Programming Assignment 1: Lisp

We have provided the code to get you started. Follow the below steps to get the code and start it running.

• Step 1: Copy the sample code.

  All you will need is a loader file and the sample program that demonstrates the basic functionality. Copy /usr/class/cs157/lisp/sample/loader.lisp and /usr/class/cs157/lisp/sample/example.lisp.

  Please note that the instructions, code, and support we are providing are only tested on the leland Solaris machines.

• Step 2: Load the code.

  Log in to one of the Leland machines that have alisp installed, e.g. the elaine's or saga's. From the directory to which you just copied loader.lisp and example.lisp, run alisp. (The first time you run it, it may take a while to load.) At the prompt, enter (load "loader.lisp"). A bunch of warnings and output will fly by. Ignore the warnings.

• Step 3: Start the webserver.
  1. Choose a random port number in the range 5000-65000. This will bind your server application to that port for the machine on which you're running your server. Try to choose a random number and remember it - you will be the only person on that machine who can use that port, and you will need it to have access over the Web.
  2. Enter the command (startserver 5000), where 5000 is an example of a port in the range 5000-65000. The response from Lisp will be a message that it is listening on port 5000. If you press Enter, you will get the prompt back.
• Step 4: Access the webserver.

  Your automated reasoner will be accessible from the Web at the address http://<machineXX>:<portnum>/, where <machineXX> refers to the Solaris machine from which you're running the Web server (e.g., saga22, elaine45, etc.) and <portnum> is the port you gave to startserver. If you were using elaine28 and port 5000, the URL would be http://elaine28:5000/.

Once you make changes to the Lisp code, you need only reload the affected files--with one exception. If you make changes to the function myfrontpage, you will need to reload at least one of the files mentioned in loader.lisp, so it is easiest to reload them all. You can even reload files without shutting down the webserver.

Shutting down the webserver is easy. It should be shut down automatically when you exit the alisp from which the server was started. But if you want to kill the server without exiting alisp, in the terminal window from which you started the webserver, execute (stopserver). Lisp returns NIL and shuts down the server process.

Now a few notes on Lisp and alisp.

• If for some reason you need to stop alisp in the middle of execution, you can use Control-C. alisp will give you a restart menu which includes a list of Restart actions. If you simply want to kill the process, choose the Return to Top Level (an "abort" restart) option. (It is usually the second option from the bottom.) Say the abort restart option is number 1; then type :cont 1. (Don't forget the colon.)

• Executing Lisp functions on the command line will always look the same as standard Lisp, as in example.lisp, e.g. (startserver 5000). Executing alisp-specific commands on the command line requires a slightly different syntax. You've already seen one example :cont 1. These alisp commands start with a colon (:) followed by the command and the arguments to that command. :help gives you a listing of these commands. :exit quits out of alisp.
• The command line doesn't care about white-space. All the below are equivalent:
  
  1. (startserver 5000)
  2. (startserver 5000
     )
  3. (
     startserver
     5000
     )
  This means that if you enter a command that is missing a right parenthesis and press Enter, alisp thinks you are still in the midst of entering a command. It will just sit there and wait.
• If you get lost in a bunch of errors, you can always do an abort restart (it will almost always be the second restart option from the bottom). The last restart option will quit out of Alisp.
• Here's a Lisp Primer.
  Here's the Common Lisp Specification
  Here's a site all about Lisp and tutorials
  If none of these suit you, try googling "lisp tutorial"