The subject is UNIX

Please answer questions and include the Exercise number.

Exercises:

8.9 (i and iii), Frame aliases to show (i) only the hidden filenames in the current directory, (ii) the listing of all symbolic links in the current directory and below, (iii) the absolute pathname of a filename specified as argument to the alias.

8.15, Why do shells use a profile as well as an rc file? What types of entries do you place in each?

8.18, How can you make all of your aliases placed in ~/.alias available in all sub-shells? Will the aliases be available in a shell script in (i) Korn, (ii) Bash?

8.19 Devise a system which allows you to use an alias named current to display recursively only the ordinary files in the current directory tree which have been modified since you logged in.

9.17 Assuming that a user may be logged in more than once, how do you (i) list only those users, (ii) mail root a sorted list of all users currently logged in, where a user is listed only once?

Thank You!