Converts a multibyte string to a wide-character string

#include <stdlib.h>
size_t mbsrtowcs ( wchar_t * restrict dest , const char * restrict src ,
                  size_t n , mbstate_t * restrict state  );

The mbsrtowcs( ) function, like mbstowcs( ), converts a multibyte string to a wide character string, and returns the number of wide characters in the result, not counting the terminating null wide character. However, mbsrtowcs( ) also stores the resulting parse state of the multibyte string in the mbstate_t object addressed by the state argument. If mbsrtowcs( ) encounters an invalid multibyte character, it returns -1 and sets the errno variable to EILSEQ ("illegal sequence").

The conversion performed is equivalent to calling mbrtowc( ) for each multibyte character in the original string, beginning in the shift state represented by the mbstate_t object addressed by the state argument.

Example

size_t result;

char mbstring[ ] = "This is originally a multibyte string.\n";
const char *mbsptr = mbstring;

wchar_t widestring[256] = { L'\0' };

mbstate_t state;
memset( &state, '\0', sizeof state );

printf( "The current locale is %s.\n", setlocale( LC_CTYPE, "" ));

result =  mbsrtowcs( widestring, &mbsptr, 256, &state );
if ( result == (size_t)-1 )
{
  fputs( "Encoding error in multibyte string", stderr );
  return -1;
}
else
{
  printf( "Converted %u multibyte characters. The result:\n", result );
  printf( "%ls", widestring );
}

See Also

mbstowcs( ), mbrtowc( ); wcsrtombs( ), wcrtomb( ), wcstombs( ), wctomb( )