//----------------------------------------------------------------
//	setconsole.cpp
//
//	This utility allows a user possessing root privilege 
//	to redirect 'printk' output to a designated console. 
//
//	compile using:
//		root# gcc -o setconsole setconsole.cpp
//		root# chmod a+s setconsole
//
//	execute using:
//		user$ setconsole 4	
//		
//	Code used here is from an example by Alesandro Rubini,	
//	"Linux Device Drivers (2nd Edition)," pages 99-100.
//	          
//	programmer: ALLAN CRUSE
//	written on: 24 NOV 2002
//	revised on: 24 JUN 2007 -- to use "/dev/console" device
//----------------------------------------------------------------

#include <fcntl.h>		// for open()		<--- added 
#include <stdio.h>		// for fprintf()
#include <errno.h>		// for errno
#include <stdlib.h>		// for exit()
#include <unistd.h>		// for STDIN_FILENO
#include <string.h>		// for strerror()
#include <sys/ioctl.h>		// for ioctl()
#include <asm/ioctls.h>		// for TIOCLINUX

int main( int argc, char **argv )
{	
	char	bytes[ 2 ] = { 11, 0 };	// 11 is the TIOCLINUX command-number

	if ( argc == 2 ) bytes[1] = atoi( argv[1] );	// console id-number
	else	{
		fprintf( stderr, "%s: need a single argument\n", argv[0] );
		exit(1);
		}

	int	fd = open( "/dev/console", O_RDWR );		// <--- added
	if ( fd < 0 ) { perror( "/dev/console" ); exit(1); }	// <--- added
	
	if ( ioctl( fd, TIOCLINUX, bytes ) < 0 )		// <--- changed
		{	
		fprintf( stderr, "%s: ioctl( fd, TIOCLINUX ): %s\n", // <--- 
						argv[0], strerror( errno ) );
		exit(1);
		}

	exit(0);
}