#!/usr/bin/perl -w

use POSIX;

eval 'sub O_NDELAY () { &O_NONBLOCK;}' unless defined(&O_NDELAY);
eval 'sub TCFLSH () {0x540b;}' unless defined(&TCFLSH);
eval 'sub TIOCSTI () {0x5412;}' unless defined(&TIOCSTI);

if(@ARGV < 2) {
   print "usage : force <device> <command string>\n";
   exit;
}
 
$Device = shift(@ARGV);
$Command = join(' ',@ARGV);

sysopen($DEVICE,$Device,&O_NDELAY|O_RDWR)||die "cannot open device '$Device' : $!\n";

if(ioctl($DEVICE,&TCFLSH,0) < 0) {
   print "ioctl TCFLSH error on '$Device' : $!\n";
}
 
foreach $Char (split(//,"$Command\n")) {
   if(!(ioctl($DEVICE,&TIOCSTI,$Char))) {
      print "ioctl TIOCSTI error on '$Device': $!\n";
   }
}
close($DEVICE)||die "cannot close device '$Device' : $!\n";