libc/stdio/perror.c

   1 /* Copyright (C) 2004       Manuel Novoa III    <mjn3@codepoet.org>
   2  *
   3  * GNU Library General Public License (LGPL) version 2 or later.
   4  *
   5  * Dedicated to Toni.  See uClibc/DEDICATION.mjn3 for details.
   6  */
   7
   8 #include "_stdio.h"
   9
  10
  11 #ifdef __UCLIBC_MJN3_ONLY__
  12 #warning CONSIDER: Increase buffer size for error message (non-%m case)?
  13 #endif
  14
  15 void perror(register const char *s)
  16 {
  17         /* If the program is calling perror, it's a safe bet that printf and
  18          * friends are used as well.  It is also possible that the calling
  19          * program could buffer stderr, or reassign it. */
  20
  21         register const char *sep;
  22
  23         sep = ": ";
  24         if (!(s && *s)) {                       /* Caller did not supply a prefix message */
  25                 s = (sep += 2);                 /* or passed an empty string. */
  26         }
  27
  28 #ifdef __UCLIBC_HAS_PRINTF_M_SPEC__
  29         fprintf(stderr, "%s%s%m\n", s, sep); /* Use the gnu %m feature. */
  30 #else
  31         {
  32                 char buf[64];
  33                 fprintf(stderr, "%s%s%s\n", s, sep,
  34                                 __glibc_strerror_r(errno, buf, sizeof(buf)));
  35         }
  36 #endif
  37 }
  38 libc_hidden_def(perror)