Linux interview questions -2

21. Q. How to remove directory with files?
A. rm -rf directory_name

22. Q. What is the difference between internal and external commands?
A. Internal commands are stored in the; same level as the operating system while external
commands are stored on the hard disk among the other utility programs.

23. Q. List the three main parts of an operating system command:
A. The three main parts are the command, options and arguments.

24 Q. What is the difference between an argument and an option (or switch)?
A. An argument is what the command should act on: it could be a filename,
directory or name. An option is specified when you want to request additional
information over and above the basic information each command supplies.

25. Q. What is the purpose of online help?
A. Online help provides information on each operating system command, the
syntax, the options, the arguments with descriptive information.
26. Q. Name two forms of security.
A. Two forms of security are Passwords and File Security with permissions specified.

27. Q. What command do you type to find help about the command who?
A. $ man who

28. Q. What is the difference between home directory and working directory?
A. Home directory is the directory you begin at when you log into the
system. Working directory can be anywhere on the system and it is where you are currently
working.

29. Q. Which directory is closer to the top of the file system tree, parent directory or current directory?
A. The parent directory is above the current directory, so it is closer to
the root or top of the
file system.

30. Q. Given the following pathname:
$ /business/acctg/payable/supplier/april
a) If you were in the directory called acctg, what would be the relative
pathname name for the file called april?
b) What would be the absolute pathname for april?
A.
a) $ payable/supplier/april
b) $ /business/acctg/payable/supplier/april

31. Q. Suppose your directory had the following files:
help. 1 help.2 help.3 help.4 help.O1 help.O2
aid.O1 aid.O2 aid.O3 back. 1 back.2 back.3
a) What is the command to list all files ending in 2?
b) What is the command to list all files starting in aid?
c) What is the command to list all "help" files with one character extension?
A.
a) ls *2
b) ls aid.*
c) ls help.?

32. Q. What are two subtle differences in using the more and the pg commands?
A. With the more command you display another screenful by pressing
the spacebar, with pg you press the return key.
The more command returns you automatically to the UNIX
shell when completed, while pg waits until you press return.

33. Q. When is it better to use the more command rather than cat command?
A. It is sometimes better to use the more command when you are viewing
a file that will display over one screen.

34. Q. What are two functions the move mv command can carry out?
A. The mv command moves files and can also be used to rename a file or directory.

35. Q. Name two methods you could use to rename a file.
A. Two methods that could be used:
a. use the mv command
b. copy the file and give it a new name and then remove the original file if no longer needed.

36. The soccer league consists of boy and girl teams. The boy file names begin
with B, the girl teams begin with G. All of these files are in one directory
called "soccer", which is your current directory:
Bteam.abc Bteam.OOl Bteam.OO2 Bteam.OO4
Gteam.win Gteam.OOl Gteam.OO2 Gteam.OO3
Write the commands to do the following:
a) rename the file Bteam.abc to Bteam.OO3.
b) erase the file Gteam. win after you have viewed the contents of the file
c) make a directory for the boy team files called "boys", and one for the girl team files
called" girls"
d) move all the boy teams into the "boys" directory
e) move all the girl teams into the "girls" directory
f) make a new file called Gteam.OO4 that is identical to Gteam.OOl
g) make a new file called Gteam.OO5 that is identical to Bteam.OO2
A.
a) mv Bteam.abc Bteam.OO3.
b) cat Gteam.win -or- more Gteam.win
rm Gteam. win
c) mkdir boys
mkdir girls
d) mv Bteam* boys
e) mv Gteam* girls
f) cd girls
cp Gteam.OO1 Gteam.OO4
g) There are several ways to do this. Remember that we are currently in the directory
/soccer/girls.
cp ../boys/Bteam.OO2 Gteam.OO5
or
cd ../boys
cp Bteam.OO2 ../girls/Gteam.OO5

37. Q. Draw a picture of the final directory structure for the "soccer"
directory, showing all the files and directories.

38. Q. What metacharacter is used to do the following:
1.1 Move up one level higher in the directory tree structure
1.2 Specify all the files ending in .txt
1.3 Specify one character
1.4 Redirect input from a file
1.5 Redirect the output and append it to a file
A.
1. 1.1 double-dot or ..
1.2 asterisk or *
1.3 question or ?
1.4 double greater than sign: >>
1.5 the less than sign or <

39. Q. List all the files beginning with A
A. To list all the files beginning with A command: ls A*

40. Q. Which of the quoting or escape characters allows the dollar sign ($) to retain its special meaning?
A. The double quote (") allows the dollar sign ($) to retain its special meaning.
Both the backslash (\) and single quote (') would remove the special meaning of the dollar sign.