CPS 006, Lab 1

Prelab

        2.What is the name of Prof. Astrachan's dog?

        3.Professors in the computer science department are involved in research in five areas. List three of these areas.

        4.What percentage of your grade is the final exam for CPS 6?

2. Write a C++ program on paper that prints your name exactly 128 times. Use only cout statements and function calls. Bring the program to lab. You should be able to modify the program to print your name 729 times. Note that 2⁷ = 128 and that 3⁶ = 729. The example program below provides a hint.

           void Print()
{
    cout << "Bjarne Stroustrup" << endl;
    cout << "Bjarne Stroustrup" << endl;
}

void One()
{
    Print();
    Print();
}

int main()
{
    One();
    One();
    return 0;
}
 

Purpose

• Login to and logout from the Sun Workstations found on campus
• Use basic UNIX tools, including:
• Copying, moving, deleting files
• Traversing and moving between directories
• Invoking programs including editors and compilers
• Edit, compile, debug, and run a C++ program

In this document, commands that you type will be in a font that looks like this, sometimes commands may be quoted --- "like this" --- do not type the quotes, just type what is between them. When instructed to type something, press the return key after typing it.

Logging in

1. Find a free workstation.

 

 

Workstations are always on, do NOT turn them off. Wiggle the mouse if the screen is blank.

2. Type your login-id, hit return, type your password (your password is not displayed).

 

 

Note: passwords are case sensitive, Banana is different from banana.

3. Wait until two windows labeled xterm appear, this may happen quickly or take a while.

 

 

Note, sometimes a message of the day window (MOTD) pops up (this window is labeled with xmessage at the top) with important information. If this window has appeared, then you can click the left mouse button on the bar that says "click here with the Left Mouse Button to continue" and this window will disappear. When this message does appear, you should read it as it usually contains important announcements.

Managing Windows in X

• The green with black dots covering most of the screen is called the background. Move the mouse to any area of the background and try clicking the three mouse buttons each at a different time. Each button brings up a different menu of applications. Do not try any of these now, you can try them on your own later.
• Most windows have title bars across the top of the window. Move the mouse to the title bar for the calculator window. Click and hold the left mouse button on the word Calculator. Move the mouse and the window should follow. Let go and the window will be in its new position. (Note: You can also move windows using the Window Ops commands that appear when you click and hold the left mouse button when the mouse points to the background.)
• Another useful window command is resizing the window. Move the mouse cursor to the Calculator title bar and click and hold the right mouse button. An outline of the window appears. Move the mouse outside of the window boundary and you will see the outline grow (and shrink if you move in the other direction). When you release the mouse button, the Calculator window is a different size than before. (Note: This command can also be found in the Window Ops menu.)
• To get rid of windows you no longer want, click once on the kill icon along the top of the screen. The cursor becomes a skull and cross bones. Move the mouse to any position inside the Calculator window and click. The window should disappear.

Getting Started with UNIX

To enter a command, type after the prompt in one of the xterm windows. You should see a prompt that may look similar to

    [1] ola@teer8%

To make the font bigger and easier to read you can hold the control key down while pressing and holding the right mouse button while the cursor is in an xterm window. Choose large for an easier-to-read window.

Next, from within an xterm window, at the prompt type ~ola/cps006/bin/setup. This runs a program that will set up some files in your directory to make it easier to use the programming tools we provide. Additionally, it creates a directory in your account, called cps006,  for you to put your CPS 6 work. Any files changed by this program are saved with a .old  extension, e.g., .cshrc.old.  If you do not get a prompt back after typing the command, consult a TA.  If you do not want to run this program because you have made your own changes to your accounts setup, you will need to look at the setup program to determine which parts of it you want to setup. Some are needed for accessing and submitting files.

In order for changes made by the setup command to take effect, you will need to logout and then log back in. To logout of your Sun workstation, click the logout icon at the top left of the window. Now, please log out, then log back in.

Creating and Traversing Directories

When you login, your session begins in your main directory. To see the name of your directory, type the UNIX command pwd (print working directory).  The complete name it prints in your terminal window should look similar to /afs/acpub.duke.edu/users/o/l/ola except your login-id should be the rightmost word.

To create a directory called lab1 for storing new files related to this lab, you will need to follow these steps:

1. Change into your cps006 directory (this directory was automatically created for you) by typing cd cps006.  This command should not produce any output, but should move you from your home directory to the cps006 directory within your home directory.  You can verify this by typing pwd again.
2. Create a new directory called lab1 by typing mkdir lab1
3. To list your files and directories, type ls (think of this as shorthand "list"). You should see the directory you just created printed.
4. Change into your lab1 directory by typing cd lab1

At any time, you can type cd (with no arguments) to return to your home directory. Now type cd cps006/lab1 to return to your new lab directory.  Now when you type ls you will see there are no files in the directory, because you have not created any yet.  Instructions for editing, compiling, and printing are given below. First, you will need to copy some files to your lab1 directory. The copy command is cp so from within your lab1 directory type (do not forget the trailing dot: "."):

   cp ~ola/cps006/lab1/* .

Test Program: Edit, Compile, Debug

 // Author:     YOUR NAME HERE
 // Date:       TODAY'S DATE
 // Course:     CPS 6
 // Lab:        YOUR SECTION NUMBER HERE (01-08)
 // Purpose: Practice C++

 #include <iostream>
 using namespace std;

 int main()
 {
     cout << "This was no time for play." << endl;
     cout << "This was no time for fun." << endl;
     cout << "This was no time for games." << endl;
     cout << "There was work to be done" << endl;
     cout << "                Dr. Seuss" << endl;

     return 0;
 }

Starting the editor emacs

Loading, Editing, Saving Files

• Use the file menu to load a file (even one that does not exist yet). Click and hold the menu and choose Open File before releasing the mouse button.

(you can also use cntrl-x cntrl-f, that is hold down the control key and press x followed by f as a substitute for using the menu.)
• The prompt for Find file: appears in the small minibuffer window at the bottom of the emacs window. You should also see a path which might be ~/ or ~/cps006/lab1/. If you do not see this, consult with a TA because you may not be in the correct directory. You can edit what appears in the minibuffer with arrow/delete keys.
• You will create a file named seuss.cpp. To do so complete the path in the minibuffer so that it reads ~/cps006/lab1/seuss.cpp and press return.
• Enter the C++ program shown previously. Be careful that you type it just as it appears. You will notice sometimes after you type something, the cursor will "automagically" move to another position to indent properly. When you type a "}", the cursor always jumps back to the "{" for a second so you can see if the "}" matches with the correct "{".  These are features of the emacs editor meant to make it easier for you to complete your programs.
• If you make a mistake, use the arrow keys or mouse to move around and edit in the window.  You can use the mouse to position the cursor within emacs by clicking in the window where you want to type.  You can also use the arrow keys and the scroll bar to move around.

Until you save your file, it is stored in a temporary buffer (the region in emacs in which you are typing). When you believe the C++ program is correct, save it by clicking the File button at the top of the emacs window, and then selecting Save Buffer. A message that the buffer has been written should appear in the minibuffer.  You should save your program often to ensure none of your changes are lost inadvertently.  You will not be granted any leniency if you lose your work because you did not save it properly. You can type cntrl-x cntrl-s to save instead of using the mouse.

Compiling a C++ program

1. Use the Compile option under the Tools menu.
2. The command make -k, which appears in the minibuffer, is the default compile command. You should compile by editing this command so that it reads make -k seuss, then hit return. It may take a while for the program to compile, but you should see an emacs sub-window with an indication that something is happening.
3. If there is a syntax error in the program, a message will appear in the *compilation* buffer. To get to the error you can click on the error with the middle mouse button. This will take your cursor to the line on which the error appears, so you can use it to cycle through multiple errors, fix them, and then recompile.

If there are multiple error messages, fix the first one only and then recompile. Sometimes one error causes the compiler to list additional errors that are not really errors.

An example of an error message is:

     seuss.cpp:5: unterminated string or character constant
     seuss.cpp:5: possible real start of unterminated constant

This message tells you the name of the file (seuss.cpp), the line number the error occurred near (line 5) and a guess as to what is wrong. You do not need to worry about where line 5 is since clicking on the error message takes you there.

If you do not have any errors with the first compile, you might want to modify the program so that there is an error. For example, remove a semi-colon and then compile the program.

Execute your program

• In an xterm window, type ls to see the files in you lab1 directory.

You should see both seuss.cpp and seuss. The file seuss is an executable program. You might also see a file called seuss.cc~. This is a backup copy of your program that emacs automatically creates. It is not an exact copy, but rather a copy before you made your most recent changes.
• To run any executable program, type its name in your terminal window, so type seuss to execute this program.
• You can type ls -l  to see how big the files are and when they were created.

Print a copy of your program

The print command sends your file to the printer in the room you are currently in. If several people try to print at the same time on the same printer, the print jobs are queued and printed one at a time. To see where in the queue your job is type lpq followed by -Pname where name name is replaced by the printer name. In Teer 106, the printers are in the back of the room.

If you want to specify a specific printer, use the lpr command. There are two printers in Teer 106, named teerlp1 (the last three symbols are lowercase L, p, and the number 1) and teerlp2. To print any text file use the lpr command, specify the printername (prefixing it with -P , specify the file is a text file by -Fl (with lowercase L here) and type the file name. To print your program seuss.cpp on the printer teerlp1, type

     lpr -Pteerlp1 -Fl seuss.cpp

Postlab

• Two point for completing the prelab activities and bringing them to lab.
• Two point for participating actively during the in lab activities.
• Two point for completing the lab.