to just print a subset of lines, I would capture into a "@" variable and use grep to filter out what you want.

#!/usr/bin/perl
use strict;
use warnings;

my @result = <DATA>;
print grep{m/\.name|\.lastmodifiedtime/}@result;

#prints:
#task.name:"abc"
#task.lastmodifiedtime: 2010-04-12T11:57:56+01:00 by user1@server1

__DATA__
task.start
# task.id: 1
task.name:"abc"
task.info: xyz
task.schedule: 
task.notify:
task.nextruntime:
task.lastmodifiedtime: 2010-04-12T11:57:56+01:00 by user1@server1
task.args:
[download]