The getnetbyaddr() call searches the local host tables for the specified network address. This call can be used only in the AF_INET domain. See z/OS Communications Server: IP Configuration Guide for information about using local host tables.
#include <manifest.h>
#include <bsdtypes.h>
#include <netdb.h>
struct netent *getnetbyaddr(unsigned long net, int type)
The return value points to static data that is overwritten by subsequent calls. A pointer to a netent structure indicates success. A NULL pointer indicates an error or end-of-file. When a NULL pointer or 0 is returned, the value of errno is indeterminate, and therefore, the output from a tcperror() call cannot be validated.
endnetent(), getnetbyname(), getnetent(), setnetent(), endhostent()