towlower, towlower_l - convert a wide character to lowercase
Standard C library (libc
, -lc
)
#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
.
For an explanation of the terms used in this section, see attributes(7).
Interface | Attribute | Value |
towlower() |
Thread safety | MT-Safe locale |
Thread safety | MT-Safe |
C99, POSIX.1-2001 (XSI). Obsolete in POSIX.1-2008 (XSI).
glibc 2.3. 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.