getnetent(3N)                                          getnetent(3N)


       NAME
             getnetent, getnetbyaddr, getnetbyname, setnetent, endnetent -
             get network entry

       SYNOPSIS
             cc [options] file -lsocket -lnsl
             #include <netdb.h>
             struct netent *getnetent(void);
             struct netent *getnetbyname(char *name);
             struct netent *getnetbyaddr(long net, int type);
             int setnetent(int stayopen);
             int endnetent(void);

       DESCRIPTION
             getnetent, getnetbyname, and getnetbyaddr each return a
             pointer to an object with the following structure containing
             the broken-out fields of a line in the network data base,
             /etc/networks.

             The structure netent include the following members:

                   char     *n_name;          /* official name of net */
                   char     **n_aliases;      /* alias list */
                   int      n_addrtype;       /* net type */
                   unsigned long  n_net;      /* network number */

             The members of this structure are:

            n_name The official name of the network.

            n_aliases
                    A zero terminated list of alternate names for the
                    network.

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

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

             getnetent reads the next line of the file, opening the file if
             necessary.





                           Copyright 1994 Novell, Inc.               Page 1

      getnetent(3N)                                          getnetent(3N)


            setnetent opens and rewinds the file.  If the stayopen flag is
            non-zero, the net data base will not be closed after each call
            to getnetent (either directly, or indirectly through one of
            the other getnet calls).

            endnetent closes the file.

            getnetbyname and getnetbyaddr sequentially search from the
            beginning of the file until a matching net name or net address
            and type is found, or until EOF is encountered.  Network
            numbers are supplied in host order.

         Files
            /etc/networks
            /var/yp/{domainname}/networks.byname
            /var/yp/{domainname}/networks.byaddr

         Return Values
            A NULL pointer is returned on EOF or error.

      REFERENCES
            networks(4), ypserv(1M)

      NOTICES
            All information is contained in a static area so it must be
            copied if it is to be saved.  For multi-threaded applications,
            this must be done on a per-thread basis.

            Functions that provide successive entries in files on
            successive calls must be called from a single thread.

            Only Internet network numbers are currently understood.

            The Network Infromation Service (NIS) will be used to obtain
            network entires when its installed and running.  Otherwise,
            entries will be read from /etc/networks.












                          Copyright 1994 Novell, Inc.               Page 2