perl -nle '$t+=$_}{print$t'

##</code><code>##

LINE: while(<>) { 
  perl -nle '$t+=$_}{print$t
}

##</code><code>##

perl -wnE '$s+=$_}{say$s'

##</code><code>##

Can't call method "say" without a package or object reference at -e line 1, <> line 2.

##</code><code>##

perl -wnE '$s+=$_;END{say$s}'

##</code><code>##

$ perl -MO=Deparse -wnE '$s+=$_}{say$s'

##</code><code>##

BEGIN { $^W = 1; }
LINE: while (defined($_ = <ARGV>)) {
    BEGIN {
        $^H{'feature_say'} = q(1);
        $^H{'feature_state'} = q(1);
        $^H{'feature_switch'} = q(1);
    }
    $s += $_;
}
{
    $s->say;
}
-e syntax OK
$