my $pid = system 1, ".\\bg_script.pl $ARG1 \"$ARG2\" $ARG3 $ARG4";
print "\$pid == '$pid'\n";

while (kill 0, $pid)
{
	print kill 0, $pid;
	print "\n";
	sleep 1;
}
print "\n\nOUT OF WHILE LOOP\n\n";



______________OUTPUT______________

C:\Script_dir>main_script.pl

$pid == '3144'
1
1
1
1
1
1
0
OUT OF WHILE LOOP