GETNETENT(3) | Library Functions Manual | GETNETENT(3) |
getnetent
,
getnetbyaddr
, getnetbyname
,
setnetent
, endnetent
— get network entry
Standard C Library (libc, -lc)
#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);
The
getnetent
(),
getnetbyname
(), and
getnetbyaddr
() functions each return a pointer to an
object with the following structure describing an internet 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:
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.
Null pointer (0) returned on EOF
or
error.
RFC 1101
The getnetent
(),
getnetbyaddr
(),
getnetbyname
(), setnetent
(),
and endnetent
() functions appeared in
4.2BSD.
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 currently understood. Expecting network numbers to fit in no more than 32 bits is probably naive.
June 4, 1993 | macOS 14.6 |