User:XiX/Bash

Bash, which stands for Bourne-Again SHell, is one of the most popular 'shells' today. 'Shells' are command-line interpreters that process user input, and they are arguably the single most powerful tool at your disposal while operating a Linux platform. Understanding Bash, or any shell for that matter, is therefore highly recommended for both efficiency benefits and your understanding of the Linux platform itself. Before we begin, it's important for you to recognize that unlike MS-DOS, Bash is case-sensitive. That is, 'ID' will be interpreted differently than 'id', so ensure that you are using the correct case before executing a command. To start with, you can find Bash on most modern OS's like so:

Description	Command	Example output
Find out what shell you are actively using	echo $SHELL	/bin/bash
Locate Bash	which bash	/bin/bash

The advent of Bash ushered in new features to modern shells. You may have recognized one already, when we ran 'echo $SHELL'. Bash supports internal variables, such as the '$SHELL' variable. Most variables are set by the shell, however you can set them yourself. To set a variable:

Description	Command	Example output
Setting a variable	NAME='XiX'	No output
Using a variable	echo Hey $NAME	Hey XiX
Show all variables	set	Output too extensive

Using commands like 'set' and 'echo' are part of a series of commands known as 'Bash builtins'. Bash builtins are tasks that can be performed independent of the host OS. A full list of Bash builtins can be found here.