I use something like these configs in my previous job.

use strict;
use warnings;
use Getopt::Long;
use Data::Dumper;

my $log;
my $account;

my $href = {};

my $globalConfig = "globalConfig.cfg";
my $localConfig = "localConfig.cfg";


GetOptions (
    "log=s" => \$log,
    "account=s" => \$account
);

&getEnv($globalConfig); 
&getEnv($localConfig); 

print Dumper $href;

exit;

sub getEnv {
#    my $href = shift(@_);
    my $file = shift(@_);
    
    unless ( -e $file ) {
        print "Could not find $file \n";
        exit(1);
    }

    open ( FILE , "< $file" );

    while (<FILE> ) {
        chomp;

        next if $_ =~ /^\#/;

        my ($key, $variable) = split(/=/,$_,2);
        if ( $variable && $key ) {
            $variable    =~ s/\s+//g;
            $key        =~ s/\s+//g;
            $href->{config}->{$key} = $variable;
        }
    }
    close FILE;
}
[download]

globalConfig.cfg

#comment
log=global.log
dir=c:\somepath
[download]

localConfig.cfg

#comment
log=local.log
account=C123454
[download]

output

$VAR1 = {
          'config' => {
                        'account' => 'C123454',
                        'log' => 'local.log',
                        'dir' => 'c:\\somepath'
                      }
        };
[download]