Convert nginx to Apache rewrites

Question

I'm trying to set up CodeIgniter from an existing site that's on nginx. My local machine is Apache and this is the redirect scheme on nginx. How do I write this using RewriteRules?

    if ($host ~* ^www\.(.*)) {
            set $host_without_www $1;
            rewrite ^(.*)$ http://$host_without_www$1 permanent;
    }
if ($request_uri ~* ^(/welcome(/index)?|/index(.php)?)/?$){
            rewrite ^(.*)$ / permanent;
    }
if ($request_uri ~* index/?$){
            rewrite ^/(.*)/index/?$ /$1 permanent;
    }
if (!-d $request_filename){
            rewrite ^/(.+)/$ /$1 permanent;
    }
if ($request_uri ~* ^/system){
            rewrite ^/(.*)$ /index.php?/$1 last;
            break;
    }
if (!-e $request_filename){
            rewrite ^/(.*)$ /index.php?/$1 last;
            break;
    }

Answer 1

Something like this:

# These go in the VirtualHost context.

RewriteEngine On
RewriteCond %{HTTP_HOST} ^www\.(.*)$ [NC]
RewriteRule ^(.*)$ http://%1$1 [R=301,L]

RewriteCond %{REQUEST_URI} ^(/welcome(/index)?|/index(.php)?)/?$ [NC]
RewriteRule ^ / [R=301,L]

RewriteRule ^/(.*)/index/?$ /$1 [R=301,L,NC]

RewriteCond %{REQUEST_URI} ^/system [NC]
RewriteRule ^/(.*)$ /index.php?/$1 [L]

<Directory /path/to/docroot>
    # This is so that these have the correct filesystem path in the
    # REQUEST_FILENAME parameter.
    # If you already have a <Directory> for here, add these to it.

    RewriteCond %{REQUEST_FILENAME} !-d
    RewriteRule ^(.*)/$ $1 [R=301,L]

    RewriteCond %{REQUEST_FILENAME} !-f
    RewriteCond %{REQUEST_FILENAME} !-d
    RewriteCond %{REQUEST_FILENAME} !-l
    RewriteRule ^/(.*)$ /index.php?/$1 [L]
</Directory>