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/*
* math_error - a simple libcalc math error routine
*
* Copyright (C) 1999 Landon Curt Noll
*
* Calc is open software; you can redistribute it and/or modify it under
* the terms of the version 2.1 of the GNU Lesser General Public License
* as published by the Free Software Foundation.
*
* Calc 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 Lesser General
* Public License for more details.
*
* A copy of version 2.1 of the GNU Lesser General Public License is
* distributed with calc under the filename COPYING-LGPL. You should have
* received a copy with calc; if not, write to Free Software Foundation, Inc.
* 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
*
* @(#) $Revision: 29.3 $
* @(#) $Id: math_error.c,v 29.3 2006/06/02 09:52:22 chongo Exp $
* @(#) $Source: /usr/local/src/cmd/calc/RCS/math_error.c,v $
*
* Under source code control: 1994/08/03 05:08:22
* File existed as early as: 1994
*
* chongo <was here> /\oo/\ http://www.isthe.com/chongo/
* Share and enjoy! :-) http://www.isthe.com/chongo/tech/comp/calc/
*/
/*
* Your program MUST provide a function called math_error. This is called
* by the math routines on an error condition, such as malloc failures or a
* division by zero. The routine is called in the manner of printf, with a
* format string and optional arguments.
*
* By default, this routine simply prints a message to stderr and then exits.
*
* If one sets up calc_jmp_buf, and then sets calc_jmp to non-zero then
* this routine will longjmp back (with the value of calc_jmp) instead.
* In addition, the last calc error message will be found in calc_error;
* this error is not printed to sttderr.
*
* For example:
*
* #include <setjmp.h>
*
* extern jmp_buf calc_jmp_buf;
* extern int calc_jmp;
* extern char *calc_error;
* int error;
*
* ...
*
* if ((error = setjmp(calc_jmp_buf)) != 0) {
*
* (* reinitialize calc after a longjmp *)
* reinitialize();
*
* (* report the error *)
* printf("Ouch: %s\n", calc_error);
* }
* calc_jmp = 1;
*/
#include <stdio.h>
#include <setjmp.h>
#include "args.h"
#include "calc.h"
#include "math_error.h"
/*
* error jump point we will longjmp to this jmp_buf if calc_jmp is non-zero
*/
jmp_buf calc_jmp_buf;
int calc_jmp = 0; /* non-zero => use calc_jmp_buf */
char calc_error[MAXERROR+1]; /* last calc error message */
/*
* math_error - print a math error and exit
*/
void
math_error(char *fmt, ...)
{
va_list ap;
/*
* format the error
*/
#ifdef VARARGS
va_start(ap);
#else
va_start(ap, fmt);
#endif
vsnprintf(calc_error, MAXERROR, fmt, ap);
va_end(ap);
calc_error[MAXERROR] = '\0';
/*
* if we should longjmp, so do
*/
if (calc_jmp != 0) {
longjmp(calc_jmp_buf, calc_jmp);
}
/*
* print error message and edit
*/
(void) fflush(stdout);
(void) fflush(stderr);
fprintf(stderr, "%s\n", calc_error);
fputc('\n', stderr);
libcalc_call_me_last();
exit(1);
}
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