Change php files to slugs

make-slugs

#1)externally redirect "/file.php" to "/file"   
RewriteCond %{THE_REQUEST} /([^.]+)\.php [NC]
RewriteRule ^ /%1 [NC,L,R]
#2)Internally map "/file" back to "/file.php"
RewriteCond %{REQUEST_FILENAME}.php -f
RewriteRule ^(.*?)/?$ /$1.php [NC,L]

from https://stackoverflow.com/questions/4908122/removing-the-php-extension-with-mod-rewrite

RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME}.php -f
RewriteRule (.) $1.php [L]
#if no file, send to 404
RewriteCond %{THE_REQUEST} "^[^ ] .?.php[? ].$" RewriteRule .* - [L,R=404]