TOWUPPER

Section: Linux Programmer's Manual (3)
Updated: 2017-09-15
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NAME

towupper, towupper_l - convert a wide character to uppercase

SYNOPSIS

#include <wctype.h>

wint_t towupper(wint_t wc);

wint_t towupper_l(wint_t wc, locale_t locale);

Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

towupper_l():

Since glibc 2.10:: _XOPEN_SOURCE >= 700
Before glibc 2.10:: _GNU_SOURCE

DESCRIPTION

The towupper() function is the wide-character equivalent of the toupper(3) function. If wc is a lowercase wide character, and there exists an uppercase equivalent in the current locale, it returns the uppercase equivalent of wc. In all other cases, wc is returned unchanged.

The towupper_l() function performs the same task, but performs the conversion based on the character type information in the locale specified by locale. The behavior of towupper_l() is undefined if locale is the special locale object LC_GLOBAL_LOCALE (see duplocale(3)) or is not a valid locale object handle.

The argument wc must be representable as a wchar_t and be a valid character in the locale or be the value WEOF.

RETURN VALUE

If wc was convertible to uppercase, towupper() returns its uppercase equivalent; otherwise it returns wc.

VERSIONS

The towupper_l() function first appeared in glibc 2.3.

ATTRIBUTES

For an explanation of the terms used in this section, see attributes(7).

Interface	Attribute	Value
towupper()	Thread safety	MT-Safe locale
towupper_l()	Thread safety	MT-Safe

CONFORMING TO

towupper(): C99, POSIX.1-2001 (XSI); present as an XSI extension in POSIX.1-2008, but marked obsolete.

towupper_l(): POSIX.1-2008.

NOTES

The behavior of these functions depends on the LC_CTYPE category of the locale.

These functions are not very appropriate for dealing with Unicode characters, because Unicode knows about three cases: upper, lower and title case.

COLOPHON

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