towlower, towlower_l - convert a wide character to lowercase
#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 towlower_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 towlower_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.
The towlower_l() function first appeared in glibc 2.3.
For an explanation of the terms used in this section, see attributes(7).
| Interface | Attribute | Value |
| towlower() | Thread safety | MT-Safe locale |
| towlower_l() | Thread safety | MT-Safe |
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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