mblen, _fmblen

Description

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

#include <stdlib.h>

int mblen( const char *mbstr, size_t count );

int __far _fmblen(const char __far *mbstr, size_t count );

Remarks

The mblen function returns the length in bytes of a valid multibyte character. It examines count or fewer bytes contained in mbstr. It will not examine more than MB_CUR_MAX bytes.

The _fmblen function is a model-independent (large-model) form of the mblen function.

Return Value

If mbstr is not NULL, both mblen and _fmblen return the length, in bytes, of the multibyte character. If mbstr is NULL, or the object that it points to is the wide-character null character (L'\0'), both functions return 0. If the object that mbstr points to does not form a valid multibyte character within the first count characters, both functions return –1.

Compatibility

mblen

Standards:ANSI

16-Bit:DOS, QWIN, WIN, WIN DLL

32-Bit:DOS32X

_fmblen

Standards:None

16-Bit:DOS, QWIN, WIN, WIN DLL

32-Bit:None

See Also

mbstowcs, mbtowc, wcstombs, wctomb, MB_CUR_MAX, MB_LEN_MAX

Example

/* MBLEN.CPP 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 a wide character to multibyte character:\n" );

i = wctomb( pmbc, wc );

printf( "\tCharacters converted: %u\n", i );

printf( "\tMultibyte character: %x\n\n", pmbc );

printf( "Find length--in bytes--of multibyte character:\n" );

i = mblen( pmbc, MB_CUR_MAX );

printf( "\tLength--in bytes--of multibyte character: %u\n", i );

printf( "\tWide character: %x\n\n", pmbc );

printf( "Attempt to find length of a NULL pointer:\n" );

pmbc = NULL;

i = mblen( pmbc, MB_CUR_MAX );

printf( "\tLength--in bytes--of multibyte character: %u\n", i );

printf( "\tWide character: %x\n\n", pmbc );

printf( "Attempt to find length of a wide-character NULL:\n" );

wc = L'\0';

wctomb( pmbc, wc );

i = mblen( pmbc, MB_CUR_MAX );

printf( "\tLength--in bytes--of multibyte character: %u\n", i );

printf( "\tWide character: %x\n", pmbc );

}

Output

Convert a wide character to multibyte character:

Characters converted: 1

Multibyte character: e56

Find length--in bytes--of multibyte character:

Length--in bytes--of multibyte character: 1

Wide character: e56

Attempt to find length of a NULL pointer:

Length--in bytes--of multibyte character: 0

Wide character: 0

Attempt to find length of a wide-character NULL:

Length--in bytes--of multibyte character: 0

Wide character: 0