mail queue issues EXIM in CPanel

Today, I have sudden issues with the Email server in Cpanel. As we know Cpanel is using EXIM as MTA. The issue was the sudden full of hard disk of the /var.  After basic troubleshooting of the logs file, I found there was a huge mail queue in the list causing /var/log/exim/input and msglog files huge sizes. 
Firstly, I deleted the files inside the input and msglogs to make some space-free. After that, I used the following command to check the mail queue.

system@system.com# exim -bp
23h       1qffqz-0002bF-0E <sandesh@abc.com>
          donj.cheri@gmail.com
          jakal_6@libero.it
          cf@fritzsche-baurecht.ch
          carlotuti@libero.it
          info@eigenheim-messen.ch
          jonny318it1800@yahoo.it
          centro@universoturismo.it
          paolaviola3@virgilio.it
          italiamassimo@yahoo.it
          ermacal5@libero.it
          chrkaelin@sunrise.ch
          pierguidi@interfree.it
          saviox@alice.it
          angelo_galassi@fastwebnet.it

This user has around 67k emails in the queue. To remove all the mail of that user I used the following command

system@system.com#exiqgrep -i -f sandesh@abc.com | xargs exim -Mrm

This command deletes all the queue emails sent by this user. After that, I suspended the user and changed the password for further troubleshooting.

For more commands:

To display the number of emails in the queue we use the command

exim -bpc

To count the emails for a particular sender we use the command

exim -bp|grep "<"|grep $user-name|wc -l

Recently one of our customers contacted us to delete all the mails in his mail queue with Exim command. Let us discuss how our Support Engineers use Exim commands to delete the queue.

 

Exim delete mail queue

To remove all messages from the queue, we use the below command.

exim -bp|grep "<"|awk {'print $3'}|xargs exim -Mrm

or

exim -bp | awk '/^ *[0-9]+[mhd]/{print "exim -Mrm " $3}' | bash

In this method, the command ‘exim -bp’ is used to find-out the message ID from the Exim mail queue.

And then remove the corresponding email from the mail queue by using the command ‘exim -Mrm’ as an argument.

We also use exiqgrep command to delete the mail queue.

exiqgrep -i | xargs exim -Mrm

 

Also, To remove a message from the queue, we use the command.

exim -Mrm {message-id}

 

Similarly, to remove all emails from a particular user from the queue.

exiqgrep -i -f $user | xargs exim -Mrm

 

Also, to remove all frozen messages, we use the below commands.

exiqgrep -z -i | xargs exim -Mrm

Read more ...

Dialog BOX in Custom Base Adaptor

package com.example.dlistview;

import java.util.ArrayList;

import android.app.AlertDialog;
import android.app.AlertDialog.Builder;
import android.app.Application;
import android.app.Dialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.DialogInterface.OnClickListener;
import android.content.Intent;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

public class CustomAdapter extends BaseAdapter {

     private static final String TAG = CustomAdapter.class.getSimpleName();
        ArrayList<DataModel> listArray;
        public CustomAdapter() {
           /* listArray = new ArrayList<DataModel>(5);
            listArray.add(new DataModel("name1", 5, 1.8, "Java"));
            listArray.add(new DataModel("name2", 10, 2.8, "Python"));
            listArray.add(new DataModel("name3", 15, 3.8, "Django"));
            listArray.add(new DataModel("name4", 20, 4.8, "Groovy"));
            listArray.add(new DataModel("name5", 25, 5.8, "Maven")); */
           
            listArray = new ArrayList<DataModel>(5);
            listArray.add(new DataModel("Class 1",1));
            listArray.add(new DataModel("Class 2",2));
            listArray.add(new DataModel("Class 3",3));
            listArray.add(new DataModel("Class 4",4));
            listArray.add(new DataModel("Class 5",5));
        }
   
        @Override
        public int getCount() {
            return listArray.size();    // total number of elements in the list
        }
   
        @Override
        public Object getItem(int i) {
            return listArray.get(i);    // single item in the list
        }
   
        @Override
        public long getItemId(int i) {
            return i;                   // index number
        }
   
        @Override
        public View getView(int index, View view, final ViewGroup parent) {
   
            if (view == null) {
                LayoutInflater inflater = LayoutInflater.from(parent.getContext());
              // view = inflater.inflate(R.layout.single_list_item, parent, false);
                view = inflater.inflate(R.layout.linear_test,parent,false);
            }
   
            //final DataModel dataModel = listArray.get(index);
           final  DataModel  dataModel = listArray.get(index);
   
           /* TextView textView = (TextView) view.findViewById(R.id.tv_string_data);
            textView.setText(dataModel.getName());
   
            Button button = (Button) view.findViewById(R.id.btn_number_data);
            button.setText("" + dataModel.getAnInt());
   
            textView = (TextView) view.findViewById(R.id.tv_double_data);
            textView.setText("" + dataModel.getaDouble()); */
           
         TextView textView = (TextView) view.findViewById(R.id.tv_question);
         textView.setText(dataModel.getName());
   
         Button btnyes = (Button) view.findViewById(R.id.button2);
         Button btnno = (Button) view.findViewById(R.id.button1);
        
        
         btnyes.setOnClickListener(new View.OnClickListener() {
           
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                //Toast.makeText(parent.getContext(), "Button Clicked"+ dataModel.getName(),Toast.LENGTH_LONG).show();
                //Intent yes= new Intent(parent.getContext(), yes(dataModel.getName().class));
                switch( dataModel.getAnInt()){
                case 1:
                    Intent intent = new Intent(parent.getContext(),Yes1.class);
                    parent.getContext().startActivity(intent);
                    break;
                   
                case 2:
                    Toast.makeText(parent.getContext(), "Button Clicked"+ dataModel.getName(),Toast.LENGTH_LONG).show();
                showmessagebox(parent.getContext(),dataModel.getName(),dataModel.getAnInt());
                    break;
   
                case 3:    
                    Toast.makeText(parent.getContext(), "Button Clicked"+ dataModel.getName(),Toast.LENGTH_LONG).show();
                default:
               
                }
               
            }
        });
        
        

        
        
        
        // button click listener
            // this chunk of code will run, if user click the button
            // because, we set the click listener on the button only
   
           /* button.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    Log.d(TAG, "string: " + dataModel.getName());
                 //   Log.d(TAG, "int: " + dataModel.getAnInt());
                  //  Log.d(TAG, "double: " + dataModel.getaDouble());
                   // Log.d(TAG, "otherData: " + dataModel.getOtherData());
   
                    Toast.makeText(parent.getContext(), "button clicked: " + dataModel.getName(), Toast.LENGTH_SHORT).show();
                }
            });   */
   
   
            // if you commented out the above chunk of code and
            // activate this chunk of code
            // then if user click on any view inside the list view (except button)
            // this chunk of code will execute
            // because we set the click listener on the whole view
   
   
            view.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    Log.d(TAG, "string: " + dataModel.getName());
                   // Log.d(TAG, "int: " + dataModel.getAnInt());
                    //Log.d(TAG, "double: " + dataModel.getaDouble());
                    //Log.d(TAG, "otherData: " + dataModel.getOtherData());
   
                    Toast.makeText(parent.getContext(), "view clicked: " + dataModel.getName(), Toast.LENGTH_SHORT).show();
                }
            });
   
            return view;
        }



        public void showmessagebox(final Context context, String msg, final int position)
        {
            AlertDialog ad = new AlertDialog.Builder(context)
            .setMessage(msg)
            .setIcon(R.drawable.ic_launcher)
            .setTitle("Terms of Service")
            .setPositiveButton("Yes", new DialogInterface.OnClickListener() {
               
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    // TODO Auto-generated method stub
                    switch(position){
                    case 1:


                        break;
                       
                    case 2:
                        Intent intent = new Intent(context,Yes1.class);
                        context.startActivity(intent);
                        break;
       
                    case 3:    


                    default:
                   
                    }

                }

               
            })
       // .setNegativeButton("No", this)
        //    .setNeutralButton("Cancel", this)
            .setCancelable(false)
            .create();
            ad.show();   
        }
   
}

Read more ...

OnClick Listner on Button on ListView/ Base Adaptor

Here is how i did onClick Listner event on button on ListView with startActivity inside BaseAdaptor.


main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:orientation="vertical"
              android:layout_width="fill_parent"
              android:layout_height="fill_parent" >
    <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="ListView Button Click Example" />

    <ListView android:id="@+id/list_data"
              android:layout_height="match_parent"
              android:layout_width="match_parent" />
</LinearLayout>



linear_test.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/layoutContainer"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_weight="5"
    android:orientation="horizontal" >

    <LinearLayout
        android:id="@+id/LinearLayout1"
        android:layout_width="match_parent"
        android:layout_weight="3"
        android:layout_height="wrap_content" >

        <TextView
            android:id="@+id/tv_question"
            android:layout_width="wrap_content"
            android:layout_height="48dp"
            android:text="Are you Sure want to make sure you can do this ?" />
    </LinearLayout>

    <LinearLayout
        android:id="@+id/LinearLayout1"
        
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" >

        <Button
            android:id="@+id/button2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Yes" />

        <Button
            android:id="@+id/button1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="No" />
    </LinearLayout>

</LinearLayout>



MainActivity.java


package com.example.dlistview;

import java.util.ArrayList;

import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.LinearLayout;
import android.os.Build;
import android.app.Activity;
import android.view.ViewGroup.LayoutParams;
import android.widget.ListView;
import android.widget.RelativeLayout;
import android.widget.TextView;

public class MainActivity extends ActionBarActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
           
            final String TAG = MainActivity.class.getSimpleName();
       
                ListView listView = (ListView) findViewById(R.id.list_data);
       
                CustomAdapter customAdapter = new CustomAdapter();
       
                listView.setAdapter(customAdapter);
       

            }
        }   



dataModel.java

package com.example.dlistview;

public class DataModel {
    private String name;
   private int anInt;


    public DataModel(String name, int anInt) {
        this.name = name;
        this.anInt=anInt;
      
    }



    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAnInt() {
        return anInt;
    }

    public void setAnInt(int anInt) {
        this.anInt = anInt;
    }
}



CustomAdaptor.java

package com.example.dlistview;

import java.util.ArrayList;

import android.content.Intent;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

public class CustomAdapter extends BaseAdapter {

     private static final String TAG = CustomAdapter.class.getSimpleName();
        ArrayList<DataModel> listArray;
   
        public CustomAdapter() {
           
            listArray = new ArrayList<DataModel>(5);
            listArray.add(new DataModel("Class 1",1));
            listArray.add(new DataModel("Class 2",2));
            listArray.add(new DataModel("Class 3",3));
            listArray.add(new DataModel("Class 4",4));
            listArray.add(new DataModel("Class 5",5));
        }
   
        @Override
        public int getCount() {
            return listArray.size();    // total number of elements in the list
        }
   
        @Override
        public Object getItem(int i) {
            return listArray.get(i);    // single item in the list
        }
   
        @Override
        public long getItemId(int i) {
            return i;                   // index number
        }
   
        @Override
        public View getView(int index, View view, final ViewGroup parent) {
   
            if (view == null) {
                LayoutInflater inflater = LayoutInflater.from(parent.getContext());
                    view = inflater.inflate(R.layout.linear_test,parent,false);
            }
   
            final DataModel dataModel = listArray.get(index);
   
           
         TextView textView = (TextView) view.findViewById(R.id.tv_question);
         textView.setText(dataModel.getName());
   
         Button btnyes = (Button) view.findViewById(R.id.button2);
         Button btnno = (Button) view.findViewById(R.id.button1);
        
        
         btnyes.setOnClickListener(new View.OnClickListener() {
           
            @Override
            public void onClick(View v) {
                   switch( dataModel.getAnInt()){
                case 1:
                    Intent intent = new Intent(parent.getContext(),Yes1.class);
                    parent.getContext().startActivity(intent);
                   
                   
                case 2:
                    Toast.makeText(parent.getContext(), "Button Clicked"+ dataModel.getName(),Toast.LENGTH_LONG).show();
                   
                case 3:    
                    Toast.makeText(parent.getContext(), "Button Clicked"+ dataModel.getName(),Toast.LENGTH_LONG).show();
                default:
               
                }
               
            }
        });
             
   
            view.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    Log.d(TAG, "string: " + dataModel.getName());
                         Toast.makeText(parent.getContext(), "view clicked: " + dataModel.getName(), Toast.LENGTH_SHORT).show();
                }
            });
   
            return view;
        }
    }


Here is the screenshot

Read more ...

Dyanmic List using code

package com.example.dynamicview;

import java.util.ArrayList;

import android.app.Activity;
import android.app.ActionBar;
import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewGroup.LayoutParams;
import android.widget.LinearLayout;
import android.widget.RelativeLayout;
import android.widget.TextView;
import android.os.Build;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

       
//        String[] StringArray = { "one", "two", "three", "four", "five" };
    /*    ArrayList<String> name = new ArrayList<String>();
        name.add("Google");
        name.add("Microsoft");
        name.add("Apple");
        name.add("Oracle");
        int topval=100;
       
        RelativeLayout layout = new RelativeLayout(this);
        RelativeLayout.LayoutParams relativeParams = new RelativeLayout.LayoutParams(
                LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
        for (int i = 0; i < name.size(); i++) {
            TextView tv = new TextView(getApplicationContext());
            tv.setText(name.get(i));
            relativeParams.addRule(RelativeLayout.BELOW, tv.getId());
            relativeParams.topMargin=topval+100;
            layout.addView(tv, relativeParams);
        }       
       
        setContentView(layout);*/
       
        ArrayList<Person> namelist = new ArrayList<Person>();
        namelist.add(new Person("Ram","Bagbazar","98011234534"));
        namelist.add(new Person("Ram","Bagbazar","98011234534"));
        namelist.add(new Person("Ram","Bagbazar","98011234534"));
        namelist.add(new Person("Ram","Bagbazar","98011234534"));
        namelist.add(new Person("Ram","Bagbazar","98011234534"));
        namelist.add(new Person("Ram","Bagbazar","98011234534"));
        namelist.add(new Person("Ram","Bagbazar","98011234534"));
        namelist.add(new Person("Ram","Bagbazar","98011234534"));
        namelist.add(new Person("Ram","Bagbazar","98011234534"));
        namelist.add(new Person("Ram","Bagbazar","98011234534"));
        namelist.add(new Person("Ram","Bagbazar","98011234534"));
        namelist.add(new Person("Ram","Bagbazar","98011234534"));
        namelist.add(new Person("Ram","Bagbazar","98011234534"));
        namelist.add(new Person("Ram","Bagbazar","98011234534"));
        namelist.add(new Person("Ram","Bagbazar","98011234534"));
        namelist.add(new Person("Ram","Bagbazar","98011234534"));
        namelist.add(new Person("Ram","Bagbazar","98011234534"));
        namelist.add(new Person("Ram","Bagbazar","98011234534"));
       
        LinearLayout layout;
        layout = (LinearLayout) findViewById(R.id.wrapper);
       
        for(int i=0;i<namelist.size();i++){
       
    View row=    getLayoutInflater().inflate(R.layout.list_row, null);
       
        TextView list_name = (TextView) row.findViewById(R.id.list_text);
        TextView list_address = (TextView) row.findViewById(R.id.list_address);
        TextView list_phone = (TextView) row.findViewById(R.id.list_phone);
   
        list_name.setText(namelist.get(i).getName());
        list_address.setText(namelist.get(i).getAddress());
        list_phone.setText(namelist.get(i).getPhone());
       
        layout.addView(row);
        }
        //setContentView(layout);
}
}











//list_view.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/LinearLayout1"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical" >
    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:paddingLeft="10dp" >
        <TextView
            android:id="@+id/tvName"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentLeft="true"
            android:layout_alignParentTop="true"
            android:hint="Amir Shrestha"
            android:textSize="20sp" />
        <TextView
            android:id="@+id/tvPhone"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentLeft="true"
            android:layout_below="@+id/tvName"
            android:hint="9801165310" />
        <TextView
            android:id="@+id/tvAddress"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_above="@+id/tvPhone"
            android:layout_marginLeft="20dp"
            android:layout_toRightOf="@+id/tvName"
            android:hint="Dhapasi" />
        <View
            android:id="@+id/view1"
            android:layout_width="match_parent"
            android:layout_height="1dp"
            android:layout_alignRight="@+id/imPhone"
            android:layout_below="@+id/tvPhone"
            android:background="#B2BEB5"
            android:paddingBottom="10dp"
            android:paddingTop="10dp" />
        <ImageView
            android:id="@+id/imPhone"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentRight="true"
            android:layout_alignParentTop="true"
            android:layout_marginRight="20dp"
            android:src="@android:drawable/ic_menu_call" />
    </RelativeLayout>
</LinearLayout>


//activity_main.xml
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
   
<RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    >
   
   
    <LinearLayout android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:orientation="vertical"
    android:id="@+id/wrapper">
   
   

</LinearLayout>
   
   

</RelativeLayout>
</ScrollView>

Read more ...

Dynamic Array and component intialization in Android

package com.example.dynamicview;

import java.util.ArrayList;

import android.app.Activity;
import android.app.ActionBar;
import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewGroup.LayoutParams;
import android.widget.RelativeLayout;
import android.widget.TextView;
import android.os.Build;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
    //    setContentView(R.layout.activity_main);

       
//        String[] StringArray = { "one", "two", "three", "four", "five" };
        ArrayList<String> name = new ArrayList<String>();
        name.add("Google");
        name.add("Microsoft");
        name.add("Apple");
        name.add("Oracle");
        int topval=100;
       
        RelativeLayout layout = new RelativeLayout(this);
        RelativeLayout.LayoutParams relativeParams = new RelativeLayout.LayoutParams(
                LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
        for (int i = 0; i < name.size(); i++) {
            TextView tv = new TextView(getApplicationContext());
            tv.setText(name.get(i));
            relativeParams.addRule(RelativeLayout.BELOW, tv.getId());
            relativeParams.topMargin=topval+100;
            layout.addView(tv, relativeParams);
        }       
       
        setContentView(layout);
    }
   

}

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Access Control List (ACL) using setfacl/getfacl in Linux

Access Control List using setfacl/getfacl in Linux

The basic Linux permission model lets you specify permissions for the file's owner and group, and all others. This article assumes that you are familiar with the basic permissions, and know how to set them. The Access Control List (ACL) feature extends the model to allow much finer control: you can specify permissions for each individual user and group defined in your system.

Consider this scenario: your server supports multiple office departments: Sales, Marketing, and Helpdesk. Each department has a manager, and one or more staff members.

You define a group for each department that comprises of its manager and staff members: sales-g, marketing-g, and helpdesk-g. Then, you also define a managers only group: managers-g.

It is normal that some departments need to share files among each other, but not with all departments. For instance, Sales needs to share a file with Marketing, but not with HelpDesk. To set that up using only the basic permissions, you can define yet more groups: sales-marketing-g, sales-marketing-managers-g, etc.

Alternatively, you can use ACL to assign permissions to individual group and user.

Before you can use ACL, you must explicitly turn it on for the partitions you want to have the ACL feature available.

As root, edit /etc/fstab. Find the partition that you want ACL enabled, and add the mount option acl.

/dev/mapper/allabtlinux-home /home ext3  defaults,acl 0 2

Next, assuming that your partition is already mounted, then either reboot the system, or better yet, remount dynamically:

mount -o remount,acl /home

                                                            

Next, you need to make sure that you have 2 ACL utilities installed: getfacl, and setfacl.

On a Debian/Ubuntu system, install the utilities like this:

$ apt-get install acl

Now, you are ready to take ACL using getfacl and setfacl command.

Let's start simple: you have a file /home/linuxacldemo/demofile.txt that you want to share between sales-g, marketing-g, and an user named aarav.

$ cd /home/linuxacldemo

$ ls -l
total 64
-rw-r--r-- 1 linuxacldemo linuxacldemo 80000 2013-12-28 10:55 demofile.txt

Use setfacl -m to set Access Control List for the file.

$ setfacl -m group:sales-g:rw-   demofile.txt

The group:sales-g:rw- parameter specifies Read and Write permissions (rw) for the group: sales-g.

To enable the Read/Write permissions for the Marketing department, and aarav the user:

$ setfacl -m group:marketing-g:rw-,user:aarav:rw- demofile.txt
$ ls -l
total 68
-rw-rw-r--+ 1 linuxacldemo linuxacldemo 8000 2013-12-28 10:55 demofile.txt

Note that ls -l does not display the actual ACL of a file. It only tells you that ACL is defined for that file: a plus character (+) is displayed to the right of the permissions.

To examine the actual ACL, run getfacl.

$ getfacl demofile.txt
# file: demofile.txt
# owner: linuxacldemo
# group: linuxacldemo
user::rw-
user:aarav:rw-
group::r--
group:sales-g:rw-
group:marketing-g:rw-
mask::rw-
other::r--

Often, you want to share files among certain groups and specific users. It is a good practice to designate a directory for that purpose. You want to allow those groups and users to read, and write files in that directory, as well as create new files into the directory.

Let's first create the directory named testacldirectory.

$ mkdir testacldirectory
$ ls -ld testacldirectory/
drwxr-xr-x 2 linuxacldemo linuxacldemo 4096 2013-12-28 14:33 testacldirectory/

We want to share the directory among the marketing-g and sales-g groups and the user named aarav. Sales, marketing and aarav need to have full access to the directory including the creation of new files in that directory.

$ setfacl -m user:aarav:rwx,group:sales-g:rwx,group:marketing-g:rwx testacldirectory
$ getfacl testacldirectory/
# file: testacldirectory
# owner: linuxacldemo
# group: linuxacldemo
user::rwx
user:aarav:rwx
group::r-x
group:sales-g:rwx
group:marketing-g:rwx
mask::rwx
other::r-x

OK, aarav, go ahead to create a file in testacldirectory.

$ su - aarav
...
$ cd /home/linuxacldemo/testacldirectory

$ touch demofile.txt
$ ls -l demofile.txt
-rw-r--r-- 1 aarav aarav 0 2013-12-28 15:06 demofile.txt
$ getfacl demofile.txt
# file: demofile.txt
# owner: aarav
# group: aarav
user::rw-
group::r--
other::r--

Now, sales and marketing, and aarav can create or copy new files into testacldirectory.

There is a slight problem: only the creator of a file can edit it. Alas only aarav can modify the above targets file.

Yes, we can manually adjust the ACL of a file after its creation by running setfacl -m on the file. A much better way is to configure the testacldirectory directory such that by default all files created under it will automatically have the proper ACL.

$ setfacl -m d:user:aarav:rwx,d:group:sales-g:rwx,d:group:marketing-g:rwx testacldirectory

Note that the d in d:user:aarav:rwx means default. That is, all files created in testacldirectory will have by default read/write/execute permission for the user named aarav.

$ getfacl testacldirectory/
# file: testacldirectory
# owner: linuxacldemo
# group: linuxacldemo
user::rwx
user:aarav:rwx
group::r-x
group:sales-g:rwx
group:marketing-g:rwx
mask::rwx
other::r-x
default:user::rwx
default:user:aarav:rwx
default:group::r-x
default:group:sales-g:rwx
default:group:marketing-g:rwx
default:mask::rwx
default:other::r-x

Now, sales, marketing, and aarav can edit mutual files.

Don't believe me, aarav? See for yourself.

$ su - aarav
$ cd /home/linuxacldemo/testacldirectory
$ touch figures.txt
$ ls -l figures.txt
-rw-rw-r--+ 1 aarav aarav 0 2013-12-28 17:32 figures.txt
$ getfacl figures.txt
# file: figures.txt
# owner: aarav
# group: aarav
user::rw-
user:aarav:rwx                 #effective:rw-
group::r-x                      #effective:r--
group:sales-g:rwx               #effective:rw-
group:marketing-g:rwx           #effective:rw-
mask::rw-
other::r--

The ACL for the newly created figures.txt file is configured with the default entries from its parent directory.

To summarize, if you want to share a directory (say some_dir) between some_user and some_group such that both will have full access to the directory, including creating new files and modifying each others' files, run these commands:

$ setfacl -m   user:some_user:rwx,group:some_group:rwx    some_dir
$ setfacl -m d:user:some_user:rwx,d:group:some_group:rwx  some_dir

To remove the ACL from a file or directory, use setfacl -b like this:

$ setfacl -b /home/linuxacldemo/testacldirectory

Note that this removes all but the very basic user/group/others ACL entries. If all you want is to delete the default ACL for the directory, execute this instead:

$ setfacl -k /home/linuxacldemo/testacldirectory

you can fine more redhat/centos reference on https://access.redhat.com/site/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Storage_Administration_Guide/ch-acls.html

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using ifconfig command

Ifconfig  is  used to configure the kernel-resident network interfaces. It is used at boot time to set up interfaces as necessary.  After that,it  is  usually  only  needed  when  debugging or when system tuning is needed. The ifconfig command simply is used for displaying current network configuration information, setting up an ip address along with netmask or broadcast address to network interface, creating an alias for network interface as well setting up hardware address and enable or disable network interfaces.

Here is basic usages of ifconfig command based on  scenario 

Ø  To view all activated  network interfaces

root@server-82:~# ifconfig 

Ø  To view the all network interface

root@server-82:~# ifconfig -a

Ø  3. To view specific network interface

root@server-82:~# ifconfig eth0

Ø  4. How to enable/disable network interface

root@server-82:~# ifconfig eth0 up or ifup eth0

root@server-82:~# ifconfig eth0 down or ifdown eth0

Ø   To assign a Ip address/netmask to network interface

 root@server-82:~# ifconfig eth0 10.10.10.1 netmask 255.255.255.0

Please note that the previous ip address of network interface will overlapped
           with this new ip address assigned and is will temporarily assigned. If you donot want to change in its network configuration file for permanently assigned, you can put it in /etc/rc.local file for startup automatic ip address setup.

Ø  To assign a broadcast address

 root@server-82:~# ifconfig eth0 broadcast 10.10.10.255

Ø  To change MTU for an network interface

root@server-82:~# ifconfig eth0 mtu 1454

Ø  To enable/disable promiscuous mode

 
Generally when a packet is received by a network card, it verifies whether the packet belongs to itself or not, if not then it drops the packet however in promiscuous mode, the network card will accept all the packets passed through it.

root@server-82:~# ifconfig eth0 promisc (for enable)
root@server-82:~# ifconfig eth0 –promisc ( for disable)

Ø  To add/remove new alias to network interface

             The alias is needed when we need multiple range of ips in single interface or
             when you are making your network interface using as trunk for manageable switch.

root@server-82:~# ifconfig eth0:0  10.11.11.1 netmask 255.255.255.0

           root@server-82:~# ifconfig eth0:0 down ( To remove the alias)

Ø  To change mac address of network interface

 
root@server-82:~# ifconfig eth0 hw ether AA:BB:CC:DD:EE:FF

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