#!Perl -w
use strict;
use File::Cache;

my $session = shift;
my $cache = get_cache_handle();

$cache->set($session, "wibble ..."); # no data yet

my $end = time () + 20;
my $count = 0;

while (time () < $end) {
    $cache->set ($session, "Count: $count\n");
    ++$count;
    sleep (1);
}

$cache->set ($session, "Completed");
exit 0; # all done

sub get_cache_handle {
    
    File::Cache->new
        ({
          namespace => 'Spawn',
          username => 'nobody',
          default_expires_in => '30 minutes',
          auto_purge_interval => '4 hours',
         });
}