PSET2 - Infinite monkeys, infinite typewriters

1. Become root and grab a copy of your syslog.  This is a file containing
various log messages from the services running on your machine.  Like most
log files, it lives in the directory /var/log.  Copy it into your
unix-course directory, and change it to be owned by you.

There is a lot of cruft and extra information in syslog, so we need a way
to condense the useful information.  Look at the format of each message:

May 23 07:05:15 localhost ypbind[213]: broadcast: RPC: Timed out.

Here we have the date, the name of the machine, a service with its PID
(process ID), and then some service dependent message.  Count the number of
messages from the kernel.

Say you want to find out which services are writing to syslog.  Write a
shell command (or a series of commands joined by pipes) which will pull out
the names of the services (here "ypbind"), and present back to the user a
list of the unique service names.  Note that ypbind[213] and ypbind[386]
are really the same service, just different actuall processes.  (This may
appear to be an exercise in learning to use sed, tr, grep or some other
similar utilities.  It is really an exercise in skirting around the weak
documentation and minor misimplementation of these utilities. )

Shell Scripts
=============

1. One the video server we have a directory structure that allows for
transparently storing the realmedia files on multiple partitions.
Each partition is mounted under /real/d01,/real/d02,etc, and in
/real there are symbolic links to the actual files.  In addition,
there are .ram files in /real/ which contain a single line referencing
the .rm file in the same directory.
For example, 

  $ ls /real
  05-10-01Lect.rm ->  d03/05-10-01Lect.rm
  05-10-01Lect.ram
  04-05-01Lect.rm ->  d04/04-05-01Lect.rm
  04-05-01Lect.ram
  $ cat 05-10-01Lect.ram
  rtsp://64.64.103.140/05-10-01Lect.rm
  $ cd /real
  $ ls d02
  03-01-01Lect.rm
  $

Write a script which looks in all subdirectories that are listed on the
command line (arguments to the shell can be reference by the shell
variable $*), creates symlinks from the current directory to files in the
given subdirectories if they do not exist, and creates the corresponding
.ram files.  In the above example, running your script from /real, with
the argument d02, would create a symbolic link in /real that points to
03-01-01Lect.rm and a new file /real/03-01-01Lect.ram that contained a
single line, "rtsp://64.64.103.140/03-01-01Lect.rm".

2. Diff, only better
There are times when you would like to compare two files, but are not
interested in differences in comments.  Let's take java files, for
instance.  Write a script which takes two filenames, removes the
text that would be commented out by '// ...' and '/* ... */', and then runs
diff on the results. 

3. See homework 3 from the Cornell course.  Obviously you can ignore the
cornell specific instructions about where to put your files and such.

BONUS:  Write a shell script that prints itself out.  There is an easy way
- using the shell's ability to read a file from the filesystem - and a
harder way ala Shai's Logo program.