'\" t
.\" Copyright (c) Bruno Haible <haible@clisp.cons.org>
.\"
.\" SPDX-License-Identifier: GPL-2.0-or-later
.\"
.\" References consulted:
.\"   GNU glibc-2 source code and manual
.\"   Dinkumware C library reference http://www.dinkumware.com/
.\"   OpenGroup's Single UNIX specification http://www.UNIX-systems.org/online.html
.\"   ISO/IEC 9899:1999
.\"
.TH wcsspn 3 2023-03-30 "Linux man-pages 6.04"
.SH NAME
wcsspn \- get length of a prefix wide-character substring
.SH LIBRARY
Standard C library
.RI ( libc ", " \-lc )
.SH SYNOPSIS
.nf
.B #include <wchar.h>
.PP
.BI "size_t wcsspn(const wchar_t *" wcs ", const wchar_t *" accept );
.fi
.SH DESCRIPTION
The
.BR wcsspn ()
function is the wide-character equivalent of the
.BR strspn (3)
function.
It determines the length of the longest initial segment of
.I wcs
which consists entirely of wide-characters listed in
.IR accept .
In other
words, it searches for the first occurrence in the wide-character string
.I wcs
of a wide-character not contained in the wide-character string
.IR accept .
.SH RETURN VALUE
The
.BR wcsspn ()
function returns the number of
wide characters in the longest
initial segment of
.I wcs
which consists entirely of wide-characters listed
in
.IR accept .
In other words, it returns the position of the first
occurrence in the wide-character string
.I wcs
of a wide-character not
contained in the wide-character string
.IR accept ,
or
.I wcslen(wcs)
if there is none.
.SH ATTRIBUTES
For an explanation of the terms used in this section, see
.BR attributes (7).
.ad l
.nh
.TS
allbox;
lbx lb lb
l l l.
Interface	Attribute	Value
T{
.BR wcsspn ()
T}	Thread safety	MT-Safe
.TE
.hy
.ad
.sp 1
.SH STANDARDS
C11, POSIX.1-2008.
.SH HISTORY
POSIX.1-2001, C99.
.SH SEE ALSO
.BR strspn (3),
.BR wcscspn (3)