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.\"     @(#)islower.3	8.1 (Berkeley) 6/4/93
.\" $FreeBSD: src/lib/libc/locale/islower.3,v 1.22 2009/09/04 07:44:58 des Exp $
.\"
.Dd July 17, 2005
.Dt ISLOWER 3
.Os
.Sh NAME
.Nm islower
.Nd lower-case character test
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In ctype.h
.Ft int
.Fn islower "int c"
.Sh DESCRIPTION
The
.Fn islower
function tests for any lower-case letters.
The value of the argument must be representable as an
.Vt "unsigned char"
or the value of
.Dv EOF .
.Pp
In the ASCII character set, this includes the following characters
(with their numeric values shown in octal):
.Pp
.Bl -column \&000_``0''__ \&000_``0''__ \&000_``0''__ \&000_``0''__ \&000_``0''__
.It "\&141\ ``a'' \t142\ ``b'' \t143\ ``c'' \t144\ ``d'' \t145\ ``e''"
.It "\&146\ ``f'' \t147\ ``g'' \t150\ ``h'' \t151\ ``i'' \t152\ ``j''"
.It "\&153\ ``k'' \t154\ ``l'' \t155\ ``m'' \t156\ ``n'' \t157\ ``o''"
.It "\&160\ ``p'' \t161\ ``q'' \t162\ ``r'' \t163\ ``s'' \t164\ ``t''"
.It "\&165\ ``u'' \t166\ ``v'' \t167\ ``w'' \t170\ ``x'' \t171\ ``y''"
.It "\&172\ ``z''"
.El
.Sh RETURN VALUES
The
.Fn islower
function returns zero if the character tests false and
returns non-zero if the character tests true.
.Sh COMPATIBILITY
The
.Bx 4.4
extension of accepting arguments outside of the range of the
.Vt "unsigned char"
type in locales with large character sets is considered obsolete
and may not be supported in future releases.
The
.Fn iswlower
function should be used instead.
.Sh SEE ALSO
.Xr ctype 3 ,
.Xr isalnum_l 3 ,
.Xr iswlower 3 ,
.Xr tolower 3 ,
.Xr ascii 7
.Sh STANDARDS
The
.Fn islower
function conforms to
.St -isoC .