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getnetent(3)

NAME

     getnetent, getnetbyaddr, getnetbyname, setnetent, endnetent -- get net-
     work entry

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #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

     The getnetent(), getnetbyname(), and getnetbyaddr() functions each return
     a pointer to an object with the following structure describing an inter-
     net 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
     AF_INET.  Network numbers are supplied in host order.

FILES

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

DIAGNOSTICS

     Null pointer (0) returned on EOF or error.

SEE ALSO

     networks(5)

     RFC 1101

HISTORY

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

BUGS

     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 func-
     tions overwrite it.  Only Internet network numbers are currently under-
     stood.  Expecting network numbers to fit in no more than 32 bits is prob-
     ably naive.

FreeBSD 5.4			 June 4, 1993			   FreeBSD 5.4

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