Unix and Shell Programming

Assignment A

1.    Discuss the features of UNIX operating system that have made them such phenomenally successful Operating systems

2.     What is shell programming? Write a shell program to print all the contents of an existing text file in    upper case

3.     Describe what the grep command does? Illustrate its use with an original example.
4.     Write a shell program to generate the first “n” terms of the following sequence without using multiplication.
        1 2 4 8 16 32………
5.     What are filters? Give some examples of commands that can be used as filters    

6.     What are the different kinds of file systems available to UNIX operating system.

7.     Write shell programs for the following:
i    To find second largest number among the 5 numbers given.
ii. To find sum of all the alternate digits in a given 7 digit number.
iii. To count number of vowels in a given string.
iv. To take 2 strings as input, concatenate them and display the length of the resultant string.
v. To display the reverse of a given number.

8.     1.     Write the UNIX commands for the following
i)              To display the sizes and names of the six largest files in /bin, listed in descending order of their size.
ii)             To display the number of words in the last 250 lines of any file.
iii)            To display the name of the oldest file (and only the oldest file) in the current working directory.
iv)            To show the number of all files and directories (including hidden ones, but not. or.) in the directory /bin.
v)             Use the ps command, and the grep command, in a pipeline to find all the processes owned by you.
Assignment B
1.    What is an i-node and what information is contained in it? Describe how named files are mapped to i-nodes.

2.    How is the information associating disc blocks with i-nodes represented?
3.    What restrictions are placed on name to i-node links to simplify file system recovery?
Assignment C

1. UNIX uses ls to list files in a directory. The corresponding command in MS environment is--    
 
Options    
lf    
list    
dir    
None of above

2. A file with extension .txt--    
 
Options    
Is a text file created using vi editor    
Is a text file created using a notepad    
Is a text file created using word    
& b) above

3. What is POSIX?    
 
Options    
A standard operating system interface and environment    
A version of the UNIX operating system.    
A portable platform for Java programming    
A subsystem of Windows NT, 2000 and XP that isolates the Executive from

4. Which of the following files in the current directory are identified by the regular expression a?b*.
 
Options    
afile    
aab    
abb    
abc

5. For some file the access permissions are modified to 764. Which of the following interpretation are valid?
 
Options    
Every one can read, group can execute only and the owner can read and write.    
Every one can read and write, but owner alone can execute.    
Every one can read, group including owner can write, owner alone can execute    
None of above

6. The file’s properties in Windows environment include which amongst the following?
 
Options    
File owners’ name    
File size    
The date of last modification    
Date of file creation    

7. Which of the following information is contained in inode structure?    
 
Options    
The file size    
The name of the owner of the file    
The access permissions for the file    
All the dates of modification since the file’s creation

8. What are utilities?    
 
Options    
Peripherals that are connected to a computer.    
Operating system routines that execute in supervisor mode.    
Data structures that are part of the kernel of an operating system    
Shells, compilers and other useful system programs.

9. Which directory under the root contains the information on devices?    
 
Options    
/usr/bin    
/usr/sbin    
/usr/peripherals/dev    
/etc/dev

10. What is the command ‘mv’ used for in Unix?    
 
Options    
To display the files in current directory    
To rename a file    
To move to a different directory    
To open a file in the Main Viewer

11. What is the result of typing the command pwd?    
 
Options    
It allows you to change the password    
allows you to enter your password to log in    
It will display the name of your computer    
It will show your current location in the file system

12. Which unix command will display all files starting with an a?    
 
Options    
mv a*    
cd    
ls    
ls a*

13. Unix Operating System is--    
 
Options    
Time Sharing Operating System    
Multi-User Operating System    
Multi-tasking Operating System    
All the Above

14. The program is known as _________ that interacts with the inner part of called kernel.    
 
Options    
Compiler    
Device Driver    
Protocol    
Shell

15. Identify the odd thing in the services of operating system--    
 
Options    
Accounting    
Protection    
Error detection and correction    
None of above    

16. Dead lock handling in ______ OS, the response time is very critical.    
 
Options    
Multitasking    
Batch    
Online    
Real-time

17. Software is a program that directs the overall operation of the computer facilitates its use and interacts with the user. What are the different types of such software?
 
Options    
Operating system    
Language Compiler    
Utilities    
All of the above

18. PCB stands for--    
 
Options    
Program Control Block    
Process Control Block    
Process Communication Block    
None of the above

19. The primary job of the operating system of a computer is to--    
 
Options    
Command Resources    
Manage Resources    
Provide Utilities    
Be user friendly

20. Super computers typically employ--    
 
Options    
Real time Operating system    
Multiprocessors OS    
Desktop OS    
None of the above

21. Which one of the following statements correctly describes the relationship between the processes and programs in a computer system at any given moment?    
 
Options    
Every program stored in secondary memory must be associated with a process.    
A different program must be associated with every process.    
Several programs may be associated with the same process.    
Several processes may be associated with the same program.

22. Multiprogramming systems --    
 
Options    
Are easier to develop than single programming systems    
Execute each job faster    
Execute more jobs in the same time    
Are used only on large main frame computers

23. Multiprocessing--    
 
Options    
Make the operating system simpler    
Allows multiple processes to run simultaneously    
Is completely understood by all major computer vendors    
Allows the same computer to have the multiple processors

24. Which is not the state of the process?
 
Options    
Blocked    
Running    
Ready    
Privileged

25. The operating system of a computer serves as a software interface between the user and the-    

 
Options    
Hardware    
Peripheral    
Memory    
Screen

26. A process is--    
 
Options    
Program in execution    
A concurrent program    
Any sequential program    
Something Which Prevents Deadlock

27. The kernel of the operating system remains in the primary memory because--    
 
Options    
It is mostly called (used)    
It manages all interrupt calls    
It controls all operations in process    
It is low level

28. Which of the following statement is not true?    
 
Options    
Multiprogramming implies multitasking    
Multi-user does not imply multiprocessing    
Multitasking does not imply multiprocessing    
Multithreading implies multi-user

29. The term “Operating System " means--    
 
Options    
A set of programs which controls computer working    
The way a computer operator works    
Conversion of high-level language in to machine level language    
The way a floppy disk drive operates

30. What is a shell?    
 
Options    
It is a hardware component    
It is a command interpreter    
It is a part in compiler    
It is a tool in CPU scheduling    

31. The operating system manages--    
 
Options    
Memory    
Processor    
Disk and I/O devices    
All of the above

32. chown means--    
 
Options    
Changes the mode of operation to kernel mode    
Creates a thread    
Changes the users and/or group ownership of each given file    
Creates a child process

33. The process which terminates before the parent process exits, is called as--    
 
Options    
Zombie    
Orphan    
Child    
None of above

34. Identify the point(s) that is not true w.r.t. signals--    
 
Options    
Signals are software generated interrupts that are sent to a process when an event happens    
Signal delivery is analogous to hardware interrupts in that a signal can be blocked from being delivered in the future.    
Most signals are synchronous by nature.    
Most signal cause termination of the receiving process if no action is taken by the process in response to the signal

35. ---------Works as a command interpretor.

Options    
Hardware    
Kernal    
Shell    
CPU

36. An important task that the operating system performs is____, which keeps track of the files stored on a PC so that they can be retrieved when needed    
 
Options    
File management    
File listing    
File recovery    
Disk management    

37. The means by which an operating system or any other program interacts with the user is called--
 
Options    
user login    
program front-end    
user interface    
programming interface    

38. ---------- was originally developed at AT&T Bell Labs as an operating system    
 
Options    
Linux    
Solaris    
Mac OS X    
UNIX

39. For multiprogramming systems, most UNIX operating systems use--    
 
Options    
Swapping    
Demand paging    
Either (a) or (b)    
Neither (a) nor (b)    

40. What are the tasks of an Operating System?    
 
Options    
To manage all hardware and software resources    
To Allow creation of documents, images and music    
To provide a user interface    
All of the above