NAME    [Toc]    [Back]

     strtok, strtok_r - string tokens

LIBRARY    [Toc]    [Back]

     Standard C Library (libc, -lc)

SYNOPSIS    [Toc]    [Back]

     #include <string.h>

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

     char *
     strtok_r(char *str, const char *sep, char **lasts);

DESCRIPTION    [Toc]    [Back]

     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 separator character itself
     with a NUL character.  Separator characters at the beginning of the
     string or at the continuation point are skipped so that zero length
     tokens are not returned.  When no more tokens remain, a null pointer is
     returned.

     The strtok_r() function implements the functionality of strtok() but is
     passed an additional argument, lasts, which points to a user-provided
     pointer which is used by strtok_r() to store state which needs to be kept
     between calls to scan the same string; unlike strtok(), it is not necessary
 to delineate tokenizing to a single string at a time when using
     strtok_r().

SEE ALSO    [Toc]    [Back]

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

STANDARDS    [Toc]    [Back]

     The strtok() function conforms to ANSI X3.159-1989 (``ANSI C'').  The
     strtok_r() function conforms to IEEE Std 1003.1c-1995 (``POSIX.1'').

BUGS    [Toc]    [Back]

     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 starting
 point, such a sequence of calls would always return NULL.

BSD                            February 3, 1994                            BSD