my $PATHconf = '/etc/astguiclient.conf'; # declared and initialized
my ( # declared with "my" but not initialized
$PATHlogs,
$VARserver_ip,
$VARDB_server,
$VARDB_database,
$VARDB_user,
$VARDB_pass,
$VARDB_custom_user,
$VARDB_custom_pass,
$VARDB_port);
You need to initialize your declared variables by defining their values:
my $PATHconf = '/etc/astguiclient.conf';
my $PATHlogs = '/path/to/logs';
my $VARserver_ip = '1.2.3.4';
my $VARDB_server = 'your_db_server';
my $VARDB_database = 'name_of_database';
my $VARDB_user = 'the_db_username';
my $VARDB_pass = 'the_db_password';