GetStringTypeEx

The GetStringTypeEx function returns character-type information for the characters in the specified source string. For each character in the string, the function sets one or more bits in the corresponding 16-bit element of the output array. Each bit identifies a given character type, such as whether the character is a letter, a digit, or neither.

Unlike its close relatives GetStringTypeA and GetStringTypeW, GetStringTypeEx exhibits appropriate A or W behavior through the use of the #define UNICODE switch. It is the recommended Win32 function.

BOOL GetStringTypeEx(

LCID Locale, // locale identifer
DWORD dwInfoType, // information-type options
LPCTSTR lpSrcStr, // address of source string
int cchSrc, // size, in bytes or characters, of source string
LPWORD lpCharType // address of buffer for output
);  

Parameters

Locale

Specifies the locale identifier. This value uniquely defines the ANSI code page to use to translate the string pointed to by lpSrcStr from ANSI to Unicode. The function then analyzes each Unicode character for character type information. Note that the W version of this function ignores this parameter.

This parameter can be a locale identifier created by the MAKELCID macro, or one of the following predefined values:

LOCALE_SYSTEM_DEFAULT Default system locale
LOCALE_USER_DEFAULT Default user locale

dwInfoType

Specifies the type of character information the user wants to retrieve. The various types are divided into different levels (see the following Remarks section for a list of the information included in each type). This parameter can specify one of the following character type flags:

CT_CTYPE1 Retrieve character type information.
CT_CTYPE2 Retrieve bidirectional layout information.
CT_CTYPE3 Retrieve text processing information.

lpSrcStr

Points to the string for which character types are requested. If cchSrc is -1, the string is assumed to be null terminated. This must be a Unicode string for the W version of this function, and an ANSI string for the A version. Note that for the A version, this can be a double-byte character set (DBCS) string if the locale is appropriate for DBCS.

cchSrc

Specifies the size, in bytes (ANSI version) or characters (Unicode version), of the string pointed to by the lpSrcStr parameter. If this count includes a null terminator, the function returns character type information for the null terminator. If this value is -1, the string is assumed to be null terminated and the length is calculated automatically.

lpCharType

Points to an array of 16-bit values. The length of this array must be large enough to receive one 16-bit value for each character in the source string. When the function returns, this array contains one word corresponding to each character in the source string.

Return Values

If the function succeeds, the return value is nonzero.

If the function fails, the return value is zero. To get extended error information, call GetLastError. GetLastError may return one of the following error codes:

ERROR_INVALID_FLAGS
ERROR_INVALID_PARAMETER

Remarks

The GetStringTypeEx function exists to circumvent a limitation caused by the difference in parameters of GetStringTypeA and GetStringTypeW. That parameter difference prevents an application from automatically invoking the proper A or W version of GetStringType* through the use of the #define UNICODE switch. GetStringTypeEx, on the other hand, behaves properly as regards that switch. Thus, it is the recommended Win32 function.

The Locale parameter is only used to perform string conversion to Unicode. It has nothing to do with the CTYPEs the function returns. The CTYPEs are solely determined by Unicode code points, and do not vary on a locale basis. For example, Greek letters are C1_ALPHA for any Locale value.

The lpSrcStr and lpCharType pointers must not be the same. If they are the same, the function fails and GetLastError returns ERROR_INVALID_PARAMETER.

The character-type bits are divided into several levels. The information for one level can be retrieved by a single call to this function. Each level is limited to 16 bits of information so that the other mapping routines, which are limited to 16 bits of representation per character, can also return character-type information.

The character types supported by this function include the following.

Ctype 1

These types support ANSI C and POSIX (LC_CTYPE) character-typing functions. A combination of these values is returned in the array pointed to by the lpCharType parameter when the dwInfoType parameter is set to CT_CTYPE1.

Name Value Meaning
C1_UPPER 0x0001 Uppercase
C1_LOWER 0x0002 Lowercase
C1_DIGIT 0x0004 Decimal digits
C1_SPACE 0x0008 Space characters
C1_PUNCT 0x0010 Punctuation
C1_CNTRL 0x0020 Control characters
C1_BLANK 0x0040 Blank characters
C1_XDIGIT 0x0080 Hexadecimal digits
C1_ALPHA 0x0100 Any linguistic character: alphabetic, syllabary, or ideographic

The following character types are either constant or computable from basic types and do not need to be supported by this function.

Type Description
Alphanumeric Alphabetic characters and digits (C1_ALPHA and C1_DIGIT)
Printable Graphic characters and blank (all C1_* types except C1_CNTRL)

Ctype 2

These types support proper layout of Unicode text. The direction attributes are assigned so that the bidirectional layout algorithm standardized by Unicode produces accurate results. These types are mutually exclusive. For more information about the use of these attributes, see The Unicode Standard: Worldwide Character Encoding, Volumes 1 and 2, Addison Wesley Publishing Company: 1991, 1992, ISBN 0201567881.

Name Value Meaning
Strong:
C2_LEFTTORIGHT 0x1 Left to right
C2_RIGHTTOLEFT 0x2 Right to left
Weak:
C2_EUROPENUMBER 0x3 European number, European digit
C2_EUROPESEPARATOR 0x4 European numeric separator
C2_EUROPETERMINATOR 0x5 European numeric terminator
C2_ARABICNUMBER 0x6 Arabic number
C2_COMMONSEPARATOR 0x7 Common numeric separator
Neutral:
C2_BLOCKSEPARATOR 0x8 Block separator
C2_SEGMENTSEPARATOR 0x9 Segment separator
C2_WHITESPACE 0xA White space
C2_OTHERNEUTRAL 0xB Other neutrals
Not applicable:
C2_NOTAPPLICABLE 0x0 No implicit directionality (for example, control codes)

Ctype 3

These types are intended to be placeholders for extensions to the POSIX types required for general text processing or for the standard C library functions. These types are supported in the current version of Windows NT. A combination of these values is returned when dwInfoType is set to CT_CTYPE3.

Name Value Meaning
C3_NONSPACING 0x1 Nonspacing mark
C3_DIACRITIC 0x2 Diacritic nonspacing mark
C3_VOWELMARK 0x4 Vowel nonspacing mark
C3_SYMBOL 0x8 Symbol
C3_KATAKANA 0x10 Katakana character
C3_HIRAGANA 0x20 Hiragana character
C3_HALFWIDTH 0x40 Half-width character
C3_FULLWIDTH 0x80 Full-width character
C3_IDEOGRAPH 0x100 Ideographic character
C3_KASHIDA 0x200 Arabic Kashida character
C3_ALPHA 0x8000 All linguistic characters (alphabetic, syllabary, and ideographic)
Not applicable:
C3_NOTAPPLICABLE 0x0 Not applicable

See Also

GetLocaleInfo, GetStringTypeA, GetStringTypeW