SIMPLE SOLUTIONS

_TOUPPER - reference manual online

Transliterate lowercase characters to uppercase.

Chapter
2013
_TOUPPER(3POSIX)                    POSIX Programmer's Manual                    _TOUPPER(3POSIX)

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() func‐ tion.
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>
IEEE/The Open Group 2013 _TOUPPER(3POSIX)