xref: /freebsd/lib/libc/locale/tolower.3 (revision b9b90a131248967679ea3943c6481203add07695)

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.\"	@(#)tolower.3	8.1 (Berkeley) 6/4/93
.\" $FreeBSD$
.\"
.Dd August 21, 2004
.Dt TOLOWER 3
.Os
.Sh NAME
.Nm tolower
.Nd upper case to lower case letter conversion
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In ctype.h
.Ft int
.Fn tolower "int c"
.Sh DESCRIPTION
The
.Fn tolower
function converts an upper-case letter to the corresponding lower-case
letter.
For single C
.Va char Ns s
locales (see
.Xr multibyte 3 )
the value of the argument is
representable as an
.Li unsigned char
or the value of
.Dv EOF .
.Sh RETURN VALUES
If the argument is an upper-case letter, the
.Fn tolower
function returns the corresponding lower-case letter if there is
one; otherwise the argument is returned unchanged.
.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 towlower
function should be used instead.
.Sh SEE ALSO
.Xr ctype 3 ,
.Xr islower 3 ,
.Xr multibyte 3 ,
.Xr towlower 3
.Sh STANDARDS
The
.Fn tolower
function conforms to
.St -isoC .