redirecting file request for subdomain and main site with certain arguments?

I am running wildcard subdomains. the aim of the site is to run a virtual subdomain. what the functionality should be is that when the files from the main site are called they will be rewritten for the clean URLs. But when i am calling the same files form the subdomain like xyz.doamin.com/my-file.php then this should be rewritten like it is calling that file with an argument of subdoamin like domain.com/my-file.php?var=xyz. Currently what i have done for the file call is this

Options +FollowSymLinks
RewriteEngine on

## Redirecting all non-www domains to www.domain.com
RewriteCond %{HTTP_HOST} ^domain.com [NC]
RewriteRule ^(.*)$ http://www.domain.com/$1 [R=301,NC,L]


RewriteCond %{HTTP_HOST} !^www\.domain\.com$ [NC]
RewriteCond %{HTTP_HOST} ^(.*)\.domain\.com$ [NC]
RewriteCond %{QUERY_STRING}  ^$
RewriteRule ^(.*)$   http://www.domain.com%{REQUEST_URI}?var=%1 [L]


RewriteCond %{HTTP_HOST} !^www\.domain\.com$ [NC]
RewriteCond %{HTTP_HOST} ^(.*)\.domain\.com$ [NC]
RewriteCond %{QUERY_STRING}  !^$
RewriteRule ^(.*)$   http://www.domain.com%{REQUEST_URI}?%{QUERY_STRING}&var=%1 [L]



RewriteCond %{HTTP_HOST} !^www\.domain\.com$ [NC]
RewriteCond %{HTTP_HOST} ^(.*)\.domain\.com$ [NC]
RewriteCond %{QUERY_STRING}  ^$
RewriteRule ^(.*)$   http://www.domain.com/index.php?subdomain=%1 [L]


RewriteCond %{HTTP_HOST} !^www\.domain\.com$ [NC]
RewriteCond %{HTTP_HOST} ^(.*)\.domain\.com$ [NC]
RewriteCond %{QUERY_STRING}  !^$
RewriteRule ^(.*)$   http://www.domain.com%{REQUEST_UR开发者_C百科I}?%{QUERY_STRING}&subdomain=%1 [L]

This is throwing a 500 internal error for the file call.

Rule set 4 will overlap with rule set 1 and 2. I suspect this is causing the issue. So I think all 3 need an extra RewriteCond check on REQUEST_URI.

Really you shouldn't need rule set 4. Just including index.php as a default should do the trick. Unless of course you don't want URL's like http://www.domain.com/?var=xyz, in this case you need rule 4, but you need to split it into 2 - one with a QUERY_STRING and one without, just like rule 1 and 2

Also, isn't %1 from the regex in the rewriteRule itself and not the preceeding rewriteConds? If so then your regex is wrong, because it'll be setting the var= to the entire original URL.

Looking in the error log is a good idea as it will give you the reason for the 500 error.

Edit: Ok, try something like this (not tested)

## Redirecting all non-www domains to www.domain.com
RewriteCond %{HTTP_HOST} ^domain.com [NC]
RewriteRule ^(.*)$ http://www.domain.com/$1 [R=301,L,QSA]

## Redirecting / requests to index.php
# Note: Use the QSA flag for handling with or without query string
RewriteCond %{REQUEST_URI} ^/$
RewriteCond %{HTTP_HOST} !^www\.domain\.com$ [NC]
RewriteCond %{HTTP_HOST} ^(.*)\.domain\.com$ [NC]
RewriteRule ^(.*)$   http://www.domain.com/index.php?var=%1 [L,QSA]

## Redirecting /something requests to index.php
# Note: Use the QSA flag for handling with or without query string
RewriteCond %{REQUEST_URI} ^/.+$
RewriteCond %{HTTP_HOST} !^www\.domain\.com$ [NC]
RewriteCond %{HTTP_HOST} ^(.*)\.domain\.com$ [NC]
RewriteRule ^(.*)$   http://www.domain.com%{REQUEST_URI}?var=%1 [L,QSA]