jack123:

Ouch--Three demerits!

1. Using a regex to parse XML (especially when the OP is clearly asking about Xpath)
2. Incorrect regex that won't solve the problem (try $str='<c>foo</c>')
3. Untested code without a warning. (Try adding g modifier to match to prevent an infinite loop.)

...roboticus

When your only tool is a hammer, all problems look like your thumb.