#include /* atoi: convert s to integer; version 2 */ int atoi(char s[]) { int i, n, sign; for (i = 0; isspace(s[i]); i++) /* skip white space */ ; sign = (s[i] == '-') ? -1 : 1; if (s[i] == '+' || s[i] == '-') /* skip sign */ i++; for (n = 0; isdigit(s[i]); i++) n = 10 * n + (s[i] - '0'); return sign * n; }