lib/perror.c

   1 /* Print a message describing error code.
   2    Copyright (C) 2008-2025 Free Software Foundation, Inc.
   3    Written by Bruno Haible and Simon Josefsson.
   4
   5    This file is free software: you can redistribute it and/or modify
   6    it under the terms of the GNU Lesser General Public License as
   7    published by the Free Software Foundation; either version 2.1 of the
   8    License, or (at your option) any later version.
   9
  10    This file is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public License
  16    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  17
  18 #include <config.h>
  19
  20 /* Specification.  */
  21 #include <stdio.h>
  22
  23 #include <errno.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26
  27 #include "strerror-override.h"
  28
  29 /* Use the system functions, not the gnulib overrides in this file.  */
  30 #undef fprintf
  31
  32 void
  33 perror (const char *string)
  34 {
  35   char stackbuf[STACKBUF_LEN];
  36   int ret;
  37
  38   /* Our implementation guarantees that this will be a non-empty
  39      string, even if it returns EINVAL; and stackbuf should be sized
  40      large enough to avoid ERANGE.  */
  41   ret = strerror_r (errno, stackbuf, sizeof stackbuf);
  42   if (ret == ERANGE)
  43     abort ();
  44
  45   if (string != NULL && *string != '\0')
  46     fprintf (stderr, "%s: %s\n", string, stackbuf);
  47   else
  48     fprintf (stderr, "%s\n", stackbuf);
  49 }