freebsd-dev/lib/libc/locale/tolower.3

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.\"	@(#)tolower.3	8.1 (Berkeley) 6/4/93
.\" $FreeBSD$
.\"
.Dd June 4, 1993
.Dt TOLOWER 3
.Os
.Sh NAME
.Nm tolower
.Nd upper case to lower case letter conversion
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.Fd #include <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 SEE ALSO
.Xr isalnum 3 ,
.Xr isalpha 3 ,
.Xr isascii 3 ,
.Xr iscntrl 3 ,
.Xr isdigit 3 ,
.Xr isgraph 3 ,
.Xr islower 3 ,
.Xr isprint 3 ,
.Xr ispunct 3 ,
.Xr isspace 3 ,
.Xr isupper 3 ,
.Xr isxdigit 3 ,
.Xr multibyte 3 ,
.Xr stdio 3 ,
.Xr toascii 3 ,
.Xr toupper 3 ,
.Xr ascii 7
.Sh STANDARDS
The
.Fn tolower
function conforms to
.St -isoC .