towupper(3)                Library Functions Manual                towupper(3)

NAME
       towupper, towupper_l - convert a wide character to uppercase

LIBRARY
       Standard C library (libc, -lc)

SYNOPSIS
       #include <wctype.h>

       wint_t towupper(wint_t wc);
       wint_t towupper_l(wint_t wc, locale_t locale);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       towupper_l():
           Since glibc 2.10:
               _XOPEN_SOURCE >= 700
           Before glibc 2.10:
               _GNU_SOURCE

DESCRIPTION
       The towupper() function is the wide-character equivalent of the
       toupper(3) function.  If wc is a lowercase wide character, and there
       exists an uppercase equivalent in the current locale, it returns the
       uppercase equivalent of wc.  In all other cases, wc is returned
       unchanged.

       The towupper_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 towupper_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 uppercase, towupper() returns its uppercase
       equivalent; otherwise it returns wc.

ATTRIBUTES
       For an explanation of the terms used in this section, see
       attributes(7).

       +-------------------------------------+---------------+----------------+
       |Interface                            | Attribute     | Value          |
       +-------------------------------------+---------------+----------------+
       |towupper ()                          | Thread safety | MT-Safe locale |
       +-------------------------------------+---------------+----------------+
       |towupper_l ()                        | Thread safety | MT-Safe        |
       +-------------------------------------+---------------+----------------+
STANDARDS
       towupper()
              C11, POSIX.1-2008 (XSI).

       towupper_l()
              POSIX.1-2008.

HISTORY
       towupper()
              C99, POSIX.1-2001 (XSI).  Obsolete in POSIX.1-2008 (XSI).

       towupper_l()
              POSIX.1-2008.  glibc 2.3.

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
       iswupper(3), towctrans(3), towlower(3), locale(7)

Linux man-pages 6.7               2023-10-31                       towupper(3)