I have a file containing positions, length and text, in paragraph format. eg first filed is position, the number in the second field is the length of the text in the forth field, the third field is the name. 
0 10 ab  hellothere
4 5  ac  notimportant
2 3  ad  notimportant

10 23 ab hellloagainhellloagainnn 
4 5   ac notimportantnotimportant
2 3   ad notimportantnotimportant

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I have another file containing positions of paragraph text I need to retain, relative to the top line (ab) of the paragraph 
0 20
40 60
100 120

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so the first line says to keep the text up to position 20 (keeping paragraph structure) 

 hellothere
 notimportant
 notimportant

 hellloagainhellloagai
 notimportantnotimport
 notimportantnotimport

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Then I would need to keep the text from position 40 to 60, and so on. So I need to filter the text based on the positions in the second file (which gives the co-ordinates of the filtered text relative to the first line in the paragraph). Hopefully this makes sense. I am already reading in the data 1 paragraph at a time and processing the resulting text. the paragraph text and names is read into an hash 
my %seqs
foreach my $sline (@slines){
      my($start,$size,$name,$text) = split /\s+/, $sline;
      $seqs{$name} = $text;
      }

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I was hoping somebody may have an idea for some kind of filter before it is put into the hash, the tricky bit for me is using the info in the second file. Many thanks!

In reply to filter one file based on another by coldy

Title:
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