Sid Sid - 11 months ago 115
HTML Question

How to match whitespace, carriage return and line feed using regular expression in PHP?

I am working with a regular expression in PHP. I have the following string:

<img
src="/files/admin/hotel_website.gif" alt="Go To The Hotel's Web
Site" align="absmiddle" border="0" class="hotel_icon" />


This string contains carriage return and line feed characters.

I want my regular expression to replace html img tags with IMG but this does not work with the above text.

I discovered it contained these characters by looping through each character in the string and printing out the hexadecimal representation which can be found here (http://pastebin.com/ViNdBsRV).

Here is my regular expression:

strip_tags(preg_replace('/^\s*<img\s*.*\/?>\s*$/i', '[IMG]', $test));


Appreciate the help.

3on 3on
Answer Source

This:

preg_replace("#<img.+?/>#is", '[IMG]', $test)

Personally when I'm making a regular expression I always try to go the shortest/simplest. Here you want to replace an entire tag, which starts with '<img' and ends with '/>', '.+?' is a non greedy (lazy) catch. And for the modifiers 'i' for the case and 's' to . the possibility to be a new lines.

More on greedyness vs lazyness : http://www.regular-expressions.info/repeat.html
More on modifiers: http://www.php.net/manual/en/reference.pcre.pattern.modifiers.php

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