Exporting Variables In Bash. What is it and how to use it?

In Bash, the export command is used to create or modify environment variables and make them available to child processes. When a variable is exported, it becomes part of the environment for any subsequent commands or scripts that are executed.

Here’s how you can use the export command to export variables in Bash:

export my_var

In this example, we create a variable my_var and assign it the value “Hello”. The export command is then used to export the variable, making it available to any child processes or scripts that are executed from the current shell.

Alternatively, you can combine the variable assignment and export in a single line:

export my_var="Hello"

Once a variable is exported, it can be accessed by other processes or scripts that are spawned from the current shell. For example, if you have a Bash script that relies on an exported variable, it can access the value of that variable.

Here’s an example script that demonstrates accessing an exported variable:


echo "The value of my_var is: $my_var"

Assuming the variable my_var has been exported in the parent shell, running this script will display the value of my_var:

The value of my_var is: Hello

By default, variables defined within a script are not automatically exported to the environment. To make them available outside the script, you need to explicitly export them using the export command.

It’s worth noting that exporting a variable makes it available to child processes, but not to parent processes. Changes made to exported variables in child processes do not affect the value of the variable in the parent process.

Exporting variables in Bash is useful when you need to pass data or configuration settings from the current shell to child processes or scripts. It allows you to establish communication and share information between different parts of your script or across different scripts.

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