Shell Programming and Scripting

open CMD "$cmd |";
while(<CMD>) {
	print '.';
	# future code to log the output of CMD
	sleep 1;
	# select(undef, undef, undef, 0.5);
}

        my $pid = fork;
        if($pid == 0) { # child
                open CMD, "$cmd 2> /dev/null |";
                while(<CMD>) { print LOG; }
                close CMD;
                print "\nprocess complete.";
                exit;
        } else { # parent
                while((my $running=`ps -p $pid`) !~ /defunct/) { print '.'; select(undef, undef, undef, 0.5); }
                waitpid($pid,0);
        }

use IO::Handle;
STDOUT->autoflush(1);
LOG->autoflush(1);

select STDOUT; $| = 1;
select LOG; $| = 1;