htaccess将子域重定向到某些页面？

Question

I need all subdomains to be redirected to a specific page, without actually changing the URL, because I will display different content on this specific page depending on what subdomain is in the URL.

Let's say my site is located at testdomain.com/site1/

I want all subdomains, like xyz.testdomain.com/site1/ or even xyz.testdomain.com to be redirected to a specific page at http://testdomain.com/site1/index.php/test.php

The browser will then need to be loading http://testdomain.com/site1/index.php/test.php , but the URL will still be xyz.testdomain.com.

The purpose of this is so that someone can go to abc.testdomain.com or xyz.testdomain.com and both will take the user to testdomain.com/site1/index.php/test.php, and then on test.php, I have some code that will grab the URL, and if the url is abc.testdomain.com, it will display certain content, whereas if the subdomain is xyz.testdomain.com it will display different content.

Is this something I can do in htaccess? If so, how?

Answer 1

Using mod_rewrite you can hack this together.

# Step 1: If the user went to example.com or www.example.com
# then we don't want to redirect them. (S=1 says skip the next rule)
RewriteCond %{HTTP_HOST} ^(www\.)?example\.com
RewriteRule ^ - [S=1]

# Step 2: Anything else is redirected to our catcher script.

# Option 1: keeps the path they went to, but discards the domain
# i.e. xyz.example.com/abc/def.txt => /var/www/cgi-bin/abc/def.txt
RewriteRule ^/?(.*) /var/www/cgi-bin/$1 [QSA,L]

# Or Option 2: take all requests to the same file
# i.e. xyz.example.com/abc/def.txt => /var/www/cgi-bin/myfile.php
RewriteRule ^ /var/www/cgi-bin/myfile.php [QSA,L]

QSA tells it to forward the query string, L tells it to stop looking for more redirects (not absolutely necessary but sometimes helps if you have a lot of this sort of thing going on).

You can also pass variables to your script as query parameters, and the QSA flag ensures they don't replace the original values;

# xyz.example.com/abc/def.txt => /var/www/cgi-bin/myfile.php?host=xyz.example.com&path=/abc/def.txt
RewriteRule ^/?(.*) /var/www/cgi-bin/myfile.php?host=%{HTTP_HOST}&path=/$1 [QSA,L]

It means you don't need to worry about figuring out where the request came from inside your script (which might actually be impossible, I'm not sure). Instead you can just read it as a normal parameter (it's hackable like a normal parameter too; be sure to sanitise it).