How to make robots.txt file for my site

I have site sujangarh.net
it use a cPanel ( site is not made yet)
i have addon domian
rundir.com .---this is working fine but
but it also work from rundir.sujangarh.net and sujangarh.net/rundir.com

so i dont want serach engine to understand them as as duplicate URL
what should i do

 

Never link from the main domain to to the sub or the directory.

If you link, link to the addon domain.com only.

It has never been a problem.

If you still can, I would edit your initial post and replace the . with dot.

 

In the root of your domain sujangarh.net, add the following
robots.txt file:

User-agent: *

Disallow: /rundir.com/

 

thanks for this but it still can be accessed from rundir.sujangarh.net
how to stop this

 

If you want to stop all access using sujangarh.net, one of the ways
is to put this php code at the start of your index.php

<?php
if (strpos($_SERVER['PHP_SELF'],'sujangarh.net' ))// Return 404 error if URL contains sujangarh.net
{
	header("HTTP/1.0 404 Not Found");
	exit;
}
?>

PHP:

This must be the start of the file before any output is sent.

 

thanks for this i will try

 

Why don't you redirect[301] your subdirectory[folder] to your subdomain. I think that would be the best solution. Then you will be free from duplication and using any URL to link. This can be done through mod_rewrite rule in .htaccess file.

 

I have tried this.
I am getting problem in this