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How to Run Our Script from Anywhere in Our System?

For any command or script, by default, the shell checks locations specified by the PATH variable. To run our script from anywhere, we need to add its location to the PATH variable. This can be done in two ways:

1 Session Level

This method is temporary and works only for the current terminal session.

Steps:

  1. Check the current PATH variable value:

    durgasoft@durgasoft:~/scripts$ echo $PATH
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin

  2. Add the script's location to the PATH variable:

    $ export PATH=$PATH:/home/durgasoft/scripts

  3. Verify the updated PATH variable:

    durgasoft@durgasoft:~/scripts$ echo $PATH
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin:/home/durgasoft/scripts

Now, you can run your script without specifying its path:

$date.sh
The current System Date and Time:
Wed Dec 4 21:01:49 IST 2019

Note: These changes are temporary. They will be lost once the terminal session is closed.

2 Setting PATH Permanently at User Level

This method ensures the changes persist across terminal sessions.

Steps:

  1. Open the .bashrc file located in your home directory:

    nano ~/.bashrc

  2. Add the following line at the bottom of the file:

    export PATH=$PATH:/home/durgasoft/scripts

  3. Save the file and exit. Apply the changes by running:

    source ~/.bashrc

Now, your script's location is permanently added to the PATH variable.

Q5 What is the Meaning of a Startup File?

  • .bashrc is a startup file that is executed automatically when a new terminal session starts.
  • To perform specific tasks (e.g., creating aliases, updating the PATH variable), you can define them in this file.

Q6 What is Meant by a Logout File?

  • .bash_logout is a logout file that is executed automatically when the terminal session exits.
  • To perform specific tasks (e.g., cleanup activities) during terminal exit, you can define them in this file.

The .bashrc file is typically located in the home directory of your user account. You can find it using the following methods:

1 Default Path

The file is located at:

~/.bashrc

Here, ~ represents your home directory (e.g., /home/username on Linux systems).

2 Check Existence

To confirm its presence, run:

ls -a ~ | grep .bashrc

This will list .bashrc if it exists.

3 Edit or View

To edit the file:

nano ~/.bashrc

To view the file:

cat ~/.bashrc

4 If .bashrc is Missing

If the .bashrc file is not present, you can create one:

touch ~/.bashrc