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

my %info = ('gi' => "", 'version' => "", 'cds' => ""); 
# here we collect all information

sub flush_info {
        # print out all information:
	   		  print "$info{gi}"."\t"."$info{version}"."\t"."$info{cds}\n";
		%info = ();
		};

my $data = '/DATA/GenBankFile.gb'; # GenBank file is located at C:\DATA
open (INFILE, '<', $data) or die "Cannot!\n";

while (<INFILE>) {
    last if m!//$!;
	
	if (m!^VERSION.*\w:(\d+)! ) {
		$info{version} = $1;
		}
	
	elsif (m!GI:(\d+)!) {
        if ($info{cds}) { # we are in a CDS block 
			$info{gi} = $1;
			};
		} 
		
		elsif (m!^\s+CDS\s+(.*)!) {
				# a new gene information has started
				flush_info();
        
				# now remember the CDS
				$info{cds} = $1;
			}   
		
		else {warn "Ignoring unknown line [$_]\n";};
};

# Output any leftover information:
flush_info();