Done and done!

I went overboard on this issue. The server has a config file that it reads the actual *nix commands from, along with a pneumonic name (i.e. inodes='df -i') and stores the key-value pairs in a hash. When a client connects to the server, the server sends the pneumonics, so the client never sees the actual command.

# from server
sub get_commands() {
    open CONF, 'query.conf' or die "No config file found: $!\n";
    while (<CONF>) {
        next if /^#/;
        chomp;
        my ($command, $query) = split(/\t/, $_);
        $commands{$command} = $query;
    }
    close CONF;
}

sub send_commands {
    my $rhost = shift;
    my @commands = sort keys %commands;
    &log_msg("Request for command list from $rhost");
    return join(":", @commands);
}

# and from the client
sub get_commands {
    my $answer;
    my $i = 'a';
    eval { $answer = $conn->rpc('send_commands', $host) };
    die "Server $rhost not responding\n" if $@;
    map { $commands{$i++} = $_ } split(":", $answer);
}

sub print_menu {
    print '#' x 30, "\n";
    map { print "# $_) $commands{$_}\n" } sort keys %commands;
    print "# q) quit\n";
    print '#' x 30, "\n";
    print "Enter choice: ";
}

# the main processing loop for the client
$SIG{ALRM} = sub { die "TIMEOUT" };
&print_menu;
while (my $arg = <>) {
    last if $arg =~ /q/;
    chomp $arg;
    
    my $answer;
    eval {
        alarm(10);
        $answer = $conn->rpc('run', $commands{$arg}, $host) };
        alarm(0);
    };
    warn "$queries{$arg} timed out - $host could be down\n" if $@ =~ /
+TIMEOUT/;
    
    print $answer;
    &print_menu;
}
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Of course the major limitation at this point is only 'a' thru 'p' commands will be available.