.htaccess file for multple control pages and wildcard subdomains

Question

I can't seem to get my head around configuring an .htaccess file that sends to different control pages based on the subdomain, then uses wildcards for user subdomains.

What I need is essentially this:

1. If domain.com, redirect to www.domain.com/index.php
2. If www.domain.com, rewrite to www.domain.com/index.php
3. If img.domain.com, rewrite to www.domain.com/img/
4. If api.domain.com, rewrite to www.domain.com/api/index.php

5. If admin.domain.com, rewrite to www.domain.com/admin/index.php

6. If (anything else).domain.com, rewrite to www.domain.com/users/index.php - also sending the value of the subdomain as a variable.

All of the tutorials I've seen send all requests to a single page which is then routed, I would like the htaccess file to do some of the work beforehand.

Answer 1

If your subdomains are not pointing to same documentroot's main domain (you will have to enable mod_proxy)

RewriteEngine on

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

# 2. skip www.domain.com
RewriteCond %{HTTP_HOST} ^www\. [NC]
RewriteRule . - [L]

# 3/4/5. manage img, api and admin subdomains
RewriteCond %{HTTP_HOST} ^(img|api|admin)\. [NC]
RewriteRule ^(.*)$ http://www.domain.com/%1/$1 [P]

# 6. manage users
RewriteCond %{HTTP_HOST} ^(.*)\.domain\.com$
RewriteRule ^(.*)$ http://www.domain.com/users/index.php?user=%1 [P]

If your subdomains are pointing to same documentroot's main domain (mod_proxy is not needed here)

RewriteEngine on

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

# 2. skip www.domain.com
RewriteCond %{HTTP_HOST} ^www\. [NC]
RewriteRule . - [L]

# 3/4/5. manage img, api and admin subdomains
RewriteCond %{HTTP_HOST} ^(img|api|admin)\. [NC]
RewriteRule ^(.*)$ /%1/$1 [L]

# 6. manage users
RewriteCond %{HTTP_HOST} ^(.*)\.domain\.com$
RewriteRule ^(.*)$ /users/index.php?user=%1 [L]

---

EDIT:

RewriteEngine on

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

# 2. www.domain.com rewritten to index.php
RewriteCond %{HTTP_HOST} ^www\. [NC]
RewriteRule . /index.php [L]

# 3. img.domain.com rewritten to img folder
RewriteCond %{HTTP_HOST} ^img\. [NC]
RewriteRule ^(.*)$ /img/$1 [L]

# 4/5. api or admin subdomains rewritten to /api/index.php or /admin/index.php
RewriteCond %{HTTP_HOST} ^(api|admin)\. [NC]
RewriteRule . /%1/index.php [L]

# 6. manage users
RewriteCond %{HTTP_HOST} ^(.+)\.domain\.com$
RewriteRule . /users/index.php?user=%1 [L]