Character Manipulation Function

int tolower(int c);

int _tolower(int c);

int towlower(wint_t c);

unsigned int _mbctolower(unsigned int c);

_TINT _totlower(_TINT c);

Internationalization (I18n) Function Overview

The functions tolower and _tolower convert a character to a lowercase character (if it is an uppercase character).

towlower is the wide character equivalent, testing and converting a wide character.

On Windows platforms only, use _mbctolower for the multibyte equivalent.

_totlower is the Windows-only Generic version of the function; with the _MBCS or _UNICODE compiler flags determining its mapping to either _mbctolower or towlower.

I18n Issues

Use the appropriate version of the function as required for internationalization support, noting the following:

On ANSI platforms, there is no multibyte version of tolower. Instead, convert the multibyte character to a wide character and call towlower.

Prior to calling towlower, ensure that the locale is set correctly, since the function depends on the locale's LC_CTYPE category setting.

The _mbctolower function depends on the multibyte code page in effect. By default, the multibyte code page is set to the system-default ANSI code page obtained from the operating system at program startup. Use _getmbcp and _setmbcp to query or change the current multibyte code page, respectively.

Recommended Replacements*

ANSI UTF-8	convert and call towlower
ANSI UTF-16	towlower
Microsoft Windows MBCS	_mbctolower
Microsoft Windows Unicode	towlower
Microsoft Windows Generic	_totlower

Character Manipulation Functions