.c" +.De +.SS "Free Carets" +.I rc +inserts carets (concatenation operators) for free in certain situations, +in order to save some typing on the user's behalf. +For +example, the above example could also be typed in as: +.Ds +.Cr "opts=(O g c) files=(malloc alloca) cc \-$opts $files.c" +.De +.PP +.I rc +takes care to insert a free-caret between the +.Rc `` \- '' +and +.Cr "$opts" , +as well +as between +.Cr $files +and +.Cr ".c" . +The rule for free carets is as follows: if +a word or keyword is immediately +followed by another word, keyword, dollar-sign or +backquote, then +.I rc +inserts a caret between them. +.SS "Variables" +A list may be assigned to a variable, using the notation: +.Ds +.Ic var " = " list +.De +.PP +Any sequence of non-special characters, except a sequence including +only digits, may be used as a variable name. +All user-defined variables are exported into the environment. +.PP +The value of a variable is referenced with the notation: +.Ds +.Ci $ var +.De +.PP +Any variable which has not been assigned a value returns the null list, +.Cr "()" , +when referenced. +In addition, multiple references are allowed: +.Ds +.Cr a=foo +.Cr b=a +.Cr "echo $$b" +.De +.PP +prints +.Ds +.Cr foo +.De +.PP +A variable's definition may also be removed by +assigning the null list to a variable: +.Ds +.Ic var =() +.De +.PP +For ``free careting'' to work correctly, +.I rc +must make certain assumptions +about what characters may appear in a variable name. +.I rc +assumes that a variable name consists only of alphanumeric characters, +underscore +.Rc ( \|_\| ) +and star +.Rc ( * ). +To reference a variable with other +characters in its name, quote the variable name. +Thus: +.Ds +.Cr "echo $'we$Ird\Variab!le'" +.De +.SS "Local Variables" +Any number of variable assignments may be made local to a single +command by typing: +.Ds +.Cr "a=foo b=bar ... command" +.De +.PP +The command may be a compound command, so for example: +.Ds +.Cr "path=. ifs=() {" +.Cr " " ... +.Cr } +.De +.PP +sets +.Cr path +to +.Cr . +and removes +.Cr ifs +for the duration of one long compound command. +.SS "Variable Subscripts" +Variables may be subscripted with the notation +.Ds +.Ci $var( n ) +.De +.PP +where +.I n +is a list of integers (origin 1). +The list of subscripts need +not be in order or even unique. +Thus, if +.Ds +.Cr "a=(one two three)" +.De +.PP +then +.Ds +.Cr "echo $a(3 3 3)" +.De +.PP +prints +.Ds +.Cr "three three three" +.De +.PP +If +.I n +references a nonexistent element, then +.Ci $var( n ) +returns the null list. +The notation +.Ci "$" n\fR, +where +.I n +is an integer, is a shorthand for +.Ci $*( n )\fR. +Thus, +.IR rc 's +arguments may be referred to as +.Cr "$1" , +.Cr "$2" , +and so on. +.PP +Note also that the list of subscripts may be given by any of +.IR rc 's +list operations: +.Ds +.Cr "$var(\`{awk 'BEGIN{for(i=1;i<=10;i++)print i;exit; }'})" +.De +.PP +returns the first 10 elements of +.Cr $var . +.PP +To count the number of elements in a variable, use +.Ds +.Cr $#var +.De +.PP +This returns a single-element list, with the number of elements in +.Cr $var . +.SS "Flat Lists" +In order to create a single-element list from a multi-element list, +with the components space-separated, use +.Ds +.Cr $^var +.De +.PP +This is useful when the normal list concatenation rules need to be +bypassed. +For example, to append a single period at the end of +.Cr $path , +use: +.Ds +.Cr "echo $^path." +.De +.SS "Backquote Substitution" +A list may be formed from the output of a command by using backquote +substitution: +.Ds +.Cr "\`{ command }" +.De +.PP +returns a list formed from the standard output of the command in braces. +.Cr $ifs +is used to split the output into list elements. +By default, +.Cr $ifs +has the value space-tab-newline. +The braces may be omitted if the command is a single word. +Thus +.Cr \`ls +may be used instead of +.Cr "\`{ls}" . +This last feature is useful when defining functions that expand +to useful argument lists. +A frequent use is: +.Ds +.Cr "fn src { echo *.[chy] }" +.De +.PP +followed by +.Ds +.Cr "wc \`src" +.De +.PP +(This will print out a word-count of all C source files in the current +directory.) +.PP +In order to override the value of +.Cr $ifs +for a single backquote +substitution, use: +.Ds +.Cr "\`\` (ifs-list) { command }" +.De +.PP +.Cr $ifs +will be temporarily ignored and the command's output will be split as specified by +the list following the double backquote. +For example: +.Ds +.Cr "\`\` ($nl :) {cat /etc/passwd}" +.De +.PP +splits up +.Cr /etc/passwd +into fields, assuming that +.Cr $nl +contains a newline +as its value. +.SH "SPECIAL VARIABLES" +Several variables are known to +.I rc +and are treated specially. +.TP +.Cr * +The argument list of +.IR rc . +.Cr "$1, $2," +etc. are the same as +.Cr $*(1) , +.Cr $*(2) , +etc. +The variable +.Cr $0 +holds the value of +.Cr argv[0] +with which +.I rc +was invoked. +Additionally, +.Cr $0 +is set to the name of a function for the duration of +the execution of that function, and +.Cr $0 +is also set to the name of the +file being interpreted for the duration of a +.Cr . +command. +.TP +.Cr apid +The process ID of the last process started in the background. +.TP +.Cr apids +The process IDs of any background processes which are outstanding +or which have died and have not been waited for yet. +.TP +.Cr cdpath +A list of directories to search for the target of a +.B cd +command. +The empty string stands for the current directory. +Note that if the +.Cr $cdpath +variable does not contain the current directory, then the current +directory will not be searched; this allows directory searching to +begin in a directory other than the current directory. +Note also that an assignment to +.Cr $cdpath +causes an automatic assignment to +.Cr $CDPATH , +and vice-versa. +.TP +.Cr history +.Cr $history +contains the name of a file to which commands are appended as +.I rc +reads them. +This facilitates the use of a stand-alone history program +(such as +.IR history (1)) +which parses the contents of the history file and presents them to +.I rc +for reinterpretation. +If +.Cr $history +is not set, then +.I rc +does not append commands to any file. +.TP +.Cr home +The default directory for the builtin +.B cd +command and is the directory +in which +.I rc +looks to find its initialization file, +.Cr .rcrc , +if +.I rc +has been started up as a login shell. +Like +.Cr $cdpath +and +.Cr $CDPATH , +.Cr $home +and +.Cr $HOME +are aliased to each other. +.TP +.Cr ifs +The internal field separator, used for splitting up the output of +backquote commands for digestion as a list. +.TP +.Cr path +This is a list of directories to search in for commands. +The empty string stands for the current directory. +Note that like +.Cr $cdpath +and +.Cr $CDPATH , +.Cr $path +and +.Cr $PATH +are aliased to each other. +If +.Cr $path +or +.Cr $PATH +is not set at startup time, +.Cr $path +assumes a default value suitable for your system. +This is typically +.Cr "(/usr/ucb /usr/bin /bin .)" +.TP +.Cr pid +The process ID of the currently running +.IR rc . +.TP +.Cr prompt +This variable holds the two prompts (in list form, of course) that +.I rc +prints. +.Cr $prompt(1) +is printed before each command is read, and +.Cr $prompt(2) +is printed when input is expected to continue on the next +line. +.I rc +sets +.Cr $prompt +to +.Cr "('; ' '')" +by default. +The reason for this is that it enables an +.I rc +user to grab commands from previous lines using a +mouse, and to present them to +.I rc +for re-interpretation; the semicolon +prompt is simply ignored by +.IR rc . +The null +.Cr $prompt(2) +also has its +justification: an +.I rc +script, when typed interactively, will not leave +.Cr $prompt(2) 's +on the screen, +and can therefore be grabbed by a mouse and placed +directly into a file for use as a shell script, without further editing +being necessary. +.TP +.Cr prompt " (function)" +If this function is set, then it gets executed every time +.I rc +is about to print +.Cr "$prompt(1)" . +.TP +.Cr status +The exit status of the last command. +If the command exited with a numeric value, +that number is the status. +If the died with a signal, +the status is the name of that signal; if a core file +was created, the string +.Rc `` +core '' +is appended. +The value of +.Cr $status +for a pipeline is a list, with one entry, +as above, for each process in the pipeline. +For example, the command +.Ds +.Cr "ls | wc" +.De +.TP +\& +usually sets +.Cr $status +to +.Cr "(0 0)" . +.PP +The values of +.Cr "$path" , +.Cr "$cdpath" , +and +.Cr $home +are derived from the environment +values of +.Cr "$PATH" , +.Cr "$CDPATH" , +and +.Cr "$HOME" . +Otherwise, they are derived from +the environment values of +.Cr $path , +.Cr $cdpath +and +.Cr $home . +This is for compatibility with other Unix programs, like +.IR sh (1). +.Cr $PATH +and +.Cr $CDPATH +are assumed to be colon-separated lists. +.SH FUNCTIONS +.I rc +functions are identical to +.I rc +scripts, except that they are stored +in memory and are automatically exported into the environment. +A shell function is declared as: +.Ds +.Cr "fn name { commands }" +.De +.PP +.I rc +scans the definition until the close-brace, so the function can +span more than one line. +The function definition may be removed by typing +.Ds +.Cr "fn name" +.De +.PP +(One or more names may be specified. +With an accompanying definition, all names receive the same definition. +This is sometimes useful +for assigning the same signal handler to many signals. +Without a definition, all named functions are deleted.) +When a function is executed, +.Cr $* +is set to the arguments to that +function for the duration of the command. +Thus a reasonable definition for +.Cr "l" , +a shorthand for +.IR ls (1), +could be: +.Ds +.Cr "fn l { ls -FC $* }" +.De +.PP +but not +.Ds +.Cr "fn l { ls -FC }" +.De +.SH "INTERRUPTS AND SIGNALS" +.I rc +recognizes a number of signals, and allows the user to define shell +functions which act as signal handlers. +.I rc +by default traps +.Cr SIGINT +when it is in interactive mode. +.Cr SIGQUIT +and +.Cr SIGTERM +are ignored, unless +.I rc +has been invoked with the +.Cr \-d +flag. +However, user-defined signal handlers may be written for these and +all other signals. +The way to define a signal handler is to +write a function by the name of the signal in lower case. +Thus: +.Ds +.Cr "fn sighup { echo hangup; rm /tmp/rc$pid.*; exit }" +.De +.PP +In addition to Unix signals, +.I rc +recognizes the artificial signal +.Cr SIGEXIT +which occurs as +.I rc +is about to exit. +.PP +In order to remove a signal handler's definition, +remove it as though it were a regular function. +For example: +.Ds +.Cr "fn sigint" +.De +.PP +returns the handler of +.Cr SIGINT +to the default value. +In order to ignore a signal, set the signal handler's value to +.Cr "{}" . +Thus: +.Ds +.Cr "fn sigint {}" +.De +.PP +causes SIGINT to be ignored by the shell. +Only signals that are being ignored are passed on to programs run by +.IR rc ; +signal functions are not exported. +.PP +On System V-based Unix systems, +.I rc +will not allow you to trap +.Cr SIGCLD . +.SH "BUILTIN COMMANDS" +Builtin commands execute in the context of the shell, but otherwise +behave exactly like other commands. +Although +.BR ! , +.B ~ +and +.B @ +are not strictly speaking builtin commands, +they can usually be used as such. +.TP +\&\fB.\fR [\fB\-i\fR] \fIfile \fR[\fIarg ...\fR] +Reads +.I file +as input to +.IR rc +and executes its contents. +With a +.Cr \-i +flag, input is interactive. +Thus from within a shell script, +.Ds +.Cr ". \-i /dev/tty" +.De +.TP +\& +does the ``right'' thing. +.TP +.B break +Breaks from the innermost +.Cr for +or +.Cr while , +as in C. +It is an error to invoke +.B break +outside of a loop. +(Note that there is no +.B break +keyword between commands in +.Cr switch +statements, unlike C.) +.TP +\fBbuiltin \fIcommand \fR[\fIarg ...\fR] +Executes the command ignoring any function definition of the +same name. +This command is present to allow functions with the +same names as builtins to use the underlying builtin or binary. +.TP +\fBcd \fR[\fIdirectory\fR] +Changes the current directory to +.IR directory . +The variable +.Cr $cdpath +is searched for possible locations of +.IR directory , +analogous to the searching of +.Cr $path +for executable files. +With no argument, +.B cd +changes the current directory to +.Cr "$home" . +.TP +\fBecho \fR[\fB\-n\fR] [\fB\-\|\-\fR] [\fIarg ...\fR] +Prints its arguments to standard output, terminated by a newline. +Arguments are separated by spaces. +If the first argument is +.Cr "\-n" +no final newline is printed. +If the first argument is +.Cr "\-\|\-" , +then all other arguments are echoed literally. +This is used for echoing a literal +.Cr "\-n" . +.TP +\fBeval \fR[\fIlist\fR] +Concatenates the elements of +.I list +with spaces and feeds the resulting string to +.I rc +for re-scanning. +This is the only time input is rescanned in +.IR rc . +.TP +\fBexec \fR[\fIarg ...\fR] +Replaces +.I rc +with the given command. +If the exec contains only redirections, +then these redirections apply to the current shell +and the shell does not exit. +For example, +.Ds +.Cr "exec >[2] err.out" +.De +.TP +\& +places further output to standard error in the file +.IR err.out . +.TP +\fBexit \fR[\fIstatus\fR] +Cause the current shell to exit with the given exit +.IR status . +If no argument is given, the current value of +.Cr $status +is used. +.TP +\fBlimit \fR[\fB\-h\fR] [\fIresource \fR[\fIvalue\fR]] +Similar to the +.IR csh (1) +.B limit +builtin, this command operates upon the +BSD-style limits of a process. +The +.Cr \-h +flag displays/alters the hard +limits. +The resources which can be shown or altered are +.BR cputime , +.BR filesize , +.BR datasize , +.BR stacksize , +.B coredumpsize +and +.BR memoryuse . +For +example: +.Ds +.Cr "limit coredumpsize 0" +.De +.TP +\& +disables core dumps. +.TP +.B newpgrp +Puts +.I rc +into a new process group. +This builtin is useful for making +.I rc +behave like a job-control shell in a hostile environment. +One example is the NeXT Terminal program, which implicitly assumes +that each shell it forks will put itself into a new process group. +.TP +\fBreturn \fR[\fIn\fR] +Returns from the current function, with status +.IR n , +where +.IR n +is a single value or a list of possible exit statuses. +Thus it is legal to have +.Ds +.Cr "return (sigpipe 1 2 3)" +.De +.TP +\& +(This is commonly used to allow a function to return with the exit status +of a previously executed pipeline of commands.) +If +.IR n +is omitted, then +.Cr $status +is left unchanged. +It is an error to invoke +.B return +when not inside a function. +.TP +\fBshift \fR[\fIn\fR] +Deletes +.I n +elements from the beginning of +.Cr $* +and shifts the other +elements down by +.IR n . +.I n +defaults to 1. +(Note that +.Cr $0 +is not affected by +.BR shift .) +.TP +\fBumask \fR[\fImask\fR] +Sets the current umask (see +.IR umask (2)) +to the octal +.IR mask . +If no argument is present, the current mask value is printed. +.TP +\fBwait \fR[\fIpid\fR] +Waits for the specified +.IR pid , +which must have been started by +.IR rc . +If no +.I pid +is specified, +.I rc +waits for any child process to exit. +.TP +\fBwhatis \fR[\fB\-s\fR] [\fB\-\|\-\fR] [\fIname ...\fR] +Prints a definition of the named objects. +For variables, their values +are printed; for functions, their definitions are; and for executable +files, path names are printed. +Without arguments, +.B whatis +prints the values of all shell variables and functions. +With a +.Cr \-s +argument, +.B whatis +also prints out a list of available signals and their handlers (if any). +Note that +.B whatis +output is suitable for input to +.IR rc ; +by saving the output of +.B whatis +in a file, it should be possible to recreate the state of +.I rc +by sourcing this file with a +.Cr . +command. +Another note: +.Cr "whatis -s > file" +cannot be used to store the state of +.IR rc 's +signal handlers in a file, because builtins with redirections +are run in a subshell, and +.I rc +always restores signal handlers to their default value after a +.Cr fork() . +.TP +\& +Since +.B whatis +uses +.IR getopt (3) +to parse its arguments, you can use the special argument +.Cr "\-\|\-" +to terminate its options. +This allows you to use names beginning with a dash, such as +the +.IR history (1) +commands. +For example, +.Ds +.Cr "whatis \-\|\- \-p" +.De +.SH GRAMMAR +Here is +.IR rc 's +grammar, edited to remove semantic actions. +.Ds +.ft \*(Cf +%term ANDAND BACKBACK BANG CASE COUNT DUP ELSE END FLAT FN FOR IF IN +%term OROR PIPE REDIR SUB SUBSHELL SWITCH TWIDDLE WHILE WORD HUH + +%left WHILE ')' ELSE +%left ANDAND OROR '\en' +%left BANG SUBSHELL +%left PIPE +%right '$' +%left SUB + +%start rc + +%% + +rc: line end + | error end + +end: END /* EOF */ | '\en' + +cmdsa: cmd ';' | cmd '&' + +line: cmd | cmdsa line + +body: cmd | cmdsan body + +cmdsan: cmdsa | cmd '\en' + +brace: '{' body '}' + +paren: '(' body ')' + +assign: first '=' word + +epilog: /* empty */ | redir epilog + +redir: DUP | REDIR word + +case: CASE words ';' | CASE words '\en' + +cbody: cmd | case cbody | cmdsan cbody + +iftail: cmd %prec ELSE + | brace ELSE optnl cmd + +cmd : /* empty */ %prec WHILE + | simple + | brace epilog + | IF paren optnl iftail + | FOR '(' word IN words ')' optnl cmd + | FOR '(' word ')' optnl cmd + | WHILE paren optnl cmd + | SWITCH '(' word ')' optnl '{' cbody '}' + | TWIDDLE optcaret word words + | cmd ANDAND optnl cmd + | cmd OROR optnl cmd + | cmd PIPE optnl cmd + | redir cmd %prec BANG + | assign cmd %prec BANG + | BANG optcaret cmd + | SUBSHELL optcaret cmd + | FN words brace + | FN words + +optcaret: /* empty */ | '^' + +simple: first | simple word | simple redir + +first: comword | first '^' sword + +sword: comword | keyword + +word: sword | word '^' sword + +comword: '$' sword + | '$' sword SUB words ')' + | COUNT sword + | FLAT sword + | '`' sword + | '`' brace + | BACKBACK word brace | BACKBACK word sword + | '(' words ')' + | REDIR brace + | WORD + +keyword: FOR | IN | WHILE | IF | SWITCH + | FN | ELSE | CASE | TWIDDLE | BANG | SUBSHELL + +words: /* empty */ | words word + +optnl: /* empty */ | optnl '\en' +.ft R +.De +.SH FILES +.Cr $HOME/.rcrc , +.Cr /tmp/rc* , +.Cr /dev/null +.SH CREDITS +.I rc +was written by Byron Rakitzis, with valuable help +from Paul Haahr, Hugh Redelmeier and David Sanderson. +The design of this shell has been copied from the +.I rc +that Tom Duff wrote at Bell Labs. +.SH BUGS +On systems that support +.Cr /dev/fd , +.Cr <{foo} +style redirection is implemented that way. +However, on other systems it is implemented with named pipes, +and it is sometimes +possible to foil +.I rc +into removing the FIFO it places in +.Cr /tmp +prematurely, or it is even possible to cause +.I rc +to hang. +.PP +The functionality of +.B shift +should be available for variables other than +.Cr "$*" . +.PP +.B echo +is built in only for performance reasons, which is a bad idea. +.PP +There should be a way to avoid exporting a variable. +.PP +The +.Cr $^var +notation for flattening should allow for using an arbitrary +separating character, not just space. +.PP +Bug reports should be mailed to +.Cr "byron@archone.tamu.edu" . +.SH INCOMPATIBILITIES +Here is a list of features which distinguish this incarnation of +.I rc +from the one described in the Bell Labs manual pages: +.PP +The treatment of +.Cr if - else +is different in the v10 +.IR rc : +that version uses an +.Cr "if not" +clause which gets executed +if the preceding +.Cr if +test does not succeed. +.PP +Backquotes are slightly different in v10 +.IR rc : +a backquote must always be followed by a left-brace. +This restriction is not present for single-word commands in this +.IR rc . +.PP +The following are all new with this version of +.IR rc : +The +.Cr \-n +option, +the list flattening operator, +here strings (they facilitate exporting of functions +with here documents into the environment), +the +.B return +and +.B break +keywords, +the +.B echo +builtin, +the support for the GNU +.IR readline (3) +library and +the support for the +.Cr prompt +function. +This +.I rc +also sets +.Cr $0 +to the name of a function being executed/file +being sourced. +.SH "SEE ALSO" +``rc \(em A Shell for Plan 9 and UNIX Systems'', +Unix Research System, +10th Edition, +vol. 2. (Saunders College Publishing) +(This paper is also distributed with this +.I rc +in PostScript form.) +.PP +.IR history (1) diff --git a/rc.h b/rc.h @@ -0,0 +1,380 @@ +#include "config.h" +#include "proto.h" + +/* datatypes */ + +/* braindamaged IBM header files #define true and false */ +#undef FALSE +#undef TRUE + +#include <stdarg.h> + +typedef void builtin_t(char **); +typedef struct Block Block; +typedef struct Dup Dup; +typedef struct Estack Estack; +typedef struct Function Function; +typedef struct Hq Hq; +typedef struct Htab Htab; +typedef struct Jbwrap Jbwrap; +typedef struct List List; +typedef struct Node Node; +typedef struct Pipe Pipe; +typedef struct Redir Redir; +typedef struct Rq Rq; +typedef struct Variable Variable; +typedef struct Word Word; +typedef struct Format Format; +typedef union Edata Edata; + +typedef enum nodetype { + nAndalso, nAssign, nBackq, nBang, nBody, nCbody, nNowait, nBrace, nConcat, + nCount, nElse, nFlat, nDup, nEpilog, nNewfn, nForin, nIf, nQword, + nOrelse, nPipe, nPre, nRedir, nRmfn, nArgs, nSubshell, nCase, + nSwitch, nMatch, nVar, nVarsub, nWhile, nWord, nLappend, nNmpipe +} nodetype; + +typedef enum ecodes { + eError, eBreak, eReturn, eVarstack, eArena, eFifo, eFd +} ecodes; + +typedef enum bool { + FALSE, TRUE +} bool; + +typedef enum inputtype { + iFd, iString +} inputtype; + +typedef enum redirtype { + rFrom, rCreate, rAppend, rHeredoc, rHerestring +} redirtype; + +typedef bool (*Conv)(Format *, int); + +union Edata { + Jbwrap *jb; + Block *b; + char *name; + int fd; +}; + +struct Estack { + ecodes e; + bool interactive; + Edata data; + Estack *prev; +}; + +struct List { + char *w, *m; + List *n; +}; + +struct Node { + nodetype type; + union { + char *s; + int i; + Node *p; + } u[4]; +}; + +struct Pipe { + int left, right; +}; + +struct Dup { + redirtype type; + int left, right; +}; + +struct Redir { + redirtype type; + int fd; +}; + +struct Word { + char *w, *m; +}; + +struct Rq { + Node *r; + struct Rq *n; +}; + +struct Function { + Node *def; + char *extdef; +}; + +struct Variable { + List *def; + char *extdef; + Variable *n; +}; + +struct Htab { + char *name; + void *p; +}; + +struct Format { + /* for the formatting routines */ + va_list args; + long flags, f1, f2; + /* for the buffer maintainence routines */ + char *buf, *bufbegin, *bufend; + int flushed; + void (*grow)(Format *, SIZE_T); + union { int n; void *p; } u; +}; + +/* Format->flags values */ +enum { + FMT_long = 1, /* %l */ + FMT_short = 2, /* %h */ + FMT_unsigned = 4, /* %u */ + FMT_zeropad = 8, /* %0 */ + FMT_leftside = 16, /* %- */ + FMT_altform = 32, /* %# */ + FMT_f1set = 64, /* %<n> */ + FMT_f2set = 128 /* %.<n> */ +}; + +/* macros */ +#define EOF (-1) +#ifndef NULL +#define NULL 0 +#endif +#define a2u(x) n2u(x, 10) +#define o2u(x) n2u(x, 8) +#define arraysize(a) ((int)(sizeof(a)/sizeof(*a))) +#define enew(x) ((x *) ealloc(sizeof(x))) +#define ecpy(x) strcpy((char *) ealloc(strlen(x) + 1), x) +#define lookup_fn(s) ((Function *) lookup(s, fp)) +#define lookup_var(s) ((Variable *) lookup(s, vp)) +#define nnew(x) ((x *) nalloc(sizeof(x))) +#define ncpy(x) (strcpy((char *) nalloc(strlen(x) + 1), x)) +#ifndef offsetof +#define offsetof(t, m) ((SIZE_T) (((char *) &((t *) 0)->m) - (char *)0)) +#endif +#define streq(x, y) (*(x) == *(y) && strcmp(x, y) == 0) +#define conststrlen(x) (sizeof (x) - 1) + +/* rc prototypes */ + +/* main.c */ +extern char *prompt, *prompt2; +extern Rq *redirq; +extern bool dashdee, dashee, dashvee, dashex, dashell, + dasheye, dashen, dashpee, interactive; +extern int rc_pid; +extern int lineno; + +/* builtins.c */ +extern builtin_t *isbuiltin(char *); +extern void b_exec(char **), funcall(char **), b_dot(char **), b_builtin(char **); +extern char *which(char *, bool); + +/* except.c */ +extern bool nl_on_intr; +extern bool outstanding_cmdarg(void); +extern void pop_cmdarg(bool); +extern void rc_raise(ecodes); +extern void except(ecodes, Edata, Estack *); +extern void unexcept(void); +extern void rc_error(char *); +extern void sigint(int); + +/* exec.c */ +extern void exec(List *, bool); +extern void doredirs(void); + +/* footobar.c */ +extern char *fun2str(char *, Node *); +extern char *list2str(char *, List *); +extern char **list2array(List *, bool); +extern char *get_name(char *); +extern List *parse_var(char *, char *); +extern Node *parse_fn(char *, char *); +extern void initprint(void); +extern void rc_exit(int); /* here for odd reasons; user-defined signal handlers are kept in fn.c */ + +/* getopt.c */ +extern int rc_getopt(int, char **, char *); + +extern int rc_optind, rc_opterr, rc_optopt; +extern char *rc_optarg; + +/* glob.c */ +extern bool lmatch(List *, List *); +extern List *glob(List *); + +/* glom.c */ +extern void assign(List *, List *, bool); +extern void qredir(Node *); +extern List *append(List *, List*); +extern List *flatten(List *); +extern List *glom(Node *); +extern List *concat(List *, List *); +extern List *varsub(List *, List *); +extern List *word(char *, char *); + +/* hash.c */ +extern Htab *fp, *vp; +extern void *lookup(char *, Htab *); +extern Function *get_fn_place(char *); +extern List *varlookup(char *); +extern Node *fnlookup(char *); +extern Variable *get_var_place(char *, bool); +extern bool varassign_string(char *); +extern char **makeenv(void); +extern char *fnlookup_string(char *); +extern char *varlookup_string(char *); +extern void alias(char *, List *, bool); +extern void starassign(char *, char **, bool); +extern void delete_fn(char *); +extern void delete_var(char *, bool); +extern void fnassign(char *, Node *); +extern void fnassign_string(char *); +extern void fnrm(char *); +extern void initenv(char **); +extern void inithash(void); +extern void setsigdefaults(bool); +extern void inithandler(void); +extern void varassign(char *, List *, bool); +extern void varrm(char *, bool); +extern void whatare_all_vars(void); +extern void whatare_all_signals(void); +extern void prettyprint_var(int, char *, List *); +extern void prettyprint_fn(int, char *, Node *); + +/* heredoc.c */ +extern int heredoc(int); +extern int qdoc(Node *, Node *); +extern Hq *hq; + +/* input.c */ +extern void initinput(void); +extern Node *parseline(char *); +extern int gchar(void); +extern void ugchar(int); +extern Node *doit(bool); +extern void flushu(void); +extern void pushfd(int); +extern void pushstring(char **, bool); +extern void popinput(void); +extern void closefds(void); +extern int last; +extern bool rcrc; + +/* lex.c */ +extern int yylex(void); +extern void inityy(void); +extern void yyerror(const char *); +extern void scanerror(char *); +extern void print_prompt2(void); +extern const char nw[], dnw[]; + +/* list.c */ +extern void listfree(List *); +extern List *listcpy(List *, void *(*)(SIZE_T)); +extern SIZE_T listlen(List *); +extern int listnel(List *); + +/* match.c */ +extern bool match(char *, char *, char *); + +/* alloc.c */ +extern void *ealloc(SIZE_T); +extern void *erealloc(void *, SIZE_T); +extern void efree(void *); +extern Block *newblock(void); +extern void *nalloc(SIZE_T); +extern void nfree(void); +extern void restoreblock(Block *); + +/* open.c */ +extern int rc_open(const char *, redirtype); + +/* print.c */ +/* + The following prototype should be: +extern Conv fmtinstall(int, Conv); + but this freaks out SGI's compiler under IRIX3.3.2 +*/ +extern bool (*fmtinstall(int, bool (*)(Format *, int)))(Format *, int); +extern int printfmt(Format *, const char *); +extern int fmtprint(Format *, const char *,...); +extern void fmtappend(Format *, const char *, SIZE_T); +extern void fmtcat(Format *, const char *); +extern int fprint(int fd, const char *fmt,...); +extern char *mprint(const char *fmt,...); +extern char *nprint(const char *fmt,...); +/* + the following macro should by rights be coded as an expression, not + a statement, but certain compilers (notably DEC) have trouble with + void expressions inside the ?: operator. (sheesh, give me a break!) +*/ +#define fmtputc(f, c) {\ + if ((f)->buf >= (f)->bufend)\ + (*(f)->grow)((f), (SIZE_T)1);\ + *(f)->buf++ = (c);\ +} + +/* y.tab.c (parse.y) */ +extern Node *parsetree; +extern int yyparse(void); +extern void initparse(void); + +/* redir.c */ +extern void doredirs(void); + +/* signal.c */ +extern void initsignal(void); +extern void catcher(int); +extern void sigchk(void); +extern void (*rc_signal(int, void (*)(int)))(int); +extern void (*sighandlers[])(int); +extern volatile SIG_ATOMIC_T slow, interrupt_happened; +#define SIGCHK sigchk() + +/* status.c */ +extern int istrue(void); +extern int getstatus(void); +extern void set(bool); +extern void setstatus(int, int); +extern List *sgetstatus(void); +extern void setpipestatus(int [], int); +extern void statprint(int, int); +extern void ssetstatus(char **); + +/* tree.c */ +extern Node *mk(int /*nodetype*/,...); +extern Node *treecpy(Node *, void *(*)(SIZE_T)); +extern void treefree(Node *); + +/* utils.c */ +extern bool isabsolute(char *); +extern int n2u(char *, unsigned int); +extern int rc_read(int, char *, SIZE_T); +extern int mvfd(int, int); +extern int starstrcmp(const void *, const void *); +extern void pr_error(char *); +extern char *clear(char *, SIZE_T); +extern void panic(char *); +extern void uerror(char *); +extern void writeall(int, char *, SIZE_T); + +/* wait.c */ +extern int rc_fork(void); +extern int rc_wait4(int, int *, bool); +extern List *sgetapids(void); +extern void waitforall(void); +extern bool forked; + +/* walk.c */ +extern bool walk(Node *, bool); +extern bool cond; + diff --git a/redir.c b/redir.c @@ -0,0 +1,77 @@ +/* redir.c: code for opening files and piping heredocs after fork but before exec. */ + +#include "rc.h" + +/* + Walk the redirection queue, and open files and dup2 to them. Also, + here-documents are treated here by dumping them down a pipe. (this + should make here-documents fast on systems with lots of memory which + do pipes right. Under sh, a file is copied to /tmp, and then read + out of /tmp again. I'm interested in knowing how much faster, say, + shar runs when unpacking when invoked with rc instead of sh. On my + sun4/280, it runs in about 60-75% of the time of sh for unpacking + the rc source distribution.) +*/ + +extern void doredirs() { + List *fname; + int fd, p[2]; + Rq *r; + for (r = redirq; r != NULL; r = r->n) { + switch(r->r->type) { + default: + panic("unexpected node in doredirs"); + /* NOTREACHED */ + case nRedir: + if (r->r->u[0].i == rHerestring) { + fname = flatten(glom(r->r->u[2].p)); /* fname is really a string */ + if (pipe(p) < 0) { + uerror("pipe"); + rc_error(NULL); + } + if (rc_fork() == 0) { /* child writes to pipe */ + setsigdefaults(FALSE); + close(p[0]); + if (fname != NULL) + writeall(p[1], fname->w, strlen(fname->w)); + exit(0); + } else { + close(p[1]); + if (mvfd(p[0], r->r->u[1].i) < 0) + rc_error(NULL); + } + } else { + fname = glob(glom(r->r->u[2].p)); + if (fname == NULL) + rc_error("null filename in redirection"); + if (fname->n != NULL) + rc_error("multi-word filename in redirection"); + switch (r->r->u[0].i) { + default: + panic("unexpected node in doredirs"); + /* NOTREACHED */ + case rCreate: case rAppend: case rFrom: + fd = rc_open(fname->w, r->r->u[0].i); + break; + } + if (fd < 0) { + uerror(fname->w); + rc_error(NULL); + } + if (mvfd(fd, r->r->u[1].i) < 0) + rc_error(NULL); + } + break; + case nDup: + if (r->r->u[2].i == -1) + close(r->r->u[1].i); + else if (r->r->u[2].i != r->r->u[1].i) { + if (dup2(r->r->u[2].i, r->r->u[1].i) < 0) { + uerror("dup2"); + rc_error(NULL); + } + } + } + } + redirq = NULL; +} diff --git a/signal.c b/signal.c @@ -0,0 +1,75 @@ +/* signal.c: a Hugh-approved signal handler. */ + +#include <signal.h> +#include <setjmp.h> +#include "rc.h" +#include "sigmsgs.h" +#include "jbwrap.h" + +Jbwrap slowbuf; +volatile SIG_ATOMIC_T slow, interrupt_happened; +void (*sighandlers[NUMOFSIGNALS])(int); + +static volatile SIG_ATOMIC_T sigcount, caught[NUMOFSIGNALS]; + +extern void catcher(int s) { + if (forked) + exit(1); /* exit unconditionally on a signal in a child process */ + if (caught[s] == 0) { + sigcount++; + caught[s] = 1; + } + signal(s, catcher); + interrupt_happened = TRUE; +#ifndef SVSIGS + if (slow) + longjmp(slowbuf.j, 1); +#endif +} + +extern void sigchk() { + void (*h)(int); + int s, i; + if (sigcount == 0) + return; /* ho hum; life as usual */ + if (forked) + exit(1); /* exit unconditionally on a signal in a child process */ + for (i = 0, s = -1; i < NUMOFSIGNALS; i++) + if (caught[i] != 0) { + s = i; + --sigcount; + caught[s] = 0; + break; + } + if (s == -1) + panic("all-zero sig vector with nonzero sigcount"); + if ((h = sighandlers[s]) == SIG_DFL) + panic("caught signal set to SIG_DFL"); + if (h == SIG_IGN) + panic("caught signal set to SIG_IGN"); + (*h)(s); +} + +extern void (*rc_signal(int s, void (*h)(int)))(int) { + void (*old)(int); + SIGCHK; + old = sighandlers[s]; + if (h == SIG_DFL || h == SIG_IGN) { + signal(s, h); + sighandlers[s] = h; + } else { + sighandlers[s] = h; + signal(s, catcher); + } + return old; +} + +extern void initsignal() { + void (*h)(int); + int i; + for (i = 1; i < NUMOFSIGNALS; i++) { + if ((h = signal(i, SIG_DFL)) != SIG_DFL) + signal(i, h); + sighandlers[i] = h; + } +} diff --git a/status.c b/status.c @@ -0,0 +1,139 @@ +/* status.c: functions for printing fancy status messages in rc */ + +#include "rc.h" +#include "sigmsgs.h" + +/* status == the wait() value of the last command in the pipeline, or the last command */ + +static int statuses[512]; +static int pipelength = 1; + +/* + Test to see if rc's status is true. According to td, status is true + if and only if every pipe-member has an exit status of zero. +*/ + +extern int istrue() { + int i; + for (i = 0; i < pipelength; i++) + if (statuses[i] != 0) + return FALSE; + return TRUE; +} + +/* + Return the status as an integer. A status which has low-bits set is + a signal number, whereas a status with high bits set is a value set + from exit(). The presence of a signal just sets status to 1. Also, + a pipeline with nonzero exit statuses in it just sets status to 1. +*/ + +extern int getstatus() { + int s; + if (pipelength > 1) + return !istrue(); + s = statuses[0]; + return (s&0xff) ? 1 : (s >> 8) & 0xff; +} + +extern void set(bool code) { + setstatus(-1, (!code) << 8); /* exit status 1 == 0x100 */ +} + +/* take a pipeline and store the exit statuses. Check to see whether any of the children dumped core */ + +extern void setpipestatus(int stats[], int num) { + int i; + for (i = 0; i < (pipelength = num); i++) { + statprint(-1, stats[i]); + statuses[i] = stats[i]; + } +} + +/* set a simple status, as opposed to a pipeline */ + +extern void setstatus(int pid, int i) { + pipelength = 1; + statuses[0] = i; + statprint(pid, i); +} + +/* print a message if termination was with a signal, and if the child dumped core. exit on error if -e is set */ + +extern void statprint(int pid, int i) { + if (i & 0xff) { + char *msg = ((i & 0x7f) < NUMOFSIGNALS ? signals[i & 0x7f].msg : ""); + if (pid != -1) + fprint(2, "%d: ", pid); + if (i & 0x80) { + if (*msg == '\0') + fprint(2, "core dumped\n"); + else + fprint(2, "%s--core dumped\n", msg); + } else if (*msg != '\0') + fprint(2, "%s\n", msg); + } + if (i != 0 && dashee && !cond) + rc_exit(getstatus()); +} + +/* prepare a list to be passed back. Used whenever $status is dereferenced */ + +extern List *sgetstatus() { + List *r; + int i; + for (r = NULL, i = 0; i < pipelength; i++) { + List *q = nnew(List); + int s = statuses[i]; + int t; + q->n = r; + r = q; + if ((t = s & 0x7f) != 0) { + const char *core = (s & 0x80) ? "+core" : ""; + if (t < NUMOFSIGNALS && *signals[t].name != '\0') + r->w = nprint("%s%s", signals[t].name, core); + else + r->w = nprint("-%d%s", t, core); /* unknown signals are negated */ + } else + r->w = nprint("%d", (s >> 8) & 0xff); + r->m = NULL; + } + return r; +} + +extern void ssetstatus(char **av) { + int i, j, k, l; + bool found; + for (l = 0; av[l] != NULL; l++) + ; /* count up array length */ + --l; + for (i = 0; av[i] != NULL; i++) { + j = a2u(av[i]); + if (j >= 0) { + statuses[l - i] = j << 8; + continue; + } + found = FALSE; + for (k = 0; k < NUMOFSIGNALS; k++) { + if (streq(signals[k].name, av[i])) { + statuses[l - i] = k; + found = TRUE; + break; + } + else { + SIZE_T len = strlen(signals[k].name); + if (strncmp(signals[k].name, av[i], len) == 0 && streq(av[i] + len, "+core")) { + statuses[l - i] = k + 0x80; + found = TRUE; + break; + } + } + } + if (!found) { + fprint(2, "bad status\n"); + set(FALSE); + return; + } + } + pipelength = i; +} diff --git a/tree.c b/tree.c @@ -0,0 +1,172 @@ +/* tree.c: functions for manipulating parse-trees. (create, copy, delete) */ + +#include "rc.h" + +/* make a new node, pass it back to yyparse. Used to generate the parsetree. */ + +extern Node *mk(int /*nodetype*/ t,...) { + va_list ap; + Node *n; + va_start(ap, t); + switch (t) { + default: + panic("unexpected node in mk"); + /* NOTREACHED */ + case nDup: + n = nalloc(offsetof(Node, u[3])); + n->u[0].i = va_arg(ap, int); + n->u[1].i = va_arg(ap, int); + n->u[2].i = va_arg(ap, int); + break; + case nWord: case nQword: + n = nalloc(offsetof(Node, u[2])); + n->u[0].s = va_arg(ap, char *); + n->u[1].s = va_arg(ap, char *); + break; + case nBang: case nNowait: + case nCount: case nFlat: case nRmfn: case nSubshell: + case nVar: case nCase: + n = nalloc(offsetof(Node, u[1])); + n->u[0].p = va_arg(ap, Node *); + break; + case nAndalso: case nAssign: case nBackq: case nBody: case nBrace: case nConcat: + case nElse: case nEpilog: case nIf: case nNewfn: case nCbody: + case nOrelse: case nPre: case nArgs: case nSwitch: + case nMatch: case nVarsub: case nWhile: case nLappend: + n = nalloc(offsetof(Node, u[2])); + n->u[0].p = va_arg(ap, Node *); + n->u[1].p = va_arg(ap, Node *); + break; + case nForin: + n = nalloc(offsetof(Node, u[3])); + n->u[0].p = va_arg(ap, Node *); + n->u[1].p = va_arg(ap, Node *); + n->u[2].p = va_arg(ap, Node *); + break; + case nPipe: + n = nalloc(offsetof(Node, u[4])); + n->u[0].i = va_arg(ap, int); + n->u[1].i = va_arg(ap, int); + n->u[2].p = va_arg(ap, Node *); + n->u[3].p = va_arg(ap, Node *); + break; + case nRedir: + case nNmpipe: + n = nalloc(offsetof(Node, u[3])); + n->u[0].i = va_arg(ap, int); + n->u[1].i = va_arg(ap, int); + n->u[2].p = va_arg(ap, Node *); + break; + } + n->type = t; + va_end(ap); + return n; +} + +/* copy a tree to malloc space. Used when storing the definition of a function */ + +extern Node *treecpy(Node *s, void *(*alloc)(SIZE_T)) { + Node *n; + if (s == NULL) + return NULL; + switch (s->type) { + default: + panic("unexpected node in treecpy"); + /* NOTREACHED */ + case nDup: + n = (*alloc)(offsetof(Node, u[3])); + n->u[0].i = s->u[0].i; + n->u[1].i = s->u[1].i; + n->u[2].i = s->u[2].i; + break; + case nWord: case nQword: + n = (*alloc)(offsetof(Node, u[2])); + n->u[0].s = strcpy((char *) (*alloc)(strlen(s->u[0].s) + 1), s->u[0].s); + if (s->u[1].s != NULL) { + SIZE_T i = strlen(s->u[0].s); + n->u[1].s = (*alloc)(i); + memcpy(n->u[1].s, s->u[1].s, i); + } else + n->u[1].s = NULL; + break; + case nBang: case nNowait: case nCase: + case nCount: case nFlat: case nRmfn: case nSubshell: case nVar: + n = (*alloc)(offsetof(Node, u[1])); + n->u[0].p = treecpy(s->u[0].p, alloc); + break; + case nAndalso: case nAssign: case nBackq: case nBody: case nBrace: case nConcat: + case nElse: case nEpilog: case nIf: case nNewfn: case nCbody: + case nOrelse: case nPre: case nArgs: case nSwitch: + case nMatch: case nVarsub: case nWhile: case nLappend: + n = (*alloc)(offsetof(Node, u[2])); + n->u[0].p = treecpy(s->u[0].p, alloc); + n->u[1].p = treecpy(s->u[1].p, alloc); + break; + case nForin: + n = (*alloc)(offsetof(Node, u[3])); + n->u[0].p = treecpy(s->u[0].p, alloc); + n->u[1].p = treecpy(s->u[1].p, alloc); + n->u[2].p = treecpy(s->u[2].p, alloc); + break; + case nPipe: + n = (*alloc)(offsetof(Node, u[4])); + n->u[0].i = s->u[0].i; + n->u[1].i = s->u[1].i; + n->u[2].p = treecpy(s->u[2].p, alloc); + n->u[3].p = treecpy(s->u[3].p, alloc); + break; + case nRedir: + case nNmpipe: + n = (*alloc)(offsetof(Node, u[3])); + n->u[0].i = s->u[0].i; + n->u[1].i = s->u[1].i; + n->u[2].p = treecpy(s->u[2].p, alloc); + break; + } + n->type = s->type; + return n; +} + +/* free a function definition that is no longer needed */ + +extern void treefree(Node *s) { + if (s == NULL) + return; + switch (s->type) { + default: + panic("unexpected node in treefree"); + /* NOTREACHED */ + case nDup: + break; + case nWord: case nQword: + efree(s->u[0].s); + efree(s->u[1].s); + break; + case nBang: case nNowait: + case nCount: case nFlat: case nRmfn: + case nSubshell: case nVar: case nCase: + treefree(s->u[0].p); + break; + case nAndalso: case nAssign: case nBackq: case nBody: case nBrace: case nConcat: + case nElse: case nEpilog: case nIf: case nNewfn: + case nOrelse: case nPre: case nArgs: case nCbody: + case nSwitch: case nMatch: case nVarsub: case nWhile: + case nLappend: + treefree(s->u[1].p); + treefree(s->u[0].p); + break; + case nForin: + treefree(s->u[2].p); + treefree(s->u[1].p); + treefree(s->u[0].p); + break; + case nPipe: + treefree(s->u[2].p); + treefree(s->u[3].p); + break; + case nRedir: + case nNmpipe: + treefree(s->u[2].p); + } + efree(s); +} diff --git a/trip.rc b/trip.rc Binary files differ. diff --git a/utils.c b/utils.c @@ -0,0 +1,125 @@ +/* utils.c: functions of general utility */ + +#include <errno.h> +#include <setjmp.h> +#include "rc.h" +#include "jbwrap.h" + +/* print error with line number on noninteractive shells (i.e., scripts) */ + +extern void pr_error(char *s) { + if (s != NULL) { + if (interactive) + fprint(2, "%s\n", s); + else + fprint(2, "line %d: %s\n", lineno - 1, s); + } +} + +/* our perror */ + +extern void uerror(char *s) { + extern int sys_nerr; + extern char *sys_errlist[]; + if (errno > sys_nerr) + return; + if (s != NULL) + fprint(2, "%s: %s\n", s, sys_errlist[errno]); + else + fprint(2, "%s\n", sys_errlist[errno]); +} + +/* Die horribly. This should never get called. Please let me know if it does. */ + +#define PANICMSG "rc panic: " + +extern void panic(char *s) { + write(2, PANICMSG, conststrlen(PANICMSG)); + write(2, s, strlen(s)); + write(2, "!\n", 2); + exit(1); +} + +/* ascii -> unsigned conversion routines. -1 indicates conversion error. */ + +extern int n2u(char *s, unsigned int base) { + unsigned int i; + for (i = 0; *s != '\0'; s++) { + unsigned int j = (unsigned int) *s - '0'; + if (j >= base) /* small hack with unsigned ints -- one compare for range test */ + return -1; + i = i * base + j; + } + return (int) i; +} + +/* The last word in portable ANSI: a strcmp wrapper for qsort */ + +extern int starstrcmp(const void *s1, const void *s2) { + return strcmp(*(char **)s1, *(char **)s2); +} + +/* tests to see if pathname begins with "/", "./", or "../" */ + +extern bool isabsolute(char *path) { + return path[0] == '/' || (path[0] == '.' && (path[1] == '/' || (path[1] == '.' && path[2] == '/'))); +} + +/* signal-safe read and write (for BSD slow devices). writeall also allows partial writes */ + +extern void writeall(int fd, char *buf, SIZE_T remain) { + int i; + for (i = 0; remain > 0; buf += i, remain -= i) { + interrupt_happened = FALSE; + if (!setjmp(slowbuf.j)) { + slow = TRUE; + if (interrupt_happened) + break; + else if ((i = write(fd, buf, remain)) <= 0) + break; /* abort silently on errors in write() */ + } else + break; + slow = FALSE; + } + slow = FALSE; + SIGCHK; +} + +extern int rc_read(int fd, char *buf, SIZE_T n) { + long /*ssize_t*/ r; + interrupt_happened = FALSE; + if (!setjmp(slowbuf.j)) { + slow = TRUE; + if (!interrupt_happened) + r = read(fd, buf, n); + else + r = -2; + } else + r = -2; + slow = FALSE; + if (r == -2) { + errno = EINTR; + r = -1; + } + SIGCHK; + return r; +} + +/* clear out z bytes from character string s */ + +extern char *clear(char *s, SIZE_T z) { + while (z != 0) + s[--z] = 0; + return s; +} + +/* duplicate a fd and close the old one only if necessary */ + +extern int mvfd(int i, int j) { + if (i != j) { + int s = dup2(i, j); + close(i); + return s; + } + return 0; +} diff --git a/var.c b/var.c @@ -0,0 +1,226 @@ +/* var.c: provide "public" functions for adding and removing variables from the symbol table */ + +#include "rc.h" + +static void colonassign(char *, List *, bool); +static void listassign(char *, List *, bool); +static int hasalias(char *); + +static char *const aliases[] = { + "home", "HOME", "path", "PATH", "cdpath", "CDPATH" +}; + +/* assign a variable in List form to a name, stacking if appropriate */ + +extern void varassign(char *name, List *def, bool stack) { + Variable *new; + List *newdef = listcpy(def, ealloc); /* important to do the listcpy first; get_var_place() frees old values */ + new = get_var_place(name, stack); + new->def = newdef; + new->extdef = NULL; +#ifdef READLINE /* need to reset readline() every time TERM or TERMCAP changes */ + if (interactive && (streq(name, "TERM") || streq(name, "TERMCAP"))) { + extern void rl_reset_terminal(char *); + rl_reset_terminal(NULL); + } +#endif +} + +/* assign a variable in string form. Check to see if it is aliased (e.g., PATH and path) */ + +extern bool varassign_string(char *extdef) { + static bool aliasset[arraysize(aliases)] = { + FALSE, FALSE, FALSE, FALSE, FALSE, FALSE + }; + char *name = get_name(extdef); + Variable *new; + int i; + if (name == NULL) + return FALSE; /* add it to bozo env */ + if ((i = hasalias(name)) != -1) { + aliasset[i] = TRUE; + i ^= 1; /* set i to the "opposite" case subscript and */ + if (i&1 && aliasset[i]) /* don't alias variables that are already set in upper case */ + return TRUE; + } + new = get_var_place(name, FALSE); + new->def = NULL; + new->extdef = ealloc(strlen(extdef) + 1); + strcpy(new->extdef, extdef); + if (i != -1) + alias(name, varlookup(name), FALSE); + return TRUE; +} + +/* + Return a List based on a name lookup. If the list is in external (string) form, + convert it to internal (List) form. Treat $n (n is an integer) specially as $*(n). + Also check to see if $status is being dereferenced. (we lazily evaluate the List + associated with $status) +*/ + +extern List *varlookup(char *name) { + Variable *look; + List *ret, *l; + int sub; + if (streq(name, "status")) + return sgetstatus(); + if (streq(name, "apids")) + return sgetapids(); + if (*name != '\0' && (sub = a2u(name)) != -1) { /* handle $1, $2, etc. */ + for (l = varlookup("*"); l != NULL && sub != 0; --sub) + l = l->n; + if (l == NULL) + return NULL; + ret = nnew(List); + ret->w = l->w; + ret->m = NULL; + ret->n = NULL; + return ret; + } + look = lookup_var(name); + if (look == NULL) + return NULL; /* not found */ + if (look->def != NULL) + return look->def; + if (look->extdef == NULL) + return NULL; /* variable was set to null, e.g., a=() echo foo */ + ret = parse_var(name, look->extdef); + if (ret == NULL) { + look->extdef = NULL; + return NULL; + } + return look->def = ret; +} + +/* lookup a variable in external (string) form, converting if necessary. Used by makeenv() */ + +extern char *varlookup_string(char *name) { + Variable *look; + look = lookup_var(name); + if (look == NULL) + return NULL; + if (look->extdef != NULL) + return look->extdef; + if (look->def == NULL) + return NULL; + return look->extdef = list2str(name, look->def); +} + +/* remove a variable from the symtab. "stack" determines whether a level of scoping is popped or not */ + +extern void varrm(char *name, bool stack) { + int i = hasalias(name); + if (streq(name, "*") && !stack) { /* when assigning () to $*, we want to preserve $0 */ + varassign("*", varlookup("0"), FALSE); + return; + } + delete_var(name, stack); + if (i != -1) + delete_var(aliases[i^1], stack); +} + +/* assign a value (List) to a variable, using array "a" as input. Used to assign $* */ + +extern void starassign(char *dollarzero, char **a, bool stack) { + List *s, *var; + var = nnew(List); + var->w = dollarzero; + if (*a == NULL) { + var->n = NULL; + varassign("*", var, stack); + return; + } + var->n = s = nnew(List); + while (1) { + s->w = *a++; + if (*a == NULL) { + s->n = NULL; + break; + } else + s = s->n = nnew(List); + } + varassign("*", var, stack); +} + +/* (ugly name, huh?) assign a colon-separated value to a variable (e.g., PATH) from a List (e.g., path) */ + +static void colonassign(char *name, List *def, bool stack) { + List dud; + if (def == NULL) { + varassign(name, NULL, stack); + return; + } + dud.w = nprint("%-L", def, ":"); + dud.n = NULL; + varassign(name, &dud, stack); +} + +/* assign a List variable (e.g., path) from a colon-separated string (e.g., PATH) */ + +static void listassign(char *name, List *def, bool stack) { + List *val, *r; + char *v, *w; + if (def == NULL) { + varassign(name, NULL, stack); + return; + } + v = def->w; + r = val = enew(List); + while ((w = strchr(v, ':')) != NULL) { + *w = '\0'; + r->w = ecpy(v); + *w = ':'; + v = w + 1; + r->n = enew(List); + r = r->n; + } + r->w = ecpy(v); + r->n = NULL; + varassign(name, val, stack); +} + +/* check to see if a particular variable is aliased; return -1 on failure, or the index */ + +static int hasalias(char *name) { + int i; + for (i = 0; i < arraysize(aliases); i++) + if (streq(name, aliases[i])) + return i; + return -1; +} + +/* alias a variable to its lowercase equivalent. function pointers are used to specify the conversion function */ + +extern void alias(char *name, List *s, bool stack) { + static void (*vectors[])(char *, List *, bool) = { + varassign, varassign, colonassign, listassign, colonassign, listassign + }; + int i = hasalias(name); + if (i != -1) + (*vectors[i])(aliases[i^1], s, stack); /* xor hack to reverse case of alias entry */ +} + +extern void prettyprint_var(int fd, char *name, List *s) { + int i; + static const char * const keywords[] = { + "if", "in", "fn", "for", "else", "switch", "while", "case" + }; + if (s == NULL) { + fprint(fd, "%S=()\n", name); + return; + } + if (streq(name, "*")) { + s = s->n; + if (s == NULL) + return; /* Don't print $0, and if $* is not set, skip it */ + } + for (i = 0; i < arraysize(keywords); i++) + if (streq(keywords[i], name)) { + fprint(fd, "%#S=", name); + goto value; + } + fprint(fd, "%S=", name); +value: + fprint(fd, s->n == NULL ? "%L\n" : "(%L)\n", s, " "); +} diff --git a/version.c b/version.c @@ -0,0 +1 @@ +const char id[] = "@(#)rc version 1.4, 5/26/92."; diff --git a/wait.c b/wait.c @@ -0,0 +1,124 @@ +#include <errno.h> +#include <setjmp.h> +#include "rc.h" +#include "jbwrap.h" + +bool forked = FALSE; + +static int rc_wait(int *); + +typedef struct Pid Pid; + +static struct Pid { + int pid, stat; + bool alive; + Pid *n; +} *plist = NULL; + +extern int rc_fork() { + Pid *new = enew(Pid); + int pid = fork(); + switch (pid) { + case -1: + uerror("fork"); + rc_error(NULL); + /* NOTREACHED */ + case 0: + forked = TRUE; + SIGCHK; + return 0; + default: + new->pid = pid; + new->alive = TRUE; + new->n = plist; + plist = new; + return pid; + } +} + +extern int rc_wait4(int pid, int *stat, bool nointr) { + Pid *r, *prev; + int ret; + /* first look for a child which may already have exited */ +again: for (r = plist, prev = NULL; r != NULL; prev = r, r = r->n) + if (r->pid == pid) + break; + if (r == NULL) { + errno = ECHILD; /* no children */ + uerror("wait"); + *stat = 0x100; /* exit(1) */ + return -1; + } + if (r->alive) { + while (pid != (ret = rc_wait(stat))) { + Pid *q; + if (ret < 0) { + if (nointr) + goto again; + return ret; + } + for (q = plist; q != NULL; q = q->n) + if (q->pid == ret) { + q->alive = FALSE; + q->stat = *stat; + break; + } + } + } else + *stat = r->stat; + if (prev == NULL) + plist = r->n; /* remove element from head of list */ + else + prev->n = r->n; + efree(r); + return pid; +} + +extern List *sgetapids() { + List *r; + Pid *p; + for (r = NULL, p = plist; p != NULL; p = p->n) { + List *q; + if (!p->alive) + continue; + q = nnew(List); + q->w = nprint("%d", p->pid); + q->m = NULL; + q->n = r; + r = q; + } + return r; +} + +extern void waitforall() { + int stat; + while (plist != NULL) { + int pid = rc_wait4(plist->pid, &stat, FALSE); + if (pid > 0) + setstatus(pid, stat); + else + set(FALSE); + SIGCHK; + } +} + +/* + rc_wait: a wait() wrapper that interfaces wait() w/rc signals. + Note that the signal queue is not checked in this fn; someone + may want to resume the wait() without delivering any signals. +*/ + +static int rc_wait(int *stat) { + int r; + interrupt_happened = FALSE; + if (!setjmp(slowbuf.j)) { + slow = TRUE; + if (!interrupt_happened) + r = wait(stat); + else + r = -1; + } else + r = -1; + slow = FALSE; + return r; +} diff --git a/walk.c b/walk.c @@ -0,0 +1,344 @@ +/* walk.c: walks the parse tree. */ + +#include <signal.h> +#include <setjmp.h> +#include "rc.h" +#include "jbwrap.h" + +/* + global which indicates whether rc is executing a test; + used by rc -e so that if (false) does not exit. +*/ +bool cond = FALSE; + +static bool isallpre(Node *); +static bool dofork(bool); +static void dopipe(Node *); + +/* Tail-recursive version of walk() */ + +#define WALK(x, y) { n = x; parent = y; goto top; } + +/* walk the parse-tree. "obvious". */ + +extern bool walk(Node *n, bool parent) { +top: SIGCHK; + if (n == NULL) { + if (!parent) + exit(0); + set(TRUE); + return TRUE; + } + switch (n->type) { + case nArgs: case nBackq: case nConcat: case nCount: + case nFlat: case nLappend: case nRedir: case nVar: + case nVarsub: case nWord: case nQword: + exec(glob(glom(n)), parent); /* simple command */ + break; + case nBody: + walk(n->u[0].p, TRUE); + WALK(n->u[1].p, parent); + /* WALK doesn't fall through */ + case nNowait: { + int pid; + if ((pid = rc_fork()) == 0) { +#if !defined(NOJOB) && defined(SIGTTOU) && defined(SIGTTIN) && defined(SIGTSTP) + setsigdefaults(FALSE); + rc_signal(SIGTTOU, SIG_IGN); /* Berkeleyized version: put it in a new pgroup. */ + rc_signal(SIGTTIN, SIG_IGN); + rc_signal(SIGTSTP, SIG_IGN); + setpgrp(0, getpid()); +#else + setsigdefaults(TRUE); /* ignore SIGINT, SIGQUIT, SIGTERM */ +#endif + mvfd(rc_open("/dev/null", rFrom), 0); + walk(n->u[0].p, FALSE); + exit(getstatus()); + } + if (interactive) + fprint(2, "%d\n", pid); + varassign("apid", word(nprint("%d", pid), NULL), FALSE); + redirq = NULL; /* kill pre-redir queue */ + break; + } + case nAndalso: { + bool oldcond = cond; + cond = TRUE; + if (walk(n->u[0].p, TRUE)) { + cond = oldcond; + WALK(n->u[1].p, parent); + } else + cond = oldcond; + break; + } + case nOrelse: { + bool oldcond = cond; + cond = TRUE; + if (!walk(n->u[0].p, TRUE)) { + cond = oldcond; + WALK(n->u[1].p, parent); + } else + cond = oldcond; + break; + } + case nBang: + set(!walk(n->u[0].p, TRUE)); + break; + case nIf: { + bool oldcond = cond; + Node *true_cmd = n->u[1].p, *false_cmd = NULL; + if (true_cmd != NULL && true_cmd->type == nElse) { + false_cmd = true_cmd->u[1].p; + true_cmd = true_cmd->u[0].p; + } + cond = TRUE; + if (!walk(n->u[0].p, TRUE)) + true_cmd = false_cmd; /* run the else clause */ + cond = oldcond; + WALK(true_cmd, parent); + } + case nWhile: { + Jbwrap j; + Edata jbreak; + Estack e1, e2; + bool testtrue, oldcond = cond; + cond = TRUE; + if (!walk(n->u[0].p, TRUE)) { /* prevent spurious breaks inside test */ + cond = oldcond; + break; + } + if (setjmp(j.j)) + break; + jbreak.jb = &j; + except(eBreak, jbreak, &e1); + do { + Edata block; + block.b = newblock(); + cond = oldcond; + except(eArena, block, &e2); + walk(n->u[1].p, TRUE); + testtrue = walk(n->u[0].p, TRUE); + unexcept(); /* eArena */ + cond = TRUE; + } while (testtrue); + cond = oldcond; + unexcept(); /* eBreak */ + break; + } + case nForin: { + List *l, *var = glom(n->u[0].p); + Jbwrap j; + Estack e1, e2; + Edata jbreak; + if (setjmp(j.j)) + break; + jbreak.jb = &j; + except(eBreak, jbreak, &e1); + for (l = listcpy(glob(glom(n->u[1].p)), nalloc); l != NULL; l = l->n) { + Edata block; + assign(var, word(l->w, NULL), FALSE); + block.b = newblock(); + except(eArena, block, &e2); + walk(n->u[2].p, TRUE); + unexcept(); /* eArena */ + } + unexcept(); /* eBreak */ + break; + } + case nSubshell: + if (dofork(TRUE)) { + setsigdefaults(FALSE); + walk(n->u[0].p, FALSE); + rc_exit(getstatus()); + } + break; + case nAssign: + if (n->u[0].p == NULL) + rc_error("null variable name"); + assign(glom(n->u[0].p), glob(glom(n->u[1].p)), FALSE); + set(TRUE); + break; + case nPipe: + dopipe(n); + break; + case nNewfn: { + List *l = glom(n->u[0].p); + if (l == NULL) + rc_error("null function name"); + while (l != NULL) { + if (dashex) + prettyprint_fn(2, l->w, n->u[1].p); + fnassign(l->w, n->u[1].p); + l = l->n; + } + set(TRUE); + break; + } + case nRmfn: { + List *l = glom(n->u[0].p); + while (l != NULL) { + if (dashex) + fprint(2, "fn %S\n", l->w); + fnrm(l->w); + l = l->n; + } + set(TRUE); + break; + } + case nDup: + redirq = NULL; + break; /* Null command */ + case nMatch: { + List *a = glob(glom(n->u[0].p)), *b = glom(n->u[1].p); + if (dashex) + fprint(2, (a != NULL && a->n != NULL) ? "~ (%L) %L\n" : "~ %L %L\n", a, " ", b, " "); + set(lmatch(a, b)); + break; + } + case nSwitch: { + List *v = glom(n->u[0].p); + while (1) { + do { + n = n->u[1].p; + if (n == NULL) + return istrue(); + } while (n->u[0].p == NULL || n->u[0].p->type != nCase); + if (lmatch(v, glom(n->u[0].p->u[0].p))) { + for (n = n->u[1].p; n != NULL && (n->u[0].p == NULL || n->u[0].p->type != nCase); n = n->u[1].p) + walk(n->u[0].p, TRUE); + break; + } + } + break; + } + case nPre: { + List *v; + if (n->u[0].p->type == nRedir || n->u[0].p->type == nDup) { + qredir(n->u[0].p); + walk(n->u[1].p, parent); + } else if (n->u[0].p->type == nAssign) { + if (isallpre(n->u[1].p)) { + walk(n->u[0].p, TRUE); + WALK(n->u[1].p, parent); + } else { + Estack e; + Edata var; + v = glom(n->u[0].p->u[0].p); + assign(v, glob(glom(n->u[0].p->u[1].p)), TRUE); + var.name = v->w; + except(eVarstack, var, &e); + walk(n->u[1].p, parent); + varrm(v->w, TRUE); + unexcept(); /* eVarstack */ + } + } else + panic("unexpected node in preredir section of walk"); + break; + } + case nBrace: + if (n->u[1].p == NULL) { + WALK(n->u[0].p, parent); + } else if (dofork(parent)) { + setsigdefaults(FALSE); + walk(n->u[1].p, TRUE); /* Do redirections */ + redirq = NULL; /* Reset redirection queue */ + walk(n->u[0].p, FALSE); /* Do commands */ + rc_exit(getstatus()); + /* NOTREACHED */ + } + break; + case nEpilog: + qredir(n->u[0].p); + if (n->u[1].p != NULL) { + WALK(n->u[1].p, parent); /* Do more redirections. */ + } else { + doredirs(); /* Okay, we hit the bottom. */ + } + break; + case nNmpipe: + rc_error("named pipes cannot be executed as commands"); + /* NOTREACHED */ + default: + panic("unknown node in walk"); + /* NOTREACHED */ + } + return istrue(); +} + +/* checks to see whether a subtree is all pre-command directives, i.e., assignments and redirs only */ + +static bool isallpre(Node *n) { + while (n != NULL && n->type == nPre) + n = n->u[1].p; + return n == NULL || n->type == nRedir || n->type == nAssign || n->type == nDup; +} + +/* + A code-saver. Forks, child returns (for further processing in walk()), and the parent + waits for the child to finish, setting $status appropriately. +*/ + +static bool dofork(bool parent) { + int pid, sp; + + if (!parent || (pid = rc_fork()) == 0) + return TRUE; + redirq = NULL; /* clear out the pre-redirection queue in the parent */ + rc_wait4(pid, &sp, TRUE); + setstatus(-1, sp); + SIGCHK; + return FALSE; +} + +static void dopipe(Node *n) { + int i, j, sp, pid, fd_prev, fd_out, pids[512], stats[512], p[2]; + bool intr; + Node *r; + + fd_prev = fd_out = 1; + for (r = n, i = 0; r != NULL && r->type == nPipe; r = r->u[2].p, i++) { + if (i > 500) /* the only hard-wired limit in rc? */ + rc_error("pipe too long"); + if (pipe(p) < 0) { + uerror("pipe"); + rc_error(NULL); + } + if ((pid = rc_fork()) == 0) { + setsigdefaults(FALSE); + redirq = NULL; /* clear preredir queue */ + mvfd(p[0], r->u[1].i); + if (fd_prev != 1) + mvfd(fd_prev, fd_out); + close(p[1]); + walk(r->u[3].p, FALSE); + exit(getstatus()); + } + if (fd_prev != 1) + close(fd_prev); /* parent must close all pipe fd's */ + pids[i] = pid; + fd_prev = p[1]; + fd_out = r->u[0].i; + close(p[0]); + } + if ((pid = rc_fork()) == 0) { + setsigdefaults(FALSE); + mvfd(fd_prev, fd_out); + walk(r, FALSE); + exit(getstatus()); + /* NOTREACHED */ + } + redirq = NULL; /* clear preredir queue */ + close(fd_prev); + pids[i++] = pid; + + /* collect statuses */ + + intr = FALSE; + for (j = 0; j < i; j++) { + rc_wait4(pids[j], &sp, TRUE); + stats[j] = sp; + intr |= (sp == SIGINT); + } + setpipestatus(stats, i); + SIGCHK; +} diff --git a/which.c b/which.c @@ -0,0 +1,114 @@ +/* which.c: check to see if a file is executable. + + This function was originally written with Maarten Litmaath's which.c as + a template, but was changed in order to accomodate the possibility of + rc's running setuid or the possibility of executing files not in the + primary group. Much of this file has been re-vamped by Paul Haahr. + I re-re-vamped the functions that Paul supplied to correct minor bugs + and to strip out unneeded functionality. +*/ + +#include <sys/types.h> +#include <sys/stat.h> +#include <sys/param.h> +#include <errno.h> +#include "rc.h" + +#define X_USR 0100 +#define X_GRP 0010 +#define X_OTH 0001 +#define X_ALL (X_USR|X_GRP|X_OTH) + +extern int stat(const char *, struct stat *); + +static bool initialized = FALSE; +static int uid, gid; + +#ifdef NGROUPS +static int ngroups, gidset[NGROUPS]; + +/* determine whether gid lies in gidset */ + +static int ingidset(int g) { + int i; + for (i = 0; i < ngroups; i++) + if (g == gidset[i]) + return 1; + return 0; +} +#endif + +/* + A home-grown access/stat. Does the right thing for group-executable files. + Returns a bool instead of this -1 nonsense. +*/ + +static bool rc_access(char *path, bool verbose) { + struct stat st; + int mask; + if (stat(path, &st) != 0) { + if (verbose) /* verbose flag only set for absolute pathname */ + uerror(path); + return FALSE; + } + if (uid == 0) + mask = X_ALL; + else if (uid == st.st_uid) + mask = X_USR; +#ifdef NGROUPS + else if (gid == st.st_gid || ingidset(st.st_gid)) +#else + else if (gid == st.st_gid) +#endif + mask = X_GRP; + else + mask = X_OTH; + if (((st.st_mode & S_IFMT) == S_IFREG) && (st.st_mode & mask)) + return TRUE; + errno = EACCES; + if (verbose) + uerror(path); + return FALSE; +} + +/* return a full pathname by searching $path, and by checking the status of the file */ + +extern char *which(char *name, bool verbose) { + static char *test = NULL; + static SIZE_T testlen = 0; + List *path; + int len; + if (name == NULL) /* no filename? can happen with "> foo" as a command */ + return NULL; + if (!initialized) { + initialized = TRUE; + uid = geteuid(); + gid = getegid(); +#ifdef NGROUPS + ngroups = getgroups(NGROUPS, gidset); +#endif + } + if (isabsolute(name)) /* absolute pathname? */ + return rc_access(name, verbose) ? name : NULL; + len = strlen(name); + for (path = varlookup("path"); path != NULL; path = path->n) { + SIZE_T need = strlen(path->w) + len + 2; /* one for null terminator, one for the '/' */ + if (testlen < need) { + efree(test); + test = ealloc(testlen = need); + } + if (*path->w == '\0') { + strcpy(test, name); + } else { + strcpy(test, path->w); + if (!streq(test, "/")) /* "//" is special to POSIX */ + strcat(test, "/"); + strcat(test, name); + } + if (rc_access(test, FALSE)) + return test; + } + if (verbose) + fprint(2, "%s not found\n", name); + return NULL; +}