DOEACC Society 2007 Advanced Level Course In Computer Science A8-R3: BASICS OF OS, UNIX AND SHELL PROGRAMMING - Question Paper

A) tar
B) cpio
C) dd
D) None of the above

1.4 Execute permission for file means
A) file may be used as running process
B) copy can be make in order to execute the file
C) read is implied before execution
D) None of the above











1.5 In vi, suppose pressing the character ] takes the cursor to next snippet. If we provide the command d], the
A) The current snippet is deleted
B) The character with cursor and up to the end of snippet is deleted
C) The character subsequent the cursor and up to ] character is deleted
D) None of the above

1.6 Which of the filter command is used for character translation?
A) tr
B) dd
C) sed
D) grep

1.7 Execution of the program on the remote machine is possible through
A) ftp
B) telnet
C) http
D) None of the above

1.8 Application programmers in X Windows environment quickly build sophisticated interface to their programs and enforce a uniform look and feel to all part of GUI by using
A) Widget set
B) X toolkit
C) Window manager
D) None of the above

1.9 Regular expression [^a-zA-Z] means that
A) the 1st character of the line is letter
B) any character other than a
C) any character that is not the letter
D) None of these

1.10 To search files which has been accessed in last n days is possible though the utility (with improper options)
A) find
B) ls
C) awk
D) None of the above




















2. Each statement beneath is either actual or FALSE. select the most improper 1 and ENTER in the “tear-off” sheet attached to the ques. paper, subsequent instructions therein. (1 x 10)

2.1 UNIX kernel provides its services transparently.
2.2 In UNIX system, mapping of virtual address to physical address is machine independent.
2.3 Inode specifies the pathname, which accesses the file.
2.4 Every directory contains at lowest 2 filenames.
2.5 Kernel may allow the mounting the identical file system again.
2.6 The sticky bit is only set by super user.
2.7 $* and $@ are identical.
2.8 http is the specification language to construct web pages.
2.9 Ping command is used to test the connecting of network.
2.10 Tk widget set and Motif widget set both provide similar look and feel to the X Windows application.

3. Match words and phrases in column X with the nearest related meaning/ word(s)/phrases in column Y. Enter your selection in the “tear-off” ans sheet attached to the ques. paper, subsequent instructions therein. (1 x 10)

X Y
3.1 Execution of the system call A. find
3.2 Frozen image of what process is doing B. FIFO (pipes)
3.3 File type C. User mode
3.4 Storing directory file D. Kernel mode
3.5 Moving cursor to middle line in screen window in vi E. ftp
3.6 The process number of last background command F. Cntl M
3.7 The choice of sh causing the shell to echo every command before its execution with substitution the shell makes G. Binary format
3.8 A techniques to transfer file from 1 computer to a different computer on network H. M
3.9 Controls access to a X display I. context
3.10 To obtain the lines containing specific word in a file J. Text format
K. $!
L. xhost
M. grep
N. -x
O. $$










4. Each statement beneath has blank space to fit 1 of the word(s) or phrases in the list beneath. Enter your option in the “tear-off” ans sheet attached to the ques. paper, subsequent instructions therein. (1 x 10)

A. inode B. 2dw C. is not
D. ls E. dw F. fsck
G. links H. fsmk I. Pair of single quote
J. pair of double quote K. include L. export
M. DNS N. www O. xterm
P. DISPLAY Q. head R. /etc/shadow
S. awk T. /etc/passwd

4.1 The kernel _______ a separate set of processes, which run parallel to user process.
4.2 Number of _______ to the file represents the number of names the file has in the directory hierarchy.
4.3 Reclaiming unlinked disk blocks is done by _______ program.
4.4 In vi, to delete 12.357 we provide _______ command.
4.5 _______ negates special properties of all enclosed character in UNIX.
4.6 A variable can be make the part of environment of current shell and of all processes (including shell script) descending from it, by using _______ command.
4.7 Conversion of domain name to an IP address is done by _______.
4.8 Applications use the value _______ variable to determine which display, keyboard and mouse to use.
4.9 _______ utility displays the beginning of the file.
4.10 All encrypted passwords are kept in the file _______.



















PART TWO
(Answer any 4 questions)

5.
a) Write sequence of vi commands to exchange top 3 lines with bottom 3 lines of the screen on the vi session.
b) Write a shell script, which asks user to enter the login name. If the name is not in the “LOGFILE”, display “Sorry! You cannot work.”, otherwise ask for password. The password in not echoed. Check the password with the “PASSWORD”. If it is not there display “ACCESS DENIED”.
(7+8)

6.
a) Write a shell script to display login names of all users who have logged off in last 10 minutes.
b) What is the purpose of having /etc/passwd and /etc/shadow files?
c) Write a shell script to print the system time.
(7+4+4)

7.
a) What is motivation for weekly or monthly backup? discuss tar utility with examples.
b) Write the shell script to add a new user in password file /etc/passwd with the subsequent details:
- group name ‘india’
- log in name ‘guru’
- user name ‘Ramauli of Vindhyachal’
- file system ‘/selected’
(9+6)

8.
a) What is the design principle of X windows? define system architecture and Window manager of X Windows. What is X-toolkits? What does it contain?
b) What is IP address? discuss its construction. compute the maximum possible numbers of class A, class B and class C networks, which can be addressed by IP scheme.
(9+6)

9.
a) Explain the booting process of Unix system.
b) Describe the data structures associated with processes. How are these affected by exec, form and exit system calls.
(9+6)

Earning:   Approval pending.