getnetbyaddr, getnetbyaddr_r - Get a network entry by
address
#include <netdb.h>
struct netent *getnetbyaddr(
in_addr_t num,
int type );
[Tru64 UNIX] The following obsolete function is supported
in order to maintain backward compatibility with previous
versions of the operating system. You should not use it
in new designs. int getnetbyaddr_r(
int num,
int type,
struct netent *net,
struct netent_data *net_data );
[Tru64 UNIX] The following definition of the getnetbyaddr()
function does not conform to current standards
and is supported only for backward compatibility: struct
netent *getnetbyaddr(
int num,
int type );
Standard C Library (libc)
Interfaces documented on this reference page conform to
industry standards as follows:
getnetbyaddr(): XNS4.0, XNS5.0
Refer to the standards(5) reference page for more information
about industry standards and associated tags.
Specifies the number of the network in host-byte order.
[Tru64 UNIX] For getnetbyaddr_r(), this points to the
netent structure. The netdb.h header file defines the
netent structure. Specifies the Internet domain address
format. The value AF_INET must be used. [Tru64
UNIX] Specifies the number of the network in host-byte
order. [Tru64 UNIX] Is data for the networks database.
The netdb.h header file defines the netent_data structure.
The getnetbyaddr() function returns a pointer to a structure
of type netent. Its members specify data obtained
from either the local /etc/networks file or the NIS distributed
networks file. To determine which file or files
to search, and in which order, the system uses the
switches in the /etc/svc.conf file. The netdb.h header
file defines the netent structure.
The getnetbyaddr() function searches the network database
file sequentially until a match with the num and type
parameters occurs. The num parameter must specify the network
number in host-byte order. The type parameter must be
the constant AF_INET. When EOF (End-of-File) is reached
without a match, an error value is returned by this parameter.
Use the endnetent() function to close the networks file.
The getnetbyaddr() function and its backward compatible
version return a pointer to thread-specific data. Subsequent
calls to these or related functions from the same
thread overwrite this data.
[Tru64 UNIX] The getnetbyaddr_r() function is an obsolete
reentrant version of the getnetbyaddr() function. It is
supported in order to maintain backward compatibility with
previous versions of the operating system and should not
be used in new designs. Note that you must set the net_fp
field of the netent_data structure to NULL before its
first access by either the setnetent_r() or getnetbyaddr_r()
function.
You must initialize the _net_stayopen option of the
netent_data structure if you are not using the setnetent()
function.
Upon successful completion, the getnetbyaddr() function
and its backward compatible version return a pointer to a
netent structure. If it fails or reaches the end of the
/etc/networks name file, it returns a null pointer.
[Tru64 UNIX] Upon successful completion, the getnetbyaddr_r()
function stores the netent structure in the
location pointed to by net, and returns a value of 0
(zero). Upon failure, it returns a value of -1.
Current industry standards do not define error values for
the getnetbyaddr() function.
[Tru64 UNIX] If any of the following conditions occurs,
the getnetbyaddr_r() function sets errno to the corresponding
value:
The net or net_data parameter is invalid. The search
failed.
The Internet network name database file. Each record in
the file occupies a single line and has three fields: the
official network name, the network number, and alias.
Functions: endnetent(3), getnetent(3), getnetbyname(3),
setnetent(3).
Files: networks(4), svc.conf(4).
Networks: nis_intro(7).
Standards: standards(5).
Network Programmer's Guide
getnetbyaddr(3)
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