From: cheloha <cheloha@openbsd.org>
Date: Sun, 10 Oct 2021 15:57:25 +0000 (+0000)
Subject: head(1): validate all line count arguments
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=3d668c255f6827a5d207253952bd0609df072e4d;p=openbsd

head(1): validate all line count arguments

We need to validate all line count option arguments, not just the last
such argument found.

While here, switch to the default strtonum(3) error message format:

	<argument-name> is <errstr>: <argument-string>

Thread: https://marc.info/?l=openbsd-tech&m=163383023212104&w=2

ok millert@
---

diff --git a/usr.bin/head/head.c b/usr.bin/head/head.c
index ccf13720dc2..f0c10cd2666 100644
--- a/usr.bin/head/head.c
+++ b/usr.bin/head/head.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: head.c,v 1.21 2016/03/20 17:14:51 tb Exp $	*/
+/*	$OpenBSD: head.c,v 1.22 2021/10/10 15:57:25 cheloha Exp $	*/
 
 /*
  * Copyright (c) 1980, 1987 Regents of the University of California.
@@ -48,11 +48,11 @@ static void usage(void);
 int
 main(int argc, char *argv[])
 {
+	const char *errstr;
 	FILE	*fp;
 	long	cnt;
 	int	ch, firsttime;
 	long	linecnt = 10;
-	char	*p = NULL;
 	int	status = 0;
 
 	if (pledge("stdio rpath", NULL) == -1)
@@ -61,7 +61,9 @@ main(int argc, char *argv[])
 	/* handle obsolete -number syntax */
 	if (argc > 1 && argv[1][0] == '-' &&
 	    isdigit((unsigned char)argv[1][1])) {
-		p = argv[1] + 1;
+		linecnt = strtonum(argv[1] + 1, 1, LONG_MAX, &errstr);
+		if (errstr != NULL)
+			errx(1, "count is %s: %s", errstr, argv[1] + 1);
 		argc--;
 		argv++;
 	}
@@ -69,7 +71,9 @@ main(int argc, char *argv[])
 	while ((ch = getopt(argc, argv, "n:")) != -1) {
 		switch (ch) {
 		case 'n':
-			p = optarg;
+			linecnt = strtonum(optarg, 1, LONG_MAX, &errstr);
+			if (errstr != NULL)
+				errx(1, "count is %s: %s", errstr, optarg);
 			break;
 		default:
 			usage();
@@ -77,14 +81,6 @@ main(int argc, char *argv[])
 	}
 	argc -= optind, argv += optind;
 
-	if (p) {
-		const char *errstr;
-
-		linecnt = strtonum(p, 1, LONG_MAX, &errstr);
-		if (errstr)
-			errx(1, "line count %s: %s", errstr, p);
-	}
-
 	for (firsttime = 1; ; firsttime = 0) {
 		if (!*argv) {
 			if (!firsttime)