CS198 Intermediate Systems Administration DeCal
Week 5 Lab - George Wu
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In this lab the focus is to just let you play with all the power tools you've
just learned about. This lab is in text format so you can use it as a corpus
for any text manipulation tasks you may want to try out. (For some questions
you are advised to copy the relevant sections you need to process into a
separate text file.)

Thus, if you want a copy of this whole text file for yourself, just log into
your server and wget the lab URL!

This is an individual lab, so I would like individual submissions from each
student this time. Email solutions to geo+decal@OCF.Berkeley.EDU.

I. Regular Expressions

I went over regular expressions very briefly in lecture on purpose; there is
so much to learn about them that it is best to just learn by example and
experiment. Please have http://www.ternent.com/tech/regexp.html open for this
question.

1. Create a regular expression that matches against hyphenated Social Security
   numbers.
2. Create a regular expression that matches against email addresses (to the
   best of your knowledge; don't stress out about being too precise.)
3. Create a regular expression that matches against RFC 822 dates (such as
   those returned by the 'date -R' command.)

II. Implementing a rudimentary database with cut, wc, sort, and grep

The following is a CSV (comma-separated values) excerpt representing a table
of student names, user IDs, group numbers, and grades. Copy this excerpt into
a separate text file so you can manipulate it.

(This is last semester's roster, the only difference is that everyone actually
passed last semester. High hopes for all this time around! :D)

Emily,cb,2,P
Graeme,cf,2,P
Joe,cg,3,NP
Gazi,cj,2,P
Jason,db,1,NP
Victor,dc,1,P

Show the command you used to find the answer, and you do have to come up with
a command; you can't just look at the data above. :P

1. Use grep to find the students that did NOT pass the class. Then, use cut to
   display only their names.
2. Use grep to find the students in group 2. Then, use wc to count how many
   students there are in that group.
4. (Open-ended.) Display the list of students' names, IN ASCENDING ORDER BY
   USER ID.

III. Using sed

For this exercise, you can use this lab questions file as an input to sed.

1. Change all capital or lowercase instances of "s" into "hooray".
2. In sed, you can use '&' in a replacement expression to represent the original
   part of the line that was matched. E.g.

   s/test/&er/

   will change 'test' into 'tester' on each line.

   Devise a sed expression that will change all instances of 'to' to 'atone'
   using this construct.
3. BONUS/JUST FOR FUN: Devise a sed expression or series of sed expressions that
   will change a sentence into pig latin. Doesn't have to be perfect. (Look it
   up if you don't know what it is.)

   You can test with the following sentence if you like:
   "The quick brown fox jumped over the lazy dog."

   The correct result should be
   "Ethay ickquay ownbray oxfay umpedjay overway ethay azylay ogday."