Agenda What is Computer Programming? The Programming Process Steps to Create Your Phobos Account Steps to Create a Program Create Source Code with Text Editor Compile Program Run Program

What is Computer Programming? The job of a computer programmer is to give instructions to tell the computer what to do. Process Data Store Data Accept input Provide output (information) Programming: The ability to tell the computer how data is to be processed

Steps to Create a Program Determine Requirements for Program (Input, Outputs, formulas & processes) Plan out Program Write Program (Create source Code using text editor) Compile Program (Convert source code to machine language) Test (Run) Program

Phobos & Learn Accounts In order to perform programming labs and assignments, you will require a Phobos account. You may have received (by mail) instructions on how to obtain your Learn and Phobos accounts If you did not receive instructions on how to create a Phobos account (via mail), please see my course notes for link. PHOBOS Account to create, compile and run programs LEARN Account to send and receive e-mail messages

Steps to Create Phobos Account 2. Check Learn e-mail for Phobos username & password 1. Learn account created Activate SIRIS account Run Telnet application to access Phobos acct. Phobos account created 3. You will learn how to create your Phobos account in ICS124 course…

What is the Telnet Application? Unix systems such as PHOBOS were originally designed to accommodate “dumb terminals” which were simply monitors and keyboards directly connected up to network Telnet allows the server to “think” that the user’s personal computer is a “dumb terminal” A common type of “dumb terminal” was Digital Equipment corporation’s VT100.

Telnet Application To launch or “run” the Telnet application from the Seneca computing lab, point and click onto the application “telnet” on the Windows 95 desktop You can obtain a free version of Telnet application for home use (assuming you have computer system with modem). More details in provided in ICS124 course.

Open Session For all Telnet applications, you must specify which server that you will connect For this Telnet application, you must point and click onto the File menu, select Open and type the server name (such as phobos). If you are logging in from another ISP you must provide the full domain name of the server (such as phobos.senecac.on.ca). Refer to ICS124 notes on where to access and download telnet application.

Logging Onto Your Phobos Account After you connect to the phobos server, you must type in your username (should be on your Seneca “one-card”) and your password. The password will be provided to you by an e-mail message in your LEARN account. It is important to get your LEARN account as soon as possible!

Learning Phobos Commands The operating system for Phobos is Unix, therefore it is recommended to learn Unix commands throughout this course How to Learn Unix Commands: ICS124 Course “Introduction to Seneca’s IBM RS/6000” (at back of Subject Notes for IPC144)

Let’s Create a Program! In order to write programs, you need a text editor that can create, edit and save programming instructions (also referred to as “source code”). A text editor differs from a word processing application (such as MS-Word) in that it does not contain special formatting characters (that can cause programs when converting to machine code to run)

Nled Text Editor Types of Text Editors in Phobos pico vi nled stands for “Neat Little Editor” and was written by one of Seneca’s Computer Studies’ Faculty members – Evan Weaver. Select a text editor that you feel comfortable using. (ICS124 course recommends nled)

Creating a Source File Logon to PHOBOS via telnet At the Unix prompt type nled file.c <ENTER> c extention indicates that file Contains C programming Instructions (source file)

The Nled Text Editor Common nled Commands: <ESC><?> Displays help menu <ESC><x> Save file & exit You will learn additional nled commands in ICS124 course

Compiling a Program After you use an editor to create a file containing your programming code, you are required to compile your source code to make the file executable. This compiling process converts your source file into machine language that the computer can understand and execute efficiently Executable File Edited File Compiler

Compiling a Program Although there is more than one Unix command that may be used to compile a program, we will show you the cc Unix command. There are two different options of using the cc compiling command. One options creates an executable file called “a.out”, the other option allows the user to name the executable file.

Compile & Run Program At the Unix prompt in Phobos, type cc file.c and press ENTER If there are no programming code errors, an executable file will be created called a.out You would need to type a.out followed by ENTER to run the program

Logging-off Phobos Always log-off of your Phobos account and exit the Telnet Application before you leave your terminal To log-off of your Phobos account, type the following command at the Phobos prompt: logout <ENTER> (or exit or <CTRL><D>) After your session is disconnected, exit the Telnet application

Homework Please obtain study notes for IPC144 by Evan Weaver, and read pages 1 to 18 for next week’s classes. Try completing assignment #0 for practice (next week, I will show you how to send typescript file to the line printer)