GetLocaleInfoA function (winnls.h)

Article
02/09/2023

Retrieves information about a locale specified by identifier.

Note For interoperability reasons, the application should prefer the GetLocaleInfoEx function to GetLocaleInfo because Microsoft is migrating toward the use of locale names instead of locale identifiers for new locales. Any application that runs only on Windows Vista and later should use GetLocaleInfoEx.

Note For global compatibility, the application should prefer the Unicode "W" API forms to the "A" forms. GetLocaleInfoA will limit the character data and could result in results that appear corrupted to users, particularly in globally enabled applications. For this API, GetLocaleInfoEx is preferred as it is Unicode and also supports modern locale name standards.

Syntax

int GetLocaleInfoA(
  [in]            LCID   Locale,
  [in]            LCTYPE LCType,
  [out, optional] LPSTR  lpLCData,
  [in]            int    cchData
);

Parameters

[in] Locale

Locale identifier for which to retrieve information. You can use the MAKELCID macro to create a locale identifier or use one of the following predefined values.

[in] LCType

The locale information to retrieve. For detailed definitions, see the LCType parameter of GetLocaleInfoEx.

Note For GetLocaleInfo, the value LOCALE_USE_CP_ACP is relevant only for the ANSI version.

[out, optional] lpLCData

Pointer to a buffer in which this function retrieves the requested locale information. This pointer is not used if cchData is set to 0. For more information, see the Remarks section.

[in] cchData

Size, in TCHAR values, of the data buffer indicated by lpLCData. Alternatively, the application can set this parameter to 0. In this case, the function does not use the lpLCData parameter and returns the required buffer size, including the terminating null character.

Return value

Returns the number of characters retrieved in the locale data buffer if successful and cchData is a nonzero value. If the function succeeds, cchData is nonzero, and LOCALE_RETURN_NUMBER is specified, the return value is the size of the integer retrieved in the data buffer; that is, 2 for the Unicode version of the function or 4 for the ANSI version. If the function succeeds and the value of cchData is 0, the return value is the required size, in characters including a null character, for the locale data buffer.

The function returns 0 if it does not succeed. To get extended error information, the application can call GetLastError, which can return one of the following error codes:

ERROR_INSUFFICIENT_BUFFER. A supplied buffer size was not large enough, or it was incorrectly set to NULL.
ERROR_INVALID_FLAGS. The values supplied for flags were not valid.
ERROR_INVALID_PARAMETER. Any of the parameter values was invalid.

Remarks

For the operation of this function, see Remarks for GetLocaleInfoEx.

Note Even when the LCType parameter is specified as LOCALE_FONTSIGNATURE, cchData and the function return are still TCHAR counts. The count is different for the ANSI and Unicode versions of the function. When an application calls the generic version of GetLocaleInfo with LOCALE_FONTSIGNATURE, cchData can be safely specified as sizeof(LOCALESIGNATURE) / sizeof(TCHAR).

The following examples deal correctly with the buffer size for non-text values:

int   ret;
CALID calid;
DWORD value;

ret = GetLocaleInfo(LOCALE_USER_DEFAULT,
                    LOCALE_ICALENDARTYPE | LOCALE_RETURN_NUMBER,
                    (LPTSTR)&value,
                    sizeof(value) / sizeof(TCHAR) );
calid = value;

LOCALESIGNATURE LocSig;

ret = GetLocaleInfo(LOCALE_USER_DEFAULT,
                    LOCALE_FONTSIGNATURE,
                    (LPWSTR)&LocSig,
                    sizeof(LocSig) / sizeof(TCHAR) );

The ANSI string retrieved by the ANSI version of this function is translated from Unicode to ANSI based on the default ANSI code page for the locale identifier. However, if LOCALE_USE_CP_ACP is specified, the translation is based on the system default ANSI code page.

When the ANSI version of this function is used with a Unicode-only locale identifier, the function can succeed because the operating system uses the system code page. However, characters that are undefined in the system code page appear in the string as a question mark (?).

Note

The winnls.h header defines GetLocaleInfo as an alias which automatically selects the ANSI or Unicode version of this function based on the definition of the UNICODE preprocessor constant. Mixing usage of the encoding-neutral alias with code that not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see Conventions for Function Prototypes.

Requirements

Requirement	Value
Minimum supported client	Windows 2000 Professional [desktop apps \| UWP apps]
Minimum supported server	Windows 2000 Server [desktop apps \| UWP apps]
Target Platform	Windows
Header	winnls.h (include Windows.h)
Library	Kernel32.lib
DLL	Kernel32.dll