Steps in putting together a servlet, as summarized by

Jim Thurmond.

A small syntax error can prevent the load of a context.

import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;

public class Three extends HttpServlet {

  public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

    response.setContentType("text/html");

    PrintWriter out = response.getWriter();

    String message, good, total, n1, n2, me;

    me = request.getContextPath() + request.getServletPath();

    message = request.getParameter("message");
    good = request.getParameter("good");
    total = request.getParameter("total");
    n1 = request.getParameter("n1");
    n2 = request.getParameter("n2");

    if (message == null) {

      n1 = (int)(Math.random() * 100 - 50) + "";
      n2 = (int)(Math.random() * 100 - 50) + "";
      good = "0";
      total = "0";
      message = "Welcome, score is: " + good + "/" + total + ". What is " + n1 + " + " + n2 + "?";

    } else {

      String answer = request.getParameter("answer");

      if (Integer.parseInt(answer) == Integer.parseInt(n1) + Integer.parseInt(n2)) {
        good = (Integer.parseInt(good) + 1) + "";
        message = "Good answer. ";
      } else {
        message = "Not good. ";
      }
      total = Integer.parseInt(total) + 1 + "";
      message +=  "score is: " + good + "/" + total + ". ";
      n1 = (int)(Math.random() * 100 - 50) + "";
      n2 = (int)(Math.random() * 100 - 50) + "";
      message += " What is " + n1 + " + " + n2 + "?";

    }

    out.println(

"<form action=\"" + me + "\">" +
"  " + message + "<p>" +
"  Type your answer here: <input type=\"text\" name=\"answer\"> <p> " +
"  Push <input type=\"submit\" value=\"Proceed\"> when ready. " +
"  <input type=\"hidden\" name=\"message\" value=\"" + message + "\">" +
"  <input type=\"hidden\" name=\"good\" value=\"" + good + "\">" +
"  <input type=\"hidden\" name=\"total\" value=\"" + total + "\">" +
"  <input type=\"hidden\" name=\"n1\" value=\"" + n1 + "\">" +
"  <input type=\"hidden\" name=\"n2\" value=\"" + n2 + "\">" +
"</form>"

    );

  }
}

<Server port="15477" shutdown="SHUTDOWN">

  <GlobalNamingResources>
    <!-- Used by Manager webapp -->
    <Resource name="UserDatabase" auth="Container"
              type="org.apache.catalina.UserDatabase"
       description="User database that can be updated and saved"
           factory="org.apache.catalina.users.MemoryUserDatabaseFactory"
          pathname="conf/tomcat-users.xml" />
  </GlobalNamingResources>

  <Service name="Catalina">
    <Connector port="15476" />

    <Engine name="Catalina" defaultHost="localhost">
      <Realm className="org.apache.catalina.realm.UserDatabaseRealm"
             resourceName="UserDatabase" />

      <Host name="localhost" appBase="webapps">

        <Context path="/nov09" docBase="nov09" debug="0" reloadable="true" />

      </Host>

    </Engine>

  </Service>
</Server>

Here are the files the current implementation relies on, for those interested:

• project-example/schedule
• project-example/usernames
• project-example/dates
• project-example/roster
• project-example/clean

The folder is restricted to IUB network IDs.

(The first batch of three available days has been posted. Others will follow, after the break).

Schedule of posted Class Notes updated today.

Here's a servlet, for you to play with.

And another one, converted to JSP:

import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;

public class One extends HttpServlet {

  public void doGet(HttpServletRequest request,
                    HttpServletResponse response)
              throws ServletException, IOException {
        String message = request.getParameter("message");
        String you = request.getContextPath() + request.getServletPath();
        PrintWriter out = response.getWriter();
        // Use "out" to send content to browser
        response.setContentType("text/html");
        if(message == null) {
          message = "1";
          out.println(message);
        }
        else {
          message = "" + (Integer.parseInt(message) + 1);
          out.println(message);
        }


        out.println(
          "<html>"+
          "<head><title>Homework 6</title></head>"+
          "<body>"+
          "<form method=\"get\" action = \""+you+"\">"+

          "<input type=\"hidden\" name= \"message\" value= \""+message+"\">"+
          "<input type= \"submit\" value= \"proceed\">"+
          "</form>"+
          "</body>"+
          "</html>"
        );

  }

}

<%
        String message = request.getParameter("message");

        String you = request.getContextPath() + request.getServletPath();

        if(message == null) {
          message = "1";
        } else {
          message = "" + (Integer.parseInt(message) + 1);
        }
 %>

<html>
  <head><title>Homework 6</title></head>
  <body>
    <form method="get" action="<%=you%>">

      The counter is: <%=message%> <p>
      <input type="hidden" name="message" value="<%=message%>">
      <input type="submit" value="proceed">
    </form>

  </body>
</html>

And here's an example of stamps within session-based JSP:

<%
	String me = request.getContextPath() + request.getServletPath(); // who am I? 
	
	String count = (String) session.getAttribute("count"); // retrieve state   
        Integer stamp = (Integer) session.getAttribute("stamp"); // this part is new (retrieve state) 
	
	int index = (count == null) ? 0 : Integer.parseInt(count); // initialize state 
        if (stamp == null) { stamp = new Integer(0); } 

        String whichWay = request.getParameter("fun"); // read input to change state (part I)
	
        if (whichWay == null) { // protecting against bad input 

	} else {

	    // the empty string is different from null!

            String userStamp = request.getParameter("stamp"); // read user's stamp (part of input) 
            boolean match; 
            try {
              match = (stamp.intValue() == Integer.parseInt(userStamp)); 
            } catch (Exception e) { match = false; } // comparing the stamps 

            if (match) { 

      	      String arg = request.getParameter("arg"); // reading input to change state (part II) 

	      if (whichWay.equals("up")) { // changing the state one way or another 

		index += Integer.parseInt(arg); 

	      } else if (whichWay.equals("down")) {

		index -= Integer.parseInt(arg); 

	      } else {

		// something went wrong (we don't do anything) 

	      }

              stamp = new Integer(stamp.intValue() + 1); 
  
              session.setAttribute("count", index + ""); // save state 
 
              session.setAttribute("stamp", stamp); // save the stamp (it's part of the state) 

           }  else { 
   
           } 

	}
 %>

<html>
  <head><title>My Last JSP</title></head>

  <body bgcolor=white><table>

    <form method="GET" action="<%=me%>"> 

      The result is currently: <%=index%> <p> 
	 <input type="text" name="arg" size=4>

	<p>
      Please choose an action: <select name="fun"> 
        <option value="nothing"> Click Me! 
        <option value="up"> Addition 
        <option value="down"> Substraction
      </select> <p> 

      Then press <input type="submit" value="Proceed"> 

      <input type="hidden" name="stamp" value="<%=stamp%>"> 

    </form> 

  </body> 

</html>

1. stage one
2. stage two
3. stage three
4. stage four
5. stage five
6. stage six
7. stage seven

As far as tables are concerned you can see how we got started here.

<?xml version="1.0" encoding="ISO-8859-1"?>

<!DOCTYPE web-app
    PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
    "http://java.sun.com/dtd/web-app_2_3.dtd">

<web-app>

    <servlet>
        <servlet-name>One</servlet-name>

        <servlet-class>One</servlet-class>
    </servlet>

    <servlet-mapping>
        <servlet-name>One</servlet-name>

        <url-pattern>/servlet/One</url-pattern>
    </servlet-mapping>

    <servlet>
        <servlet-name>Fv2_3</servlet-name>

        <servlet-class>Two</servlet-class>
    </servlet>

    <servlet-mapping>
        <servlet-name>Fv2_3</servlet-name>

        <url-pattern>/servlet/Fancy</url-pattern>
    </servlet-mapping>


</web-app>

Also we noticed he had a .bash-profile file.

Well, it went perfectly well with /usr/local/gnu/bin/tar for Brian.

So I am sure it's going to work for all of us, that way. (Please check Brian's server.)

<html>
  <script>
  c_choice = Math.round(Math.random() * 2);
  names = new Array("Paper", "Rock", "Scissors");
  function process() {
    alert("User has selected: " + document.forms[0].u_choice.options[document.forms[0].u_choice.selectedIndex].value);
    c_choice = Math.round(Math.random() * 2);
    document.getElementById("c_choice").innerHTML =  names[c_choice];
  }
  </script>

  <body>

  Computer has chosen: <span id="c_choice"></span> <p>

  <script>
    document.getElementById("c_choice").innerHTML =  names[c_choice];
  </script>

  <form>
     User chooses: <select name="u_choice">
       <option value="Paper"> Paper
       <option value="Rock"> Rock
       <option value="Scissors"> Scissors
     </select>

     <p> Then the user presses <input type="button"
                                      value="Submit"
                                      onClick="process()">
  </form>
  </body>

</html>

As Aaron says,

• "[t]he working (mostly) demo of the project can be found here
• and the source can be viewed here."

Aaron will be talking about secure credit card payment processing with PHP.

Here's the code for Lab Eight addition:

<?
   function get_book_cats($isbn) {

       $conn = db_connect(); 

       $query = "select dgerman_php_catboo.catid, catname 
                 from dgerman_php_categories, dgerman_php_catboo 
                 where '$isbn' = dgerman_php_catboo.isbn and
                       dgerman_php_categories.catid = dgerman_php_catboo.catid"; 

       $result = @mysql_query($query); 


       if (! $result) return false;



       $num_cats = @mysql_num_rows($result); 
       if ($num_cats == 0) return false; 



              $cat_array = array(); 

              for (
                   $count = 0; 
                   $row = @mysql_fetch_array($result); 
                   $count++
                  ) 
                $cat_array[$count] = $row; 

       if (! is_array($cat_array)) {
                     echo "No categories currently available. <br>"; 
              }



              foreach ($cat_array as $row) {

                     $url = "show_cat.php?catid=".($row["catid"]); 
                     $title = $row["catname"]; 



                     do_html_url($url, $title); 

              }


   } 
 ?>

<? session_start(); 

   if ($message && !$reset) { // no new user

     if ($age == $ageCopy) { 

       if ($n1 + $n2 == $answer) {
        $message = "Good answer"; 
        $g = $g + 1; 
       } else {
        $message = "No way."; 
       }
       $t = $t + 1;
       $message .= " Now your score is: " . $g . " out of " . $t; 

       $n1 = rand(0, 100); 
       $n2 = rand(0, 100); 

       $age += 1; 

     } else {
       $message = "I am sorry, you can't reload."; 
       $message .= "<p>Your score is still: " . $g . " out of " . $t; 

     } 

   } else { // no state, new user, initialize state

     session_register("g"); 
     session_register("t"); 
     session_register("n1"); 
     session_register("n2"); 
     session_register("message"); 

     session_register("age"); 
     $age = 1; 

     $g = 0; 
     $t = 0; 
     $message = "Welcome, your score is: " . $g . " out of " . $t;
     $n1 = rand(0, 100); 
     $n2 = rand(0, 100); 
   } 
 ?> 

<form>
  <?=$message?> <p>
  What is <?=$n1?> + <?=$n2?>? <input type="text" name="answer" size=4> <p>
  <input type="hidden" name="ageCopy" value="<?=$age?>">
  Click to <input type="submit" value="Proceed">
  <p> Click here to <a href="<?=$SCRIPT_NAME?>">reset</a>.
  <p> Click here to <input type="submit" name="reset" value="Reset">
</form>


Do you understand what is special about it?

Exam is open-book, open-notes, no computers allowed.

• PHP with sessions (server-side state with PHP)
• PHP with hidden fields (client-side state with PHP).
• CGI/Perl with hidden fields (client-side state with CGI/Perl)
• CGI/Perl with DBI (server-side state with CGI/Perl, Part One)
• CGI/Perl with DBI (server-side state with CGI/Perl, Part Two)

First the hidden-fields state:

<?
  if ($message) {
    if ($answer == $key) {
      $good += 1; 
    } 
    $total += 1; 
    $message = "Current score: $good/$total."; 
    $one = rand(-50, 50); 
    $two = rand(-50, 50); 
    $key = $one + $two; 
  } else {
    $message = "Welcome to the game."; 
    $good = 0; 
    $total = 0; 
    $one = rand(-50, 50); 
    $two = rand(-50, 50); 
    $key = $one + $two; 
  } 
 ?>

<html>
  <head><title>Game with hidden fields</title></head>
  <body bgcolor="white">

    <form>

      <?=$message?> <p>

      What is <? echo $one?> + <?=$two?>? <p>
      Type your answer here: <input type="text" size=4 name="answer"> <p>

      Click <input type="submit" value="Proceed"> when done.

      <input type="hidden" name="message" value="<?=$message?>">
      <input type="hidden" name="good" value="<?=$good?>">
      <input type="hidden" name="total" value="<?=$total?>">
      <input type="hidden" name="key" value="<?=$key?>">

    </form>
  </body>
</html>



And here's the conversion to session-based state:

<? 
  session_start(); 

  if ($message) {
    if ($answer == $key) {
      $good += 1; 
    } 
    $total += 1; 
    $message = "Current score: $good/$total."; 
    $one = rand(-50, 50); 
    $two = rand(-50, 50); 
    $key = $one + $two; 
  } else {
    session_register("message"); 
    $message = "Welcome to the game."; 
    session_register("good");
    session_register("total"); 
    session_register("key"); 
    $good = 0; 
    $total = 0; 
    $one = rand(-50, 50); 
    $two = rand(-50, 50); 
    $key = $one + $two; 
  } 
 ?>

<html>
  <head><title>Game with hidden fields</title></head>
  <body bgcolor="white">

    <form>

      <?=$message?> <p>

      What is <? echo $one?> + <?=$two?>? <p>
      Type your answer here: <input type="text" size=4 name="answer"> <p>

      Click <input type="submit" value="Proceed"> when done.

    </form>
  </body>
</html>


Can you see the differences?

Here's an announcement received earlier today:

From: "Miller, Mary P" 
To: "Whitehead, Matthew Emery Neal", "German, Dan-Adrian", "Smart, David L" 
Subject: Looking for Perl programmer

Hello,
I'm writing from Learn More Resource Center on the IUB campus. We are
currently looking for a Perl programmer to work on our Web site at
http://www.learnmoreindiana.org. I retrieved your names from the course
listing for A348. Our site is programmed in an open-source environment
and I thought you might know of someone who would be a good candidate.

The position is listed at
https://webdb.iu.edu/humanresources/secure/app-new/pa_browse.cfm#00008803. 

It is a full-time position, PA level, with full benefits.

If you can think of another avenue to reach possible candidates, could
you let me know? It seems Perl programmers are hard to find right now.
Any insight you can give me on this would be most appreciated.

Thanks in advance,
Mary Miller

Mary P. Miller
Director of Web Services
Learn More Resource Center
http://www.learnmoreindiana.org 
(812)856-8247

Here's a design discussion, and here's an update to it.

Here's the way the program looks in Java.

#!/usr/bin/perl

use DBI;
use MD5;
use CGI;

$WORDS     = '/usr/share/lib/dict/words';
$EXPIRE    = 60 * 60 * 24 * 30;     # allow 30 days before expiration
$DB        = "DBI:mysql:a348";      # data source name (database)
$username  = "a348";                # username
$password  = "a348AG";              # password
$DBAUTH    = "$username:$password";
$SECRET    = " ***( something secret, whatever )*** ";
$MAX_TRIES = 10;
$DB_TABLE  = "djmoss_prs";
$ID_LENGTH = 8;                     # length of the session ID

$q = new CGI; #----------------------------(program starts)------------------- 

$DBH = DBI->connect($DB, $username, $password, {PrintError => 0})
  || die "Couldn't open database: ", $DBI::errstr;

my ($session_id, $note) = &get_session_id();#---(amounts to redirection)------

print $q->header, $q->start_html; #---(never print header before this)--

my $state = &get_state($session_id); #---(retrieve state)---------------------

$message = $state->{message}; #---(name the elements of the state)-----------
$compChoice = $state->{compChoice};
$compScore = $state->{compScore};
$userScore = $state->{userScore};
$a = $state->{session_id};
$b = $state->{modified};

@choices = ("paper", "rock", "scissors"); #---(helpful list of names)---------

if ($message) { #---(is state empty? if we have a message it's not)-----------
  $message = "Existing User"; #---(if state is not empty, read the input)-----
  $userChoice = $q->param('userChoice'); #---(and update the state)--------
  if ($userChoice == 1 && $computerChoice == 2 || # user rock comp scissors
      $userChoice == 2 && $computerChoice == 0 || # user scisssors comp paper
      $userChoice == 0 && $computerChoice == 1) { # user paper comp rock
    $userScore += 1;
  } else {
    $compScore += 1;
  }
  $compChoice = int(rand(3)); #---(update of state ends here)-----------------
} else { #---(if state is empty we need to initialize it)---------------------
  $message = "Welcome!";
  $compScore = 0;
  $userScore = 0;
  $compChoice = int(rand(3)); #---(initialization ends here)------------------
}

$state->{message} = $message; #---(at the end, get ready to store state)---
$state->{compScore} = $compScore;
$state->{compChoice} = $compChoice;
$state->{userScore} = $userScore;
&save_state($state, $session_id); #---(state is saved here)-------------------

$compChoice = $choices[$compChoice]; 
#---(report state and get ready for more input)-------------------------------

print qq{ 
  ($a, $b) <p>

  $message <p>

  <form method="post">
    <table><tr><td>Computer <td> User
           <tr><td> $compScore <td> $userScore
    </table> <p>
    The computer has chosen: $compChoice <p>
    What do you choose: <select name="userChoice">
      <option value="0"> Paper
      <option value="1"> Rock
      <option value="2"> Scissors
    </select>
    <p> Press <input type="submit" value="Proceed"> to continue.
  </form>
};

print $q->end_html; #----(end of program. essential subroutines follow)----

sub get_session_id {

  my (@result);

  &expire_old_sessions();

  my ($id) = $q->path_info() =~ m:^/([a-h0-9]{$ID_LENGTH}):o;

  return @result if $id and @result = &check_id($id);

  # if we get here, there's not already an ID in the path info

  my $session_id = &generate_id();

  die "Couldn't make a new session id" unless $session_id;
  print $q->redirect($q->script_name() . "/$session_id");
  exit 0;
}

# find a new unique ID and insert it into the database -------generate_id---
sub generate_id {
  # create a new session id
  my $tries = 0;
  my $id = &hash($SECRET . rand());

  while ($tries++ < $MAX_TRIES) {
    last if $DBH->do("INSERT INTO $DB_TABLE (session_id) VALUES ('$id')");
    $id = &hash($id);
  }

  return undef if $tries >= $MAX_TRIES; # we failed
  return $id;
}

# check to see that an old ID is valid --------------------------check_id---
sub check_id {

  my $id = shift;

  return ($id, '')

    if $DBH->do("SELECT 1 FROM $DB_TABLE WHERE session_id = '$id'") > 0;

  return ($id, 'The record of your game may have expired. Restarting.')

    if $DBH->do("INSERT INTO $DB_TABLE (session_id) VALUES ('$id')");

  return ();

}

# generate a hash value ---------------------------------------------hash---
sub hash {
  my $value = shift;
  return substr(MD5->hexhash($value), 0, $ID_LENGTH);
}

sub expire_old_sessions { # --------------------------expire_old_sessions---
  $DBH->do(<<END);
DELETE FROM $DB_TABLE
  WHERE (unix_timestamp() - unix_timestamp(modified)) > $EXPIRE
END
}

# get the state from the database ------------------------------get_state---
sub get_state {
  my $id = shift;
  my $query =
      "SELECT * FROM $DB_TABLE WHERE session_id = '$id'";
  my $sth = $DBH->prepare($query) || die "Prepare: ", $DBH->errstr;
  $sth->execute || die "Execute: ", $sth->errstr;
  my $state = $sth->fetchrow_hashref;
  $sth->finish;
  return $state;
}

sub save_state {

  my ($state, $id) = @_;

  my $sth = $DBH->prepare(<<END) || die "prepare: ", $DBH->errstr;
UPDATE $DB_TABLE
  SET compChoice=?,compScore=?,userScore=?,message=?
  WHERE session_id='$id'
END
  $sth->execute(@{$state}{qw(compChoice compScore userScore message)})
    || die "execute: ", $DBH->errstr;
  $sth->finish;
}

Homework Three and Four posted, with due dates.

Homework Four will ask you to install PHP and implement the game both ways:

• client-side state
• state kept in sessions

Notes will be updated tomorrow. Grades will be posted in PostEm from now on.

Details forthcoming.

Here's the first set of guidelines and some information about the grading process.

• part one no CGI.pm (in action)
• part two w/ CGI.pm (in action)

Try "concatenation in Perl" in Google. Our lecture 2 is one of the pages found.

#!/usr/bin/perl
use CGI; 
$q = new CGI; 
print $q->header, qq{<html><head><title>Calculator</title></head><body>};
$balance = $q->param('bal');
foreach $k ($q->param) {
 print "<font color=lightgrey>", $k, " has a value of ", $q->param($k), "</font><p>";
}
if ($q->param('fun') eq "add") {
  $balance += $q->param('arg');
} elsif ($q->param('fun') eq "sub") {
  $balance -= $q->param('arg');
} else { }
print qq{
  <form>
    Your balance is: $balance <p>
    What's the amount: <input type="text" name="arg"> <p>
    What do you do with it: <select name="fun">
      <option value="non"> Click me!
      <option value="add"> Deposit
      <option value="sub"> Withdraw
    </select>
    <p> Click here to <input type="submit" value="Proceed"> <p>

    Please don't write below the line:
    <hr>
    <input type="text" name="bal" value="$balance">
  </form>
};
print qq{</body></html>};

You can play with it here.

#!/usr/bin/perl

print qq{Content-type: text/html

<html><head><title>Calculator</title></head><body>};

$user = $ENV{QUERY_STRING};
@pairs = split(/&/, $user);

foreach $pair (@pairs) {
  ($name, $value) = split(/=/, $pair, 2);
  $in{$name} = $value;
}

$balance = $in{bal};

foreach $k (keys %in) {
 print "<font color=lightgrey>", $k, " has a value of ", $in{$k}, "</font><p>";
}

if ($in{fun} eq "add") {
  $balance += $in{arg};
} elsif ($in{fun} eq "sub") {
  $balance -= $in{arg};
} else {

}

print qq{
  <form>
    Your balance is: $balance <p>
    What's the amount: <input type="text" name="arg"> <p>
    What do you do with it: <select name="fun">
      <option value="non"> Click me!
      <option value="add"> Deposit
      <option value="sub"> Withdraw
    </select>
    <p> Click here to <input type="submit" value="Proceed"> <p>

    Please don't write below the line:
    <hr>
    <input type="hidden" name="bal" value="$balance">

  </form>
};

print qq{</body></html>};

This is the code we developed in class on Tuesday:

#!/usr/bin/perl

print qq{Content-type: text/html

<html><head><title>One</title></head><body bgcolor="white">}; 

$user = $ENV{QUERY_STRING}; 

if ($user eq "01") {
  $pic = "http://www.cs.indiana.edu/dept/img/lh01.gif"; 
} elsif ($user eq "07") {
  $pic = "http://www.cs.indiana.edu/dept/img/lh07.gif"; 
} elsif ($user eq "08") {
  $pic = "http://www.cs.indiana.edu/dept/img/lh08.gif"; 
} elsif ($user eq "09") {
  $pic = "http://www.cs.indiana.edu/dept/img/lh09.gif"; 
} else {
  $pic = "http://www.cs.indiana.edu/l/www/classes/a202-dger/sum99/a202.gif"; 
} 

$me = $ENV{SCRIPT_NAME}; 

print qq{

<table>
<tr>
<td> <a href="$me?01">Lindley 01</a> 
<td> <a href="$me?07">Lindley 07</a> 
<td> <a href="$me?08">Lindley 08</a> 
<td> <a href="$me?09">Lindley 09</a> 
</table>

<img src="$pic"> 

</body></html>
}; 

EDITOR=pico
export EDITOR

Then to set up your server for graceful restart four times a day do this:

• run crontab -e
• type 15 1,7,13,19 * * * /u/username/apache/apache_1.3.26/bin/apachectl graceful
• then save the file (ignore the file name, it will be random and unique)

To disable mail you should add this to the line: > /dev/null

#!/usr/bin/perl

# state is ________ of:
#   $mess___
#   $____Score
#   $user_____
#   $comp______

# _____ is provided by the:
#   $user

print qq{Content-type: ____/____\n\n};

$in = $ENV{____________}; # what if it's POST?
@_____ = split(/&/, $in);
foreach $____ (@pairs) {
  ($nam, $___) = split(/=/, $pair);
  $in{$___} = $val;
}

# foreach $k (keys %in){
#   print $k, " --> ", $in{$k}, "<p>";
# }

$message = $in{message};
$compScore = ______________;
$userScore = $in{userScore};
$__________ = $in{compChoice};

if (________) {
  $user = $__{user};
  if (($user + 1) % 3 == $compChoice) {
    $message = "________";
    $_________ += 1;
  } elsif (($__________ + 1) % 3 == $user) {
    $message = "You lose.";
    $compScore __ _;
  } else {
    $message = "This is a tie.";
  }
  $compChoice = ____________;
} else {
  $_______ = "Welcome.";
  $compScore = 0;
  $userScore = 0;
  $compChoice = ___(rand(3));
}

print qq{

<form method=GET action=_________________>
  $message <p>
  The computer has chosen: $compChoice, now it's your ____. <p>
  <table border><tr><td> ________ <td> User
         <tr><td> $compScore <td> $userScore </table> <p>
  What: <select name="user">

          <option value="0"> _____
          <option value=___> Rock
          <______ value="2"> Scissors
        </select> <p>
  When finished please press <input type="submit" value="Proceed"> <p>

  <_____ type="hidden" name="compScore" value="$compScore">
  <input type="______" name="_______" value="$message">
  <input type="hidden" name="userScore" value="__________">
  <input type="hidden" ____="compChoice" value="$compChoice">

</form>
}; 

Individual e-mail messages will be sent tonight.

Here's the program we discussed on Thu, more to come tomorrow:

#!/usr/bin/perl

$balance = 0;
print "Your balance is: " . $balance . "\n";
print "Type: ";
while ($line = <STDIN>) {
  print "You just typed: " . $line;
  ($cmd, $arg) = split(/ /, $line, 2);
  if ($cmd eq "deposit") {
    $balance += $arg;
  } elsif ($cmd eq "withdraw") {
    $balance -= $arg;
  } else {
    print "I don't know what you mean by " . $cmd . "\n";
  }
  print "Your balance is: " . $balance . "\n";
  print "Type: ";
}

Reading assignments until midterm to be posted.

Here's the script that will be used to grade Lab Assignment One:

#!/usr/bin/perl

$username = $ARGV[0];

if ($username eq "") { `yes | rm -ir wh* exp* `; print `ls -ld * `; exit; }

`cp /u/$username/public/whoa.tar.gz . `;

`gunzip whoa.tar.gz`;

`tar xvf whoa.tar`;

print `du -a exp*`;

print `more exp*/doc*/doc?.txt`;

print "Should I delete it? ";

$answer = <STDIN>;
chop($answer); 
if ($answer eq "yes") {
  `yes | rm -ir wh* exp* ` ; print ` ls -ld * `;
}

• edit ~/.bashrc to add the following two lines in it
• EDITOR=pico followed by
• export EDITOR

then run source ~/.bashrc (or log out, then log back in).

Next time you do:

crontab -e

chmod 711 ~
chmod 755 ~/public
chmod 644 ~/public/whoa.tar.gz

Matt Whitehead	mewhiteh	SE045	Wed	04:15pm-05:30am
Adrian German	dgerman	SE045	Wed	05:45pm-07:00pm
Adrian German	dgerman	SE045	Thu	09:30am-10:45pm
David Smart	dsmart	HP154	Thu	04:00pm-05:15pm

Lab and lecture notes for this week posted.

Labs tomorrow:

• 9:30-10:45am (SE045, Adrian German)
• and 4:00-5:15pm (HP154, David Smart).

Assignment of ports for servers this semester posted (check Students).

Here's the schedule of Office Hours for this semester:

Adrian German	1-2pm	MTWR or by appointment	LH201D
David Smart	10:15am-12:15pm	W	LH201D
Matt Whitehead	2:30pm-4:30pm	M	LH401F

Here's a campus map in case you need to look up other buildings too.

The current assignment to labs is (subject to change):

Matt Whitehead	mewhiteh	SE045	Wed	04:15pm-05:30am
Adrian German	dgerman	SE045	Thu	09:30am-10:45pm
David Smart	dsmart	HP154	Thu	04:00pm-05:15pm

Here's how our class appears in OneStart (snapshot taken Aug. 24).