getnetent(3) BSD Library Functions Manual 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(uint32_t 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 information obtained from
opendirectoryd(8), including records in /etc/networks.
struct netent {
char *n_name; /* official name of net */
char **n_aliases; /* alias list */
int n_addrtype; /* net number type */
uint32_t 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
/etc/networks
/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 thread-specific; if future use
requires the data, it should be copied before any subsequent calls to
these functions overwrite it. Only Internet network numbers are cur-
rently understood. Expecting network numbers to fit in no more than 32
bits is probably naive.
BSD June 4, 1993 BSD
Mac OS X 10.8 - Generated Sat Aug 25 18:18:31 CDT 2012