iswupper man page

iswupper, iswupper_l — test for an uppercase letter wide-character code


This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ (consult the corresponding Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.


#include <wctype.h>

int iswupper(wint_t wc);
int iswupper_l(wint_t wc, locale_t locale);


For iswupper(): 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.1-2008 defers to the ISO C standard.

The iswupper() and iswupper_l() functions shall test whether wc is a wide-character code representing a character of class upper in the current locale, or in the locale represented by locale, respectively; see the Base Definitions volume of POSIX.1-2008, Chapter 7, Locale.

The wc argument is a wint_t, the value of which the application shall ensure is a wide-character code corresponding to a valid character in the current locale, or equal to the value of the macro WEOF. If the argument has any other value, the behavior is undefined.

The behavior is undefined if the locale argument to iswupper_l() is the special locale object LC_GLOBAL_LOCALE or is not a valid locale object handle.

Return Value

The iswupper() and iswupper_l() functions shall return non-zero if wc is an uppercase letter wide-character code; otherwise, they shall return 0.


No errors are defined.

The following sections are informative.



Application Usage

To ensure applications portability, especially across natural languages, only these functions and the functions in the reference pages listed in the See Also section should be used for character classification.



Future Directions


See Also

iswalnum(), iswalpha(), iswcntrl(), iswctype(), iswdigit(), iswgraph(), iswlower(), iswprint(), iswpunct(), iswspace(), iswxdigit(), setlocale(), uselocale()

The Base Definitions volume of POSIX.1-2008, Chapter 7, Locale, <locale.h>, <wctype.h>

Referenced By

iswalnum(3p), iswalpha(3p), iswblank(3p), iswcntrl(3p), iswctype(3p), iswdigit(3p), iswgraph(3p), iswlower(3p), iswprint(3p), iswpunct(3p), iswspace(3p), iswxdigit(3p), setlocale(3p), wchar.h(0p), wctype.h(0p).

2013 IEEE/The Open Group POSIX Programmer's Manual