xref: /freebsd/lib/libc/locale/tolower.3 (revision 9981ef2702b1f3f392f1059ce4c97314db3afdff)

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.\"	@(#)tolower.3	8.1 (Berkeley) 6/4/93
.\" $FreeBSD$
.\"
.Dd October 3, 2002
.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
Although
.Fn tolower
accepts arguments outside of the range of the
.Vt "unsigned char"
type in locales with large character sets,
this is a
.Bx 4.4
extension and the
.Fn towlower
function should be used instead for maximum portability.
.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 .