UMBC CMSC 201, Computer Science I, Fall 1995 Sections 0101, 0102, 0103 and Honors

Project 1 Comments

New Announcement:

This is very important for the orderly submission of projects for such a large class. Unlike the other commands which I have asked you to copy (e.g., cc201, lynx201, etc) which saves you typing, the mail2chang command saves me typing. Using the mail2chang command triggers a mail filter program which automatically sorts your project to the correct directory, generates a response and starts the "cheat-checker" program. So, even if you have no trouble using email, it is imperative that you use mail2chang.

Announcements:

If you haven't been able to copy the "201" commands to your directory yet, you are really behind. Read through the instructions. If you are still having trouble, get someone to help you. Yes, it means you have to do this on campus.

If you haven't played with your UNIX account yet, you are really really behind. Plan on spending a lot of time in front of the computer this week.

Questions and Comments (and some answers)

In this section, we have some questions and comments from the students. As usual, names have been withheld to protect the innocent and the questions have been edited for spelling and grammar.

Prof. Chang,

I copied the mail2chang command to my bin directory but when I issue the mail2chang command, UNIX says that the command was not found. I looked in the bin directory and the mail2chang command is really there.

Dear Student,

As before, if you copy a command to your bin directory, UNIX does not know it is there until you either log out and log back in, or you issue the rehash command. So, do one of these and the command should be available. (See Copying the "201" commands".)

Prof. Chang,

After sending my project to you I cannot access my files without the "ready to mail the project " program coming up. I cannot run my programs. Every time I want to, it asks me if I want to mail the project to you. How do I get rid of that?

Dear Frequent Mailer,

It seems you have screwed-up your UNIX account in a bizarre way. I am not sure what you mean by "access" your files. Does it happen when you issue the "ls" or "vi" commands? Most likely you have over-written some file with the mail2chang command. Get a knowledgeable person (me, a TA, a Help Center tutor or a UNIX consultant) to fix it for you.

Prof. Chang,

I accidentally sent you the wrong file. Should I send you the right one?

Dear Student,

Yes, just run the mail2chang command again. The new file will replace the old one. (Actually, I do keep a copy of every submission. We will grade the newest submission. So, if you sent something embarassing, you have to ask me to delete it explicitly.)

Prof. Chang,

I am having trouble compiling my program. I type in the command

     cc201 project1 
  

and the response is

     Object file format error in: project 1: bad file magic number
  

What does that mean? I saved my C program as "project1".

Dear Student,

The file name for C source code must end with ".c". So, rename your file as project1.c by issuing the command:

    mv project1 project1.c
  

Then, you should be able to compile your program.

Prof. Chang,

Would you consider two break statements in one while loop a bad programing style?

The reason I am asking is because I've looked through all the examples in the textbook and I haven't found any which includes two breaks. I only found it true for switch statements.

Oh Stylish one,

Yes, if you want to use two break statements in a while loop, that's fine. The while loop for Project 1 should be short enough, it would not cause any confusion. The break statements for switch statements are quite different. We will cover break statements very soon.

Prof. Chang,

Looking at this Project 1 craps program, it seems that we would need some command that generates random numbers. I looked in the book and tried what they had but I could not get it to work. Could you please tell me what commands to use to make random numbers in C?

Dear Student,

No, don't use random numbers. Just have the user type in the result of the dice roll. You can play with random numbers later.