How To Use Linux Commands

Linux is case sensitive…

From windows to Linux

• GUI is just another software only • Linux can provide diskless workstation • Same Kernel for all purposes Kernel

• • • •

AB aB aB ab

Four different strings in Linux One string in Windows

• ls /boot/vmliuz Æ tab key • du –ah /boot/vmlinuzÆ

User 1, 2, 3

.......................................................... HW

shell

•

Linux shell is multitasking program as well as a program Interpreter. •

Default shell is BASH

•

To view user database cat /etc/passwd

• Linux does not use 3 character file extensions. – .(dot) is just another character only

apache.conf ……………………..

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• myfile.txt can be and excitable file in Linux

• GUI is optional, it you use Linux as server...

Create a file…… touch file name… …………………………….

Everything reduced to files.

ASCII text files

Binary files

The term "ASCII file • The term "ASCII file" refers to a "text" file that is readable by the naked eye (it only contains the letters a-z, numbers, carriage returns, and punctuation marks). Conversely, a binary fie is not readable by the naked eye (it contains the ASCII characters in addition to binary codes). Therefore, any file that one can read with a common editor is considered an ASCII file.

Device files

A binary file • A binary file is a file whose content must be interpreted by a program or a hardware processor that understands in advance exactly how it is formatted. That is, the file is not in any externally identifiable format so that any program that wanted to could look for certain data at a certain place within the file. A program (or hardware processor) has to know exactly how the data inside the file is laid out to make use of the file.

• A file stored in binary format. A binary file is computer -readable but not humanreadable. All executable programs are stored in binary files, as are most numeric data files. In contrast, text files are stored in a form (usually ASCII) that is humanreadable.

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Device file…. • i) Locate in /dev directory cd /dev ls ls hd* ….. ……. ……. ……

• Ex • Useradd –d /home/debian –s /bin/bash debian

How to use Linux commands. • Linux programs or command has many options or arguments. Which can be supplied at command prompt to get various tasks done. • Theses options/ arguments sometimes get implicitly ( as a default)

• 1. using argument. • cd /usr

cmd

Single letter options are supplied with an arguments are separated bye one more space. More than one letter options are supplied with each options and argument are separated at least one space.

using options

implicit argument • cd • pwd path

Argument

ls –a cd $HOME environment variable for users home dir

when you type some commands alone if it has no defult argument option it will provide basic syntax help or prompt user to view help ‘

ls –a –l => ls –al netstat –tnlp = > netstat –t –n –l –p More than one charector options mv --help =/ mv –h –e –l –p

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