//-------------------------------------------------------------------
//	watchnic.cpp
//	
//	This program continuously reads and displays the contents of
//	the '/proc/nicports' pseudo-file, in order to give its users
//	a dynamic view of the volatile RealTek 8139 register-values.
//	The program expects our 'nicports.c' module to be installed.
//
//	programmer: ALLAN CRUSE
//	written on: 04 MAY 2005
//-------------------------------------------------------------------

#include <stdio.h>	// for printf(), perror() 
#include <fcntl.h>	// for open() 
#include <stdlib.h>	// for exit() 
#include <unistd.h>	// for read() 
#include <signal.h>	// for signal()

int done = 0;
void upon_signal( int signum ) { done = 1; }


int main( int argc, char **argv )
{
	// open the pseudo-file for reading
	int	fd = open( "/proc/nicports", O_RDONLY );
	if ( fd < 0 ) { perror( "/proc/nicports" ); exit(1); }

	// install our signal-handler
	signal( SIGINT, upon_signal );	

	// initialize the display screen
	printf( "\e[H\e[J" );		// clear the screen
	printf( "\e[?25l\e[?1c ");	// cursor invisible
	printf( "\e[%d;%dH", 7, 14 );	// cursor placement
	printf( "RealTek 8139 Network Interface Controller registers" );

	// continuously read and display the RealTek register-values	
	while ( !done )
		{
		unsigned int	data[ 64 ] = {0};
		int 	nbytes = read( fd, data, sizeof( data ) );
		if ( nbytes < 0 ) { perror( "read" ); exit(1); }

		printf( "\e[%d;%dH", 8, 1 );
		for (int i = 0; i < 64; i++)
			{
			if ( ( i % 8 ) == 0 ) printf( "\n  %02X: ", i*4 );
			printf( "%08X ", data[ i ] );
			}	
		fflush( stdout );
		}

	// restore cursor's visibility near the bottom of the screen
	printf( "\e[%d;%dH", 22, 1 );	// cursor position
	printf( "\e[?25h\e[?0c" );	// cursor visibile
	printf( "\n" );			// output new-line
}