/* Search the character array s1 for the substring in character array s2.
Returns a pointer to that sbstring, or NULL. If s2 is of length zero,
returns s1.
*/
/* Search the character array s1 for the substring in character array s2.
Returns a pointer to that sbstring, or NULL. If s2 is of length zero,
returns s1.
*/
/* In a series of subsequent calls, parse a C string into tokens.
On the first call to strtok(), the first argument is a pointer to the to-be-
/* In a series of subsequent calls, parse a C string into tokens.
On the first call to strtok(), the first argument is a pointer to the to-be-