EX:
...
open(LIBIN, "gunzip -c $read_file |") or die "\nERROR: ...";
...
while($line = <LIBIN>) {
  $self->{LINENUMBER}++;
  $file_line_location{$self->{LINENUMBER}} = tell LIBIN;
.....
   # Return to the start of a section after pre-parsing
   seek  LIBIN , $file_line_location{$section_reentry_line}, 0;
....
}