mbstowcs()

Convert a multibyte-character string into a wide-character string

Synopsis:

#include <stdlib.h>

size_t mbstowcs( wchar_t * pwcs,
                 const char * s,
                 size_t n );

Arguments:

pwcs: A pointer to a buffer where the function can store the wide-character string.
s: The string of multibyte characters that you want to convert.
n: The maximum number of wide characters to store in the buffer that pwcs points to.

Library:

libc

Use the -l c option to qcc to link against this library. This library is usually included automatically.

The mbstowcs() function converts a sequence of multibyte characters pointed to by s into their corresponding wide-character codes pointed to by pwcs, to a maximum of n wide characters. It doesn't convert any multibyte characters beyond a NULL character.

This function is affected by LC_TYPE.

The mbsrtowcs() function is a restartable version of mbstowcs().

Returns:

The number of array elements modified, not including the terminating zero code, if present, or (size_t)-1 if an invalid multibyte character was encountered.

If the number of elements is equal to n, the array isn't terminated by a null character.

Errors:

EILSEQ: Invalid character sequence.

Examples:

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

int main( void )
{
    char *wc = "string";
    wchar_t wbuffer[50];
    int i, len;

    len = mbstowcs( wbuffer, wc, 50 );
    if( len != -1 ) {
        wbuffer[len] = '\0';
        printf( "%s(%d)\n", wc, len );
        
        for( i = 0; i < len; i++ ) {
            printf( "/%4.4x", wbuffer[i] );
        }
        
        printf( "\n" );
    }
    
    return EXIT_SUCCESS;
}

This produces the output:

string(6)
/0073/0074/0072/0069/006e/0067

Classification:

ANSI, POSIX 1003.1

Safety:
Cancellation point	No
Interrupt handler	No
Signal handler	Yes
Thread	Yes