The Linux Juggernaut

SSH communication works on two principles
1)Communication should be done in encrypted channel
2)This encryption can be done by exchanging a PUBLIC KEY between two parties and a PRIVATE KEY for decrypting the data.
So how SSH communicate works?
When SSH package is installed on any machine a PUBLIC KEY and A PRIVATE KEY will be generated or installed by default on it.
Lets explain this with an example.
I have two machines … Continue Reading

This is bit advanced topic, people new to Shell scripting and administration can skip this post.

Today I have come across an awesome internal variable to get the piped command output status. Let me explain a scenario which I faced in automating a task.

I am executing the following command to get two entries from password file, one entry is google and other  term is vijay. The out put should verify both exit status..

cat … Continue Reading

This is a common question asked by Interviewers, When ever I remember this question I do get laugh. What is this guy asking such type of question which I don’t know how to answer. But if you think seriously you will come to know about you how capable you are in Linux Administration and will make you think are you different from other admins.

If you give very normal answers like

1)I am a graduate.… Continue Reading

We can always set time to the commands showed in history command. Why we require to set time for this?

This is totally a security measure and used for troubleshooting/fingerprinting a security threat.

history command sample output before setting this variable.

 466  df -h
 467  df 
 468  exit
 469  nfsstat 
 470  find / -iname *.ppt
 471  ftp2
 472  man ping
 473  ping -R google.com

So how to set that?

Use inbuilt variable HISTTIMEFORMAT to set … Continue Reading

Want to write meaningful scripts and become good Shell scripting expert? Then this post is for you.

In Linux/Unix when you execute a command or a script, they will exit with a meaning full exit status for your understanding purpose. So that we can take necessary actions on the out come of those commands.

In linux some command are there which will not show the output, for example “mount -a” command which we use after … Continue Reading

Q. I have access rights to one of the remote server through SSH protocol and there is no File share services such as Samba, NFS or FTP etc are enabled on the server. Now I want to mount data from that remote server, is it possible to mount remote folders?

A. The answer to this is yes, We can share data/mount folder on a local machine by using just SSH protocol. This can be done … Continue Reading