#!/usr/bin/perl
 # timestamp.pl
while(time - $^T<10){
select undef,undef,undef, 0.1;
if ( rand()<0.5) {
    print STDERR time(), " warn\n";
} else {
    print time(), " info\n"; }
}
print "end\n";
__END__

use IPC::Run qw ( start pump finish timeout );
my $in;
my $out;

my @cmd = qw( perl timestamp.pl);

## Build the harness, open all pipes, and launch the subprocesses
   my $h = start \@cmd, \$in, \$out, \$out ;
   $in = "" ;

   ## Now do I/O.  start() does no I/O.
   pump $h while length $in ;  ## Wait for all input to go

   ## Now do some more I/O.
   while (1){
       pump $h until $out =~ s/(.+)\n$//gm ;
       last if ("end" eq $1);
        print time, " : $1\n";
    }

   ## Clean up
   finish $h or die "cat returned $?" ;
__END__

1215226647 : 1215226647 info
1215226647 : 1215226647 info
1215226647 : 1215226647 warn
1215226647 : 1215226647 info
1215226647 : 1215226647 warn
1215226647 : 1215226647 warn
1215226647 : 1215226647 info
1215226647 : 1215226647 info
1215226647 : 1215226647 info
1215226648 : 1215226648 warn