Linux: netstat command

netstat (network statistics) is a command used for monitoring network connections (incoming & outgoing) as well as viewing routing tables, interface statistics etc. netstat is available on all Unix-like Operating Systems and also available on Windows operating system.

Features:
a. Useful in terms of network troubleshooting (traffic, ports, network connections), networking statistics and performance measurement.
b. netstat is one of the most basic network service debugging tools, telling you what ports are open and whether any programs are listening on ports.
c. provide detailed information about how a computer is communicating with other computers or network devices.

Grant Users Access to your Outlook Calendar

Outlook Calendar -  a very powerful tool to manage your emails, appointments, meetings, calendars, notes, contacts etc. Everyone has used the Outlook product of Microsoft, which has really made our lives easy. We all know that we can schedule our appointments and send meeting invitations in Outlook calendar but today we are going to reveal another trick to grant user access to our calendar so that other person (having permission) can edit our calendar. You must open Microsoft Outlook to perform the steps below:

Error: Could not open command file ‘/usr/local/nagios/var/rw/nagios.cmd’ for update!

Error: Could not open command file ‘/usr/local/nagios/var/rw/nagios.cmd’ for update!,An error that comes up from time to time and is quite annoying to deal with, I found a way to fix the problem, it is not the best way, but it is simple and fast.

Apache : James - Generating Users list

We have gone through about James server in previous post. In this post, we'll see how to generate user list from James Server.
James server provides a very good utility to check the users list on the server. Either we can see the user list on the console or we can redirect the userlist in any text file.  This article contains the steps to generate the user list from James server:

Apache: James Server

The Apache Java Mail Server Version 3.0 is a 100% pure Java SMTP, IMAP4 and POP3 Mail server designed to be a complete and portable enterprise mail engine solution. Apache James Server is based on currently available open protocols. 
Advantages
a. Standard

• 100% pure Java Mail server designed to be a complete and portable enterprise mail engine solution.
• Supports currently available IETF protocols, including SMTP, LMTP, POP3 and IMAP4.
• Apache James Server is able to store user and message data either in a file-system (Maildir), any JPA-compatible database and even JCR, allowing fast, reliable, even real-time replicated storage.
• Provides a powerful, flexible mail application engine through support for the Apache Mailet API. With its Mailet pipeline architecture, Apache James Server can be used not only to provide standard e-mail services, but also to implement custom e-mail applications.

Ubuntu: Segmentation fault (core dumped)

Segmentation fault: Generally such kind of errors are caused by addressing non-existent/allocated memory location. Today I encountered this error while executing "apt-get install" command.

   root@gh008:~# apt-get install binutils
   Segmentation fault (core dumped)

 

I googled around for this issue and finally got two solution for this problem. 

MySQL: Database Backup and Restore Using Command Line

MySQL, one of the most commonly & widely used database in world for web applications. Its popularity for use with web applications is closely tied to the popularity of PHP, which is often combined with MySQL. Several high-traffic web sites use MySQL for its data storage and logging of user data, including Flickr, Facebook, Wikipedia, Google, Nokia and YouTube.

MySQL provide a great command line utility to take backup of your MySQL database and restore it. mysqldump command line utility is available with MySQL installation (bin directory) that can be used to take backup of databases and perform various task using command line.