HOME

Mini Shell 1.0
Current File : //usr/share/man/overrides/en/man3/toupper.3
.\" Copyright (c) 1993 by Thomas Koenig (ig25@rz.uni-karlsruhe.de)
.\"
.\" %%%LICENSE_START(VERBATIM)
.\" Permission is granted to make and distribute verbatim copies of this
.\" manual provided the copyright notice and this permission notice are
.\" preserved on all copies.
.\"
.\" Permission is granted to copy and distribute modified versions of this
.\" manual under the conditions for verbatim copying, provided that the
.\" entire resulting derived work is distributed under the terms of a
.\" permission notice identical to this one.
.\"
.\" Since the Linux kernel and libraries are constantly changing, this
.\" manual page may be incorrect or out-of-date.  The author(s) assume no
.\" responsibility for errors or omissions, or for damages resulting from
.\" the use of the information contained herein.  The author(s) may not
.\" have taken the same level of care in the production of this manual,
.\" which is licensed free of charge, as they might when working
.\" professionally.
.\"
.\" Formatted or processed versions of this manual, if unaccompanied by
.\" the source, must acknowledge the copyright and authors of this work.
.\" %%%LICENSE_END
.\"
.\" Modified Sat Jul 24 17:45:39 1993 by Rik Faith (faith@cs.unc.edu)
.\" Modified 2000-02-13 by Nicol�s Lichtmaier <nick@debian.org>
.TH TOUPPER 3  1993-04-04 "GNU" "Linux Programmer's Manual"
.SH NAME
toupper, tolower \- convert letter to upper or lower case
.SH SYNOPSIS
.nf
.B #include <ctype.h>
.sp
.BI "int toupper(int " "c" );
.br
.BI "int tolower(int " "c" );
.fi
.SH DESCRIPTION
.BR toupper ()
converts the letter
.I c
to upper case, if possible.
.PP
.BR tolower ()
converts the letter
.I c
to lower case, if possible.
.PP
If
.I c
is not an
.I "unsigned char"
value, or
.BR EOF ,
the behavior of these functions
is undefined.
.SH RETURN VALUE
The value returned is that of the converted letter, or
.I c
if the conversion was not possible.
.SH ATTRIBUTES
For an explanation of the terms used in this section, see
.BR attributes (7).
.TS
allbox;
lbw24 lb lb
l l l.
Interface	Attribute	Value
T{
.BR toupper (),
.BR tolower (),
.br
.BR toupper_l (),
.BR tolower_l ()
T}	Thread safety	MT-Safe
.TE
.SH CONFORMING TO
C89, C99, 4.3BSD.
.SH BUGS
The details of what constitutes an uppercase or lowercase letter depend
on the current locale.
For example, the default
.B """C"""
locale does not know about umlauts, so no conversion is done for them.
.PP
In some non-English locales, there are lowercase letters with no
corresponding uppercase equivalent; the German sharp s is one
example.
.SH SEE ALSO
.BR isalpha (3),
.BR setlocale (3),
.BR towlower (3),
.BR towupper (3),
.BR locale (7)
.SH COLOPHON
This page is part of release 3.53 of the Linux
.I man-pages
project.
A description of the project,
and information about reporting bugs,
can be found at
\%http://www.kernel.org/doc/man\-pages/.