Good profile urls using .htaccess - php

Question

I've three url types which are as follows:
http://www.mywebsite.com/myprofile.php?user_username=username
http://www.mywebsite.com/input.php?user_username=username
http://www.mywebsite.com/users.php?user_username=username
Currently, users have to type the whole address like (http://www.mywebsite.com/myprofile.php?user_username=username) to go to their profiles and the same with input and users.
What I want is if a user types http://www.mywebsite.com/profile/username, he would be automatically redirected to http://www.mywebsite.com/myprofile.php?user_username=username.
When a user types http://www.mywebsite.com/input/username, he would be redirected to
http://www.mywebsite.com/input.php?user_username=username.
When a user types http://www.mywebsite.com/username, he would be redirected to http://www.mywebsite.com/users.php?user_username=username.
I know that this can only be achieved through .htaccess. However, I've searched but with no fruitful result.
Any help please!
Update
I think that the following code is close to being correct. However, I'm not getting the correct result and the css is also getting messed a lot. Individually they are working but together they are messing up. Any help please.
RewriteEngine On
RewriteCond %{THE_REQUEST} ^(GET|POST)\ /myprofile\.php\?user_username=(.*)\ HTTP
RewriteRule ^ /myprofile/%2\? [R=301,L]
RewriteCond %{QUERY_STRING} !user_username=
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^(.*)$ myprofile.php?user_username=$1 [L]
RewriteCond %{THE_REQUEST} ^(GET|POST)\ /user\.php\?user_username=(.*)\ HTTP
RewriteRule ^ //%2\? [R=301,L]
RewriteCond %{QUERY_STRING} !user_username=
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^(.*)$ user.php?user_username=$1 [L]
RewriteCond %{THE_REQUEST} ^(GET|POST)\ /input\.php\?user_username=(.*)\ HTTP
RewriteRule ^ /input/%2\? [R=301,L]
RewriteCond %{QUERY_STRING} !user_username=
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^(.*)$ input.php?user_username=$1 [L]

Answer 1

Have it this way:
RewriteEngine On
RewriteCond %{THE_REQUEST} \s/+input\.php\?user_username=([^\s&]+) [NC]
RewriteRule ^ /input/%1? [R=302,L]
RewriteCond %{THE_REQUEST} \s/+myprofile\.php\?user_username=([^\s&]+) [NC]
RewriteRule ^ /profile/%1? [R=302,L]
RewriteCond %{THE_REQUEST} \s/+user\.php\?user_username=([^\s&]+) [NC]
RewriteRule ^ /%1? [R=302,L]
RewriteCond %{REQUEST_FILENAME} -d [OR]
RewriteCond %{REQUEST_FILENAME} -f
RewriteRule ^ - [L]
RewriteRule ^input/([^/]+)/?$ input.php?user_username=$1 [NC,QSA,L]
RewriteRule ^profile/([^/]+)/?$ myprofile.php?user_username=$1 [NC,QSA,L]
RewriteRule ^([^/]+)/?$ users.php?user_username=$1 [NC,QSA,L]

Answer 2

Add these to the .htaccess file in your DOCUMENT_ROOT
RewriteEngine On
RewriteRule ^([^/]+)/?$ users.php?user_username=$1 [DPI,L]
RewriteRule ^input/([^/]+)/?$ input.php?user_username=$1 [DPI,L]
RewriteRule ^profile/([^/]+)/?$ myprofile.php?user_username=$1 [DPI,L]
Tested in Apache 2.2 and 2.4 :)
This assumes that mod_rewrite is both installed and activated for htaccess files.
If you are not sure, to check if mod_rewrite is installed, look at the list of installed modules in the output of phpinfo();
By default, mod_rewrite is not enabled for htaccess files. If you are managing your own server, open httpd.conf
and make sure that the webroot directory block contains one of these lines: AllowOverride FileInfo or AllowOverride All