use strict;
use warnings;

open(my $fh2, '<', $file2name)
   or die("Can't open $file2name for reading: $!\n");

while (<$fh1>)
    my (undef, $posA) = split(/\s+/);

    local $/ = "";
    while (<$fh2>){
       my @lines = split(/\n/);
       my ($posB, $posend) = findpos(@lines);
       next if $posA < $posB;
       last if $posA > $posB + $posend;
       processPara(@lines);
   }
}