/**************************************************************************** **** File: error.c**** Author: Mike Borella**** Comments: Try to gracefully handle errors.  *******************************************************************************/#include <stdio.h>#include <stdarg.h>#include <string.h>#include <sys/types.h>#include <errno.h>#include "error.h"#include "config.h"int GWF_error_flag = 0;/* * This avoids a warning with glibc compilation  */#ifndef errnoextern int errno;#endif/* * If we have strerror() we won't use sys_errlist, so don't bother defining * it. */#ifndef HAVE_STRERRORextern char * sys_errlist[];#endif/*----------------------------------------------------------------------------**** Function: GWFi_strerror()**** Comments: Use strerror() if this system supports it. Roll our own otherwise.****----------------------------------------------------------------------------*/char *GWFi_strerror(int errnum){#ifdef HAVE_STRERROR  return (strerror(errnum));#else  extern int sys_nerr;  static char ebuf[20];    if ((int) errnum < sys_nerr)    return ((char *) sys_errlist[errnum]);  sprintf(ebuf, "Unknown error: %d", errnum);  return(ebuf);#endif}/*----------------------------------------------------------------------------**** GWF_error()**** Generic error dumping.  Here's how the arguments are used**** syserr: 0 is not an error from a system call, non-zero otherwise** filename: filename of the caller.  Optional.** line: line number of the caller.  Optional, set to 0 is filename and **       line number info is not to be printed****----------------------------------------------------------------------------*/void GWF_error(int syserr, char *filename, int line, const char *fmt, 	       va_list args){  /*   * Dump the error message   */  fprintf(stderr,"ERROR: ");  if (line)    fprintf(stderr, "%s line %d: ", filename, line);  vfprintf(stderr, fmt, args);  /*   * If this is a system error, print the errno info.  Otherwise, don't   */  if (syserr)    {      fprintf(stderr," (%d ", errno);      fprintf(stderr, "%s)\n", GWFi_strerror(errno));    }  else    fprintf(stderr, "\n");}/***************************************************************************** * Externally-visible functions are below here ****************************************************************************//*----------------------------------------------------------------------------**** GWF_error_fatal()**** General fatal error.****----------------------------------------------------------------------------*/void GWF_error_fatal(char *fmt, ...){  va_list       args;  va_start(args,fmt);  GWF_error(0, "", 0, fmt, args);  va_end(args);  abort();}/*----------------------------------------------------------------------------**** GWF_error_system()**** General system error.****----------------------------------------------------------------------------*/void GWF_error_system(char *fmt, ...){  va_list args;  va_start(args, fmt);  GWF_error(1, "", 0, fmt, args);  va_end(args);  abort();}/*----------------------------------------------------------------------------**** GWF_error_message()**** General non-terminal error.****----------------------------------------------------------------------------*/void GWF_error_message(char *fmt, ...){  va_list args;  va_start(args, fmt);  GWF_error(1, "", 0, fmt, args);  va_end(args);}