stdio-common/perror.c

   1 /* Copyright (C) 1991-1993,1997,1998,2000,2001 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 Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the 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    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #include <errno.h>
  20 #include <stdio.h>
  21 #include <string.h>
  22 #include <wchar.h>
  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   const char *errstring;
  34
  35   if (s == NULL || *s == '\0')
  36     s = colon = "";
  37   else
  38     colon = ": ";
  39
  40   errstring = __strerror_r (errnum, buf, sizeof buf);
  41
  42 #ifdef USE_IN_LIBIO
  43   if (_IO_fwide (stderr, 0) > 0)
  44     (void) fwprintf (stderr, L"%s%s%s\n", s, colon, errstring);
  45   else
  46 #endif
  47     (void) fprintf (stderr, "%s%s%s\n", s, colon, errstring);
  48 }