Performing RegEx on open file

[drwbns]

I found a better way of how to open a file. But I need help trying to match a url using boost::xpressive. I got the following off the web that doesn't match anything, other examples I tried throw a compile error. Does anyone know of a boost compatible regex to match a URI? I tried to match using this but I'm not sure if I'm escaping correctly -

sregex::compile("(\?:ftp\|https\?:\/\/)\+(\?:\\S+\.)\+(\?:\\S\.)\+(\?:\S)\+");