How to remove index.php from the middle of URL Dreamhost

Question

1. I want to remove index.php from the middle of the URL.
2. I am using Dreamhost Webhosting.
3. And Believe me, Dreamhost Webhosting configuration is very different from others.
4. Normal Webhosting configuration is not working in Dreamhost.

Here is the problem I am facing:

PROBLEM 1:

The link below:
https://www.example.com/index.php/gallery

Should redirect to:
https://www.example.com/gallery

PROBLEM 2:

The link below:
https://www.example.com/index.php/profile/juhi/168

Should redirect to:
https://www.example.com/profile/juhi/168

PROBLEM 3:

The link below:
https://www.example.com/index.php

Should redirect to:
https://www.example.com/

htaccess code is below:

RewriteEngine On

# Existing files and directories remain accessible
RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^.* - [L]

# Redirect the rest
RewriteCond $1 !^(index\.php|images|robots\.txt)
RewriteRule ^(.*)$ /index.php?/$1 [QSA,L]

Answer 1

https://www.example.com/index.php/gallery

The part of the URL-path after /index.php (a valid file), ie. /gallery in this example, is called "additional pathname information" (aka path-info for short). (This is used by many CMS to route the URL when mod_rewrite/.htaccess is not available.)

To remove the /index.php part of the URL you could add the following redirect directive immediately after the RewriteEngine directive.

# Redirect URLs of the form "/index.php/<URL>" to "/<URL>"
# Also handles "/index.php" only
RewriteCond %{ENV:REDIRECT_STATUS} ^$
RewriteRule ^index.php(?:/(.*))?$ /$1 [R=301,L]

Test first with a 302 (temporary) redirect and only change to 301 (permanent) - if that is the intention - once you have confirmed that it works as intended. 301s are cached persistently by the browser so can make testing problematic.

---

Aside:

RewriteRule ^(.*)$ /index.php?/$1 [QSA,L]

As I mentioned in comments, your .htaccess directives are rewriting the request to a query string (not path-info as mentioned above). This means that your pages are accessible via a 3rd URL. For example:

/index.php?/gallery
/index.php?/profile/juhi/168

2. I am using Dreamhost Webhosting.
3. And Believe me, Dreamhost Webhosting configuration is very different from others.
4. Normal Webhosting configuration is not working in Dreamhost.

FWIW, nothing mentioned in your question, or the solution, is specific to any particular web-host.