UTF-8 <-> UTF-16 iconv 변환 문제...

#include <stdio.h>
#include <iconv.h>
#include <string.h>
#include <errno.h>
#include <stdarg.h>
 
 
int ap_iconv( iconv_t iconv_a2b, char *dst, int dstmax, const char *src, int srclen )
{
    int wrbytes, tmpidx;
    size_t cvtsrclen, cvtdstlen, cvtlen;
    char *cvtsrcptr;
    char *cvtdstptr, tmpbuf[32];
    FILE *fp;
    int i=0;
 
    if(iconv_a2b == (iconv_t)(-1))
        return 0;
    //*dst = '\0';
    memset( dst, 0, dstmax );
    cvtsrcptr = src;
    cvtsrclen = srclen;
    cvtdstptr = dst;
    cvtdstlen = dstmax;
    printf("srclen:%d dstmax %d\n", srclen, dstmax);
 
    cvtlen = iconv( iconv_a2b, &cvtsrcptr, &cvtsrclen, &cvtdstptr, &cvtdstlen );
    if( cvtlen == (iconv_t)-1 ) {
        printf( "error:%s, %d\n", strerror(errno), errno );
        return( 0 );
        }
    printf("iconv:%s, cvtdstlen:%u, cvtlen:%u\n", dst, cvtdstlen,cvtlen);
    wrbytes = dstmax - cvtdstlen;
    if( wrbytes >= 0 ) dst[wrbytes] = '\0';
    printf( "cvtdstlen:%d, wrbytes:%d\n", cvtdstlen, wrbytes ); fflush( stdout );
    return( wrbytes );
}
 
 
void printDebug(char *msg, ...)
{
    va_list args;
 
    va_start(args, msg);
    vprintf(msg, args);
    va_end(args);
    printf("\n");
}
 
int main(int argc, char **argv)
{
    char *inbuf;
    char *outbuf;
    size_t insize;
    size_t outsize;
    size_t ret;
    iconv_t icon;
 
    icon = iconv_open(argv[1], argv[2]);
    //icon = iconv_open("UTF-8", "UTF-16");
    inbuf = malloc(12);
    sprintf(inbuf, "apple");
    insize = strlen(inbuf);
    outsize = insize*2;
    outbuf = malloc(outsize+1);
 
    ap_iconv(icon, outbuf, outsize, inbuf, insize);
    iconv_close(icon);
 
    free(inbuf);
    free(outbuf);
    return 1;
}