NAME    [Toc]    [Back]

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

LIBRARY    [Toc]    [Back]

     Standard C Library (libc, -lc)

SYNOPSIS    [Toc]    [Back]

     #include <netdb.h>

     struct netent *
     getnetent(void);

     struct netent *
     getnetbyname(const char *name);

     struct netent *
     getnetbyaddr(unsigned long 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 describing an internet
 network.  This structure contains either the information obtained
     from the nameserver, named(8), broken-out fields of a line in the network
     data base /etc/networks, or entries supplied by the yp(8) system.	The
     order of the lookups is controlled by the `networks' entry in
     nsswitch.conf(5).

	   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 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 data base will not be closed after each call to
     getnetbyname() or getnetbyaddr().

     The endnetent() function closes the file.

     The getnetbyname() function 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.  The type argument must be
     AF_INET.  Network numbers are supplied in host order.

FILES    [Toc]    [Back]

     /etc/networks
     /etc/nsswitch.conf
     /etc/resolv.conf

DIAGNOSTICS    [Toc]    [Back]

     Null pointer (0) returned on EOF or error.

SEE ALSO    [Toc]    [Back]

     networks(5)

     RFC 1101

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 probably
 naive.


FreeBSD 5.2.1			 June 4, 1993			 FreeBSD 5.2.1