_mbclen, mblen

Get the length and determine the validity of a multibyte character.

size_t_mbclen(constunsignedchar*c);

intmblen(constchar*mbstr,size_tcount**);**

Routine	Required Header	Compatibility
_mbclen	<mbstring.h>	Win 95, Win NT
mblen	<stdlib.h>	ANSI, Win 95, Win NT

For additional compatibility information, see Compatibility in the Introduction.

Libraries

LIBC.LIB	Single thread static library, retail version
LIBCMT.LIB	Multithread static library, retail version
MSVCRT.LIB	Import library for MSVCRT.DLL, retail version

Return Value

_mbclen returns 1 or 2, according to whether the multibyte character c is one or two bytes long. There is no error return for _mbclen. If mbstr is not NULL, mblen returns the length, in bytes, of the multibyte character. If mbstr is NULL, or if it points to the wide-character null character, mblen returns 0. If the object that mbstr points to does not form a valid multibyte character within the first count characters, mblen returns –1.

Parameters

c

Multibyte character

mbstr

Address of multibyte-character byte sequence

count

Number of bytes to check

Remarks

The _mbclen function returns the length, in bytes, of the multibyte character c. If c does not point to the lead byte of a multibyte character as determined by an implicit call to _ismbblead, the result of _mbclen is unpredictable.

mblen returns the length in bytes of mbstr if it is a valid multibyte character. It examines count or fewer bytes contained in mbstr, but not more than MB_CUR_MAX bytes. mblen determines multibyte-character validity according to the LC_CTYPE category setting of the current locale. For more information on the LC_CTYPE category, see setlocale.

Generic-Text Routine Mappings

TCHAR.H Routine	_UNICODE & _MBCS Not Defined	_MBCS Defined	_UNICODE Defined
_tclen	Maps to macro or inline function	_mbclen	Maps to macro or inline function

Example

/* MBLEN.C illustrates the behavior of the mblen function
 */

#include <stdlib.h>
#include <stdio.h>

void main( void )
{
    int      i;
    char    *pmbc = (char *)malloc( sizeof( char ) );
    wchar_t  wc   = L'a';

    printf( "Convert wide character to multibyte character:\n" );
    i = wctomb( pmbc, wc );
    printf( "\tCharacters converted: %u\n", i );
    printf( "\tMultibyte character: %x\n\n", pmbc );

    i = mblen( pmbc, MB_CUR_MAX );
    printf( "Length in bytes of multibyte character %x: %u\n", pmbc, i );

    pmbc = NULL;
    i = mblen( pmbc, MB_CUR_MAX );
    printf( "Length in bytes of NULL multibyte character %x: %u\n", pmbc, i );
}

Output

Convert wide character to multibyte character:
   Characters converted: 1
   Multibyte character: 2c02cc

Length in bytes of multibyte character 2c02cc: 1
Length in bytes of NULL multibyte character 0: 0

Character Classification Routines |  Locale Routines |  Interpretation of Multibyte-Character Sequences

See Also   _mbccpy, _mbslen