What does the following sequence do?

file * | grep -v 'directory' | cut -d: -f1 | xargs ls -l | sort +4 -5 -r | head -10
        

Sort /etc/passwd alphabetically with the comment field as key.

Enter the following by cat >, or with vi.

Peter Jensen		4321 2701
Hans Andersen		3133 2399
Lotte Pedersen		4377 7777
Henning Just
Jørgen Larsen		4377 7799
Lise-Lotte Pedersen	4377 7783
Inge Hansen		4477 4477
Poul Larsen		4477 4478
Anna Jensen		9999 9999
Lotte Petersen		4377 7781
Lotte Pedersen		4377 7700

Save the file as ex72

Check the man sort. Sort ex72 outputting into ex73. Sorting must use surname as primary, and first name as secondary sort criteria.