v4.0/src/CMD/FC/NTOI.C

   1 /* convert an arbitrary based number to an integer */
   2
   3 #include <ctype.h>
   4 #include "tools.h"
   5
   6 /* p points to characters, return -1 if no good characters found
   7  * and base is 2 <= base <= 16
   8  */
   9 int ntoi (p, base)
  10 char *p;
  11 int base;
  12 {
  13     register int i, c;
  14     flagType fFound;
  15
  16     if (base < 2 || base > 16)
  17         return -1;
  18     i = 0;
  19     fFound = FALSE;
  20     while (c = *p++) {
  21         c = tolower (c);
  22         if (!isxdigit (c))
  23             break;
  24         if (c <= '9')
  25             c -= '0';
  26         else
  27             c -= 'a'-10;
  28         if (c >= base)
  29             break;
  30         i = i * base + c;
  31         fFound = TRUE;
  32         }
  33     if (fFound)
  34         return i;
  35     else
  36         return -1;
  37 }