gio:resource-info (resource path lookup)

resource -- a g:resource instance
path -- a string with a pathname inside the resource
lookup -- a g:resource-lookup-flags value

size -- an integer with the length of the contents of the file
flags -- an unsigned integer with the flags about the file

Looks for a file at the specified path in the resource and if found returns information about it. The lookup argument controls the behaviour of the lookup.