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

use File::Grep qw(fgrep);
use Data::Dumper;

my @line = fgrep { /^[2-6] .+$/ } *DATA;
print Dumper(\@line);

__DATA__
2 foo
3 bar
4 baz
5 qux
6 quux
7 thingy
8 widget