1                 : /* num2long.c: bcmath library file. */
       2                 : /*
       3                 :     Copyright (C) 1991, 1992, 1993, 1994, 1997 Free Software Foundation, Inc.
       4                 :     Copyright (C) 2000 Philip A. Nelson
       5                 : 
       6                 :     This library is free software; you can redistribute it and/or
       7                 :     modify it under the terms of the GNU Lesser General Public
       8                 :     License as published by the Free Software Foundation; either
       9                 :     version 2 of the License, or (at your option) any later version.
      10                 : 
      11                 :     This library is distributed in the hope that it will be useful,
      12                 :     but WITHOUT ANY WARRANTY; without even the implied warranty of
      13                 :     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      14                 :     Lesser General Public License for more details.  (COPYING.LIB)
      15                 : 
      16                 :     You should have received a copy of the GNU Lesser General Public
      17                 :     License along with this library; if not, write to:
      18                 : 
      19                 :       The Free Software Foundation, Inc.
      20                 :       59 Temple Place, Suite 330
      21                 :       Boston, MA 02111-1307 USA.
      22                 : 
      23                 :     You may contact the author by:
      24                 :        e-mail:  philnelson@acm.org
      25                 :       us-mail:  Philip A. Nelson
      26                 :                 Computer Science Department, 9062
      27                 :                 Western Washington University
      28                 :                 Bellingham, WA 98226-9062
      29                 :        
      30                 : *************************************************************************/
      31                 : 
      32                 : #include <config.h>
      33                 : #include <stdio.h>
      34                 : #include <assert.h>
      35                 : #include <stdlib.h>
      36                 : #include <ctype.h>
      37                 : #include <stdarg.h>
      38                 : #include "bcmath.h"
      39                 : #include "private.h"
      40                 : 
      41                 : /* Convert a number NUM to a long.  The function returns only the integer
      42                 :    part of the number.  For numbers that are too large to represent as
      43                 :    a long, this function returns a zero.  This can be detected by checking
      44                 :    the NUM for zero after having a zero returned. */
      45                 : 
      46                 : long
      47                 : bc_num2long (num)
      48                 :      bc_num num;
      49               5 : {
      50                 :   long val;
      51                 :   char *nptr;
      52                 :   int  index;
      53                 : 
      54                 :   /* Extract the int value, ignore the fraction. */
      55               5 :   val = 0;
      56               5 :   nptr = num->n_value;
      57              12 :   for (index=num->n_len; (index>0) && (val<=(LONG_MAX/BASE)); index--)
      58               7 :     val = val*BASE + *nptr++;
      59                 : 
      60                 :   /* Check for overflow.  If overflow, return zero. */
      61               5 :   if (index>0) val = 0;
      62               5 :   if (val < 0) val = 0;
      63                 : 
      64                 :   /* Return the value. */
      65               5 :   if (num->n_sign == PLUS)
      66               5 :     return (val);
      67                 :   else
      68               0 :     return (-val);
      69                 : }
      70                 :