getnetent(3N) NETWORK FUNCTIONS getnetent(3N)
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 contain-
ing the broken-out fields of a line in the network data
base, /etc/networks.
struct netent {
char *nname; /* official name of net */
char **naliases; /* alias list */
int naddrtype; /* net number type */
long nnet; /* 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 AFINET.
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 getnetent() (either directly,
or indirectly through one of the other "getnet" calls).
endnetent() closes the file. getnetbyname() and getnet-
byaddr() 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.
Last change: 1
getnetent(3N) NETWORK FUNCTIONS getnetent(3N)
FILES
/etc/networks
SEE ALSO
networks(4)
DIAGNOSTICS
A NULL pointer is 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.
Last change: 2