Linux Interview Questions And Answers Set - 1

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.

You wish to restore the file memo.ben which was backed up in the tarfile MyBackup.tar. What command should you type?
tar xf MyBackup.tar memo.ben

This command uses the x switch to extract a file. Here the file memo.ben will be restored from the tarfile MyBackup.tar.

You need to view the contents of the tarfile called MyBackup.tar. What command would you use?
tar tf MyBackup.tar

The t switch tells tar to display the contents and the f modifier specifies which file to examine.

You want to create a compressed backup of the users' home directories. What utility should you use?
tar

You can use the z modifier with tar to compress your archive at the same time as creating it.

What daemon is responsible for tracking events on your system?
syslogd

The syslogd daemon is responsible for tracking system information and saving it to specified log files.

You have a file called phonenos that is almost 4,000 lines long. What text filter can you use to split it into four pieces each 1,000 lines long?
split

The split text filter will divide files into equally sized pieces. The default length of each piece is 1,000 lines.

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

The set command is used to assign environment variables. In this case, you are instructing your shell to assign vi as your command line editor. However, once you log off and log back in you will return to the previously defined command line editor.

What account is created when you install Linux?
root

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

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

repquota

The repquota command is used to get a report on the status of the quotas you have set including the amount of allocated space and amount of used space.

In order to run fsck on the root partition, the root partition must be mounted as
readonly

You cannot run fsck on a partition that is mounted as read-write.

In order to improve your system's security you decide to implement shadow passwords. What command should you use?
pwconv

The pwconv command creates the file /etc/shadow and changes all passwords to 'x' in the /etc/passwd file.

Bob Armstrong, who has a username of boba, calls to tell you he forgot his password. What command should you use to reset his command?
passwd boba

The passwd command is used to change your password. If you do not specify a username, your password will be changed.

The top utility can be used to change the priority of a running process? Another utility that can also be used to change priority is ___________?
nice

Both the top and nice utilities provide the capability to change the priority of a running process.

What command should you type to see all the files with an extension of 'mem' listed in reverse alphabetical order in the /home/ben/memos directory.
ls -r /home/ben/memos/*.mem

The -c option used with ls results in the files being listed in chronological order. You can use wildcards with the ls command to specify a pattern of filenames.