There are many ways to use config files within perl, one popular way is with YAML.

appconf.yaml:

dsn: 'foo'
user: 'userid'
password: 'supersecret'
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configtest.pl:

#!/usr/bin/perl

use strict;
use warnings;
use YAML::XS 'LoadFile';

my $config = LoadFile('appconf.yaml');

my $dsn = $config->{dsn};
my $user = $config->{user};
my $password = $config->{password};

print "dsn: $dsn - user: $user - password: $password\n";
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Update: forgot the output:

dsn: foo - user: userid - password: supersecret
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