This sounds a bit like homework...

#!/usr/bin/perl

use strict;
use Data::Dumper;

open FILE, "/tmp/stuff.txt" or die $!;
my @contents = split /\n/,
    do { local $/; <FILE> };
close FILE;

my @results = grep { /^here/ } @contents;

print Dumper(\@results);

__END__

[ contents of /tmp/stuff ]

here
hereitis
hereitwas
hereitwillbe
thisaintit

[ program results ]

$VAR1 = [
          'here',
          'hereitis',
          'hereitwas',
          'hereitwillbe'
        ];
[download]