create a script backup.sh which contains a command to create a compressed archive of the work subdirectory.

Sure, here is a simple script that you can use to create a compressed archive of the work subdirectory.

1. Open a text editor to create a new file. You can use any text editor you like, such as nano, vim, or emacs. For this example, we'll use nano:

nano backup.sh

2. In the text editor, write the following lines:

#!/bin/bash
tar -czvf work_backup.tar.gz /path/to/work/

In this script, tar is the command used to create the archive. The -c option tells tar to create a new archive, -z tells it to compress the archive using gzip, -v is for verbose output (so you can see what's happening), and -f allows you to specify the name of the archive file.

Replace /path/to/work/ with the actual path to the work subdirectory.

3. Save the file and exit the text editor. If you're using nano, you can do this by pressing Ctrl+X, then Y to confirm that you want to save the changes, and then Enter to confirm the file name.

4. Make the script executable by running the following command:

chmod +x backup.sh

Now you can run the script with ./backup.sh whenever you want to create a backup of the work subdirectory.