misc/error.c

   1 /* error.c -- error handler for noninteractive utilities
   2    Copyright (C) 1990, 91, 92, 93, 94, 95 Free Software Foundation, Inc.
   3
   4 This file is part of the GNU C Library.  Its master source is NOT part of
   5 the C library, however.  The master source lives in /gd/gnu/lib.
   6
   7 The GNU C Library is free software; you can redistribute it and/or
   8 modify it under the terms of the GNU Library General Public License as
   9 published by the Free Software Foundation; either version 2 of the
  10 License, or (at your option) any later version.
  11
  12 The GNU C Library is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15 Library General Public License for more details.
  16
  17 You should have received a copy of the GNU Library General Public
  18 License along with the GNU C Library; see the file COPYING.LIB.  If
  19 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  20 Cambridge, MA 02139, USA.  */
  21
  22 /* Written by David MacKenzie <djm@gnu.ai.mit.edu>.  */
  23
  24 #ifdef HAVE_CONFIG_H
  25 #include <config.h>
  26 #endif
  27
  28 #include <stdio.h>
  29
  30 #if HAVE_VPRINTF || HAVE_DOPRNT || _LIBC
  31 # if __STDC__
  32 #  include <stdarg.h>
  33 #  define VA_START(args, lastarg) va_start(args, lastarg)
  34 # else
  35 #  include <varargs.h>
  36 #  define VA_START(args, lastarg) va_start(args)
  37 # endif
  38 #else
  39 # define va_alist a1, a2, a3, a4, a5, a6, a7, a8
  40 # define va_dcl char *a1, *a2, *a3, *a4, *a5, *a6, *a7, *a8;
  41 #endif
  42
  43 #if STDC_HEADERS || _LIBC
  44 # include <stdlib.h>
  45 # include <string.h>
  46 #else
  47 void exit ();
  48 #endif
  49
  50 /* This variable is incremented each time `error' is called.  */
  51 unsigned int error_message_count;
  52
  53 /* If NULL, error will flush stdout, then print on stderr the program
  54    name, a colon and a space.  Otherwise, error will call this
  55    function without parameters instead.  */
  56 void (*error_print_progname) () = NULL;
  57
  58 #ifdef _LIBC
  59 #define program_name program_invocation_name
  60 #endif
  61
  62 /* The calling program should define program_name and set it to the
  63    name of the executing program.  */
  64 extern char *program_name;
  65
  66 #if HAVE_STRERROR || _LIBC
  67 # ifndef strerror               /* On some systems, strerror is a macro */
  68 char *strerror ();
  69 # endif
  70 #else
  71 static char *
  72 private_strerror (errnum)
  73      int errnum;
  74 {
  75   extern char *sys_errlist[];
  76   extern int sys_nerr;
  77
  78   if (errnum > 0 && errnum <= sys_nerr)
  79     return sys_errlist[errnum];
  80   return "Unknown system error";
  81 }
  82 #define strerror private_strerror
  83 #endif
  84
  85 /* Print the program name and error message MESSAGE, which is a printf-style
  86    format string with optional args.
  87    If ERRNUM is nonzero, print its corresponding system error message.
  88    Exit with status STATUS if it is nonzero.  */
  89 /* VARARGS */
  90
  91 void
  92 #if defined(VA_START) && __STDC__
  93 error (int status, int errnum, const char *message, ...)
  94 #else
  95 error (status, errnum, message, va_alist)
  96      int status;
  97      int errnum;
  98      char *message;
  99      va_dcl
 100 #endif
 101 {
 102 #ifdef VA_START
 103   va_list args;
 104 #endif
 105
 106   if (error_print_progname)
 107     (*error_print_progname) ();
 108   else
 109     {
 110       fflush (stdout);
 111       fprintf (stderr, "%s: ", program_name);
 112     }
 113
 114 #ifdef VA_START
 115   VA_START (args, message);
 116 # if HAVE_VPRINTF || _LIBC
 117   vfprintf (stderr, message, args);
 118 # else
 119   _doprnt (message, args, stderr);
 120 # endif
 121   va_end (args);
 122 #else
 123   fprintf (stderr, message, a1, a2, a3, a4, a5, a6, a7, a8);
 124 #endif
 125
 126   ++error_message_count;
 127
 128   if (errnum)
 129     fprintf (stderr, ": %s", strerror (errnum));
 130   putc ('\n', stderr);
 131   fflush (stderr);
 132   if (status)
 133     exit (status);
 134 }