Due Tuesday Sept 17, 9:50am.

Will be collected on Tuesday before lab session.

Reminder...

1. All file names and paths must be exactly correct.
2. Set the permissions of your web folders and files to 755.
   example: chmod 755 3350
            chmod 755 lab3
            etc.

Assignment

1. Finish all elements of the lab-3 assignment.
2. Create a real Data Flow Diagram.

Data Flow Diagram Help

Step 1:

As we learned in class, a DFD uses 4 symbols only.
Your symbols can vary slightly, but you must use 4 symbols only.



Step 2:

Look at this sample.




Step 3:

Here's one way to start the homework-3 diagram...



1. The user enters host and page data on the command-line.

2. The lab3sget program starts running and converts the input data into some
   kind of output data, then it flows on to some other entity, like maybe the
   Odin server using some kind of protocol like maybe HTTP.

3. You wrote and put into place many of the components of this system.
   Show where they fit in to your DFD.

4. The HTTP protocol is a request-response protocol. This means that data
   flows outward and then something comes back. Show it.

5. Your diagram probably should not have: a cloud, a router, wifi, a modem,
   a keyboard, a stick person, a dragon, a puppy, a C++ program, etc.
   Try to build a perfect and clean DFD.

Generally follow these rules as a guide...
 1. Each function should have at least one input and an output.
 2. Each file/database should have at least one data flow out.
 3. Data stored in a system must go through a process.

References...

Refer to online tutorials:

Wikipedia
Lucidchart
Smartdraw
others may be acceptable.

Scoring will be done by ranking the diagrams from best to worst.
Taken into account will be:

 . effort
 . understanding of lab-3 components
 . understanding of a DFD
 . individual work

You may be somewhat creative, but remember that a DFD is a very
organized and restricted document designed so that no one has to
think too much to understand it.

Use the symbols to describe.

You may replace your lab3_diagram.gif document with this new document
in your /public_html/3350/lab3 folder.

Thanks.