wcstok - Man Page

split wide-character string into tokens


Standard C library (libc, -lc)


#include <wchar.h>

wchar_t *wcstok(wchar_t *restrict wcs, const wchar_t *restrict delim,
                wchar_t **restrict ptr);


The wcstok() function is the wide-character equivalent of the strtok(3) function, with an added argument to make it multithread-safe. It can be used to split a wide-character string wcs into tokens, where a token is defined as a substring not containing any wide-characters from delim.

The search starts at wcs, if wcs is not NULL, or at *ptr, if wcs is NULL. First, any delimiter wide-characters are skipped, that is, the pointer is advanced beyond any wide-characters which occur in delim. If the end of the wide-character string is now reached, wcstok() returns NULL, to indicate that no tokens were found, and stores an appropriate value in *ptr, so that subsequent calls to wcstok() will continue to return NULL. Otherwise, the wcstok() function recognizes the beginning of a token and returns a pointer to it, but before doing that, it zero-terminates the token by replacing the next wide-character which occurs in delim with a null wide character (L'\0'), and it updates *ptr so that subsequent calls will continue searching after the end of recognized token.

Return Value

The wcstok() function returns a pointer to the next token, or NULL if no further token was found.


For an explanation of the terms used in this section, see attributes(7).

wcstok()Thread safetyMT-Safe


C11, POSIX.1-2008.


POSIX.1-2001, C99.


The original wcs wide-character string is destructively modified during the operation.


The following code loops over the tokens contained in a wide-character string.

wchar_t *wcs = ...;
wchar_t *token;
wchar_t *state;
for (token = wcstok(wcs, L" \t\n", &state);
    token != NULL;
    token = wcstok(NULL, L" \t\n", &state)) {

See Also

strtok(3), wcschr(3)

Referenced By

signal-safety(7), strtok(3).

2023-10-31 Linux man-pages 6.7