use strict;
use File::Find;

my $path = "/somwhere/to";

find (sub {
    return unless -f;# only files
    &followup($File::Find::name);
    }, $path);

sub followup {
    my $contents = slurp($_[0]);
    if ( $contents =~ /line3/g ) {
        if ( $contents =~ /(line2-)(\w*)/g
         print $2;
        }
     }

sub slurp {
    local $/ = undef;
    local *X;
    open X, $_[0] or die "Can't open $_[0]: $!";
    my $slurp = <X>;
    close X or die "Can't close $_[0]: $!";
    $slurp;
}