xref: /freebsd/usr.bin/perror/perror.c (revision aa1a8ff2d6dbc51ef058f46f3db5a8bb77967145)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2009 Hudson River Trading LLC
5  * Written by: George V. Neville-Neil <gnn@FreeBSD.org>
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 #include <stdio.h>
32 #include <stdlib.h>
33 #include <string.h>
34 #include <err.h>
35 #include <locale.h>
36 #include <sys/errno.h>
37 
38 static void usage(void) __dead2;
39 
40 int
41 main(int argc, char **argv)
42 {
43 	char *cp;
44 	char *errstr;
45 	long errnum;
46 
47 	(void) setlocale(LC_MESSAGES, "");
48 	if (argc != 2)
49 		usage();
50 
51 	errno = 0;
52 
53 	errnum = strtol(argv[1], &cp, 0);
54 
55 	if (errno != 0)
56 		err(1, NULL);
57 
58 	if ((errstr = strerror(errnum)) == NULL)
59 		err(1, NULL);
60 
61 	printf("%s\n", errstr);
62 
63 	exit(0);
64 }
65 
66 static void
67 usage(void)
68 {
69 	fprintf(stderr, "usage: perror number\n");
70 	exit(1);
71 }
72 
73