export command

Detailed Explanation

export is a shell built-in command used to mark variables to be passed to child processes. By default, variables created in a shell are local to that shell. Using export ensures that if you start another program (like a script or a text editor) from that shell, the program will inherit that variable.

Basic Syntax

export [name[=value]] ...

Common Usage

Usage	Description
export	Display a list of all exported variables in the current shell.
export VAR=value	Assign a value to a variable and export it in one step.
export -p	List all exported variables in a format that can be reused as input.

Real-world Examples

Set a variable and export it:

export PATH=$PATH:/home/user/custom/bin

Export an already existing local variable:

MY_VAR="hello"
export MY_VAR

View all exported variables:

export -p

(Note: Variables exported in the terminal are lost when the session ends. To make them permanent, add the export command to ~/.bashrc or ~/.profile.)