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Nov 05, 2015
INTRODUCTION---------------------------------------------------------------------------------A command prompt is used in a text-based or "command-line" interface, such as a UNIX terminal or a DOS shell. It is a symbol or series of characters at the beginning of a line that indicates the system is ready to receive input. It other words, it prompts the user for a command (hence the name).
Since a command prompt requires specific input, it is basically useless if you don't know the syntax of the command you want to enter. Therefore, knowledge of some basic commands is required to use a command-line interface. Fortunately, most operating systems now use a graphical user interface GUI as their main way of requesting input from the user. This means you don't have to learn any special commands in order to use the computer. However, learning to use a command-line interface is kind of like learning to drive a car with a manual transmission. You never know when it might come in handy.
1.1 What is a command prompt or Terminal?
A command prompt is a non-graphical interface that allows you to interact with your operating system. At the command prompt, you enter commands by typing their names followed by options and arguments. Most modern computers use a graphical user interface (GUI), which allows users to more intuitively access programs and documents. However, some programs and commands are still only available only through a command prompt. To access the command prompt, follow the instructions appropriate to your operating system.A user can type commands at the command prompt, such as cd /, which means "change directory to the root folder." The "cd" command allows the user to browse through different directories of files on a hard disk or network. There are dozens of other commands that a user can type, which can be used to list, move, delete, and copy files, run programs, or perform other operations. While the "cd" command is the same in both DOS and UNIX, many other commands have different syntax.
1.2 Windows Command Prompt :-To access the command prompt in Windows, in Windows 7, click the Start button and enter cmd. In other versions, from the Start menu, select Run... and then enter cmd. The command prompt is often preceded by the current directory of the system the user is working with. For example, the default prompt in DOS may be C:\, which indicates the user is working at the root level of the main C: drive.Command Prompt is officially called Windows Command Processor but is also sometimes called the command shell or by its file name cmd.exe. Command Prompt is sometimes incorrectly referred to as "the DOS prompt" or as MS-DOS itself. Command Prompt is a Windows program that emulates many of the command line abilities available in MS-DOS but it is not actually MS-DOS. Command Prompt is most commonly used to execute batch files, perform advanced administrative functions, and troubleshoot and solve certain kinds of Windows issues.1.3 Unix terminal :-When you log into a UNIX computer, your shell begins to run and provides you with a command prompt. The command prompt's appearance varies depending on the shell you're using. In UNIX, the prompt may be ~ user$, where "user" is the name of the current user. The tilde (~) indicates the current directory is the user's home folder.Every user has a unique username. When they logon to the system, they are placed in a HOME directory, which is a portion of the disk space reserved just for them. When you log onto a UNIX system, your main interface to the system is called the UNIX SHELL. This is the program that presents you with the dollar sign ($) prompt. This prompt means that the shell is ready to accept your typed commands. There is more than one variety of shell that can be used on a UNIX system. one of the most standard UNIX shells called the Bourne Shell. Other shells such as the Korn Shell or Bourne Again Shell work very similarly at this level. They all use the dollar sign as their prompt.UNIX commands are strings of characters typed in at the keyboard. To run a command, you just type it in at the keyboard and press the ENTER key. We will look at several of the most common commands below. UNIX extends the power of commands by using special flags or switches. These switches are one of the most powerful features of UNIX commands. Switches are usually preceded with a dash (-) and precede any filenames or other arguments on the command line.
1.4 Comparison between Windows and UNIX commands :-There are many commands which are use for same task but have different syntax in different operating systems. Their comparison is as follows:
In windows, the command for listing files directory is dir while in Unix, command for same task is ls.
In windows, the command for clearing the screen is cls while in Unix, command for same task is clear. In windows, the command for copying a file is Copy while in Unix, command for same task is cp.
In windows, the command for removing a file Del while in Unix, command for same task is rm.
In windows, the command for moving a file Move while in Unix, command for same task is mv.
Windows or DOS commands are not case sensitive, UNIX systems are case sensitive (upper and lower case characters are considered different). Nearly all command names and most of their command line switches will be in lowercase.
1.5 Difficulty :-The main difficulty is, as all operating system such as Unix, windows has their own commands. Therefore, the new user fined it difficult to work on these command prompt or terminal.
To resolve this difficulty, new application is created called Multi-Platform based Virtual terminal. In this terminal, the commands used are common for all platforms such as windows, Unix, etc.
1.6 Multi-platform based Virtual Terminal :-This terminal works as the virtual command prompt on multiple platforms. It is platform independent. It recovers disadvantages of terminal. In this we create user define commands. Same command can be execute on all platform. It also has a built in editor which lets you write files. It is written in Java, So, java must be installed in system i.e. machine has to be a Java Virtual Machine (JVM).
1.6.1 Features of Virtual Terminal :- 1. It supports multiple entries of filenames & website names under a single command, all these entries are then processed sequentially.2. It also has a built in editor which lets you write files:
a) Type "edit" at the command-line.
b) Write whatever you want to write.
c) Type "save example" where, "example" is the name of the file you have
d) Type "exit" at command-line to exit from the editor mode and go back to command mode of Virtual Terminal"
e) To edit an existing file type "edit hello.txt" where, "hello.txt" is the existing file you want to edit.
3. A directory cannot delete with files inside it. the files inside have to be deleted, then delete the directory.4. It supports "command-line surfing". Its just like as of "doskey" in DOS. You can easily switch between your previous commands using the UP arrow & DOWN arrow keys.5. It supports multiple video modes (like orange text on black background etc.).6. It can run any number of programs with a single 'command-line' command e.g. "run calc write mplayer" will start the programs "calc", "write" & "mplayer" simultaneously.
7. It cannot access any other partition or drivedirectly from the command-line. If the Terminal.class file is in yourdrive C:\, then only C drive can be accessed.
Chapter2SOFTWARE ENGINEERING PARADIGM------------------------------------------------------------------------------------------------------------Every project has its own methodology. Various methodology models such as waterfall, incremental, prototyping, spiral etc. The model suitable for our project is waterfall model.
2.1 Phases of Project :-This section explains the various phases of the project. The software model followed for implementing this project is waterfall model.
Fig 2.1 Waterfall Model
This project consists of following phases:-
2.1.1 Requirements Phase :- In this phase, all the requirements of the project will be gathered based on which the problem will be analyzed. We will try to understand the specific requirements that must be achieved to implement this project. At the end of this phase, we will have detailed understanding of the nature of application to be developed by identifying the problem and specify refined preliminary set of proposed solution.
This phase will state following points in detail
*Need for building this application
*Scope of the Project.
*Deliverables of the Project.220.127.116.11 Requirement specification :-In the context of computer-based systems (and software), the term specification means different things to different people, a specification can be written document, a graphical model, a formal mathematical model, and a collection of usage of scenarios, prototype or any combination of these. The System specification is the final work product produced by the system and requirements engineer. It serves as the foundation for the hardware engineering, software engineering, database engineering and human engineering. It describes the function and performance of a computer-based system and the constrained that will govern its development. The specification also describes the information that is input to and output from the system.18.104.22.168 Hardware requirements :-These are the minimum requirements of the computer setup for the product developed to run, givin