#!/usr/bin/perl

use warnings; 
use strict;

open(KEY, "<hashKey.txt") 
	or die "error reading key list";
open(REG, "<testReg.txt") 
	or die "error reading file";

my %Chr;
while (my $key = <KEY>) {
    chomp $key;
    $Chr{$key} = undef;
}

my %R;
while (my $reg = <REG>) {
    chomp $reg;
    my @reg_split = split("\t", $reg);
    push @{$R{$reg_split[0]}}, $reg;
}

foreach my $key (sort keys %R) {
  next unless exists $Chr{$key};
  for my $out (@{$R{$key}}){ 
    print "$out\n";
  }
  print q{-} x 20, qq{\n};

}

close(KEY);
close(REG);

##</code><code>##

chr1	100	159	0
chr1	200	260	0
chr1	500	750	0
--------------------
chr11	679	687	0
--------------------
chr22	100	200	0
chr22	300	400	0
--------------------
chr3	450	700	0
--------------------
chr4	100	300	0
--------------------
chr7	350	600	0
--------------------
chr9	100	125	0
--------------------