www.LinuxHowtos.org

towupper

Section: C Library Functions (3)
Updated: 202-0-08
Index Return to Main Contents

NAME

towupper, towupper_l - convert a wide character to uppercase

LIBRARY

Standard C library (libc,~-lc)

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 wid-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.

ATTRIBUTES

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

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

STANDARDS

towupper(): C11, POSIX.-2008 (XSI).
towupper_l(): POSIX.-2008.

HISTORY

towupper(): C99, POSIX.-2001 (XSI). Obsolete in POSIX.-2008 (XSI).
towupper_l(): POSIX.-2008. glibc 2.3.

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.