Locale-Sensitive C/C++ String Operation Function

char *getenv(const char* varname);

wchar_t *_wgetenv(const wchar_t* varname);

TCHAR *_tgetenv(const TCHAR* varname);

Internationalization (I18n) Function Overview

The getenv function returns a pointer to the environment table entry containing varname, or NULL if varname is not found. On Windows, the match is case-insensitive, treating lowercase characters as if they were uppercase.

Only Windows platforms supply a wide-character version of this call - _wgetenv. The argument and return value are both wide-character strings.

_tgetenv is the Windows-only Generic version of the function; with the _MBCS or _UNICODE compiler flags determining its mapping to either getenv or _wgetenv.

I18n Issues

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

On ANSI platforms, there is no corresponding wide function call. Instead, use string conversion routines and call getenv.

For Windows MBCS support, ensure that the multibyte code page is set properly, as getenv depends on it. 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	getenv
ANSI UTF-16	convert and call getenv
Microsoft Windows MBCS	getenv
Microsoft Windows Unicode	_wgetenv
Microsoft Windows Generic	_tgetenv

Locale-Sensitive C/C++ String Operation Functions