SEO Url for Profiles - .htaccess

Question

Preface
I'm trying to re-write a URL for a profile page. All of my application pages have a .html extension, so I'm trying to match just letters, numbers, -, and ..
So these would be valid
site.com/steve
site.com/steve-robbins
site.com/steve.robbins
But these wouldn't be
site.com/steve.html
site.com/steve-robbins.php
Assume I have a check in place so that custom URLs don't have .html or .php on the end.
Problem
I'm currently using this but it's not working
RewriteRule ^([a-zA-Z0-9\.-]+)$ profile.php?url=$1 [L]
It should set url to steve, but it's setting it to profile.php
What am I doing wrong?
My complete .htaccess
Options +FollowSymLinks
RewriteEngine On
RewriteBase /
RewriteCond %{HTTP_HOST} ^[^.]+\.[^.]+$
RewriteRule ^(.*) http://www.%{HTTP_HOST}/$1 [R=301]
#
# LOGIN
#
RewriteRule ^([a-z0-9]{255})/activate\.html$ login.php?activate=$1 [L]
RewriteRule ^logout\.html$ login.php?logout [L]
#
# SETTINGS
#
RewriteRule ^change-([a-z]+)\.html$ account-settings.php?$1 [L]
RewriteRule ^([a-zA-Z0-9\.-]+)$ profile.php?url=$1 [L]
# SEO friendly URLs
RewriteRule ^([a-zA-Z0-9-_.]+)\.html$ $1.php [L]
RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /([a-zA-Z0-9-_.]+)\.php
RewriteRule ^([a-zA-Z0-9-_.]+)\.php$ $1.html [R=301]

Answer 1

Add this to the top of your rules (under the RewriteBase / directive):
RewriteCond %{ENV:REDIRECT_STATUS} 200
RewriteRule ^ - [L]
That should stop it from looping. The rewrite engine will keep re-applying all the rules until the URI going in (sans query string) is the same as the URI that comes out of the rules. That's why the value of url is profile.php.

Answer 2

I'm kind of a beginner in interpreting mod_rewrite rules but if I understand it correctly your rule is matched and than matched again, either add something to the url matching scheme like /profile/user or add a condition to not redirect if already redirected

Answer 3

Try adding a leading slash to the redirect like this:
RewriteRule ^([a-zA-Z0-9.-]+)$ /profile.php?url=$1 [L]
The reason you're getting a url value of profile.php is because the [L] flag is kinda misleading when it comes to the .htaccess file. In the server config files it does exactly what you'd think, but in the .htaccess file it stops reading rules at that rule, but then goes through the rules again until path is unchanged by any of the rules. By adding the leading /, your rule will not match the second time around as you exclude / from the regex. I spent a while struggling with this feature myself.