_strncnt, _wcsncnt, _mbsnbcnt, _mbsnbcnt_l, _mbsnccnt, _mbsnccnt_l

Article
04/28/2015

Returns the number of characters or bytes within a specified count.

Important

_mbsnbcnt, _mbsnbcnt_l, _mbsnccnt, and _mbsnccnt_l cannot be used in applications that execute in the Windows Runtime. For more information, see CRT functions not supported with /ZW.

size_t _strncnt(
   const char *str,
   size_t count
);
size_t _wcsncnt(
   const wchar_t *str,
   size_t count
);
size_t _mbsnbcnt(
   const unsigned char *str,
   size_t count 
);
size_t _mbsnbcnt_l(
   const unsigned char *str,
   size_t count,
   _locale_t locale
);
size_t _mbsnccnt(
   const unsigned char *str,
   size_t count
);
size_t _mbsnccnt_l(
   const unsigned char *str,
   size_t count,
   _locale_t locale
);

Parameters

str
String to be examined.
count
Number of characters or bytes to be examined in str.
locale
Locale to use.

Return Value

_mbsnbcnt and _mbsnbcnt_l return the number of bytes found in the first count of multibyte characters of str. _mbsnccnt and _mbsnccnt_l return the number of characters found in the first count of bytes of str. If a NULL character is encountered before the examination of str has completed, they return the number of bytes or characters found before the NULL character. If str consists of fewer than count characters or bytes, they return the number of characters or bytes in the string. If count is less than zero, they return 0. In previous versions, these functions had a return value of type int rather than size_t.

_strncnt returns the number of characters in the first count bytes of the single-byte string str. _wcsncnt returns the number of characters in the first count wide characters of the wide-character string str.

Remarks

_mbsnbcnt and _mbsnbcnt_l count the number of bytes found in the first count of multibyte characters of str. _mbsnbcnt and _mbsnbcnt_l replace mtob and should be used in place of mtob.

_mbsnccnt and _mbsnccnt_l count the number of characters found in the first count of bytes of str. If _mbsnccnt and _mbsnccnt_l encounter a NULL in the second byte of a double-byte character, the first byte is also considered to be NULL and is not included in the returned count value. _mbsnccnt and _mbsnccnt_l replace btom and should be used in place of btom.

If str is a null pointer or is count is 0, these functions invoke the invalid parameter handler as described in Parameter Validation, errno is set to EINVAL, and the function returns 0.

The output value is affected by the setting of the LC_CTYPE category setting of the locale; see setlocale for more information. The versions of these functions without the _l suffix use the current locale for this locale-dependent behavior; the versions with the _l suffix are identical except that they use the locale parameter passed in instead. For more information, see Locale.

Generic-Text Routine Mappings

Routine	_UNICODE and _MBCS not defined	_MBCS defined	_UNICODE defined
_tcsnbcnt	_strncnt	_mbsnbcnt	_wcsncnt
_tcsnccnt	_strncnt	_mbsnbcnt	n/a
_wcsncnt	n/a	n/a	_mbsnbcnt
_wcsncnt	n/a	n/a	_mbsnccnt
n/a	n/a	_mbsnbcnt_l	_mbsnccnt_l

Requirements

Routine	Required header
_mbsnbcnt	<mbstring.h>
_mbsnbcnt_l	<mbstring.h>
_mbsnccnt	<mbstring.h>
_mbsnccnt_l	<mbstring.h>
_strncnt	<tchar.h>
_wcsncnt	<tchar.h>

For more compatibility information, see Compatibility.

Example

// crt_mbsnbcnt.c

#include  <mbstring.h>
#include  <stdio.h>

int main( void )
{
   unsigned char str[] = "This is a multibyte-character string.";
   unsigned int char_count, byte_count;
   char_count = _mbsnccnt( str, 10 );
   byte_count = _mbsnbcnt( str, 10 );
   if ( byte_count - char_count )
      printf( "The first 10 characters contain %d multibyte characters\n", char_count );
   else
      printf( "The first 10 characters are single-byte.\n");
}

Output

The first 10 characters are single-byte.

.NET Framework Equivalent

Not applicable. To call the standard C function, use PInvoke. For more information, see Platform Invoke Examples.

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