Would I be OK to spawn a thread and use a shared data structure to get the results from the thread ?

Hmm. Seems select doesn't timeout on pipes! If the spawn process writes output regulalry as my test.pl did, then this works, but if it doesn't, the select never times out and it blocks forver:(

Update2: This works now even if the process produces no ouput.

That's the way I would do it. I don't see any reason this shouldn't work equally well on non-win systems (assuming a threaded perl), but I don't have the facility to test that.

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

sub captureWithTimeout {
    my( $cmd, $Q, $timeout ) = @_;
    my $pid = open CMD, "$cmd |" or die "$cmd : $!";
    sleep $timeout;
    my $rv;
    $rv = kill 9, $pid if kill 0, $pid;
    $Q->enqueue( $_ ) while defined( $_ = <CMD> );
    return $rv;
}

my $Q = new Thread::Queue;
my $t = threads->create( 
    \&captureWithTimeout, 
    $ARGV[ 0 ],
    $Q, $ARGV[ 1 ]
);
print "Running '$ARGV[ 0 ] for $ARGV[ 1] seconds";
print "It took too long, so I killed it" if $t->join;
print 'It produced the following output:';
printf $Q->dequeue while $Q->pending;

__END__
P:\test>435776 "perl test.pl 15" 10
Running 'perl test.pl 15 for 10 seconds
It took too long, so I killed it
It produced the following output:
Starting
1
2
3
4
5
6
7
8
9

P:\test>435776 "perl test.pl 15" 20
Running 'perl test.pl 15 for 20 seconds
It produced the following output:
Starting
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Stopping
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