How to save a file's absolute path as an environment variable in Linux?

Saving a File's Absolute Path as an Environment Variable in Linux

In Linux, environment variables are a set of key-value pairs that store information about the current working environment. These variables are accessible to all running processes and can be used to configure system behavior or store important data. Saving a file's absolute path as an environment variable can be useful for various purposes, such as accessing the file easily from different parts of your script or application.

Here's how you can save a file's absolute path as an environment variable in Linux:

Step 1: Determine the Absolute Path of the File

The first step is to determine the absolute path of the file you want to save as an environment variable. You can use the readlink command to get the absolute path of a file or directory. For example, if you have a file named "example.txt" in your current working directory, you can get its absolute path like this:

ABSOLUTE_PATH=$(readlink -f example.txt)

This will store the absolute path of the "example.txt" file in the ABSOLUTE_PATH environment variable.

Step 2: Set the Environment Variable

Once you have the absolute path, you can set it as an environment variable. You can do this in two ways:

1. Temporarily set the environment variable for the current shell session:

   export EXAMPLE_FILE_PATH=$ABSOLUTE_PATH

   This will set the EXAMPLE_FILE_PATH environment variable for the current shell session only. The variable will be available until the session is closed.

2. Permanently set the environment variable:

   To make the environment variable persist across shell sessions, you can add the variable definition to your shell's configuration file, such as ~/.bashrc (for Bash) or ~/.zshrc (for Zsh). For example:

   echo "export EXAMPLE_FILE_PATH=$ABSOLUTE_PATH" >> ~/.bashrc

   After saving the configuration file, the EXAMPLE_FILE_PATH environment variable will be available in all subsequent shell sessions.

Accessing the Environment Variable

Once you have set the environment variable, you can access its value from your scripts or applications using the $ prefix. For example:

echo "The file's absolute path is: $EXAMPLE_FILE_PATH"

This will output the value of the EXAMPLE_FILE_PATH environment variable.

Mermaid Diagram

Here's a Mermaid diagram that illustrates the steps to save a file's absolute path as an environment variable in Linux:

By following these steps, you can easily save a file's absolute path as an environment variable in Linux, making it accessible from different parts of your scripts or applications.