Question Bank 10CS44: UNIX & SHELL PROGRAMMING

Transcription

1 Question Bank 10CS44: UNIX & SHELL PROGRAMMING CHAPTER 1 : UNIX OS AND SOME BASIC COMMANDS,FILE SYSTEM OBJECTIVE: UNIX Born in the dark and somber portals of Bell Labs, it was a dream that one man nurtured and cherished. Like a parent, he reared the infant with compassion and zeal. And as the fledgling grew and spread its wings, it caught the attention of the world. This chapter will explore through the basics of UNIX, along with certain commands which itself are categorized accordingly. The File System and Some File Handling Commands : The file system is one of the its simplest and it lets users not to access files not belonging to them, You will be learning about categorization of files, the significance of HOME directory, mkdir, rmdir, and absolute,relative path name. 1 What is the use of kernel in UNIX operating system? 3 2 How will you prevent others from using your terminal? Explain in brief. 3* 3 Write a short note on UNIX philosophy? 3 4 What is the difference between an argument and an option? Explain with example 4 5 Explain multi-user capability of UNIX. 4* Explain the significance of quoting with examples. 4* 7 Explain briefly different types of shells available in Unix O.S? 4 8 What are the different types of files in an UNIX operating system? Explain briefly. 5* CS 10CS44-1

2 9 Explain the following: banner, calendar, echo, ispell each with an example. 10 With a block diagram explain UNIX operating system organization and explain Kernel- Shell relationship. 11 Describe the salient features of UNIX Operating system. 12 Explain the following: date, who, try, uname, password, lock. 13 What is the difference between internal command and external command? Explain general format of command with examples. 14 With example, explain the date and lock commands 15 What are different layers of UNIX Operating system and explain the relationship between kernel and shell. 1 What are general-purpose utilities of UNIX system? Explain with example. 17 With a neat diagram, explain the relationship between the kernel and the shell of the UNIX operating system. 18 Discuss the history of the UNIX operating system development 19 Write a neat diagram, Explain the kernel shell relationship 10* 20 Bring out the differences between internal and external commands also explain the commands uname, lock, who 10* 21 With a neat diagram, explain the relationship between kernel and shell in UNIX. 8* 22 Describe the salient features of the UNIX operating system. 8* 23 Give the directory structure of UNIX file System * 24 How will you remove a directory tree even when it is not empty without using rmdir. Explain that used command. 25 Explain the Commands wc,od,cmp 2 What is a file? Explain the different types of files as available in UNIX operating system 10* 27 What is the difference between the following commands : 8 CS 10CS44-2

3 cp and copy cp and my comm and cmp comm and diff 28 What are the different types of files in an UNIX operating system? Explain briefly. 29 Write some of the commands used for handling ordinary files. Explain them. 30 What is more function? Explain its usage with example. 31 What are the various types of files? Explain rules and conventions used in naming a file. 32 What is a pipeline? Construct a pipeline for the following jobs:- 33 (1) List all files beginning with the char B on the screen and also store them in a file called 1. (2) All the files present in dir-dir 1 should be deleted. Any error, if it occurs while carrying out this operation, should be stored in a file error file. 34 What is file? Explain the different types of files in UNIX. 35 Explain absolute path name and relative path name each with an example 3 Mention at least four directories that will be present in a UNIX file system very briefly explain what these directories contain? 37 Explain the following file handling commands wc, split, comm and cmp each with an example. 8 8* 38 Write a note on the man command. 39 Why does a machine need an operating system? 40 What are the system calls,and what role do they play in the system?how is C programming to different and powerful in the UNIX environment compared to windows? UNIT 2: FILE ATTRIBUTES, vi EDITOR CS 10CS44-3

4 OBJECTIVE: You will be discussing about Significance of seven fields of ls l output, How to obtain the listing of a specific directory, and the importance of ownership and other features. This Chapter deals with editor that is widely used vi Editor. Learning vi is going to be a shot in the arm to your aspiration of learning UNIX. With enough landmarks along the way, it s a smooth journey through the Portals of Power. 1. Explain the need for two special files /dev/null and /dev/tty 2. What are file and directory permissions? Explain how directory permissions are used in conjunction with file permissions to determine overall permissions. 3. Give the contents of a typical personnel data base file with six fields (emp-id,name, designation, department, date of birth and salary). Show at least three entries on this file, clearly indicating the demarcation of various fields. With reference to this data base, explain the cut and paste commands What are the different attributes of a file? Explain how they are modified 8 5. With an example explain the ls command to obtain long listings. Also explain the sty command 8. Explain the system variables with example. 8* 7. Explain each column of the output of ls l command. 8* 8. What are file permissions? How permissions of a regular file may be manipulated? Discuss. 9. What is the use of the following directories? Explain i) /bin ii) /usr/bin iii) /mnt iv) /tmp v) /etc vi) /usr 10. What is file permission? What are different ways of setting file permission? Explain. 11. What is the need for file permissions? How will you change file permissions? 12. Give the sequence of commands(pipeline) for: (1) To remove duplicate records from a file. (2)o list five largest files in the current dir. CS 10CS44-4

5 13. Explain the following Environment variables PATH, HOME, IFS 14. What are file attributes? Explain how to change basic file permissions, with an example. 15. Explain each column of the output of ls l command. 8* 1. Write a sequence to combine the input of three files and then split the output into multiple files, each containing 2000 lines. 10* 17. Explain ls command with options x, f, a, r, R 18. To find out the number of times the character? occurs in a file. 19. What is file permission? What are the different ways to set the file permission? 20. Explain the different types of files supported in UNIX 21. Explain following commands with suitable examples. Pwd, mkdir, cp, wc. 8* 22 Write short note on vi editor. 23 Find out all users from /etc/passwd and sort them 24 What are the different ways in which a text can be inserted in Vi editor? Explain. 25 Explain the three modes of the Vi-Editor. 1. Give the sentence It is slow in getting started but is quite powerful and the cursor is on the character d of the word started,give the vi i editor commands to i) move to the beginning of the work Started ii) then to move to the end of the word but iii) then to move to the beginning of the last word powerful iv) then to move to the beginning of the given sentence and v)finally to the end of the given sentence. 8 2 What are different modes of vi editor? Explain. 8* 27 With an example explain the ls command to obtain long listings. Also explain the sty command 8 CS 10CS44-5

6 28 Explain the 3 modes of operation in a vi editor. 8* 29 Explain the commands search for pattern and search & replace in Vi editor 30 What is the output of the following command (i) echo $PATH (ii) man man (iii) cmp f1 f2[f1 and f2 are identical] (iv) ls -i 4* UNIT 3 : THE SHELL, PROCESS, COMMUNICATION IN UNIX OBJECTIVE: You will be learning about shell s interpretive cycle, The Significance of meta characters and their use in wild-card, use of escaping and quoting, three standard files, finally shell variables and their useful. You will be looking everything as a process. An overview of the Kernel s Role in Process management, Learning about Process attributes, Process attributes with ps, Kill process, Job Control, Schedule jobs for one time execution with at and batch. UNIX provides a few real time Communication tools and an impressive collection of agents and tools. You will be Locking user information with finger, online text chat with talk, using pine as a menu based mail client and its address book facility. 1. What are standard input, standard output and standard error? Explain with respect to UNIX. 2. Explain the main features of KORN and BASH shells. 8* 3. Explain the system variables with example. 8* CS 10CS44 -

7 4. Explain the following : export, expr, eval, exec 8* 5. Write a short note on system variables. 8. Explain with example different types of commands recognized by the shell 7. Explain the following environment variables i) HOME ii) PS1 and PS2 iii) TERM 8. Explain the following file handling commands wc, split, comm. and cmp each with an example. 8* 9. What are shell variables? Explain with examples. 10. What is the standard input and standard output? How do you achieve redirection using pipes and tees? Explain with an example. 11. Explain briefly different types of shells available in Unix O.S? 12. Explain the shell treatment of the command line. 13. Define System variable. What are the variables used to define environment. 14 What is process status? Explain Ps with options. 8* 15 What is process? Explain the mechanisms of process creation. 1 Explain any four commands related to process in UNIX OS 8* 17 Explain the commands bg, fg, fg, and kill. 4* 18 What is the parent and child process? Explain briefly. 19 What is a process? Explain the commands bg, fg, fg, and kill. 20 What are standard input, standard output and standard error? Explain how the error is i) Stored in a file ii) not stored any where or displayed. 21 Explain the concept of Parent-child process with an example. 22 What is parent child relationship? With the help of a diagram explain the UNIX file system. 8* CS 10CS44-7

8 23 How the jobs can be run in background? Explain. 8* 24 Explain Pine, talk, and mail commands as related to Communication under UNIX OS 25 Explain with syntax the use of write, mail and wall commands. 2 Explain finger Command and its significance 27 How finger command is different from cat command 28 How two-way communication can be established on UNIX. Explain. 29 What is the default location of a user s mailbox on UNIX systems 4* 30 Why pine is so useful on the internet 4* 31 Name two features of pine not found in mailx 4* 32 Mention four common headers found in a mail message, What is the significance of BCC: header 5* 33 Write a note on finger command. 4* CHAPTER 4:MORE FILE ATTRIBUTES, SIMPLE FILTERS OBJECTIVE: This chapter features the different link files like hard link and symbolic links,file system and inodes.simple filters performs a simple function. Learning about the Commands like head, tail, cut, paste, grep. 1. Explain the following: (i)touch (ii)find 2. Explain where to use hard links? 3. Explain symbolic links and hard links 4. Explain file systems and inodes? CS 10CS44-8

9 5. What is umask?. What happens when you use head with multiple filenames. 7. How to slitting a file vertically. 8. Explain the following head,tail,sort,paste 4* UNIT 5 : FILTERS using REGULAR EXPRESSIONS grep AND sed OBJECTIVE: This chapter features the simple filters of the system- Commands which accept data from Standard input manipulate it and write the results to standard output. Filers are the central tools of the UNIX tool kit, and each filter performs a simple function. 1. Write a short note on filters command. 2. Explain the following with examples : head, tail, cut and paste 3. Explain grep, egrep and fgrep with examples. 4. Explain the grep command with the aid of an example. Mention some options that are permitted to use with it and the purpose of these options. 5. Explain the grep command, with options c, r, v, I and l each with an example. 8*. Give the contents of a typical personnel data base file with six fields (emp-id,name, designation, department, date of birth and salary). Show at least three entries on this file, clearly indicating the demarcation of various fields. With reference to this data base, explain the cut and paste commands Explain different communication methods provided by UNIX. 10* 8. How do you paginate in UNIX? Explain the command with all options. 8* 9. How does grep help in searching for a pattern? Explain each option with an example. 10. CS 10CS44-9

10 UNIT : THE SHELL PROGRAMMING: OBJECTIVE: You will be discussing about the Programming features of the shell in some detail and to put them to productive use in real world situations. A shell program runs in interpretive mode. How the shell scripts are executed and their role of the interpretive cycle, Positional Parameters, role of the exit command and other shell programming feature. 1. What do you mean by exporting shell variables? Explain with examples. 4* 2. How to define and invoke functions in shell scripts? Explain with examples List and explain various special parameters used by shell scripts 4* 4. What do you mean by command line arguments in shell script? How these arguments are handled. 5* 5. How will you test various file attributes while writing shell scripts 5*. How will you replace string Linux by Red Hat Linux. 5* 7. Write a sed sequence to find out the number of occurrences of a pattern in a file(note that one pattern may occur more than once in a file 5 8. Write a short note on BOURNE shell? 9. Write a shell script to create a menu, which displays the list of files, current data, process status and current users of the system. 10. Explain Line addressing and Context addressing using sed, each with an example. 11. State any six built in variables in awk, and explain each. 12. How do you determine the length of a string, extract a sub string and locate the position of a character in the string using Expr: Explain with an example. 13. What is shell script? Write a script that accepts a filename as argument and displays the last modification time if the file exists and a suitable message if it does not. 8* 14. What is sed? Explain any five applications of sed. 15. What is a here document? Explain with an example. Also mention its use. CS 10CS44-10

11 1. Explain line addressing and context addressing using sed, each with an example 17. What is for loop in a shell script? Explain the different ways of making the lists 18. Write a shell script to display the processes in the system every 30 seconds, but five times. 19. What is and export statement? Illustrate its use with examples. 20. What are the shell parameters $*, $#, $? And $? Discuss very briefly 21. Write a sed instruction to replace the word actor by the word writer from line 4 to line 7, inclusive of both lines. Discuss. Show how the above instruction may be converted so that global substitution takes place. 22. Explain sed commands with all options. 7* 23. What do you understand by shell variables? Explain briefly What is a mail command? Give any six mail internal commands and explain them Explain the list and array use in pert. Also, write a pert program to convert decimal number to binary number. 2. The length and breadth of a rectangle are input through the keyboard. Write a shell script to calculate the area of the rectangle and display the same. Mention the ways in which the above written script may be executed. 27. Write a shell script that prints out date information in the order: time day of week number day number month year, i.e like PDT MON 17 Oct Write a shell script that sends a banner THANK YOU to your screen every 40 seconds * Write a shell script to accept a string as command line argument and reverse it Write a shell script that reads data from a text file and appends the lines starting with an alphabet from a through k to a file name ask and the lines starting with the alphabet l through s to a file name ls and the lines between t and z into the file tz. Then display the number of the files ak ls and tz individually Write a shell script to find out whether a user whose login name passed as the parameter is currently logged in or out. If the user is logged in, send the file hello 10 CS 10CS44-11

12 which is available in the current directory to his terminal 32. Locate lines longer than 100 and smaller than 150 characters using grep, sed, and awk Give three Programming language constructs supported by Bourne shell 34. How will you convert all characters in a file to uppercase without using shell redirection? 35. Write a shell script that accepts two filenames as arguments, check if permissions of these files are identical, if identical, print these permissions other wise print them separately. 10 8* UNIT 7: awk OBJECTIVE: The awk command which made a late entry in UNIX System to augment the toolkit with suitable report formatting capabilities. You will be understanding awk s unusual syntax with its selection criteria and action components. Splitting the line int fields, awk s built in variables, use of arrays and other features of awk. 1. Explain programming features supported by awk for flow control. 2. Explain with an example the built in function awk. 3. Explain with examples simple awk filtering. 4. What is awk? Give and explain any three built-in functions in awk. 5. Give the general format of a typical awk command and explain. Wrie a awk program to print the transpose of matrix 7. Expalin the BEGIN and END sections used in awk scripts. 4* 8. Write a note on awk with options. 9. State any six built in variables in awk, and explain each. 8* 10. Explain if statement,for and while loop statement with respect to awk with suitable example. 10* CS 10CS44-12

13 UNIT 8 : perl OBJECTIVE: perl is UNIX s latest major acquisition, and one of its finest. perl combines the power of some of the most powerful UNIX tool the shell, grep, tr, sed and awk. This chapter gives the overview of perl Program. Chop to remove the Last character of a line or variable, develop subroutine for repeated file and other features of perl programming 1. Explain with example the handling of subroutine in perl. 2. What are the variables and operators used in perl? 3. Expalin briefly the features offered by perl. 10* 4. Explain the variables and the operations in perl 5. How are the arrays handled in perl. Explain.. Write a simple perl program that asks for the user s name and accepts it, asks for temperature in centigrade and accepts it, converts the temperature into Fahrenheit using the relation C=5/9(F-32) and prints out the result. Hence or otherwise comment on the use of variables in perl programs and their evaluation. 7. Write an awk sequence to find the HRA, DA and net pay of an employee, where DA is 30% of basic, HRA is 10% of basic and net pay is the sum of HRA, DA and the basic pay with suitable headings 8 8* 8. Using command line arguments write a perl program to find a given year is leap year. 8* 9. How substitution can be achieved using sed. Command? Explain. 8* 10. Explain how the perl handles the list? * Using perl how do you print lines in reverse order? How will you use perl script to convert a binary number (supplied as argument To decimal) Explain the string handling functions in perl. 14. How is file handling managed in perl? Explain with an example. CS 10CS44-13

14 15. Explain the following in perl. (i)split (ii)join (iii)$ - default variable 1. Using command line arguments,write a perl program to find whether a given year is leap year. 17. Write a perl program that accepts decimal number as arguments and convert it into binary number. 7* 7* Note: * indicates questions appeared in previous exam papers. CS 10CS44-14