That's an excellent follow-up question! The last sentence of the current step is a perfect lead-in to that.
The key difference between a regular shell variable (like my_var you just created) and an environment variable lies in their scope and availability:
Shell Variables (Local Variables):
- Scope: They exist only within the specific shell session (or script) where they are defined.
- Availability: They are not automatically passed to child processes (like new commands or scripts executed from that shell).
- Example: If you open a new terminal tab right now,
my_varwould not be defined there.
Environment Variables:
- Scope: They are also defined within a shell, but they are exported to the environment.
- Availability: They are automatically inherited by any child processes that the shell creates. This means if you run a script or open a new program from a shell where an environment variable is set, that script or program will have access to that variable's value.
- Purpose: This makes them crucial for configuring how your system, applications, and other processes behave. For example, your
PATHenvironment variable tells your shell where to look for executable commands.
The current step explicitly mentions this: "However, this variable is only available in the current shell session. If you open a new terminal window or tab, this variable won't be available there. This is where environment variables come in handy."
We'll dive into creating and using environment variables in the upcoming steps. But for now, just think of environment variables as having a much broader reach within your system compared to the my_var you just created.
Does that explanation make sense? Let's continue with the lab to see them in action!
