NAME

wcsspn — get the length of a wide substring

SYNOPSIS

#include <wchar.h>

size_t wcsspn(const wchar_t *ws1, const wchar_t *ws2);


DESCRIPTION

^[CX] The functionality described on this reference page is aligned with the ISO C standard. Any conflict between the requirements described here and the ISO C standard is unintentional. This volume of POSIX.1-2024 defers to the ISO C standard.

The wcsspn() function shall compute the length (in wide characters) of the maximum initial segment of the wide-character string pointed to by ws1 which consists entirely of wide-character codes from the wide-character string pointed to by ws2.

^[CX] The wcsspn() function shall not change the setting of errno on valid input.

RETURN VALUE

The wcsspn() function shall return the length of the initial substring of ws1; no return value is reserved to indicate an error.

ERRORS

No errors are defined.

EXAMPLES

None.

APPLICATION USAGE

None.

RATIONALE

None.

FUTURE DIRECTIONS

None.

SEE ALSO

wcscspn

XBD <wchar.h>

CHANGE HISTORY

First released in Issue 4. Derived from the MSE working draft.

Issue 5

The RETURN VALUE section is updated to indicate that wcsspn() returns the length of ws1 rather that ws1 itself.

Issue 8

Austin Group Defect 448 is applied, adding a requirement that wcsspn() does not change the setting of errno on valid input.