NAME    [Toc]    [Back]

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

SYNOPSIS    [Toc]    [Back]

     #include <netdb.h>

     struct netent *
     getnetent(void);

     struct netent *
     getnetbyname(const char *name);

     struct netent *
     getnetbyaddr(in_addr_t net, int type);

     void
     setnetent(int stayopen);

     void
     endnetent(void);

DESCRIPTION    [Toc]    [Back]

     The  getnetent(),  getnetbyname(),  and getnetbyaddr() functions each return
     a pointer to an object with the following structure containing the broken-out
   fields   of   a  line  in  the  network  database,
/etc/networks.

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

     The  getnetent()  function  reads the next line of the file,
opening the
     file if necessary.

     The setnetent() function opens and rewinds the file.  If the
stayopen
     flag  is non-zero, the net database will not be closed after
each call to
     getnetbyname() or getnetbyaddr().

     The endnetent() function closes the file.

     The getnetbyname() and getnetbyaddr() functions  search  the
domain name
     server  if  the  system  is  configured  to use one.  If the
search fails, or
     no name server is configured, they 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    [Toc]    [Back]

     /etc/networks

DIAGNOSTICS    [Toc]    [Back]

     Null pointer (0) returned on EOF or error.

SEE ALSO    [Toc]    [Back]

     resolver(3), networks(5)

HISTORY    [Toc]    [Back]

     The     getnetent(),     getnetbyaddr(),     getnetbyname(),
setnetent(), and
     endnetent() functions appeared in 4.2BSD.

BUGS    [Toc]    [Back]

     The data space used by these functions is static; if  future
use requires
     the data, it should be copied before any subsequent calls to
these functions
 overwrite it.  Only Internet network numbers are  currently understood.
   Expecting network numbers to fit in no more than 32
bits is
     naive.

OpenBSD     3.6                          March      13,      1997