This is a fake shell I use. It's limited in what it really does but I like it a lot for testing and playing with simple things.

#!/usr/bin/perl -wn
BEGIN {
    sub cl { print `clear` }  # i like a clear screen
    sub q  { exit 0 }         # i like a simple exit
    $SIG{$_} = 'IGNORE' for keys %SIG;
    print "\n\tType\e[1m exit\e[0m when you are ready to stop.\n";
    $history = 1;
    sub prompt {
        print "\n", $ENV{USER}, '@perl-shell[', $history++, ']>';
    }
    prompt();
}
eval;
$@ ne "" and warn $@;  # give perl errors back to the user
prompt();              # print a fresh prompt with updated history
END { print "\n\t\tBye!\n\n"; }
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