'\" t .\" Copyright (c) Bruno Haible .\" .\" 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 2024-05-02 "Linux man-pages 6.8" .SH NAME wcsspn \- get length of a prefix wide-character substring .SH LIBRARY Standard C library .RI ( libc ", " \-lc ) .SH SYNOPSIS .nf .B #include .P .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). .TS allbox; lbx lb lb l l l. Interface Attribute Value T{ .na .nh .BR wcsspn () T} Thread safety MT-Safe .TE .SH STANDARDS C11, POSIX.1-2008. .SH HISTORY POSIX.1-2001, C99. .SH SEE ALSO .BR strspn (3), .BR wcscspn (3)