H P L A   143 TYR   202  OH  -->  O2   2014 MC9   500 A
H P L A   143 TYR   202  OH  <--  O2   2014 ASH   500 A
H P L A   237 SER   532  OG  -->  O1   2015 MC9   500 A
H P L A   237 SER   532  OG  <--  O1   2015 AGM   500 A
H P L A   274 ARG   821  NH1 -->  O1   2015 MC9   500 A
H P L A   278 SER   851  OG  -->  O2   2014 VIA   500 A

##</code><code>##

#!/usr/bin/perl -w

use strict;
use IO::File;

use constant FILE => 'search.txt'; 
use constant FIND => 'string to find'; 

IO::File->input_record_separator(FIND);

my $fh = IO::File->new(FILE, O_RDONLY)
  or die 'Could not open file ', FILE, ": $!";

$fh->getline;  


print IO::File->input_record_separator 
  while $fh->getline; 

$fh->close;