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Name

wcstok - split wide-character string into tokens

Library

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 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'\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). allbox; lbx lb lb T{ wcstok()
InterfaceAttributeValue
T}Thread safetyMT-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)) {
    ...
}

See Also

  1. strtok(3),
  2. wcschr(3)