Name
wcstok - split wide-character string into tokensLibrary
Standard C library ( libc ", " -lc )Synopsis
#include <wchar.h> wchar_t *wcstok(wchar_t *restrict wcs \
", const wchar_t *restrict " delim , wchar_t **restrict ptr );
Description
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 fromdelim
. 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'\e0'), 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.Attributes
For an explanation of the terms used in this section, see attributes(7).Interface | Attribute | Value |
T} | Thread safety | MT-Safe |
Standards
C11, POSIX.1-2008.History
POSIX.1-2001, C99.Notes
The original wcs wide-character string is destructively modified during the operation.Examples
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" \et\en", &state); token != NULL; token = wcstok(NULL, L" \et\en", &state)) { ... }