php-src/ext/bcmath/libbcmath/src/num2long.c

71 lines
2.1 KiB
C

/* num2long.c: bcmath library file. */
/*
Copyright (C) 1991, 1992, 1993, 1994, 1997 Free Software Foundation, Inc.
Copyright (C) 2000 Philip A. Nelson
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser 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
Lesser General Public License for more details. (COPYING.LIB)
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to:
The Free Software Foundation, Inc.
59 Temple Place, Suite 330
Boston, MA 02111-1307 USA.
You may contact the author by:
e-mail: philnelson@acm.org
us-mail: Philip A. Nelson
Computer Science Department, 9062
Western Washington University
Bellingham, WA 98226-9062
*************************************************************************/
#include <config.h>
#include <stdio.h>
#include <assert.h>
#include <stdlib.h>
#include <ctype.h>
#include <stdarg.h>
#include "bcmath.h"
#include "private.h"
/* Convert a number NUM to a long. The function returns only the integer
part of the number. For numbers that are too large to represent as
a long, this function returns a zero. This can be detected by checking
the NUM for zero after having a zero returned. */
long
bc_num2long (num)
bc_num num;
{
long val;
char *nptr;
int index;
/* Extract the int value, ignore the fraction. */
val = 0;
nptr = num->n_value;
for (index=num->n_len; (index>0) && (val<=(LONG_MAX/BASE)); index--)
val = val*BASE + *nptr++;
/* Check for overflow. If overflow, return zero. */
if (index>0) val = 0;
if (val < 0) val = 0;
/* Return the value. */
if (num->n_sign == PLUS)
return (val);
else
return (-val);
}