/*
 *  LIBML library - read, write and manipulate MATLAB MAT-files
 *  Copyright (C) 1994 Michael J. Maurer
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Library General Public
 *  License as published by the Free Software Foundation; either
 *  version 2 of the License, or (at your option) any later version.
 *
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Library General Public License for more details.
 *
 *  You should have received a copy of the GNU Library General Public
 *  License along with this library; if not, write to the Free
 *  Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 *  Michael Maurer <maurer@nova.stanford.edu>
 *  Durand Bldg - Room 232
 *  Stanford, CA 94305-4055
 *  (415) 723-1024
 */
/******************************************************************************
  error

A general-purpose error message routine, inspired by a similar GNU
function.  Before calling this function, set the value of 'progn' to be
the name of your program, e.g. "progn = argv[0]".  Optionally, set
'error_cleanup' to point to a function you want executed before abnormal
exit.

When error() is called, it prints the error message 'message' (a
printf-style format string) to stderr using the additional printf
arguments on the argument list.  If 'errnum' is nonzero, it is assumed
to have the value of an error code in <errno.h>, and error() prints the
corresponding error message.  If 'status' is nonzero, the function will
exit with status 'status', but only after calling error_cleanup() first
if it is non-NULL.  If status==0, error() returns after printing the
message.
******************************************************************************/

#include <stdio.h>
#include <stdarg.h>

void  (*error_cleanup)(int)     = NULL;
char  *progn                    = NULL;

void
error(int status,
      int errnum,
      char *message,
      ...)
{
   extern char *sys_errlist[];
   extern int sys_nerr;
   va_list args;

   if (progn)
      fprintf(stderr,"%s: ",progn);
   va_start(args,message);
   vfprintf(stderr,message,args);
   va_end(args);

   if (errnum > 0 && errnum < sys_nerr)
      fprintf(stderr,": \"%s\"",sys_errlist[errnum]);
   putc('\n',stderr);
   fflush(stderr);
   if (status) {
      if (error_cleanup)
         (*error_cleanup)(status);
      exit(status);
   }
}