diffrence between method call and function call in perl

Applications Infrastructure Monitoring
1

Hello,
I have a problem with package and name space.

require "/Mehran/DSGateEngineLib/general.pl";
use strict;
sub System_Status_Main_Service_Status_Intrusion_Prevention
{
 my %idpstatus;
        my @result;
        &General_ReadHash("/var/dsg/idp/settings",\%idpstatus);
        #print $idpstatus{'ENABLE_IPS'};
        if( $idpstatus{'ENABLE_IPS'} )
        {
                $result[0] = 'on';
                if( $idpstatus{'POLICY'} eq "default" )
                {
                        $result[1] = "Default";
                  }elsif ($idpstatus{'POLICY'} eq "alert")
                  { $result[1] = "Alert"; }
                  else { $result[1] = "Action"; }
        }elsif ($idpstatus{'ENABLE_IPS'} eq 'off')
        {
          $result[0] = 'off';
        }

                print $result[0]
}
&System_Status_Main_Service_Status_Intrusion_Prevention();

This is my script that work properly, but when I pack this function to other namespace and used it to another namespace an error arise. this error: used of intialized value $result[0] . Note that file have been opened and haven't any error.
below is my master file that on interpreting got me error. Code from aspect of spell and common concepts are true but I think there are an exclusive concept on package and namespace's method call that I don't know it. REALLY IT IS IMPORTANT. HELP ME Experts plz.
Thanks in advance.

package DSGateEngineLib::System;

require "DSGateEngineLib/general.pl";
#use strict;
sub new #Constructor
{
    my ($class) = @_;
    my $self = {    };
    bless $self, $class;
    return $self;
}

sub Do_Action
{
    my ($self, @arg) = @_;
    $_=$arg[0];
    #print $arg[0];
    #case "Object_Address_ListAll"
    if ($_ eq "System_Status_Main_Resource_Usage_CPU")
    {
        #print $arg[0];
        my @result =  &System_Status_Main_Resource_Usage_CPU();
        return \@result;
    }
    elsif($_ eq "System_Status_Main_Service_Status_Firewall")
    {
        my @result = &System_Status_Main_Service_Status_Firewall();
        return \@result;
    }elsif($_ eq "System_Status_Main_Service_Status_Intrusion_Prevention")
    {
        my @result = &System_Status_Main_Service_Status_Intrusion_Prevention();
        return \@result;
    }

}

#--------------------------------------------
#System -> Status -> Main -> Service Status
#--------------------------------------------
sub System_Status_Main_Service_Status_Firewall
{
    my $hash;
    my $line = `sed -n "/^firewall=/p" /var/dsg/license`;
    my $stat = index $line,'on';
    if ($stat>=0) 
    {
        return 'on';
    }elsif($stat<= -1) 
    {
        return 'off';
    }
}

sub System_Status_Main_Service_Status_Intrusion_Prevention
{
 #my %idpstatus;
    my @result;
    &General_ReadHash("/var/dsg/idp/settings",\%idpstatus);
    #print $idpstatus{'ENABLE_IPS'};
    if( $idpstatus{'ENABLE_IPS'} )
    { 
        $result[0] = 'on';
        if( $idpstatus{'POLICY'} eq "default" ) 
        { 
            $result[1] = "Default"; 
          }elsif ($idpstatus{'POLICY'} eq "alert") 
          { $result[1] = "Alert"; } 
          else { $result[1] = "Action"; }
    }elsif ($idpstatus{'ENABLE_IPS'} eq 'off') 
    { 
      $result[0] = 'off';
    }
print $result[0];
}

sub System_Status_Main_Service_Status_Web_Filter
{
}

sub System_Status_Main_Service_Status_Anti_Virus
{
}

sub System_Status_Main_Service_Status_Anti_Spam
{
}

sub System_Status_Main_Service_Status_IMnP2P
{
}

sub System_Status_Main_Service_Status_VPN
{
}

#-----------------------------------------------------
#System -> Status -> Main -> Resource Usage
#-----------------------------------------------------
sub System_Status_Main_Resource_Usage_CPU
{
    my @cpu = `ps aux`;
    chomp @cpu;
    my @cpuusage;
    $cpuusage[0]=0;
    my $flag;
    $flag = 0;chomp @cpu;
    my @partss = split('\n', $cpu[0]);
    foreach my $l (@partss)
    {
         if ($flag == 0)
        {
            $flag=1;
            next;
        }
        my @parts = split(' ', $l);
        $cpuusage[0] += $parts[2];
    }
  return $cpuusage[0];
}

sub System_Status_Main_Resource_Usage_Memory
{

  my @echom = `/usr/bin/free -ot |grep Mem`;
  my $mperc;
  #chomp(@echom);
  foreach my $mline (@echom) 
  {
    chomp($mline);
    my ($mdev, $mtotal, $mused, $mfree, $mshared, $mbuffers, $mcached) = split(/\s+/, $mline);
    my $memuse = $mfree + $mbuffers + $mcached;
    $mperc = int((($memuse/$mtotal)*100));
    $mperc = 100 - $mperc;
  }
  return $mperc;
}

sub System_Status_Main_Resource_Usage_Data_Disk
{
  my @hdddata = `df -hT | grep \"\/$\"`;
  chomp @hdddata;
  my @parts = split(' ', $hdddata[0]);
  my $HddData = $parts[5];
  return $HddData;
}

sub System_Status_Main_Resource_Usage_Log_Disk
{
  my @hddlog = `df -hT | grep \"\/var\/log$\"`;
  chomp @hddlog;
  my @parts = split(' ', $hddlog[0]);
  my $HddLog = $parts[5];
  return $HddLog;
}

#-----------------------------------------------------
#System -> Status -> Main -> System Information
#-----------------------------------------------------
sub System_Status_Main_System_Information_Serial_Number
{
}
sub System_Status_Main_System_Information_Model
{
}
sub System_Status_Main_System_Information_Firmware_Version
{
}
sub System_Status_Main_System_Information_System_Time
{
}
sub System_Status_Main_System_Information_Uptime
{
}
sub System_Status_Main_System_Information_Last_DSGate_Update
{
}
sub System_Status_Main_System_Information_Last_IDP_Update
{
}
sub System_Status_Main_System_Information_Last_AntiVirus_Update
{
}

#-----------------------------------------------------
#System -> Status -> Main -> Network Information
#-----------------------------------------------------
sub System_Status_Main_Network_Information_Port_status # Note that, this method would have loop for supporting all ports 
{
}
sub System_Status_Main_Network_Information_Packet_Statistic_All
{
}
sub System_Status_Main_Network_Information_Packet_Statistic_TCP
{
}
sub System_Status_Main_Network_Information_Packet_Statistic_ICMP
{
}
sub System_Status_Main_Network_Information_Packet_Statistic_HTTP
{
}
sub System_Status_Main_Network_Information_Packet_Statistic_UDP
{
}

#-----------------------------------------------------
#System -> Status -> Main -> Traffic Graph
#-----------------------------------------------------
sub System_Status_Main_Traffic_Graph_Ports # Note that, this method would have loop for supporting all ports
{
}

#-----------------------------------------------------
#System -> Status -> Main -> Last Signatures Updates
#-----------------------------------------------------
sub System_Status_Main_Last_Signatures_Update
{
}

#-----------------------------------------------------
#System -> Status -> Main -> Alert Message
#-----------------------------------------------------
sub System_Status_Main_Alert_Messages
{
}

##################################################################################
#---------------------------------------------------------------------------------
#System -> Status -> Monitor
#_________________________________________________________________________________
##################################################################################
sub System_Status_Monitor_System_Resources
{
}

#---------------------------------------------------------------------------------
#System -> Status -> Monitor -> System Resources
#---------------------------------------------------------------------------------
sub System_Status_Monitor_System_Resources_Traffic_On_Ports
{
}

sub System_Status_Monitor_System_Resources_Memory_Usage_Over_Last_Hour
{
}

sub System_Status_Monitor_System_Resources_CPU_Load_Over_The_Last_Hour
{
}

##################################################################################
#---------------------------------------------------------------------------------
#System -> Status -> Sessions
#_________________________________________________________________________________
##################################################################################
sub System_Status_Session_Conntrack_Viewer
{
}
sub System_Status_Session_Active_Connections
{
 #Total: 1    connections    TCP: 1    UDP: 0    ICMP: 0
}
sub System_Status_Session_Connections_ListAll
{
 #There are fields Proto-SRCIP-SRCPort-SRCPackets-SRCbytes-State-DSTIP-DSTPort-DSTPackets-DSTbytes
}


################################################
#--------------------------------------------
#System -> Admin -> Users
#--------------------------------------------
################################################
sub System_Admin_Current_Users_Lists
{
}
sub System_Admin_Current_Users_Edit
{
}
sub System_Admin_Current_Users_Delete
{
}

sub System_Admin_AddNew_User
{
}
################################################
#--------------------------------------------
#System -> Admin -> Permissions
#--------------------------------------------
################################################

sub System_Admin_Permissions_List_Of_Users_and_Permissions
{
}
sub System_Admin_Permissions_Edit_Permissions
{
}
sub System_Admin_Permissions_Delete
{
}
################################################
#--------------------------------------------
#System -> Config -> Time
#--------------------------------------------
################################################
sub System_Config_Time_Apply
{
    #Some of inputed variable
    #(Time Zone, Time and Date, Network Time Retrieval, Network Time Servers)
}
sub System_Config_Time_Get
{
    #Some of inputed variable
    #(Time Zone, Time and Date, Network Time Retrieval, Network Time Servers)
}

################################################
#--------------------------------------------
#System -> Config -> Admin
#--------------------------------------------
################################################
sub System_Config_Admin_Authenticate_Time_Out_Set
{

}
sub System_Config_Admin_Authenticate_Time_Out_Get
{

}

################################################
#--------------------------------------------
#System -> Config -> ISPUtil GUI
#--------------------------------------------
################################################
sub System_Config_ISPUtil_Interface_Check_Status
{
}

sub System_Config_ISPUtil_Connector_Apply
{
}
sub System_Config_ISPUtil_Connector_Get
{
}

sub System_Config_ISPUtil_Parameters_List_Apply
{
}
sub System_Config_ISPUtil_Parameters_List_Get
{
}
################################################
#--------------------------------------------
#System -> Config -> SNMP
#--------------------------------------------
################################################
sub System_Config_SNMP_Status_Apply
{
}
sub System_Config_SNMP_Status_Get
{
}
################################################
#--------------------------------------------
#System -> Maintenance -> Backup
#--------------------------------------------
################################################
sub System_Maintenace_Make_Backup
{
}

sub System_Maintenace_Restore_Backup
{
}

################################################
#--------------------------------------------
#System -> Maintenace -> Update
#--------------------------------------------
################################################
sub System_Maintenace_AutoUpdate_Settings
{
}
sub System_Maintenace_ManualUpdate_Settings
{
}
sub System_Maintenace_ManualUpdate_Install
{
}
################################################
#--------------------------------------------
#System -> Maintenace -> Update
#--------------------------------------------
################################################
sub System_Maintenace_License_CurrentLicense
{
}

################################################
#--------------------------------------------
#System -> Maintenace -> Tools
#--------------------------------------------
################################################
sub System_Maintenace_Tools_Ping_Traceroute_Whois
{
}
sub System_Maintenace_Tools_SystemOperation_Default_Factory
{
}
sub System_Maintenace_Tools_SystemOperation_Reboot_Shutdown
{
}
################################################
#--------------------------------------------
#System -> Notifications -> Setting
#--------------------------------------------
################################################
sub System_Notifications_Setting_List_All
{
}
sub System_Notifications_Setting_Groups_AddNew
{
}
sub System_Notifications_Setting_Edit
{
}
sub System_Notifications_Setting_Delete
{
}

################################################
#--------------------------------------------
#System -> Notifications -> Alerts
#--------------------------------------------
################################################
sub System_Notifications_Alerts_List_All
{
}
sub System_Notifications_Alerts_Groups_AddNew
{
}
sub System_Notifications_Alerts_Edit
{
}
sub System_Notifications_Alerts_Delete
{
}
################################################
#--------------------------------------------
#System -> User -> Radius
#--------------------------------------------
################################################
sub System_User_Current_Radius_Server_AddNew
{
}
sub System_User_Current_Radius_Server_Get
{
}

################################################
#--------------------------------------------
#System -> User -> Ldap
#--------------------------------------------
################################################

sub System_User_Current_Ldap_Server_AddNew
{
}
sub System_User_Current_Ldap_Server_Get
{
}

#&System_Status_Main_Service_Status_Intrusion_Prevention();For debuging reasons
1;
2

Just guessing....

After cleaning up this sloppy code to make it readable you can see that $result[0] has the chance of never being defined:

rrequire "/Mehran/DSGateEngineLib/general.pl";
use strict;
sub System_Status_Main_Service_Status_Intrusion_Prevention {
   my %idpstatus;
   my @result;
   &General_ReadHash("/var/dsg/idp/settings",\%idpstatus);
   #print $idpstatus{'ENABLE_IPS'};
   if( $idpstatus{'ENABLE_IPS'} ){
      $result[0] = 'on';
      if( $idpstatus{'POLICY'} eq "default" ){
         $result[1] = "Default";
      }
      elsif ($idpstatus{'POLICY'} eq "alert"){
         $result[1] = "Alert";
      }
      else {
         $result[1] = "Action";
      }
   }
   elsif ($idpstatus{'ENABLE_IPS'} eq 'off'){
      $result[0] = 'off';
   }
   print $result[0]
}
&System_Status_Main_Service_Status_Intrusion_Prevention();

You should add a fall-through condition to the end of the if/elsif block to make sure $result[0] will always be defined:

require "/Mehran/DSGateEngineLib/general.pl";
use strict;
sub System_Status_Main_Service_Status_Intrusion_Prevention {
   my %idpstatus;
   my @result;
   &General_ReadHash("/var/dsg/idp/settings",\%idpstatus);
   #print $idpstatus{'ENABLE_IPS'};
   if( $idpstatus{'ENABLE_IPS'} ){
      $result[0] = 'on';
      if( $idpstatus{'POLICY'} eq "default" ){
         $result[1] = "Default";
      }
      elsif ($idpstatus{'POLICY'} eq "alert"){
         $result[1] = "Alert";
      }
      else {
         $result[1] = "Action";
      }
   }
   elsif ($idpstatus{'ENABLE_IPS'} eq 'off'){
      $result[0] = 'off';
   }
   else { #<-- fall-through condition 
      $result[0] = 'unknown status';
   }
   print $result[0]
}
&System_Status_Main_Service_Status_Intrusion_Prevention();
3

Its worth nothing that the below elsif condition will never be evaluated:

   elsif ($idpstatus{'ENABLE_IPS'} eq 'off'){
      $result[0] = 'off';
   }

I leave it up to you to figure out why that is.

4

Kevin thanks.
it's sloppy code due to it is under constructor.:smiley:
but my problem isn't fall through condition. I have two code. the first code work properly. my problem is method call. Mr kevin, when I call the first code, it works good due to I call that function at the end of same name space (file)."&System_Status_Main_Service_Status_Intrusion_Prevention();".

but when I call it from an other perl file (name space ) which System.pm used on it, an error occured. sake is strange!:eek::frowning: .
Error is use of uninitialized idpstatus{"ENABLE_IPS"}.

5

You should at least test the code with the fall-through condition added and see if that gets the script to run without reporting the warning (its not an error) about the unintialized variable. If it does not get rid of the warning you will know my suggestion is wrong, but if it does then your assumption of what is causing the warning could be wrong. And please note, it is a warning, not an error. Sometimes variables do have the chance of being uniitialized, which is why a default or fall-through condition is almost always a good idea.

Also, writing neat and readable code during constructions is very important, that is no excuse for writing sloppy code. Slopy code always makes tracking down bugs much harder than it should be. Its very good though that you are using "strict" and I assume "warnings".