'\" 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 iswlower 3 2024-05-02 "Linux man-pages 6.9.1" .SH NAME iswlower \- test for lowercase wide character .SH LIBRARY Standard C library .RI ( libc ", " \-lc ) .SH SYNOPSIS .nf .B #include .P .BI "int iswlower(wint_t " wc ); .fi .SH DESCRIPTION The .BR iswlower () function is the wide-character equivalent of the .BR islower (3) function. It tests whether .I wc is a wide character belonging to the wide-character class "lower". .P The wide-character class "lower" is a subclass of the wide-character class "alpha", and therefore also a subclass of the wide-character class "alnum", of the wide-character class "graph" and of the wide-character class "print". .P Being a subclass of the wide-character class "print", the wide-character class "lower" is disjoint from the wide-character class "cntrl". .P Being a subclass of the wide-character class "graph", the wide-character class "lower" is disjoint from the wide-character class "space" and its subclass "blank". .P Being a subclass of the wide-character class "alnum", the wide-character class "lower" is disjoint from the wide-character class "punct". .P Being a subclass of the wide-character class "alpha", the wide-character class "lower" is disjoint from the wide-character class "digit". .P The wide-character class "lower" contains at least those characters .I wc which are equal to .I towlower(wc) and different from .IR towupper(wc) . .P The wide-character class "lower" always contains at least the letters \[aq]a\[aq] to \[aq]z\[aq]. .SH RETURN VALUE The .BR iswlower () function returns nonzero if .I wc is a wide character belonging to the wide-character class "lower". Otherwise, it returns zero. .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 iswlower () T} Thread safety MT-Safe locale .TE .SH STANDARDS C11, POSIX.1-2008. .SH HISTORY POSIX.1-2001, C99. .SH NOTES The behavior of .BR iswlower () depends on the .B LC_CTYPE category of the current locale. .P This function is not very appropriate for dealing with Unicode characters, because Unicode knows about three cases: upper, lower, and title case. .SH SEE ALSO .BR islower (3), .BR iswctype (3), .BR towlower (3)