#!/usr/bin/perl -w
# perl.ID.match.pl
use strict; use warnings;

open(KEY, "<chr1.coverage.txt") or die "error reading file";
my %Chr;
my (@Key,@line);
while (my $key = <KEY>) {
	chomp $key;
	@Key=split("\t",$key);
	$Chr{$Key[0]} = undef; 
}


open(FULL, "<chr1.txt") or die "error reading file";
open(OUT, ">chr1.match.txt") or die "error reading file";

while (my $line=<FULL>)
{
	
	chomp $line;
	@line=split("\t",$line);
	foreach my $key (sort keys %Chr) 
	{
	
		if ($line[0] eq $key)
		{
		print OUT "$line\n";
		}
	}
}

close KEY;
close FULL;
close OUT;
exit;