#use strict;
use warnings;
use Term::ReadLine;

my $prompt = "prompt> ";
my $prog = Term::ReadLine->new('Script');
$prog->ornaments(0);

while (defined (my $cmd = $prog->readline($prompt))) {
    chomp $cmd;

    # nothing
    if ($cmd =~ /^\s*$/)        { next }
    # exit
    if ($cmd =~ /^\s*exit\s*$/) { last }

    # execute
    eval $cmd;
    warn $@ if $@;

    print "\n"
}

sub command {
    print "Special command";
}

##</code><code>##

VinsWorldcom@C:\Users\VinsWorldcom\tmp> perl script.pl

prompt> command
Special command

prompt> $var1 = "variable"


prompt> print $var1
variable

prompt> $var1 = "variable1"


prompt> print $var1
variable1

prompt> exit

VinsWorldcom@C:\Users\VinsWorldcom\tmp>

##</code><code>##

package MyPackage;

...

sub variables {

    my %SKIP = (
        # list var names that you want to ignore
    );

    for my $var (sort(keys(%MyPackage::))) {
        if (defined(${$var}) && !defined($SKIP{$var})) {
            print "\$$var = ${$var}\n"
        }
    }
}