stagit-gopher

commit cbb963db3795ea24cd0d68f73b415f9fc48922cc
parent 1dd611d990843966e50b23dac30617d6aa5b2b2e
Author: Hiltjo Posthuma <hiltjo@codemadness.org>
Date:   Sat, 19 Mar 2022 12:51:57 +0100

improve stream read and write error handling

Diffstat:
M
stagit-gopher-index.c
 | 
13
+++++++++++++
M
stagit-gopher.c
 | 
35
+++++++++++++++++++++++++++--------

2 files changed, 40 insertions(+), 8 deletions(-)
diff --git a/stagit-gopher-index.c b/stagit-gopher-index.c
@@ -20,6 +20,16 @@ static const char *relpath = "";
 static char description[255] = "Repositories";
 static char *name = "";
 
+/* Handle read or write errors for a FILE * stream */
+void
+checkfileerror(FILE *fp, const char *name, int mode)
+{
+	if (mode == 'r' && ferror(fp))
+		errx(1, "read error: %s", name);
+	else if (mode == 'w' && (fflush(fp) || ferror(fp)))
+		errx(1, "write error: %s", name);
+}
+
 /* Format `len' columns of characters. If string is shorter pad the rest
  * with characters `pad`. */
 int
@@ -289,6 +299,7 @@ main(int argc, char *argv[])
 				description[strcspn(description, "\t\r\n")] = '\0';
 			else
 				description[0] = '\0';
+			checkfileerror(fp, "description", 'r');
 			fclose(fp);
 		}
 
@@ -303,5 +314,7 @@ main(int argc, char *argv[])
 	git_repository_free(repo);
 	git_libgit2_shutdown();
 
+	checkfileerror(stdout, "<stdout>", 'w');
+
 	return ret;
 }
diff --git a/stagit-gopher.c b/stagit-gopher.c
@@ -83,6 +83,16 @@ static char lastoidstr[GIT_OID_HEXSZ + 2]; /* id + newline + NUL byte */
 static FILE *rcachefp, *wcachefp;
 static const char *cachefile;
 
+/* Handle read or write errors for a FILE * stream */
+void
+checkfileerror(FILE *fp, const char *name, int mode)
+{
+	if (mode == 'r' && ferror(fp))
+		errx(1, "read error: %s", name);
+	else if (mode == 'w' && (fflush(fp) || ferror(fp)))
+		errx(1, "write error: %s", name);
+}
+
 /* Format `len' columns of characters. If string is shorter pad the rest
  * with characters `pad`. */
 int
@@ -878,6 +888,7 @@ writelog(FILE *fp, const git_oid *oid)
 			writeheader(fpfile, ci->summary);
 			printshowfile(fpfile, ci);
 			writefooter(fpfile);
+			checkfileerror(fpfile, path, 'w');
 			fclose(fpfile);
 		}
 err:
@@ -1018,14 +1029,13 @@ writeblob(git_object *obj, const char *fpath, const char *filename, size_t files
 	fprintf(fp, " (%zuB)\n", filesize);
 	fputs("---\n", fp);
 
-	if (git_blob_is_binary((git_blob *)obj)) {
+	if (git_blob_is_binary((git_blob *)obj))
 		fputs("Binary file.\n", fp);
-	} else {
+	else
 		lc = writeblobgph(fp, (git_blob *)obj);
-		if (ferror(fp))
-			err(1, "fwrite");
-	}
+
 	writefooter(fp);
+	checkfileerror(fp, fpath, 'w');
 	fclose(fp);
 
 	return lc;
@@ -1337,6 +1347,7 @@ main(int argc, char *argv[])
 	if (fpread) {
 		if (!fgets(description, sizeof(description), fpread))
 			description[0] = '\0';
+		checkfileerror(fpread, path, 'r');
 		fclose(fpread);
 	}
 
@@ -1349,8 +1360,9 @@ main(int argc, char *argv[])
 	if (fpread) {
 		if (!fgets(cloneurl, sizeof(cloneurl), fpread))
 			cloneurl[0] = '\0';
-		cloneurl[strcspn(cloneurl, "\n")] = '\0';
+		checkfileerror(fpread, path, 'r');
 		fclose(fpread);
+		cloneurl[strcspn(cloneurl, "\n")] = '\0';
 	}
 
 	/* check LICENSE */
@@ -1408,13 +1420,15 @@ main(int argc, char *argv[])
 			while (!feof(rcachefp)) {
 				n = fread(buf, 1, sizeof(buf), rcachefp);
 				if (ferror(rcachefp))
-					err(1, "fread");
+					break;
 				if (fwrite(buf, 1, n, fp) != n ||
 				    fwrite(buf, 1, n, wcachefp) != n)
-					err(1, "fwrite");
+					break;
 			}
+			checkfileerror(rcachefp, cachefile, 'r');
 			fclose(rcachefp);
 		}
+		checkfileerror(wcachefp, tmppath, 'w');
 		fclose(wcachefp);
 	} else {
 		if (head)
@@ -1424,6 +1438,7 @@ main(int argc, char *argv[])
 	fprintf(fp, "[0|Atom feed|%s/atom.xml|server|port]\n", relpath);
 	fprintf(fp, "[0|Atom feed (tags)|%s/tags.xml|server|port]\n", relpath);
 	writefooter(fp);
+	checkfileerror(fp, "log.gph", 'w');
 	fclose(fp);
 
 	/* files for HEAD */
@@ -1432,6 +1447,7 @@ main(int argc, char *argv[])
 	if (head)
 		writefiles(fp, head);
 	writefooter(fp);
+	checkfileerror(fp, "files.gph", 'w');
 	fclose(fp);
 
 	/* summary page with branches and tags */
@@ -1439,16 +1455,19 @@ main(int argc, char *argv[])
 	writeheader(fp, "Refs");
 	writerefs(fp);
 	writefooter(fp);
+	checkfileerror(fp, "refs.gph", 'w');
 	fclose(fp);
 
 	/* Atom feed */
 	fp = efopen("atom.xml", "w");
 	writeatom(fp, 1);
+	checkfileerror(fp, "atom.xml", 'w');
 	fclose(fp);
 
 	/* Atom feed for tags / releases */
 	fp = efopen("tags.xml", "w");
 	writeatom(fp, 0);
+	checkfileerror(fp, "tags.xml", 'w');
 	fclose(fp);
 
 	/* rename new cache file on success */