How to remove the protocol and domain from a url string?

Question

I am running the following code in PHP. My intention is to get "contact.html" in the response, but what I actually get in the output is ntact.html

$str = 'http://localhost/contact.html';
echo $str . "<br>";
echo ltrim($str,'http://localhost');

Any thoughts why PHP is behaving this way and what can I do to fix this?

Answer 1

ltrim doesn't do what you think it does. It uses a character collection, so all characters within are deleted. You should delete the substring using str_replace.

http://php.net/manual/en/function.str-replace.php

$str = 'http://localhost/contact.html';
echo $str . "<br>";
echo str_replace('http://localhost/', '', $str);

Output:

http://localhost/contact.html
contact.html

I do realize that you're trying to only replace a string that's at the beginning of your string, but if you have an http://localhost later in your string, you might have bigger problems.

Documentation on ltrim: http://php.net/manual/en/function.ltrim.php (The Hello World example should be enlightening on explaining exactly what ltrim is doing)

Another example of ltrim misuse: PHP ltrim behavior with character list

Answer 2

Other answers explain why ltrim isn't doing what you thought it would, but there's probably a better tool for this job.

Your string is a URL. PHP has a built-in function to handle those neatly.

echo parse_url($str, PHP_URL_PATH);

(parse_url does return the path with a leading slash. If you need to remove that, then ltrim will work just fine since you'll only trimming one character.)