atoi, atol---string to integer#include <stdlib.h> int atoi(const char *s); long atol(const char *s);Description
atoi converts the initial portion of a string to an int.
atol converts the initial portion of a string to a long.
atoi(s) is implemented as (int)strtol(s, NULL, 10).
atol(s) is implemented as strtol(s, NULL, 10).
Returns
The functions return the converted value, if any. If no conversion was
made, 0 is returned.
Portability
atoi is ANSI.
No supporting OS subroutines are required.