my $last = (map {/^.*(pat)/} <>)[-1];

##</code><code>##

my ($last) = (`grep pat file`)[1] =~ /^.*(pat)/;

##</code><code>##

use autodie;
open my $fh, "<", "file";
my $last;
while (<>) {
    $last = $1 if /^.*(pat)/;
}