LINUX Technical Interview Questions

You need to see the last fifteen lines of the files dog, cat and horse. What command should you use?
tail -15 dog cat horse

The tail utility displays the end of a file. The -15 tells tail to display the last fifteen lines of each specified file.


Who owns the data dictionary?
The SYS user owns the data dictionary. The SYS and SYSTEM users are created when the database is created.


You routinely compress old log files. You now need to examine a log from two months ago. In order to view its contents without first having to decompress it, use the _________ utility.
zcat

The zcat utility allows you to examine the contents of a compressed file much the same way that cat displays a file.



You suspect that you have two commands with the same name as the command is not producing the expected results. What command can you use to determine the location of the command being run?
which

The which command searches your path until it finds a command that matches the command you are looking for and displays its full path.



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

The whatis command displays a summary line from the man page for the specified command.

You wish to create a link to the /data directory in bob's home directory so you issue the command ln /data /home/bob/datalink but the command fails. What option should you use in this command line to be successful.
Use the -F option

In order to create a link to a directory you must use the -F option.



When you issue the command ls -l, the first character of the resulting display represents the file's ___________.
type

The first character of the permission block designates the type of file that is being displayed.



What utility can you use to show a dynamic listing of running processes? __________
top

The top utility shows a listing of all running processes that is dynamically updated.


Where is standard output usually directed?
to the screen or display

By default, your shell directs standard output to your screen or display.

Linux admin interview question

1. How do you list the files in an UNIX directory while also showing hidden files? ls ltra

2. How do you execute a UNIX command in the background? Use the “&”.

3. What UNIX command will control the default file permissions when files are

created? Umask

4. Explain the read, write, and execute permissions on a UNIX directory. Read allows

you to see and list the directory contents. Write allows you to create, edit and delete files and subdirectories in the directory. Execute gives you the permissions to run programs or shells from the directory.

5. What is the difference between a soft link and a hard link? A symbolic (soft) linked file and the targeted file can be located on the same or different file system while for a hard link they must be located on the same file system.

6. Give the command to display space usage on the UNIX file system. df -lk

7. Explain iostat, vmstat and netstat. iostat reports on terminal, disk and tape I/O activity.

vmstat reports on virtual memory statistics for processes, disk, tape and CPU activity. netstat reports on the contents of network data structures.

8. How would you change all occurrences of a value using VI? %s/(old value)/(new value)/g

9. Give two UNIX kernel parameters that effect an Oracle install. SHMMAX & SHMMNI

10. Briefly, how do you install Oracle software on UNIX? Basically, set up disks, kernel parameters, and run orainst.