#include <string.h>
char *strtok(char *p, const char *q);
strtok() breaks the string p into tokens, separated by at least one character appearing in q. The first time, call strtok() using the original string as the first parameter. Afterwards, pass NULL as first parameter: strtok() continues from its previous stopping position. strtok() saves the string p unless it is NULL.
A pointer to the token found, or NULL, if no token was found.