Mine

#!/usr/bin/env perl

use Term::ReadLine;

$term = new Term::ReadLine 'oneliner evaluator';
$prompt = "oneliner> ";
$OUT = $term->OUT || \*STDOUT;

use warnings;

while ( defined ($_ = $term->readline($prompt)) ) {
  $cmd = "\$|=1; $_";  # make the cmd force output before the next prompt
  eval($cmd);
  warn $@ if $@;
  $term->addhistory($_) if /\S/;
}