xref: /original-bsd/lib/libc/net/getnetent.3 (revision 21df4bd6)
Copyright (c) 1983 The Regents of the University of California.
All rights reserved.

%sccs.include.redist.man%

@(#)getnetent.3 6.5 (Berkeley) 06/23/90

GETNETENT 3 ""
C 5
NAME
getnetent, getnetbyaddr, getnetbyname, setnetent, endnetent - get network entry
SYNOPSIS
#include <netdb.h>

struct netent *getnetent()

struct netent *getnetbyname(name) char *name;

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

setnetent(stayopen) int stayopen;

endnetent()

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 .

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:

\w'n_addrtype'u+2n n_name The official name of the network.

\w'n_addrtype'u+2n n_aliases A zero terminated list of alternate names for the network.

\w'n_addrtype'u+2n n_addrtype The type of the network number returned; currently only AF_INET.

\w'n_addrtype'u+2n 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.

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 getnetbyname or getnetbyaddr .

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
"SEE ALSO"
networks(5)
DIAGNOSTICS
Null pointer (0) returned on EOF or error.
BUGS
All information is contained in a static area so it must be copied if it is to be saved. Only Internet network numbers are currently understood. Expecting network numbers to fit in no more than 32 bits is probably naive.