It doesn't work this way. In the master script you define your variables, however you run another perl script via system. It knows nothing about the variables in the master script. Consider the following example: master.pl

#!/usr/bin/perl

use strict;
use warnings;

my $secret = 'BruceWayneisBatman';

my @cmd = ('perl', 'child.pl', $secret);
system(@cmd) == 0 or die "system @cmd failed: $?";
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child.pl

#!/usr/bin/perl

use strict;
use warnings;

my $message = $ARGV[0];

print "The master script passed: $message\n";
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Again see system.

Nothing technically wrong with this, just a remark/reminder.

Passing a secret via the command line exposes the secret in the process list. Everybody with access to 'ps' or /proc/<pid>/cmdline can see the secret. (This may include some totally unrelated piece of software which logs the contents of 'ps -ef' for debugging/troubleshooting purposes.)

Yes, this is kinda obvious, but I wanted to put attention to it anyway.

$secret was a light hearted variable name, it should have just been $message. Obviously Bruce Wayne isn't Batman, how could he possibly keep up crime fighting at night while tending to the affairs of the Wayne foundation? (a Simpsons reference if you're unaware ;). Your point is valid however. See further down the thread were 20 or so paths are supposed to be getting passed to 50 different child scripts, and the suggestion using config files rather than passing anything in this manner.