#! /usr/bin/perl
use strict;
use warnings;

my $hash_ref= parse_pdb("pdb.txt");
use Data::Dumper;
print Dumper($hash_ref);

sub parse_pdb{
    my $file = shift;
    my %hash_pdb = ();
    my %val_seen=();
    # Opening of PDB file after dowloading
    open(FH, $file);
    my @atomrecord = <FH>;
    for my $record (@atomrecord){
        chomp($record);
        if($record =~/^ATOM/) {
            my $con_key = "";
            $con_key = "$temp[3]"." "."$temp[4]";
            my $count = 0;
            if( $hash_pdb{$con_key} ) {
                if($val_seen{$temp[5]}) { }
                else {
                    $hash_pdb{$con_key} = $hash_pdb{$con_key}."\t"."$temp[5]";
                }
            }   
            else {
                $hash_pdb{$con_key} = $temp[5];
            }   
            $val_seen{$temp[5]} = 1;
        }   
        if($record =~ /^ENDMDL/){
            print "i am going out of loop\n";
            last;
        }   
    }   
    return \%hash_pdb;
}