SURVEY OF OPERATING SYSTEMS
6th Edition
ISBN: 9781260096002
Author: Holcombe
Publisher: RENT MCG
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Expert Solution & Answer
Chapter 2, Problem 1EQ
Explanation of Solution
Requirement of security in automatic login:
Automatic login represents the action where password to unlock the system is automatically displayed but it is hidden, and characters of password are not displayed. User can set auto login option to computer.
- The user sets such option once and password is displayed during every login in the computer.
- Such option allows computer to start quickly and reduces user work.
- There are some reasons where such option is good but it is not secure.
- The computers that contain confidential information and the government agencies should avoid using this option. Because, it requires high level of security.
- There are several steps to set up automatic system login depending on the type of
operating system installed in computer...
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Students have asked these similar questions
Whentheuserenters!!,themostrecentcommandinthehistoryisexecuted.In the example above, if the user entered the command:
Osh> !!
The ‘ls -l’ command should be executed and echoed on user’s screen. The command should also be placed in the history buffer as the next command.
Whentheuserentersasingle!followedbyanintegerN,theNthcommandin the history is executed. In the example above, if the user entered the command:
Osh> ! 3
The ‘ps’ command should be executed and echoed on the user’s screen. The command should also be placed in the history buffer as the next command.
Error handling:
The program should also manage basic error handling. For example, if there are no commands in the history, entering !! should result in a message “No commands in history.” Also, if there is no command corresponding to the number entered with the single !, the program should output "No such command in history."
Activity No.
Activity
Time (weeks)
Immediate Predecessors
1
Requirements collection
3
2
Requirements structuring
4
1
3
Process analysis
3
2
4
Data analysis
3
2
5
Logical design
50
3,4
6
Physical design
5
5
7
Implementation
6
6
c. Using the information from part b, prepare a network diagram. Identify the critical path.
2. UNIX Shell and History Feature [20 points]
This question consists of designing a C program to serve as a shell interface that
accepts user commands and then executes each command in a separate process. A
shell interface gives the user a prompt, after which the next command is entered.
The example below illustrates the prompt osh> and the user's next command:
cat prog.c. The UNIX/Linux cat command displays the contents of the file
prog.c on the terminal using the UNIX/Linux cat command and your program
needs to do the same.
osh> cat prog.c
The above can be achieved by running your shell interface as a parent process.
Every time a command is entered, you create a child process by using fork(),
which then executes the user's command using one of the system calls in the
exec() family (as described in Chapter 3). A C program that provides the general
operations of a command-line shell can be seen below.
#include
#include
#define MAX LINE 80 /* The maximum length command */
{
int…
Chapter 2 Solutions
SURVEY OF OPERATING SYSTEMS
Ch. 2 - Prob. 1KTQCh. 2 - Prob. 2KTQCh. 2 - Prob. 3KTQCh. 2 - Prob. 4KTQCh. 2 - Prob. 5KTQCh. 2 - Prob. 6KTQCh. 2 - Prob. 7KTQCh. 2 - Prob. 8KTQCh. 2 - Prob. 9KTQCh. 2 - Prob. 10KTQ
Ch. 2 - Prob. 1MCQCh. 2 - This type of annoyance appears uninvited in a...Ch. 2 - With this Windows feature turned on (as it is by...Ch. 2 - Prob. 4MCQCh. 2 - Prob. 5MCQCh. 2 - Prob. 6MCQCh. 2 - Prob. 7MCQCh. 2 - Prob. 8MCQCh. 2 - Prob. 9MCQCh. 2 - Prob. 10MCQCh. 2 - Prob. 11MCQCh. 2 - Prob. 12MCQCh. 2 - Prob. 13MCQCh. 2 - Prob. 14MCQCh. 2 - Prob. 15MCQCh. 2 - Prob. 1EQCh. 2 - Consider the following statement: User Account...Ch. 2 - Why should you disable the Guest account?Ch. 2 - Prob. 4EQCh. 2 - Prob. 5EQ
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