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Command: getnetent | Section: 3 | Source: OpenBSD | File: getnetent.3
GETNETENT(3) FreeBSD Library Functions Manual GETNETENT(3)
NAME
getnetent, getnetbyaddr, getnetbyname, setnetent, endnetent - get network
entry
SYNOPSIS
#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
The getnetbyname() and getnetbyaddr() functions return a pointer to an
object with the following structure:
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 null-terminated list of alternate names for the network.
n_addrtype The type of the network number returned; it is always
AF_INET.
n_net The network number. Network numbers are returned in machine
byte order.
On OpenBSD, these legacy functions perform a lookup in a similar fashion
as gethostbyname(3) and gethostbyaddr(3), respectively. On other
systems, they may use a separate network database file, /etc/networks.
In contrast to gethostbyaddr(3), the net argument is expected in machine
byte order.
The setnetent(), getnetent(), and endnetent() functions are deprecated
and no longer have any effect. They could be used in the past to iterate
over entries in the former file /etc/networks.
RETURN VALUES
The getnetbyaddr() and getnetbyname() functions return NULL if the
requested entry is not found.
The getnetent() function always returns NULL.
FILES
/etc/hosts The local host and network name database.
SEE ALSO
getaddrinfo(3), gethostbyname(3), getnameinfo(3), res_init(3), hosts(5)
STANDARDS
These functions conform to IEEE Std 1003.1-2008 ("POSIX.1").
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
functions overwrite it. Only Internet network numbers are currently
understood. Expecting network numbers to fit in no more than 32 bits is
naive.
FreeBSD 14.1-RELEASE-p8 August 30, 2019 FreeBSD 14.1-RELEASE-p8