towlower(3) Library Functions Manual towlower(3)
NAME
towlower, towlower_l - convert a wide character to lowercase
LIBRARY
Standard C library (libc, -lc)
SYNOPSIS
#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
DESCRIPTION
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 un-
changed.
The towlower_l() function performs the same task, but performs the con-
version 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 char-
acter in the locale or be the value WEOF.
RETURN VALUE
If wc was convertible to lowercase, towlower() returns its lowercase
equivalent; otherwise it returns wc.
ATTRIBUTES
For an explanation of the terms used in this section, see attrib-
utes(7).
┌────────────────────────────────────┬───────────────┬────────────────┐
│ Interface │ Attribute │ Value │
├────────────────────────────────────┼───────────────┼────────────────┤
│ towlower() │ Thread safety │ MT-Safe locale │
├────────────────────────────────────┼───────────────┼────────────────┤
│ towlower_l() │ Thread safety │ MT-Safe │
└────────────────────────────────────┴───────────────┴────────────────┘
STANDARDS
towlower()
C11, POSIX.1-2008 (XSI).
towlower_l()
POSIX.1-2008.
STANDARDS
towlower()
C99, POSIX.1-2001 (XSI). Obsolete in POSIX.1-2008 (XSI).
towlower_l()
glibc 2.3. POSIX.1-2008.
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 char-
acters, because Unicode knows about three cases: upper, lower, and ti-
tle case.
SEE ALSO
iswlower(3), towctrans(3), towupper(3), locale(7)
Linux man-pages 6.7 2023-10-31 towlower(3)
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