Thursday, August 18, 2011

Basic Linux Commands Intervewer may Ask

1)Give me 15 commands which you use frequently
Depends on the environment you work. Some examples are
mkdir — For creating folders( use -p option to create multiple folders at a time)
ls –List folders/files( check what ls -1 do)
top — To monitor system activities
lsof –To check whats happening on the server and which process open which file.
netstat -tcp –Gives you complete picture about network connection details.
vnstat –Gives you Network band width statics
sh –For running shell scripts
history –For monitoring the commands executed by users
cd –For changing directories
vi --For editing configuration files.
chmod –To change permissions of folders and files.
mount –For mounting formated partitions.
service –For start/restart/stop a service.
chkconfig –For permanent on/off a service.
fdisk -l –To list all the partitions
This is my own list, you can have your list.
2)Give me some commands for user management.
last, chage, chsh, lsof, chown, chmod, useradd, userdel, newusers.
3)Give me syntax checking commands for following services
DNS, SAMBA, Apache etc
4)What is the command to do password less logins to other machines.
expect and ssh-keygen
5)Give me some security monitoring related commands.
lsof, netstat, top, ps -ef, tail, last, tcpdump, sestatus, history, w.
6)What is the difference between man, info, whatis commands and a –help option for a command?
whatis gives you one line answer.
–help option for a command gives you one line answers for each option supported by a command
man command gives you medium size info.
info command gives full details about a commands, lots and lots of information about a command.
Please share your interview questions with us, we post them here so that others can get help from this.