some basic interview question for linux 1

You would like to temporarily change your command line editor to be vim. What command should you type to change it? 
set -o vim 

Give me some security monitoring related commands.

Tail, lsof, tcpdump, netstat, top, ps -ef, last, , sestatus, history.

What account is created when you install Linux?  
Whenever you install Linux, only one user account is created. This is the superuser account also known as root.

what is zombi process?

 it is a state of process which is been killed by #kill (pid ) command but there is something which is still there in the server.

What command should you use to check the number of files and disk space used and each user's defined quotas? 
repquota 

 what is runlevel?

 for redhat server there are six runlevels 0,1,2,3,4,5. every runlevel consists some lib files or services. you can see them in /etc/inittab file. at the time of booting the boot initrd went to the runlevel for booting the server as per the runlevel value set in inittab file.

You locate a command in the /mnt directory but do not know what it does. What command can you use to determine its purpose. 
whatis 

How do you find out the current directory you’re in?

Use  #pwd command.

How do you find out about all running processes?

Use  # ps –ag command.

How do you write a while loop in shell?

while {condition} do {statement} done.