A brief discussion on how to extract image addresses using php regular rules

In html pages, the html code of the image URL specification is generally: 囧2 and 囧4 are optional, but 囧1, A brief discussion on how to extract image addresses using php regular rules, 囧5, and 囧6 are essential to pass XHTML authentication. If we talk about regularity, the shortest match is: (?

However, this will report an error in php: Warning: preg_match_all() [function.preg-match-all]: Compilation failed: lookbehind assertion is not fixed length at offset *** in ***

The problem is in the zero-width assertion (? Copy code Code example: (?Simple (?

Is it okay to list the suffixes of the pictures? For example:

The URLs above are all pictures, but none of them have traditional suffixes. When encountering such addresses, you will still be at a loss.

At this point, you can do this:

Suggestions on php regular extraction of image addresses: If the format of the image address is img space src=, please use: (?

Let’s just introduce these. The writing is a bit messy, but I really hope it can help everyone understand the usage of PHP regularization.