http://giggles.vernccvbvyi5qhfzyqengccj7lkove6bjot2xhh5kajhwvidqafczrad.onion/study/learn-from-phoebos.html
In the case of the script there is no program bein specified, so the exec is being used to set the redirections, that is, from this line on the standard output will be the file $HOME/public_html/activity/index.html , thats a cool way to let an script generate/regenerate the contents of a file (eg: a webpage).
If you carefully looked at the script, you noticed it will generate a web page redirecting the output of the following commands to the file specified before using...