Simple htaccess mod rewrite with possible query string

I've tried and tried and tried by my htaccess knowledge isn't great, and I cannot find anything to suit my needs (but then I'm not sure what i'm searching for).

Effectively my question is twofold:

I want to convert: http://subdomain.domain.com/hello

To: http://subdomain.domain.com/index.php?string=hello

But occasionally there could be a querystring as well so...

From: http://subdomain.domain.com/hello?query=true

To: http://subdomain.domain.com/index.php?string=hello&query=true

So far I've managed the first:

RewriteEngine on
RewriteCond %{REQUEST_FILENAME} -f [NC,OR]
RewriteCond %{REQUEST_FILENAME} -d [NC]
RewriteRule .* - [L]
RewriteRule ^([^/\.]+)/?$ client开发者_高级运维.php?user=$1&$2 [L]

Remember, the second is a potential :) Thanks!

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You just need to set the QSA flag for the last rule:

RewriteRule ^([^/\.]+)/?$ client.php?user=$1 [L,QSA]

Then the original requested query will automatically appended to the new one.