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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.
NAME
_toupper — transliterate lowercase characters to uppercase
SYNOPSIS
#include <ctype.h> int _toupper(int c);
DESCRIPTION
The _toupper() macro shall be equivalent to toupper() except that the application shall ensure that the
argument c is a lowercase letter.
RETURN VALUE
Upon successful completion, _toupper() shall return the uppercase letter corresponding to the argument
passed.
ERRORS
No errors are defined.
The following sections are informative.
EXAMPLES
None.
APPLICATION USAGE
Applications should use the toupper() function instead of the obsolescent _toupper() function.
RATIONALE
None.
FUTURE DIRECTIONS
The _toupper() function may be removed in a future version.
SEE ALSO
islower(), toupper()
The Base Definitions volume of POSIX.1‐2008, Chapter 7, Locale, <ctype.h>
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 .