Prototype Question

We have added a global counter, from Peirre Omidyar, which keeps track of the access counts of all files. The Central.count file is kept in /~cdavid/public_html/ and in it are separate lines for each program which calls &count.

#!/usr/local/bin/perl -- -*-perl-*-
use CGI;
require  "CleanUp.pl";
require  "explain.pl";
require  "count.pl";
srand;
$query = new CGI;
print $query->header;
print $query->start_html('Prototype Question_2');

$scriptname = $query->script_name();#this gives the question name
#print $query->dump;#use this to check that it worked! Just remove comment(#).

print "<a href=/~cdavid/cgi-bin/test_send_memo.pl?var=$scriptname>Click here to send a message concerning errors in this question.<br></a>";

# this question was called via html?owner=Jones&name=SomeOne
$faculty_id = $query->param('owner');
$student_id = $query->param('name');
print "<br>";
print "<a href=send_memo.html>Click here to get a notation explanation</a>";
print "<br>";

HERE IS THE CALL

&count($scriptname);

which (based on the require line above) calls a common subroutine located in the cgi-bin subdirectory. The filename of this program is passed to &count, and that name is what is recorded in Central.count.

print $query->start_form;
print <<EOF;
This is teacher created text concerning this particular question.
Without explicit print statements, it must be entered using a
special format.
<br>The faculty owner of this question is $faculty_id.
<br>The student owner of this questions is $student_id.
EOF
print "<br>Answer = ",$query->textfield('ans','',50,80);
print"<P> Query, is the above formula/number correct?",$query->submit;
print $query->end_form;

if ( $query->param('ans') ne '')
{
$stu_ans = $query->param('ans');
$saved_stu_ans = $stu_ans;
&CleanUp($stu_ans);#this removes potential hacker imbedded illegal commands
$ans = "sqrt(4/x)"; 
$x = rand;
$ans =~s/x/$x/gi;
$stu_ans =~s/x/$x/gi;
print "student_answer = $saved_stu_ans";
$stu_ans = eval($stu_ans);
$ans =  eval($ans);
#print "student_answer  = $stu_ans <p>";
#print "student_answer evaluated = $stu_ans<p>";
#print "answer evaluated = $ans <p>";
if (eval (($stu_ans - $ans)**2 - 0.0001  ) ge 0.0 ) 
	{print ", <EM> Wrong</EM>,
	<IMG SRC=../icons/checkno.gif>"}
 else {print ", <EM> Right! </EM>,
	<IMG SRC=../icons/check.gif>" };
};

print $query->end_html;

The author, Pierre Omidyar can be visited.

sub count
{

#
# A simple counter program which maintains counts for
# all files in a single counts file. Some systems may
# not allow "." files to be created, so you should
# rename the count file.
#
# Comments to pierre@best.com (Pierre Omidyar)
#

#
# get name of accessed document

#
# open counts file for read & write
#
$doc = $_[0];
#print $doc;
$host = $query->remote_host();

#we will place the Central.counts file in public_html.
$location = "../Central.counts";
open(COUNTS, "$location") || print "<br>having trouble opening Central.counts file";
#					die("pierre:can't open .counts.
");
#flock(COUNTS, 2);		# will wait for lock
# this statement is causing local trouble.

#
# read counts database into associative array
#
while (<COUNTS>) {
	chop;
	($count, $file) = split(/:/, $_);
#print "<br> after split",$file;
	if ($file eq ''){$file = $doc;
			$count = 0;
			};
	$counts{$file} = $count;
#print "<br>",$counts{$doc};
}
close(COUNTS);
#
# increment count of hit document, but not if I'm the
# one accessing it.
#
	
	#
	# increment count for this file
	#
#print "<br>",$counts{$doc};
	$counts{$doc} = $counts{$doc}+1;
#print "<br> after incrementing ",$counts{$doc};
	#
	# rewrite count file
	# put file marker back at beginning
	#
open(COUNTS, ">$location") || print "<br>having trouble opening file";
	foreach $file (keys %counts) {
		print COUNTS $counts{$file}, ":", $file, "
";
	}
close(COUNTS);

#
# print count string to STDOUT to be imbedded into WWW page
#

print "<br>This document has been called ",$counts{$doc}," times.";
}
return -1;

To try this prototype question (with counter), click here