towupper

Defined in header `<wctype.h>`
wint_t towupper( wint_t wc );		(since C95)

Converts the given wide character to uppercase, if possible.

Parameters

wc

-

wide character to be converted

Return value

Uppercase version of wc or unmodified wc if no uppercase version is listed in the current C locale.

Notes

Only 1:1 character mapping can be performed by this function, e.g. the uppercase form of 'ß' is (with some exceptions) the two-character string "SS", which cannot be obtained by towupper.

ISO 30112 specifies which pairs of Unicode characters are included in this mapping.

Example

Run this code

#include <stdio.h>
#include <wchar.h>
#include <wctype.h>
#include <locale.h>
 
int main(void)
{
    wchar_t wc =  L'\u017f'; // Latin small letter Long S ('ſ')
    printf("in the default locale, towupper(%#x) = %#x\n", wc, towupper(wc));
    setlocale(LC_ALL, "en_US.utf8");
    printf("in Unicode locale, towupper(%#x) = %#x\n", wc, towupper(wc));
}

Output:

in the default locale, towupper(0x17f) = 0x17f
in Unicode locale, towupper(0x17f) = 0x53

References

C11 standard (ISO/IEC 9899:2011):

7.30.3.1.2 The towupper function (p: 453)

C99 standard (ISO/IEC 9899:1999):

7.25.3.1.2 The towupper function (p: 399)

Compiler support
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Headers
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Program utilities
Variadic function support
Error handling
Dynamic memory management
Strings library
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Numerics
Date and time utilities
Input/output support
Localization support
Concurrency support (C11)
Technical Specifications
Symbol index

towlower (C95)	converts a wide character to lowercase (function)
toupper	converts a character to uppercase (function)
C++ documentation for towupper