/*==================== basic IO access : port_read.c ===============

  PURPOSE - show port read.
          - usage ./port_read port_num
*/
#include <iostream.h>
#include <iomanip.h>
#include <stdlib.h> 
#include <unistd.h>
#include <sys/io.h>

int main( int argc, char *argv[] )
{
        // check have one parameter:
        if ( argc != 2 ) {
                cerr << "usage: " << argv[ 0 ] << " port_num\n"
                     << "Port number is in hexadecimal.\n";
                exit( 1 );
        }
  
        // Read the data byte port:
        int  port_num = strtol( argv[1], NULL, 16  ) & 0x3ff;
        int value = inb( port_num ) & 0xff;
        cout << showbase << "    Read from port " << hex << port_num
             << " (" << dec << port_num << "), data value "
             << hex << value << " (" << dec << value << ").\n";
        exit( 0 ); 
}