[Linux] Bash export Uso equivalente: Set environment variables

The export command is used to set environment variables in a Bash shell, making them available to child processes.

Overview

The export command allows you to create environment variables or mark existing shell variables for export to child processes. This is essential for passing configuration settings or other data to scripts and programs that are executed from the shell.

Usage

The basic syntax of the export command is as follows:

export [options] [arguments]

Common Options

• -n: Unsets the export property for the specified variable, making it a regular shell variable.
• -p: Displays all exported variables and their values.

Common Examples

Example 1: Exporting a new variable

To create and export a new environment variable named MY_VAR with the value Hello, World!, use:

export MY_VAR="Hello, World!"

Example 2: Exporting an existing variable

If you already have a variable and want to export it, you can do so like this:

MY_VAR="Hello, World!"
export MY_VAR

Example 3: Unsetting an exported variable

To unset the export property of a variable, use the -n option:

export -n MY_VAR

Example 4: Displaying all exported variables

To see all currently exported variables, you can use:

export -p

Tips

• Always use quotes around variable values that contain spaces to avoid syntax errors.
• Remember that exported variables are available to any child processes, so be cautious with sensitive information.
• Use unset to remove a variable entirely if it is no longer needed.