#include	<stdio.h>
#include	<stdlib.h>
#include	<termios.h>

/*
 * setecho.c
 *   usage:  setecho [y|n|f]
 *   shows:  how to read, change, reset tty attributes
 */

int main(int ac, char *av[])
{
	struct termios info;
	int	rv;

	if ( ac == 1 ) 
		exit(0);

	rv = tcgetattr( 0, &info );		/* get attribs 		*/
	if ( rv == -1 )
		exit(1);

	if ( av[1][0] == 'y' )
		info.c_lflag |= ECHO ;		/* turn on bit		*/
	else if ( av[1][0] == 'n' )
		info.c_lflag &= ~ECHO ;		/* turn off bit		*/
	else if ( av[1][0] == 'f' )		/* flip a bit		*/
		info.c_lflag ^= ECHO;

	tcsetattr( 0, TCSANOW, &info ); 	/* set attribs		*/
	return 0;
}