숫자를 hex 코드로 변환

/* print input in hex */
void print_hex( int input ){
    int var, i;
    int len = 0;
    char buf[255];

    do{
        var = input % 16;
        input /= 16;

        /* try to convert ascii code */
        if( var<10 ) buf[len] = var+48;
        else buf[len] = var+55;
        len++;
    }while( input>0 ); /* bigger than 16? then try again */

    /* print reversely */
    for ( i=len; i>0; i-- ) putchar( buf[i-1] );
    putchar( '\n' );

}

int main( int argc, char** argv ){
    int input;

    printf( "input number: " );
    scanf( " %d", &input );

    /* print hex with printf */
    printf( "%x\n", input );

    /* print hex with my function */
    print_hex( input );

    return 0;

}