src/stdlib/atoi.c

   1 #include <stdlib.h>
   2 #include <ctype.h>
   3
   4 int atoi(const char *s)
   5 {
   6         int n=0, neg=0;
   7         while (isspace(*s)) s++;
   8         switch (*s) {
   9         case '-': neg=1;
  10         case '+': s++;
  11         }
  12         /* Compute n as a negative number to avoid overflow on INT_MIN */
  13         while (isdigit(*s))
  14                 n = 10*n - (*s++ - '0');
  15         return neg ? n : -n;
  16 }