How to redirect a URL always with bar (/) at the end?

Question

I have that code:

<IfModule mod_rewrite.c>
    RewriteEngine On
    RewriteBase /
    RewriteRule ^index\.php$ - [L]
    RewriteRule . /index.php [L]
</IfModule>

When I type http://localhost/path I’d like him to redirect to: http://localhost/path/

I would like to do this without changing my base code:
In the code above when you put http://localhost/path it redirects to index.php (I want to keep this).
I want my code to be flexible to accept any URL changes and to accept both http and https.
I also want it to detect the folder my site is in if it changes folder. Example:
Of localhost/ for localhost/www/site
And I don’t want it to ignore the path of existing files and directories.

How to do this?

Answer 1

RewriteEngine On
RewriteBase /
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_URI} !index.php
RewriteCond %{REQUEST_URI} !(.*)/$
RewriteRule ^(.*)$ /$1/ [L,R=301]

The lines with !-f and !-d make the rule not work if it is an existing file path or directory.

You need to see in your practical case if this is what you want when dealing with images and static files. Extra rules may be required depending on the desired result.