You could use a hash to hold the tell() positions of the lines in the file. We use a hash instead of an array, because we don't want to HAVE to hold 10,000 elements just to have $array9999. 
open FILE, "file" or die "can't open file: $!";
$position{1} = 0;
while (<FILE>) {
  # $. holds line number of file being read from
  $position{$.+1} = tell(FILE);  # record byte offset

  # do stuff with $_
  # access a previous line by doing:

  if (CONDITION) {
    seek FILE, $position{$LINE_NUMBER}, 0;
    $data = <FILE>;
    # ...
    # when done, get back to where you were
    seek FILE, $position{$.+1}, 0;
  }
}
close FILE;

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Incidentally, dlc, unshift() requires an explicit list of expressions to prepend to an array, and does not default to prepending $_. -- Jeff Pinyan, japhy@pobox.com http://www.pobox.com/~japhy/

In reply to Re: read lines... wait by japhy
in thread read lines... wait, back up? by Konda

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