bsd man page for strtok

STRTOK(3)						     Library Functions Manual							 STRTOK(3)

NAME
       strtok - string tokens

SYNOPSIS
       #include <string.h>

       char *
       strtok(str, sep)
       char *str;
       char *sep;

DESCRIPTION
       This interface is obsoleted by strsep(3).

       The  strtok() function is used to isolate sequential tokens in a null-terminated string, str .  These tokens are separated in the string by
       at least one of the characters in sep .	The first time that strtok() is called, str should be  specified;  subsequent  calls,  wishing	to
       obtain  further	tokens	from the same string, should pass a null pointer instead.  The separator string, sep , must be supplied each time,
       and may change between calls.

       The strtok() function returns a pointer to the beginning of each subsequent token in the string, after replacing the token  itself  with  a
       NUL character.  When no more tokens remain, a null pointer is returned.

SEE ALSO
       index(3), memchr(3), rindex(3), strchr(3), strcspn(3), strpbrk(3), strrchr(3), strsep(3), strspn(3), strstr(3

STANDARDS
       The strtok() function conforms to ANSI C X3.159-1989 (``ANSI C'').

BUGS
       There is no way to get tokens from multiple strings simultaneously.

       The  System  V strtok(), if handed a string containing only delimiter characters, will not alter the next starting point, so that a call to
       strtok() with a different (or empty) delimiter string may return a non-NULL value.  Since this implementation always alters the next start-
       ing point, such a sequence of calls would always return NULL.

4.4 Berkeley Distribution					 January 12, 1996							 STRTOK(3)