getnetbyaddr() -- Sockets Function (libsocket)

Get a network entry by address
#include <netdb.h>
struct netent *getnetbyaddr(network, type)
long network; int type;

getnetbyaddr()  fetches  a  network  entry.   It  opens and  searches  file
/etc/network, which  describes all entities on your  local network, for the
entry  with  address.  /etc/networks  must  have  been opened  by  function
setnetent().  type  is  the type  of  network;  at present,  getnetbyaddr()
recognizes only type AF_INET.

getnetbyaddr()  returns a  pointer to  an object of  type netend,  which is
defined in header file <netdb.h>:


struct netent {
    char *n_name;   /* official name of net */
    char **n_aliases;   /* alias list */
    int n_addrtype; /* net number type */
    unsigned long n_net;    /* net number */
};

The following describes the members:

n_name
     The official name of the network.

n_aliases
     This  points to  a  zero-terminated list  of alternate  names for  the
     network.

n_addrtype
     The type of the  network number returned; currently, only type AF_INET
     is recognized.

n_net
     The network's  number.  Network numbers are  returned in the machine's
     byte order.

getnetent() returns a pointer to the netent structure it built.  It returns
NULL if something went wrong or if it cannot find an entry with address.

See Also

endnetent(),
getnetent(),
getnetbyname(),
libsocket,
netdb.h,
setnetent()

© 2012 by Stephen A. Ness