Advanced Linux Commands

alias

• Launch any command or group of commands by entering a pre-set string
• Allows a user to create simple names or abbreviations for commands

Basic Syntax

alias <String> = <Command>

Examples

alias p = "pwd"

Alias

An alias can be created with the same name as the core name of a command

An alias named ls could be created for the command ls -al

alias ls= "ls -al"

Alias

Multiple commands can be included in the same alias

Insert them within the same pair of quotation marks and Separate them with semicolons

alias pl = 'pwd; ls'

Alias

Aliases can even be created to call other aliases

alias l='ls -a'

alias pl='p; l'

Aliases can be used with any argument that the command can be used with

l /home/Documents

Alias

Any alias set up with it remains in effect only during the current login session

Type alias only to see a list of aliases.

Use unalias alias-name to remove an alias

bc

A basic Calculator

In the bc environment type expressions and get their results

5*5+3*23

Use last to use last answer in your expression.

last * 2 - 1

I/O Redirection

Pipe

Symbol used to provide output of one command as input to another command

>

Used to direct the output to a file.

>>

Used to append the output to a file

grep

Used to search text for patterns specified by the user

Basic Syntax:

To see the occurances of 'is' in a file 'Intro.txt':
grep 'is' Intro.txt