Hi,
I thought I would write this hotlinking topic guide in order to help those who may wish to play with there HTACCESS file.
Warning Editing your HTACCESS file is extremely hazardous, and could stop you and anyone else accessing it. Always make sure that if editing it, you have a multiple window open with the old untouched HTACCESS file present so you can click "save" and save yourself!
What is Hotlinking?
Hot linking is for example where I own www.mysite.com and I have a picture of a flower I took. Now some happy client on www.evilsite.com thinks "ooh, nice flower, I will link to it and display it on my website". Thus, your picture is now being linked, legally, to another site where its being displayed
Why should this bother me??
Well for a number of reasons, but most importantly, because its taking up your bandwidth. Each time that picture is looked at, the total size of your picture is being added to your bandwidth. That means that say my picture of the flower is 30K and www.evilsite.com has 1000 people looking at this picture, thats 30 x 1000 = 30,000 = 30 megs of my own bandwidth!!!!!! And we all know how precious bandwidth is!
What can I do about this?
Turn on hotlinking protection in CPANEL. Its relatively straight forward to do and will (hopefully) stop people from hotlinking.
Its not working / I want more control / I want to be able to manually do it so I know whats going on
Ok then, its simple enough to do, but make sure you have that back-up window open!
(Side note, I always work in notepad first, and whilst I know there are other ways to do this, keeping it simple and nicely laid out is the way to do it)
Right, if if I have mysite.com, and I want to stop all pictures being taken, this is what I need to have in my htaccess file:
>RewriteEngine on
RewriteCond %{HTTP_REFERER} !^$
RewriteCond %{HTTP_REFERER} !^http://mywebsite.com/ [NC]
RewriteCond %{HTTP_REFERER} !^http://mywebsite.com [NC]
RewriteCond %{HTTP_REFERER} !^http://www.mywebsite.com/ [NC]
RewriteCond %{HTTP_REFERER} !^http://www.mywebsite.com [NC]
#RewriteRule .*\.(jpg|jpeg|gif|png|bmp)$ - [F,NC]
What does all that jargon mean? Please explain!
OK, here goes:
RewriteEngine This is a server command saying to re-write something, in this case (overall) to stop images going missing
Rewritecond This command searches the string (string is where you put Http://www. or www.) and trys to match anything after it
Using ! and $ and ^ The ! means "not", so anything with the proceeding address is fine and not to be rewritten. $ and ^ are used in the string searching. ^ at the start and $ at the end
www.mywebsite.com The url which you want to ALLOW (Remember that whilst your telling it to rewrite and stop images, the ! symbol says don't re-write so its like a double negative)
NC Means to ignore the namecase, so it searches for both caps and lower case.
Rewrite This tells the server what to do if its finding a string which is not in the list above and matches the string. In the case above, looks for anything with JPG or GIF etc
If it finds something which has passed all the rewrites above (aka not matched) then it proceeds to do something.
[F] In the case above, F = forbidden, aka not allowed. The NC is again in there to stop JPG and jpg being different.
.(jpg|jpeg|gif|png|bmp) These are the files I want to stop. They could be anything from mp3 to php
Right, I think I understand, but why the 4 lines for just one domain name?
There is a shorter way, but then if there is a problem, its more complex to untangle. Here with four lines, I can see instantly if I have a problem and if something is not working and why its not working
Ah ok. What happens if I have subdomains?
Not a problem, just continue the same principles as above, just remember to add it before the Rewrite bit! E.g. I have a subdomain called gallery:
>RewriteCond %{HTTP_REFERER} !^http://gallery.mywebsite.com/ [NC]
RewriteCond %{HTTP_REFERER} !^http://gallery.mywebsite.com [NC]
hence my entire code would look like:
>RewriteEngine on
RewriteCond %{HTTP_REFERER} !^$
RewriteCond %{HTTP_REFERER} !^http://mywebsite.com/ [NC]
RewriteCond %{HTTP_REFERER} !^http://mywebsite.com [NC]
RewriteCond %{HTTP_REFERER} !^http://www.mywebsite.com/ [NC]
RewriteCond %{HTTP_REFERER} !^http://www.mywebsite.com [NC]
RewriteCond %{HTTP_REFERER} !^http://gallery.mywebsite.com/ [NC]
RewriteCond %{HTTP_REFERER} !^http://gallery.mywebsite.com [NC]
#RewriteRule .*\.(jpg|jpeg|gif|png|bmp)$ - [F,NC]
Ok, what about if I want to allow say a forum to display a picture?
Not a problem, just put in a line or two lines of coding, depending on the domain!
e.g. I want to allow totalchoicehosting forums to allow to hotlink too? (I want to show my flower picture off to everyone!)
I would just add the line:
>RewriteCond %{HTTP_REFERER} !^http://www.totalchoicehosting.com/forums [NC]
I've seen shorter more complex hot link protections about. Why is this so long for?
Short and complex is fine if you I) 100% understand it and II) It does not go wrong. Often laying something out simply whilst may take 5 minutes first time around, saves you so much time in the future.
Arrrg, help, its all gone wrong, I forgot to have a second window open and I can't do or see anything. Now what???
Not to worry, please submit a help ticket and wait for us to fix it.
Well thats the end of my 1st possible help topic, please let me know if its any good or just rubbish!
