Shell scripts on mac in a nutshell:

1. Create a new shell script file with nano:

   nano script.sh

2. Enter the following code to signify it's a shell script and to run a command:

   #!/bin/sh
   ls

3. Make it executable with chmod:

   chmod 777 script.sh

4. Run it with the sh command:

   sh script.sh

https://stackoverflow.com/questions/36854193/scheduling-a-terminal-command-or-script-file-to-run-daily-at-a-specific-time-mac