#! perl -slw
use strict;
use threads;
use Thread::Queue;

sub pipeCommand {
    my $cmd = shift;
    my $Q = new Thread::Queue;
    async{
        my $pid = open my $pipe, $cmd or die $!;
        $Q->enqueue( $_ ) while <$pipe>;
        $Q->enqueue( undef );
    }->detach;
    return $Q;
}

my $pipe = pipeCommand(
    'perl -le"$|++;print localtime().q[: some text] and sleep 1 for 1 .. 10" |'
) or die;

while( 1 ) {
    if( $pipe->pending ) {
        my $line = $pipe->dequeue or last;
        chomp( $line );
        ## Do stuff with $line
        printf "Got: '%s'\n", $line;
    }
    else {
        ## Do something else
        print 'Tum te tum';
        Win32::Sleep 500;
    }
}

__END__
C:\test>621058-t
Tum te tum
Got: 'Thu Jun 14 01:43:13 2007: some text'
Tum te tum
Got: 'Thu Jun 14 01:43:14 2007: some text'
Tum te tum
Tum te tum
Got: 'Thu Jun 14 01:43:15 2007: some text'
Tum te tum
Tum te tum
Got: 'Thu Jun 14 01:43:16 2007: some text'
Tum te tum
Tum te tum
Got: 'Thu Jun 14 01:43:17 2007: some text'
Tum te tum
Tum te tum
Got: 'Thu Jun 14 01:43:18 2007: some text'
Tum te tum
Tum te tum
Tum te tum
Got: 'Thu Jun 14 01:43:19 2007: some text'
Tum te tum
Got: 'Thu Jun 14 01:43:20 2007: some text'
Tum te tum
Tum te tum
Got: 'Thu Jun 14 01:43:21 2007: some text'
Tum te tum
Tum te tum
Got: 'Thu Jun 14 01:43:22 2007: some text'
Tum te tum
Tum te tum