find all the numeric positions of a character that appears in a string multiple times

Hi guys. What is the best way to find all the numeric positions of a character that appears in a string multiple times? E.g. let's say I have the following string: $str = "<a href=http://foo.bar><b>test</b></a>"; And I want to parse the string and extract everything between <>. Now if the string only had a single occurrence of "<" and ">" I can use strpos() and substr() to extract it, but how do I do it for multiple occurrences? I suppose I can keep chopping up the string to do this but I'm not sure if that's the best way. Thanks. David