UPDATE: The OP was changed in a major way after my original reply. This no longer applies...

It seems like you just want to ignore your datestamp lines: 

use strict;
use warnings;

while (<DATA>) {
    next if /\[datestamp\[/;
    print if /crap/;
}
__DATA__
[datestamp] [DEBUG] something here
[datestamp] [DEBUG] something else here
[datestamp] [ERROR] blah blah
<chunk of crap>
[datestamp] [INFO] bla bla bla

[download]

In reply to Re: Parsing a file in "chunks" by toolic
in thread Parsing a file in "chunks" by vxp

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