Converts wide-character strings to tokens.
Standard C Library (libc.a)
A sequence of calls to the wcstok subroutine breaks the wide-character string pointed to by WcString1 into a sequence of tokens, each of which is delimited by a wide-character code from the wide-character string pointed to by WcString2. The third argument points to a caller-provided wchar_t pointer where wcstok stores information necessary for it to continue scanning the same wide-character string.
The first call in the sequence has WcString1 as its first argument and is followed by calls with a nullpointer as their first argument. The separator string pointed to by WcString2 may be different from call to call.
The first call in the sequence searches the wide-character string pointed to by WcString1 for the first wide-character code that is not contained in the current separator string pointed to by WcString2. If no such wide-character code is found, then there are no tokens in the wide-character string pointed to by WcString1 and wcstok returns a null pointer. If such a wide-character code is found, it is the start of the first token.
The wcstok subroutine then searches from there for a wide-character code that is contained in the current separator string. If no such wide-character code is found, the current token extends to the end of the wide-character string pointed to by WcString1, and subsequent searches for a token returns a null pointer. If such a wide-character code is found, it is overwritten by a null wide-character, which terminates the current token. The wcstok subroutine saves a pointer to the following wide-character code, from which the next search for a token starts.
Each subsequent call, with a null pointer as the value of the first argument, starts searching from the saved pointer and behaves as described above.
The implementation behaves as if no function calls wcstok.
| Item | Description |
|---|---|
| ptr | Contains a pointer to a caller-provided wchar_t pointer where wcstok stores information necessary for it to continue scanning the same wide-character string. |
| WcString1 | Contains a pointer to the wide-character string to be searched. |
| WcString2 | Contains a pointer to the string of wide-character token delimiters. |
Upon successful completion, wcstok returns a pointer to the first wide-character code of a token. Otherwise, if there is no token, wcstok returns a null pointer.
To convert a wide-character string to tokens, use the following:
#include <wchar.h>
#include <locale.h>
#include <stdlib.h>
main()
{
wchar_t WCString1[] = L"?a???b,,,#c";
wchar_t *ptr;
wchar_t *pwcs;
(void)setlocale(LC_ALL, "");
pwcs = wcstok(WCString1, L"?", &ptr);
/* pwcs points to the token L"a"*/
pwcs = wcstok((wchar_t *)NULL, L",", &ptr);
/* pwcs points to the token L"??b"*/
pwcs = wcstok( (wchar_t *)NULL, L"#,", &ptr);
/* pwcs points to the token L"c"*/
}