I have noticed that path_set(ENTITY*,STRING* name) returns the number of nodes in the path.
That is useful but it is not to day in the manual.
Other path functions return a value, what is it ? A pointer ?
Can we access to data struct such as node info or edge info ?
It would be interesting to read more in these pages.

The path data can be only indirectly accessed, using path functions. I'll add the info about the returned number of nodes.