It's that time again, NVCC Course Evaluations! Please visit https://nova.direct.iota360.cc, enter your VCCS email and your NVCC student number and complete your evaluations. NVCC will provide me with regular updates as to your participation rates, so I will nag relentlessly until you get this done :-)

We'll begin class today by checking the running versions of CLISUM that you wrote for homework.

Next we'll look at file I/O. Using The Buffered File I/O Functions section on page 133 of the BDS C User's Guide, I was able to write COPY.C.

Wow, this was so much easier than it was in 8080 assembly language, right? Abstraction rocks!

One caution: last year I changed the c variable in this program from int to char and it broke it. It turns out that EOF is not a character! That link is to a wonderful blog post, by the way, well worth a quick reading.

Rewrite the disk access program you wrote as your final project with assembly language in C. Come to next class ready to show it running on your computer.

Since many of you were not ready with your disk I/O programs, and I ended up with only a single application of what I was hoping for (batch processing of lines of input with a text file containing corresponding lines of output), we needed to postpone our plans to start C by a day. We'll find a time to share presentations of the working assembly programs later, but for now just email them to me and let me confirm they work before we share them in class.

Today we will compile (we're not assembling any more baby! ;-) our first C program on CP/M using BDS C, the infamous helloworld.c.

Here's what to do:

1. Create a file named CSTUFF.SUB on your C drive with the following contents:

   PIP $1:=C:CC.COM
   PIP $1:=C:CC2.COM
   PIP $1:=C:CLINK.COM
   PIP $1:=C:C.CCC
   PIP $1:=C:DEFF.CRL
   PIP $1:=C:DEFF2.CRL
   PIP $1:=C:STDIO.H
   

   Now, if you want to use drive D for compiling C programs, you can switch to the A and run:

   submit c:cstuff D
   

   and it will copy the 7 files you need from drive C to drive D.

2. Using your favorite text editor (ED of course! ;-) create a file named HELLO.C in the D drive with the following contents:

   #include <stdio.h>
   
   main()
   {
       printf("hello, world!\n");
   }
   

3. Compile and link your program with:

   D>CC HELLO
   

4. Finally, run your program with:

   D>CLINK HELLO
   

   Then Run:

   D>HELLO
   

   and you should see:

   hello, world!
   

ARGS.C

The next program we'll look at reads arguments from the command line:

#include <stdio.h>

main (argc, argv)
int argc;
char **argv;
{
    int i;

    printf("Command line argument test\n");

    for (i = 1; i < argc; i++) {
        printf("%s\n", argv[i]);
    }
}

Compile it and run it with:

D>args 1 2 buckle my shoe 3 4 shut the door

and see what you get.

You'll work individually for this first C programming assignment, since you all need to have the process down so we can continue.

Your task is to write a program named CLISUM that takes a sequence of integer values at the CP/M command line and prints out their sum. An A submission should gracefully handle invalid input. Sample runs might include:

D>clisum 5 15 22 8
Sum is 50
D>clisum 1 1 1 1 1 1 1 
Sum is 7
D>clisum 5 15 icecream 8
OOPS! ICECREAM is not a number

In addition to ARGS.C, you should use the ndigit discussion beginning on page 20, and the atoi discussion beginning on page 39 of The C Programming Language as resources for this assignment.

This assignment is due before our next class! I'll come around at the beginning of class and check you off for showing it to me running on your laptop.