Gadgets
 Authentication
Crypto
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HTTP
Regex
Regex 2
Robots
Snarfs
SSL
Stepper
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Anyone who's ever run a Web site has seen this: duplicate sets of
data from a form. Sometimes three, four sets. Are users really
filling out and sending in reports two, three, four times?
Of course not. They're banging away at the form's "Submit" button
while a stubborn CGI script taps its finger and clears its throat.
What makes them think clicking twice will speed things up?
At any rate, it's easy enough to prove that this is what's happening.
Set up a simple script that time-stamps the data and writes it to a
file.
#!/usr/bin/perl
use CGI;
my $query = new CGI;
print $query->header;
$name = $query->param('name');
$game = $query->param('game');
$number = $query->param('number');
$date = localtime(time());
open(DATA, ">>/usr/temp/data") || die "Can't open data file";
print DATA "$date\t$name\t$game\t$number\n";
close DATA;
print <<EOT;
<html>
<head>
<title>Thanks</title>
</head>
<body>
<h1 align=center>Thanks!</h1>
$date<br>
Name: $name<br>
Game: $game<br>
Number: $number<br>
</body>
</html>
EOT
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Now, an HTML form that posts to our script.
<html>
<head>
<title>Do Stuff</title>
</head>
<body>
<form action="/cgi-bin/getstuff.cgi" method="POST">
<input type="hidden" name="name" value="John">
<input type="hidden" name="game" value="crypto">
<input type="hidden" name="number" value="4"><br>
<br>
<input type="submit" value="Submit">
</form>
</body>
</html>
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