towlower (3)

#include <wctype.h>

wint_t towlower(wint_t wc);

wint_t towlower_l(wint_t wc, locale_t locale);

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

towlower_l():

Since glibc 2.10:

_XOPEN_SOURCE >= 700

Before glibc 2.10:

_GNU_SOURCE

The towlower() function is the wide-character equivalent of the tolower(3) function. If wc is an uppercase wide character, and there exists a lowercase equivalent in the current locale, it returns the lowercase 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.

If wc was convertible to lowercase, towlower() returns its lowercase equivalent; otherwise it returns wc.

Multithreading (see pthreads(7))

The towlower() function is thread-safe with exceptions. It can be safely used in multithreaded applications, as long as setlocale(3) is not called to change the locale during its execution.

The towlower_l() function first appeared in glibc 2.3.

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

towlower_l(): POSIX.1-2008.

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.

iswlower(3), towctrans(3), towupper(3), locale(7)

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