#!/opt/perl/bin/perl # # This script will take a student's quote for bananas and create # a web page for the results of the highest and lowest of the week. # # James Judd juddjam@eng.auburn.edu 960729 # for Auburn University's Political Science Department # under the MCI grant for U102 Online # $datafile = "/home/duc1/juddjam/public_html/banana/banana.pits"; $lockfile = "/home/duc1/juddjam/public_html/banana/banana.pits.lock"; $expiry = 60; # seconds before lockfile invalidated $later = "

Busy.. please try again a little later.\n

"; $error = "

Unexpected error.. notify your instructor.\n

"; print "Content-type: text/html\n\n"; read(STDIN, $buffer, $ENV{'CONTENT_LENGTH'}); @pairs = split(/&/, $buffer); foreach $pair (@pairs) { ($name, $value) = split(/=/, $pair); # Un-Webify plus signs and %-encoding $value =~ tr/+/ /; $value =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C", hex($1))/eg; # Stop people from using subshells to execute commands $value =~ s/~!/ ~!/g; $FORM{$name} = $value; } ($store = $FORM{'store'}) =~ y/_/ /; ($price = $FORM{'price'}) =~ s#(\.\d\d)\d+#$1#; $week = $FORM{'weeknum'}; print < Banana Page

Banana Price Page


EOT &result_generation() if $FORM{'store'} && $FORM{'price'}; &show_data(); $week++; print <


You may now review the

or you may

Go Back

to the main banana page EOT sub show_data { local($_,$earliest,$latest,$highest,$lowest,@stuff); local($average,$sum,$number,$store,$price,$time); unless (open F, $datafile) { print $error; exit; } @stuff = ; close F; ## determine bounds local($week_length) = 3600 * 24 * 7; $earliest = ($latest = time()) - $week_length; $earliest -= $week * $week_length; $latest -= $week * $week_length; foreach (@stuff) { ($store,$price,$time) = split(/\t/); next unless $time >= $earliest && $time <= $latest; if ($highest < $price || $highest eq "") { $highest = $price; $highstore = $store; } if ($lowest > $price || $lowest eq "") { $lowest = $price; $lowstore = $store; } @data = (@data, "\n", scalar localtime($time), " $price¢ $store\n"); $sum += $price; $number++; } unless ($number) { if ($week == 0) { print "

No prices have been entered for this week.

\n"; } elsif ($week == 1) { print "

No prices were entered for last week.

\n"; } else { print "

No prices were entered for the week starting $week weeks ago.

\n"; } return; } ($average = $sum / $number) =~ s#(\.\d\d)\d+#$1#; print "

Highest of the week: $highest¢ per pound at $highstore

Lowest of the week: $lowest¢ per pound at $lowstore

Average for this week: $average¢ per pound

\n"; print "

", scalar localtime($earliest), " through " , scalar localtime($latest), ":

\n"; print "\n"; print ""; print ""; print "\n"; print "@data"; print "\n"; print "
Entry Date/Time Price Store
\n"; print "

\n"; } sub result_generation { local($winks); if (-e $lockfile) { unlink $lockfile if (time() - (stat $lockfile)[9] > $expiry); } sleep 1 while (-e $lockfile && $winks++ < 5); if (-e $lockfile) { print $later; exit; } symlink("lockfile", $lockfile); unless (open F, ">>$datafile") { print "$error: $!"; exit; } print F "$store\t$price\t", time(), "\n"; close F; unlink $lockfile; }