G'day goldenblue,

This is something of an XY Problem inasmuch as you've provided a solution idea without specifying the actual problem you are attempting to solve. Consequently, my response is based on guesses regarding the problem and is, therefore, somewhat generic.

One of the first things that leapt out at me was your use of symbolic references. If you follow that link, you'll find problems with your code: see what it says about package vs. lexical variables and that it's the "refs" stricture (of strict) that will complain about using symbolic references.

However, I'm not suggesting you fix those coding problems! Use of symbolic references can result in all sorts of problems and I recommend you avoid them unless you have a very good reason not to and know exactly what you are doing and why. For a more detailed discussion, read "Why it's stupid to `use a variable as a variable name' - Parts I, II and III" by Mark Jason Dominus.

Here's an alternative, general solution that may be better:

#!/usr/bin/env perl -l

use strict;
use warnings;

my %cmd_gen = (
    backup => sub {
        my ($bak_cmd, $client, $file) = @_;
        return [ $bak_cmd, $client, '>', $file ];
    },
    list => sub {
        my ($list_cmd, $client) = @_;
        return [ $list_cmd, '-le', $client ];
    },
);

my $bak_cmd = 'some_backup_prog';
my $list_cmd = 'some_list_prog';

for my $client (qw{XXX YYY ZZZ}) {
    my $file = $client . '.bak';
    my $backup_cmd_ref = $cmd_gen{backup}->($bak_cmd, $client, $file);
    #system(@$backup_cmd_ref);  # for production
    print "@$backup_cmd_ref";   # for debugging
    my $list_cmd_ref = $cmd_gen{list}->($list_cmd, $client);
    #system(@$list_cmd_ref);  # for production
    print "@$list_cmd_ref";   # for debugging
}
[download]

Output:

some_backup_prog XXX > XXX.bak
some_list_prog -le XXX
some_backup_prog YYY > YYY.bak
some_list_prog -le YYY
some_backup_prog ZZZ > ZZZ.bak
some_list_prog -le ZZZ
[download]

Some values (e.g. for $bak_cmd and $list_cmd) may be known in advance from configuration, environment variables, defaults, command line options, etc. In this case, your function calls would be simpler, e.g. $cmd_gen{list}->($client).