stdio-common/perror.c

   1 /* Copyright (C) 1991, 1992, 1993, 1997 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Library General Public License as
   6    published by the Free Software Foundation; either version 2 of the
   7    License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Library General Public License for more details.
  13
  14    You should have received a copy of the GNU Library General Public
  15    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  16    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17    Boston, MA 02111-1307, USA.  */
  18
  19 #include <stdio.h>
  20 #include <errno.h>
  21
  22 extern char *_strerror_internal __P ((int, char *buf, size_t));
  23
  24 /* Print a line on stderr consisting of the text in S, a colon, a space,
  25    a message describing the meaning of the contents of `errno' and a newline.
  26    If S is NULL or "", the colon and space are omitted.  */
  27 void
  28 perror (const char *s)
  29 {
  30   char buf[1024];
  31   int errnum = errno;
  32   const char *colon;
  33
  34   if (s == NULL || *s == '\0')
  35     s = colon = "";
  36   else
  37     colon = ": ";
  38
  39   (void) fprintf (stderr, "%s%s%s\n",
  40                   s, colon, _strerror_internal (errnum, buf, sizeof buf));
  41 }