towlower(3) — Linux manual page


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

NAME         top

       towlower, towlower_l - convert a wide character to lowercase

SYNOPSIS         top

       #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

           Since glibc 2.10:
               _XOPEN_SOURCE >= 700
           Before glibc 2.10:

DESCRIPTION         top

       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.

RETURN VALUE         top

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

VERSIONS         top

       The towlower_l() function first appeared in glibc 2.3.

ATTRIBUTES         top

       For an explanation of the terms used in this section, see

       │Interface                      Attribute     Value          │
       │towlower()                     │ Thread safety │ MT-Safe locale │
       │towlower_l()                   │ Thread safety │ MT-Safe        │

CONFORMING TO         top

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

       towlower_l(): POSIX.1-2008.

NOTES         top

       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         top

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

COLOPHON         top

       This page is part of release 5.13 of the Linux man-pages project.
       A description of the project, information about reporting bugs,
       and the latest version of this page, can be found at

GNU                            2021-03-22                    TOWLOWER(3)

Pages that refer to this page: iswlower(3)toupper(3)towctrans(3)towupper(3)wcscasecmp(3)wcsncasecmp(3)