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)