The following are the most likely basic interview questions that are asked by the interviewers. If you are going to be a UNIX Administrator, UNIX support personnel, Data Warehouse Developer on UNIX/LINUX platform, Oracle or Sybase Developer, or even a Database Administrator, You must know the answers to the following questions before appearing for an interview.

Interview Questions:

1. Which Shells are available or installed on your system
2. Which file gets executed first when a user logs in
3. Display total number of users currently logged on. Do not display the list of users, Display the number only
4. Write a shell script to print "High Load" if more than 100 user are logged on to the system.
5. List the size of all files in /etc directory only of the size is more than 10MB
6. List the owner and the name of all files in /tmp directory and its sub-directories if the file permission is 777
7. Mention at least 2 differences between hard link and soft link
8. How many Oracle databases are currently running on the server
9. Which users have been assigned a bash as a login shell to them
10. List of users who have more that 5 sessions opened.
11. Move all files owned by user john under /home directory to /tmp. Move only those files whose size is more than 100MB
12. Configure your account in such a way that your home directory is automatically backup-ed up to /backup directory every time you logout.
13. Write a shell script to send an email to root if any filesystem is more than 80% full.
14. List out a PID, owner and the name of the process which is taking the highest amount of CPU.
15. List out a PID, owner and the name of the process which is taking the highest amount of RAM
16. How to start a job in background
17. How to bring a background job to foreground
18. How do you assign an output of a command to a variable
19. How to perform mathematical calculations in shell script usning bc
20. How to debug a shell script
21. How to read a file one line at a time
22. How to read a file one word at a time
23. How do you check if a command has been successfully completed or not
24. Write a while loop to print odd numbers.
25. How to automate the file transfer from one machine to another
26. What is the difference between kill -9 and kill commands
27. How to change your login shell
28. How to display line 4 till 10 from a file
29. How to change a word named "Bill" to "Bob" in a file. - vi not allowed
30. How to remove blank lines from a file.
31. Can you create a hard link across filesystems
32. What is the purpose of /dev/null file
33. If I run ls -z > /dev/null  Will anything be displayed on the terminal.
34. How to capture stdout and stderr of a command to a same file
35. What is the difference between  "wc -l /etc/passwd" and "wc -l < /etc/passwd
36. How to find out the OS kernel you are running
37. How to find out if your hardware supports 64 bit OS or not
38. What command will delete all 0 byte files from your home directory
39. What is the size of the internal hard-diskon your system
40. How to schedule a specific command to run every 5 minutes on 1st day of every month of the first financial quarter of a year. Assume that the financial year starts on 1st of April.