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.TH _TOLOWER "3P" 2013 "IEEE/The Open Group" "POSIX Programmer's Manual"

.SH PROLOG

This manual page is part of the POSIX Programmer's Manual.

The Linux implementation of this interface may differ (consult

the corresponding Linux manual page for details of Linux behavior),

or the interface may not be implemented on Linux.

.SH NAME

_tolower

\(em transliterate uppercase characters to lowercase

.SH SYNOPSIS

.LP

.nf

#include <ctype.h>

.P

int _tolower(int \fIc\fP);

.fi

.SH DESCRIPTION

The

\fI_tolower\fR()

macro shall be equivalent to \fItolower\fP(\fIc\fP) except that the

application shall ensure that the argument

.IR c

is an uppercase letter.

.SH "RETURN VALUE"

Upon successful completion,

\fI_tolower\fR()

shall return the lowercase letter corresponding to the argument

passed.

.SH ERRORS

No errors are defined.

.LP

.IR "The following sections are informative."

.SH EXAMPLES

None.

.SH "APPLICATION USAGE"

Applications should use the

\fItolower\fR()

function instead of the obsolescent

\fI_tolower\fR()

function.

.SH RATIONALE

None.

.SH "FUTURE DIRECTIONS"

The

\fI_tolower\fR()

function may be removed in a future version.

.SH "SEE ALSO"

.IR "\fItolower\fR\^(\|)",

.IR "\fIisupper\fR\^(\|)"

.P

The Base Definitions volume of POSIX.1\(hy2008,

.IR "Chapter 7" ", " "Locale",

.IR "\fB<ctype.h>\fP"

.SH COPYRIGHT

Portions of this text are reprinted and reproduced in electronic form

from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology

-- Portable Operating System Interface (POSIX), The Open Group Base

Specifications Issue 7, Copyright (C) 2013 by the Institute of

Electrical and Electronics Engineers, Inc and The Open Group.

(This is POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the

event of any discrepancy between this version and the original IEEE and

The Open Group Standard, the original IEEE and The Open Group Standard

is the referee document. The original Standard can be obtained online at

http://www.unix.org/online.html .

Any typographical or formatting errors that appear

in this page are most likely

to have been introduced during the conversion of the source files to

man page format. To report such errors, see

https://www.kernel.org/doc/man-pages/reporting_bugs.html .