通过正则表达式从字符串中拉出第二个URL

Question

I am looking for a way within PHP to pull the second link http://secure.hello.com out of the following string via regex.

http://hello.com/http://secure.hello.com

The string may or may not contain https in either of the spots.

Answer 1

Try this regular expression:

://\S*/(\w+://\S*)

It searches for the first :// then searches for a slash followed by some word characters, then ://, then anything apart from spaces. The text you want is in the first capturing group.

In a PHP string literal it can be written as:

'#://\S*/(\w+://\S*)#'

See it working online: ideone

If you want to restrict to http or https, change the \w+ to https?.