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.\"	@(#)toupper.3	8.1 (Berkeley) 6/4/93
.\" $FreeBSD: src/lib/libc/locale/toupper.3,v 1.21 2009/09/04 07:44:58 des Exp $
.\"
.Dd July 17, 2005
.Dt TOUPPER 3
.Os
.Sh NAME
.Nm toupper ,
.Nm toupper_l
.Nd lower case to upper case letter conversion
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In ctype.h
.Ft int
.Fo toupper
.Fa "int c"
.Fc
.In ctype.h
.In xlocale.h
.Ft int
.Fo toupper_l
.Fa "int c"
.Fa "locale_t loc"
.Fc
.Sh DESCRIPTION
The
.Fn toupper
function converts a lower-case letter to the corresponding
upper-case letter.
The argument must be representable as an
.Vt "unsigned char"
or the value of
.Dv EOF .
.Pp
Although the
.Fn toupper
function uses the current locale, the
.Fn toupper_l
function may be passed a locale directly. See
.Xr xlocale 3
for more information.
.Sh RETURN VALUES
If the argument is a lower-case letter, the
.Fn toupper
function returns the corresponding upper-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 towupper
function should be used instead.
.Sh SEE ALSO
.Xr ctype 3 ,
.Xr isupper 3 ,
.Xr towupper 3 ,
.Xr xlocale 3
.Sh STANDARDS
The
.Fn toupper
function conforms to
.St -isoC .