TOWLOWER(3)                                                             Linux Programmer's Manual                                                            TOWLOWER(3)

NAME
       towlower, towlower_l - convert a wide character to lowercase

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 equiva‐
       lent 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 be‐
       havior 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.

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

VERSIONS
       The towlower_l() function first appeared in glibc 2.3.

ATTRIBUTES
       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        │
       └───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┴───────────────┴────────────────┘

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

       towlower_l(): 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 characters, because Unicode knows about three cases: upper, lower, and title case.

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

GNU                                                                            2021-03-22                                                                    TOWLOWER(3)