usr.bin/perror/perror.c

   1 /*-
   2  * Copyright (c) 2009 Advanced Computing Technologies LLC
   3  * Written by: George V. Neville-Neil <gnn@FreeBSD.org>
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  25  * SUCH DAMAGE.
  26  *
  27  * $FreeBSD: head/usr.bin/perror/perror.c 199642 2009-11-22 05:17:22Z edwin $
  28  */
  29
  30 #include <stdio.h>
  31 #include <stdlib.h>
  32 #include <string.h>
  33 #include <err.h>
  34 #include <locale.h>
  35 #include <sys/errno.h>
  36
  37 static void usage(void);
  38
  39 int
  40 main(int argc, char **argv)
  41 {
  42         char *cp;
  43         char *errstr;
  44         long errnum;
  45
  46         setlocale(LC_MESSAGES, "");
  47         if (argc != 2)
  48                 usage();
  49
  50         errno = 0;
  51
  52         errnum = strtol(argv[1], &cp, 0);
  53
  54         if (errno != 0)
  55                 err(1, NULL);
  56
  57         if ((errstr = strerror(errnum)) == NULL)
  58                 err(1, NULL);
  59
  60         printf("%s\n", errstr);
  61
  62         exit(0);
  63 }
  64
  65 static void
  66 usage(void)
  67 {
  68         fprintf(stderr, "usage: perror number\n");
  69         exit(1);
  70 }
  71