lib/ansi/atol.c

   1 /*
   2  * (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands.
   3  * See the copyright notice in the ACK home directory, in the file "Copyright".
   4  */
   5 /* $Header$ */
   6
   7 #include        <ctype.h>
   8 #include        <stdlib.h>
   9
  10 /* We do not use strtol here for backwards compatibility in behaviour on
  11    overflow.
  12 */
  13 long
  14 atol(register const char *nptr)
  15 {
  16         long total = 0;
  17         int minus = 0;
  18
  19         while (isspace(*nptr)) nptr++;
  20         if (*nptr == '+') nptr++;
  21         else if (*nptr == '-') {
  22                 minus = 1;
  23                 nptr++;
  24         }
  25         while (isdigit(*nptr)) {
  26                 total *= 10;
  27                 total += (*nptr++ - '0');
  28         }
  29         return minus ? -total : total;
  30 }