Linux Shell or “Terminal”
A shell is a program that receives commands from the user and gives it to the OS to process, and it shows the output. Linux's shell is its main part. Its distros come in GUI (graphical user interface), but basically, Linux has a CLI (command line interface).
Linux Basic Commands
‘pwd’ command prints the absolute path to current working directory.
$ pwd /home/infomax
Displays the calendar of the current month.
This command will echo whatever we provide it.
$ echo "infomaxacademy.com" infomaxacademy.com
Displays current time and date.
$ date Fri Jul 6 01:07:09 IST 2012
This command clears the screen.
Linux Filesystem commands
Changing Directories (CD) Command
$ cd [path-to-directory] $ cd /usr/share/
Listing File And Directories Command
$ ls [files-or-directories]
List files and/or directories. If no argument is given, the contents of current directory are shown.
Creating/Deleting files and directories
To create a directory, the ‘mkdir’ command is used.
$ mkdir olevel
To remove a directory, the 'rm' command is used
Qus. What are various categories of software?
Ans: Software are classified into following categories –
(i) System Software
a. Operating System
b. Language Processor
(ii) Application Software
c. Customized software
d. Developer Tools
Qus. What is the difference between an interpreter and a compiler?
Interpreter: Interpreter is a type of system software that translates and executes instructions written in a computer program lini-by-line, unit by unit etc. It is slower in execution because each time when you run the program translation is required.
Compiler: Compiler is another type of system software that translates and executes instructions written in a computer program in one go. Once compiled program need not to translate again so it works faster.
Qus. What is application software? Why it is required?
Ans: Application software is the set of programs necessary to carry out operations for a specific task. Such as for word processing there are many application software like MS-Word, Wordpad etc. These software are required to perform special task using the computer like painting, recording, typing, data handling etc.
Qus. What is system software?
Ans: The software that controls internal computer operations is called system software. It manages all the resources of a system. Its example is Operating System.
Qus. Discuss the role of utility software in the context of computer performance?
Ans: Utilities are those application programs that assist the computer by performing housekeeping functions like backing up disk or scanning/cleaning viruses or arranging information etc. its example is Antivirus software.
Qus. What is the importance of an OS?
Ans: An operating system is a program which acts as an interface between a user and the hardware. It manages all the resources of the computer system. It provides and environment to the user to work with. All the application are installed after the operating system is installed. It manages memory, processing, storage, memory etc.
Qus. What is the utility of these software?
(a) disk fragmentor (b) backup software
(a) disk fragmentor: A file is fragmented when it becomes too large for your computer to store in a single location on a disk. When this happens, your computer splits the file up and stores in pieces. You can use fragmented files, but it takes your computer longer to access them.
(b) Backup software: This utility program facilitates the backing-up of disk. Back-up means duplicating the disk information so that in case of any damage or data-loss, this backed-up data may be used.
Qus. Describe the role of Operating System as a resource Manager.
Ans: A computer system has many resources (hardware and software), which may be require to complete a task. The commonly required resources are input/output devices, memory, file storage space, CPU etc. The operating system acts as a manager of the above resources and allocates them to specific programs and users, whenever necessary to perform a particular task. Therefore operating system is the resource manager i.e. it can manage the resource of a computer system internally. The resources are processor, memory, files, and I/O devices. In simple terms, an operating system is the interface between the user and the machine.
Operating System Management Tasks
1. Processor management which involves putting the tasks into order and pairing them into manageable size before they go to the CPU.
2. Memory management which coordinates data to and from RAM (random-access memory) and determines the necessity for virtual memory.
3. Device management which provides interface between connected devices.
4. Storage management which directs permanent data storage.
5. Application which allows standard communication between software and your computer.
6. User interface which allows you to communicate with your computer.
Qus. What are the advantages of parallel computing?
Ans: Parallel computing is a type of computation in which many calculations or the execution of processes are carried out simultaneously. Large problems can often be divided into smaller ones, which can then be solved at the same time. It refers to the simultaneous working of multiple processors to solve a computational problem. Its advantages are –
(i) It saves time and the cost too.
(ii) It makes easier to solve larger or complex problems.
(iii) It provides efficient use of underlying hardware.
(iv) It can utilize the resources available remotely.