How to determine what macport (if any) containing an specific file?

For some reason looking for an macport package what containing an specific file, in this case looking for the file:

sapi/embed/php_embed.h (probably should be somewhere in the `/opt/local/include/...`)

and some php package should contains it.

I have installed the php55 macport but it doesn't contains the above file.

Unfortunately the port contents portname show only the content of already installed packages.

Is possible to show (or find somewhere) what files containing some macport packages without installing them - e.g. how to find what package i need to install to get the sapi/embed/php_embed.h file?