open(FILE, "<file.txt");
my @thing = <FILE>;
close FILE;
for(@thing) {
	if(/this/) {
		push @other,$_;
	}
	elsif(/that/) {
		push @another,$_;
	}
	else {
		push @crap,$_;
	}
}

##</code><code>##

open(FILE, "<file.txt");
while(local $_ = <FILE>) {
	if(/this/) {
		push @other,$_;
	}
	elsif(/that/) {
		push @another,$_;
	}
	else {
		push @stuff,$_;
	}
}
close FILE;

##</code><code>##

open(FILE,"<file.txt");
my $template = '';
while(my $line = <FILE>) {
	$template .= $line;
}
close FILE;

##</code><code>##

my $template = '';
open(FILE, "<file.txt") && while($template .= <FILE>) {};
close FILE;
die "bad stuff happened" unless length $template;