dist/ntp/libntp/octtoint.c

   1 /*      $NetBSD$        */
   2
   3 /*
   4  * octtoint - convert an ascii string in octal to an unsigned
   5  *            long, with error checking
   6  */
   7 #include <stdio.h>
   8 #include <ctype.h>
   9
  10 #include "ntp_stdlib.h"
  11
  12 int
  13 octtoint(
  14         const char *str,
  15         u_long *ival
  16         )
  17 {
  18         register u_long u;
  19         register const char *cp;
  20
  21         cp = str;
  22
  23         if (*cp == '\0')
  24             return 0;
  25
  26         u = 0;
  27         while (*cp != '\0') {
  28                 if (!isdigit((int)*cp) || *cp == '8' || *cp == '9')
  29                     return 0;
  30                 if (u >= 0x20000000)
  31                     return 0;   /* overflow */
  32                 u <<= 3;
  33                 u += *cp++ - '0';       /* ascii dependent */
  34         }
  35         *ival = u;
  36         return 1;
  37 }