stdio/perror.c

   1 /* Copyright (C) 1991, 1992, 1993 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
  16 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  17 Cambridge, MA 02139, USA.  */
  18
  19 #include <ansidecl.h>
  20 #include <stdio.h>
  21 #include <errno.h>
  22
  23 extern char *_strerror_internal __P ((int, char buf[1024]));
  24
  25 /* Print a line on stderr consisting of the text in S, a colon, a space,
  26    a message describing the meaning of the contents of `errno' and a newline.
  27    If S is NULL or "", the colon and space are omitted.  */
  28 void
  29 DEFUN(perror, (s), register CONST char *s)
  30 {
  31   char buf[1024];
  32   int errnum = errno;
  33   CONST char *colon;
  34
  35   if (s == NULL || *s == '\0')
  36     s = colon = "";
  37   else
  38     colon = ": ";
  39
  40   (void) fprintf (stderr, "%s%s%s\n",
  41                   s, colon, _strerror_internal (errnum, buf));
  42 }