preg_rerest的正则表达式模式，包含最后一个斜杠和所有后续字符

I can't figure out how to write the right pattern for my preg_replace pattern.
My situation is this: I've got an URL, let's suppose this:

$url = "first/second/third/fourth"

Now, I need to remove only the last "/" and all the characters after that. So my result should become like this:

first/second/third

For this moment I solved this way:

$result = substr($url, 0, (strrpos($url, "/")));

but I know there should be the right patter to be writted into my preg_replace.
Any suggestion?

Use what you have; it's simple and efficient. Less parentheses could make it look less complicated:

$result = substr($url, 0, strrpos($url, '/'));

The regular expression would look like this:

$result = preg_replace('#/[^/]*$#', '', $url);

Just as long, slightly more confusing.

Match a slash, followed by zero or more characters that are not slashes, followed by the end of the string:

preg_replace("/[^/]*$", "", $url)

Or, using a non-greedy match (*?), this should also work:

preg_replace("/.*?$", "", $url)