#include <unistd.h> long gethostid(void);
The gethostid() function returns the 32-bit identifier for the current host. If the hardware capability exists, this identifier is taken from platform-dependent stable storage; otherwise it is a randomly generated number. It is not guaranteed to be unique.
If the calling thread's process is executing within a non-global zone that emulates a host identifier, then the zone's emulated 32-bit host identifier is returned.
See attributes(5) for descriptions of the following attributes: