NAME

towupper, towupper_l — transliterate lowercase wide-character code to uppercase

SYNOPSIS

#include <wctype.h>

wint_t towupper(wint_t wc);


[CX] wint_t towupper_l(wint_t wc, locale_t locale);

DESCRIPTION

For towupper(): ^[CX]  The functionality described on this reference page is aligned with the ISO C standard. Any conflict between the requirements described here and the ISO C standard is unintentional. This volume of POSIX.1-2024 defers to the ISO C standard.

The towupper() ^[CX]  and towupper_l()  functions have as a domain a type wint_t, the value of which the application shall ensure is a character representable as a wchar_t, and a wide-character code corresponding to a valid character in the locale used by the function or the value of WEOF. If the argument has any other value, the behavior is undefined. If the argument of towupper() ^[CX]  or towupper_l() represents a lowercase wide-character code, and there exists a corresponding uppercase wide-character code as defined by character type information in the current locale ^[CX]  or in the locale represented by locale,  respectively (category LC_CTYPE ), the result shall be the corresponding uppercase wide-character code. All other arguments in the domain are returned unchanged.

^[CX] The behavior is undefined if the locale argument to towupper_l() is the special locale object LC_GLOBAL_LOCALE or is not a valid locale object handle.

RETURN VALUE

Upon successful completion, the towupper() ^[CX]  and towupper_l()  functions shall return the uppercase letter corresponding to the argument passed. Otherwise, they shall return the argument unchanged.

ERRORS

No errors are defined.

EXAMPLES

None.

APPLICATION USAGE

None.

RATIONALE

None.

FUTURE DIRECTIONS

None.

SEE ALSO

setlocale, uselocale

XBD 7. Locale, <locale.h>, <wctype.h>

CHANGE HISTORY

First released in Issue 4.

Issue 5

The following change has been made in this version for alignment with ISO/IEC 9899:1990/Amendment 1:1995 (E):

• The SYNOPSIS has been changed to indicate that this function and associated data types are now made visible by inclusion of the <wctype.h> header rather than <wchar.h>.

Issue 6

The normative text is updated to avoid use of the term "must" for application requirements.

Issue 7

The towupper_l() function is added from The Open Group Technical Standard, 2006, Extended API Set Part 4.

POSIX.1-2008, Technical Corrigendum 1, XSH/TC1-2008/0681 [302], XSH/TC1-2008/0682 [283], and XSH/TC1-2008/0683 [283] are applied.

POSIX.1-2008, Technical Corrigendum 2, XSH/TC2-2008/0374 [685] is applied.