How do I remove http, https and slash from user input in php

Question

Example user input

http://domain.com/
http://domain.com/topic/
http://domain.com/topic/cars/
http://www.domain.com/topic/questions/

I want

Answer 1

I'd suggest using the tools PHP gave you, have a look at parse_url.

The above example will output:

Array
(
    [scheme] => http
    [host] => hostname
    [user] => username
    [pass] => password
    [path] => /path
    [query] => arg=value
    [fragment] => anchor
)
/path

It sounds like you're after at least host + path (add others as needed, e.g. query):

$parsed = parse_url('http://www.domain.com/topic/questions/');

echo $parsed['host'], $parsed['path'];

    > www.domain.com/topic/questions/

Cheers