Exit with a non-zero exit status if a given file does not exist

Sadly, the diff is quite large as we will have to change the API
of `blaze822_loop` to differentiate the number of processed messages
and a status code indicating a missing mail. Note that currently
execution is not aborted upon encountering the first non-existent
mail; hence, we can't do both via the return value.

Surprisingly, very few utilities actually use the number of processed
messages as return by `blaze822_loop`. Therefore, we could reduce the
diff quite a bit by differentiating the two use cases through separate
function (e.g. `blaze822_loop` and `blaze822_loop_num`), which would
allow the API of blaze822_loop to remain largely unchanged.

The new `blaze822_loop` API would also allow us to improve error
handling for blaze822_seq_next but I haven't done this so far.

There are also some tests, but these should be expanded.

Fixes leahneukirchen#264

blaze822.h

@@ -85,8 +85,8 @@ struct blaze822_seq_iter {
 };
 
 char *blaze822_seq_next(char *map, char *range, struct blaze822_seq_iter *iter);
-long blaze822_loop(int, char **, void (*)(char *));
-long blaze822_loop1(char *arg, void (*cb)(char *));
+int blaze822_loop(long *num, int, char **, void (*)(char *));
+int blaze822_loop1(long *num, char *arg, void (*cb)(char *));
 char *blaze822_home_file(char *basename);
 
 // filter.c

maddr.c

@@ -114,9 +114,7 @@ main(int argc, char *argv[])
 	xpledge("stdio rpath", "");
 
 	if (argc == optind && isatty(0))
-		blaze822_loop1(":", addr);
+		return blaze822_loop1(NULL, ":", addr);
 	else
-		blaze822_loop(argc-optind, argv+optind, addr);
-
-	return 0;
+		return blaze822_loop(NULL, argc-optind, argv+optind, addr);
 }

magrep.c

@@ -232,9 +232,9 @@ main(int argc, char *argv[])
 	}
 
 	if (argc == optind && isatty(0))
-		blaze822_loop1(":", magrep);
+		blaze822_loop1(NULL, ":", magrep);
 	else
-		blaze822_loop(argc-optind, argv+optind, magrep);
+		blaze822_loop(NULL, argc-optind, argv+optind, magrep);
 
 	if (cflag && !qflag && !mflag)
 		printf("%ld\n", matches);

mdeliver.c

@@ -331,9 +331,7 @@ main(int argc, char *argv[])
 		if (argc == optind + 1 && isatty(0))
 			goto usage;
 		else
-			blaze822_loop(argc - 1 - optind, argv + optind, refile);
-
-		return 0;
+			return blaze822_loop(NULL, argc - 1 - optind, argv + optind, refile);
 	}
 
 	int c;

mexport.c

@@ -148,9 +148,9 @@ main(int argc, char *argv[])
 	xpledge("stdio rpath", "");
 
 	if (argc == optind && isatty(0))
-		blaze822_loop1(":", export);
+		status |= blaze822_loop1(NULL, ":", export);
 	else
-		blaze822_loop(argc-optind, argv+optind, export);
+		status |= blaze822_loop(NULL, argc-optind, argv+optind, export);
 
 	return status;
 }

mflag.c

@@ -141,31 +141,29 @@ main(int argc, char *argv[])
 
 	if (vflag) {
 		if (argc == optind && !isatty(0)) {
-			blaze822_loop(0, 0, flag);  // read from stdin
-			return 0;
+			return blaze822_loop(NULL, 0, 0, flag);  // read from stdin
 		}
 
 		args = calloc(argsalloc, sizeof (char *));
 		if (!args)
 			exit(-1);
 
+		int status;
 		if (argc == optind)
-			blaze822_loop1(".", add);
+			status = blaze822_loop1(NULL, ".", add);
 		else
-			blaze822_loop(argc-optind, argv+optind, add);
+			status = blaze822_loop(NULL, argc-optind, argv+optind, add);
 
 		if (isatty(0))
-			blaze822_loop1(":", flag);
+			status |= blaze822_loop1(NULL, ":", flag);
 		else
-			blaze822_loop(0, 0, flag);
+			status |= blaze822_loop(NULL, 0, 0, flag);
 
-		return 0;
+		return status;
 	}
 
 	if (argc == optind && isatty(0))
-		blaze822_loop1(".", flag);
+		return blaze822_loop1(NULL, ".", flag);
 	else
-		blaze822_loop(argc-optind, argv+optind, flag);
-
-	return 0;
+		return blaze822_loop(NULL, argc-optind, argv+optind, flag);
 }

mhdr.c

@@ -250,9 +250,9 @@ main(int argc, char *argv[])
 	xpledge("stdio rpath", "");
 
 	if (argc == optind && isatty(0))
-		blaze822_loop1(".", header);
+		status |= blaze822_loop1(NULL, ".", header);
 	else
-		blaze822_loop(argc-optind, argv+optind, header);
+		status |= blaze822_loop(NULL, argc-optind, argv+optind, header);
 
 	return status;
 }

minc.c

@@ -81,7 +81,7 @@ main(int argc, char *argv[])
 	if (optind == argc) {
 		if (isatty(0))
 			goto usage;
-		blaze822_loop(0, 0, inc);
+		status = blaze822_loop(NULL, 0, 0, inc);
 	} else {
 		for (i = optind; i < argc; i++)
 			inc(argv[i]);

mlist.c

@@ -282,10 +282,11 @@ main(int argc, char *argv[])
 			flagsum++;
 	}
 
+	int status = 0;
 	if (optind == argc) {
 		if (isatty(0))
 			goto usage;
-		blaze822_loop(0, 0, listarg);
+		status = blaze822_loop(NULL, 0, 0, listarg);
 	} else {
 		for (i = optind; i < argc; i++)
 			listarg(argv[i]);
@@ -300,5 +301,5 @@ main(int argc, char *argv[])
 			    tunseen, tflagged, tcount);
 	}
 
-	return 0;
+	return status;
 }

mpick.c

@@ -1464,11 +1464,12 @@ main(int argc, char *argv[])
 
 	xpledge("stdio rpath wpath cpath proc exec", 0);
 
+	int status;
 	void (*cb)(char *) = need_thr ? collect : oneline;
 	if (argc == optind && isatty(0))
-		i = blaze822_loop1(":", cb);
+		status = blaze822_loop1(&i, ":", cb);
 	else
-		i = blaze822_loop(argc-optind, argv+optind, cb);
+		status = blaze822_loop(&i, argc-optind, argv+optind, cb);
 
 	/* print and free last thread */
 	if (Tflag && thr)
@@ -1488,5 +1489,5 @@ main(int argc, char *argv[])
 		free(files);
 	}
 
-	return 0;
+	return status;
 }

mscan.c

@@ -559,10 +559,9 @@ main(int argc, char *argv[])
 
 	if (nflag) {
 		if (argc == optind && isatty(0))
-			blaze822_loop1(":", numline);
+			return blaze822_loop1(NULL, ":", numline);
 		else
-			blaze822_loop(argc-optind, argv+optind, numline);
-		return 0;
+			return blaze822_loop(NULL, argc-optind, argv+optind, numline);
 	}
 
 	now = time(0);
@@ -623,16 +622,17 @@ main(int argc, char *argv[])
 	}
 
 	long i;
+	int status;
 	if (argc == optind && isatty(0))
-		i = blaze822_loop1(":", oneline);
+		status = blaze822_loop1(&i, ":", oneline);
 	else
-		i = blaze822_loop(argc-optind, argv+optind, oneline);
+		status = blaze822_loop(&i, argc-optind, argv+optind, oneline);
 
 	if (pager_pid > 0)
 		pipeclose(pager_pid);
 
 	if (vflag)
 		fprintf(stderr, "%ld mails scanned\n", i);
 
-	return 0;
+	return status;
 }

msed.c

@@ -330,9 +330,7 @@ main(int argc, char *argv[])
 	optind++;
 
 	if (argc == optind && isatty(0))
-		blaze822_loop1(".", sed);
+		return blaze822_loop1(NULL, ".", sed);
 	else
-		blaze822_loop(argc-optind, argv+optind, sed);
-
-	return 0;
+		return blaze822_loop(NULL, argc-optind, argv+optind, sed);
 }

mseq.c

@@ -301,12 +301,13 @@ main(int argc, char *argv[])
 
 	xpledge("stdio rpath wpath cpath", "");
 
-	if (cflag)
-		blaze822_loop1(cflag, overridecur);
+	if (cflag) {
+		if (blaze822_loop1(NULL, cflag, overridecur))
+			return 1;
+	}
 
 	if (Cflag) {
-		blaze822_loop1(Cflag, setcur);
-		return 0;
+		return blaze822_loop1(NULL, Cflag, setcur);
 	}
 
 	if (Sflag && optind != argc) {

mshow.c

@@ -587,13 +587,13 @@ extract_cb(char *file)
 	blaze822_walk_mime(msg, 0, extract_mime);
 }
 
-void
+int
 extract(char *file, int argc, char **argv, int use_stdout)
 {
 	extract_argc = argc;
 	extract_argv = argv;
 	extract_stdout = use_stdout;
-	blaze822_loop1(file, extract_cb);
+	return blaze822_loop1(NULL, file, extract_cb);
 }
 
 static char *newcur;
@@ -832,21 +832,22 @@ main(int argc, char *argv[])
 		}
 	}
 
+	int status = 0;
 	if (xflag) { // extract
 		xpledge("stdio rpath wpath cpath", NULL);
-		extract(xflag, argc-optind, argv+optind, 0);
+		status = extract(xflag, argc-optind, argv+optind, 0);
 	} else if (Oflag) { // extract to stdout
 		xpledge("stdio rpath", NULL);
-		extract(Oflag, argc-optind, argv+optind, 1);
+		status = extract(Oflag, argc-optind, argv+optind, 1);
 	} else if (tflag) { // list
 		xpledge("stdio rpath", NULL);
 		if (argc == optind && isatty(0))
-			blaze822_loop1(".", list);
+			status = blaze822_loop1(NULL, ".", list);
 		else
-			blaze822_loop(argc-optind, argv+optind, list);
+			status = blaze822_loop(NULL, argc-optind, argv+optind, list);
 	} else if (Rflag) { // render for reply
 		xpledge("stdio rpath", NULL);
-		blaze822_loop(argc-optind, argv+optind, reply);
+		status = blaze822_loop(NULL, argc-optind, argv+optind, reply);
 	} else { // show
 		/* XXX pledge: still r/w on the whole file-system + fork/exec */
 		if (!(qflag || rflag || Fflag)) {
@@ -857,9 +858,9 @@ main(int argc, char *argv[])
 				filters = blaze822(f);
 		}
 		if (argc == optind && isatty(0))
-			blaze822_loop1(".", show);
+			status = blaze822_loop1(NULL, ".", show);
 		else
-			blaze822_loop(argc-optind, argv+optind, show);
+			status = blaze822_loop(NULL, argc-optind, argv+optind, show);
 		if (!nflag) // don't set cur
 			if (newcur)
 				blaze822_seq_setcur(newcur);
@@ -875,5 +876,5 @@ main(int argc, char *argv[])
 		return 1;
 	}
 
-	return 0;
+	return status;
 }

msort.c

@@ -323,10 +323,11 @@ main(int argc, char *argv[])
 	if (!mails)
 		exit(-1);
 
+	int status;
 	if (argc == optind && isatty(0))
-		blaze822_loop1(":", add);
+		status = blaze822_loop1(NULL, ":", add);
 	else
-		blaze822_loop(argc-optind, argv+optind, add);
+		status = blaze822_loop(NULL, argc-optind, argv+optind, add);
 
 	qsort(mails, idx, sizeof (struct mail), order);
 
@@ -337,5 +338,5 @@ main(int argc, char *argv[])
 		for (i = 0; i < idx; i++)
 			printf("%s\n", mails[i].file);
 
-	return 0;
+	return status;
 }

mthread.c

@@ -421,7 +421,7 @@ main(int argc, char *argv[])
 
 	while ((c = getopt(argc, argv, "S:prv")) != -1)
 		switch (c) {
-		case 'S': blaze822_loop1(optarg, thread); break;
+		case 'S': blaze822_loop1(NULL, optarg, thread); break;
 		case 'v': vflag = 1; break;
 		case 'p': pflag = 1; break;
 		case 'r': rflag = 1; break;
@@ -432,10 +432,11 @@ main(int argc, char *argv[])
 
 	optional = 0;
 
+	int status;
 	if (argc == optind && isatty(0))
-		blaze822_loop1(":", thread);
+		status = blaze822_loop1(NULL, ":", thread);
 	else
-		blaze822_loop(argc-optind, argv+optind, thread);
+		status = blaze822_loop(NULL, argc-optind, argv+optind, thread);
 
 	// the tree of all toplevel threads has depth -1,
 	// so toplevel threads have depth 0.
@@ -446,5 +447,5 @@ main(int argc, char *argv[])
 	sort_tree(top, -1);
 	print_tree(top, -1);
 
-	return 0;
+	return status;
 }