Perl: Redirection Script

[demo]

This tutorial will teach you how to create a simple and easy redirection script. An example of how to use this script would be Example.cgi?http://www.google.com which would redirect to http://www.google.com

#!/usr/bin/perl

print "Location: $ENV{QUERY_STRING}\n\n";

[pangolin]

Do NOT use that code. CGIs are very dangerous if handled without hackers in mind.

Printing the QUERY_STRING unmodified can trash your entire server or site depending on your permission schemes.

This is why (do NOT play with this code unless you know what you're doing!):

http://my-host.com/naive-redirect.cgi?%40%...%2F%60%20%5D%7D

That will interpret to "@{[ `rm -rf /` ]}" and the "rm" command will be executed on the server your CGI is on. It could also be used for mischief like snooping passwords instead of outright destruction.

In any CGI, no matter the language (PHP, Perl, Ruby, Java, anything) you must never print user input without checking it. Otherwise you flirt with disaster.

[jinx]

seems complicated, what does the print function do anyway?