FHimageprotect V1.2
December 20, 1999
FHimageprotect V1.2
is a nifty little cgi script written
by Dale Bulmer, former owner of free-help.com, a free internet
help site. FHimageprotect prevents someone from stealing your
bandwidth by linking directly to your images. Oh.... they can
still link, but what is served up is not what they expect.
Want to
see what happens when an unauthorized site tries to
link to an image on your server?
The zipped version of the script may be downloaded
from WebGuard,
or you can copy/paste the
text into your favorite text editor,
saving it with a .pl or .cgi extension. (Note, not all servers
are set up to execute a .pl extension. It may be necessary
to change the extension to .cgi.)
The first thing you'll need to do is change the variables in the
script so that they point to your files and directories. The
script itself is fairly basic only requiring four changes.
Open the script in your favorite text editor, making
adjustments to the lines indicated below.
| #!/usr/bin/perl |
This line must reflect the location of perl on your server.
If you have telnet access you can type "whereis perl" at the
command prompt. All others contact their system admin or ISP
for the location of perl. |
@re=("yourdomain.com","www.yourdomain.com");
#Set the above line to valid refer's (refer assumed bad if not
listed)
|
Specify your own domain as well as any other domains you would
like to have access to your images. If a domain is not listed
here, that site will not be able to link directly to your
images.
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$graphicsdir = "graphics";
#The relevant dir of the graphics |
Change "graphics" to the location of your images
directory; this is the directory where you will store the
images you want to protect.
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| print "Location: http://yourdomain.com/cgi/stolen.gif\n\n";
|
The "\n\n" at the end of the line sends two line breaks
(one for each "\n") which is standard when printing out
an HTTP mime type (here, the type is location=some.gif)
|
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This line reflects the location of a specially prepared image
that notifies the general public that the image they were
supposed to be viewing was stolen. Create an image that says
something to the effect of "The image you are trying to view
is stolen. Please send email to email@mydomain.com with the
URL of the website attempting to post this image". Place
the image in your root directory; if you place it elsewhere,
you'll need to adjust the path to it in the
script.
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Now that all of the changes have been made to the cgi-script,
you can upload it to your cgi-bin. Be sure to upload as ASCII
text, not binary. The script should have permissions set
to Read, Write, Execute for owner and Read,
Execute for everyone else. Permissions are probably
one of the most difficult concepts for the newbie to grasp,
so if you're having trouble check out the
Permissions Chart.
A slight change to your HTML file is necessary to get the
script to work. The IMG SRC needs to be changed from
<IMG SRC = "image_directory/image.jpg">
to
<IMG align=left SRC="/cgi-bin/fhimageprotect.pl?image_jpg">
Note the dot (.) between the image name and the jpg extension
has changed to an underscore (_). The path reflects the
location of fhimageprotect.pl rather than the image itself.
Upload the html file to the directory specified in the cgi
script and you're all set!
Disable Images Right Click
Protecting Images and Bandwidth
Conclusion
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