/*
 * txflow.c
 *
 * Test xon/xoff handshaking by stty'ing a port to a known state,
 * blasting a burst of characters to the port, and watching for (and
 * displaying) any characters coming back from the port.
 *
 * Peter Berger; 14 September 1998
 */
#define VERSION "1.3"
#define BUFFSIZE 256
#define USAGE "txflow [-n terminal] [softflow | softflow] [-version] [-s 1200|9600|19200|38400]\n"

#include <termios.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <signal.h>
#include <stdio.h>

static int chan = -1;
static pid_t listen_pid;

void fail( char *mes )
{
	printf( "%s", mes );
	close( chan );
	exit( 1 );

}

usage()
{
	fail( USAGE );

}

void writechar( int c )
{
		if( write( chan, &c, 1 ) != 1 )
			fail( "write failed\n" );
}

void testpat( void )
{
	int i, c;

	for( i=1; i<1000; ++i ) {
		for( c='A'; c<='Z'; ++c )
			writechar( c );
		writechar( ' ' );
	}
}

void listen() {
	int i, count;
	char buf[BUFFSIZE];

	while( 1 ) {
		count = read( chan, &buf, BUFFSIZE );
		if( count < 0 )
			fail( "listen read failed\n" );
		for( i=0; i<count; ++i ) {
			printf( "<'%c' -> %xx>\n", isprint(buf[i])? buf[i] : '*', buf[i] );
		}

	}


}

void init( int argc, char *argv[] ) {
	struct termios t;
	char c;
	static softflow = 0;
	static char *termname = "/dev/ttyD0";
	static speed_t speed = B9600;

	while( --argc ) {

		++argv;

		if( !strcasecmp( *argv, "-version" ) ) {
			printf( "Version %s\n", VERSION ); 
			fail( "" );
		} else if( !strcasecmp( *argv, "-n" ) ) {
			if( --argc > 0 ) {
				termname = *(++argv);
			} else {
				usage();
			}
		} else if( !strcasecmp( *argv, "-s" ) ) {
			if( --argc > 0 ) {
				++argv;
				if( !strcasecmp( *argv, "1200" ) )
					speed = B1200;
				else if( !strcmp( *argv, "9600" ) )
					speed = B9600;
				else if( !strcmp( *argv, "19200" ) )
					speed = B19200;
				else if( !strcmp( *argv, "38400" ) )
					speed = B38400;
				else {
					printf( "Unsupported baudrate: '%s'\n", *argv );
					usage();
				}
			} else {
				usage();
			}
		} else if( !strcasecmp( *argv, "softflow" ) )
			softflow = 1;
		else if( !strcasecmp( *argv, "-softflow" ) )
			softflow = 0;
		else if( !strcasecmp( *argv, "-help" ) ) {
			printf( "txflow version %s\n", VERSION ); 
			usage();
		} else {
			printf( "Unknown argument: '%s'\n", *argv );
			usage();
		}
	}

//printf( "termname:%s\n", termname );
//getchar();
	if( (chan = open( termname, O_RDWR|O_NOCTTY)) == -1 ) {
		printf( "Cannot open terminal:'%s'\n", termname );
		exit( 1 );
	}

	if( tcgetattr(chan, &t) != 0 )
		fail( "Cannot get attributes\n" );
	t.c_iflag &= ~(BRKINT | IGNPAR | PARMRK | INPCK
		| ISTRIP | INLCR |IGNCR |ICRNL |IXOFF | IXON );
//t.c_iflag |= IGNBRK | IXOFF | IXON;
	if( softflow ) {
printf( "Setting software flow control\n" );
		t.c_iflag |= IGNBRK | IXON | IXOFF;
	} else {
printf( "Setting NO software flow control\n" );
		t.c_iflag |= IGNBRK;
	}
	t.c_oflag &= ~(OPOST);
	t.c_lflag &= ~( ECHO|ECHOE|ECHOK|ECHONL|ICANON|ISIG|NOFLSH|TOSTOP);
	t.c_cflag &= ( CSIZE|CSTOPB|HUPCL|PARENB);
	t.c_cflag |= CLOCAL|CREAD|CS8;


	if( cfsetispeed( &t, speed ) == -1 )
		fail( "Cannot set input speed\n" );
	if( cfsetospeed( &t, speed ) == -1 )
		fail( "Cannot set output speed\n" );
	if( tcflush( chan, TCIFLUSH ) == -1 )
		fail( "Cannot flush\n" );

	if( tcsetattr( chan, TCSANOW, &t ) == -1 )
		fail( "Cannot set attributes\n" );

}



int main( int argc, char *argv[] )
{

	init( argc, argv );
	if( (listen_pid = fork()) == 0 )
		listen();

printf( "About to call testpat\n" );
getchar();

	testpat();
	
	if( kill( listen_pid, SIGKILL ) != 0 )
		fail( "Failed to kill listen process\n" );
	close( chan );

}