man3/wcsncasecmp.3

.\" Copyright (c) Bruno Haible <haible@clisp.cons.org>
.\"
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.\" 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
.\"
.TH WCSNCASECMP 3 2021-03-22 "GNU" "Linux Programmer's Manual"
.SH NAME
wcsncasecmp \- compare two fixed-size wide-character strings, ignoring case
.SH SYNOPSIS
.nf
.B #include <wchar.h>
.PP
.BI "int wcsncasecmp(const wchar_t *" s1 ", const wchar_t *" s2 ", size_t " n );
.fi
.PP
.RS -4
Feature Test Macro Requirements for glibc (see
.BR feature_test_macros (7)):
.RE
.PP
.BR wcsncasecmp ():
.nf
    Since glibc 2.10:
        _POSIX_C_SOURCE >= 200809L
    Before glibc 2.10:
        _GNU_SOURCE
.fi
.SH DESCRIPTION
The
.BR wcsncasecmp ()
function is the wide-character equivalent of the
.BR strncasecmp (3)
function.
It compares the wide-character string pointed to
by
.I s1
and the wide-character string
pointed to by
.IR s2 ,
but at most
.I n
wide characters from each string, ignoring case differences
.RB ( towupper (3),
.BR towlower (3)).
.SH RETURN VALUE
The
.BR wcsncasecmp ()
function returns zero
if the wide-character strings at
.I s1
and
.IR s2 ,
truncated to at most length
.IR n ,
are equal except
for case distinctions.
It returns a positive integer if truncated
.I s1
is
greater than truncated
.IR s2 ,
ignoring case.
It returns a negative integer
if truncated
.I s1
is smaller than truncated
.IR s2 ,
ignoring case.
.SH VERSIONS
The
.BR wcsncasecmp ()
function is provided in glibc since version 2.1.
.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 wcsncasecmp ()
T}	Thread safety	MT-Safe locale
.TE
.hy
.ad
.sp 1
.SH CONFORMING TO
POSIX.1-2008.
This function is not specified in POSIX.1-2001,
and is not widely available on other systems.
.SH NOTES
The behavior of
.BR wcsncasecmp ()
depends on the
.B LC_CTYPE
category of the
current locale.
.SH SEE ALSO
.BR strncasecmp (3),
.BR wcsncmp (3)