Name
getnetent_r, getnetbyname_r, getnetbyaddr_r — get network entry (reentrant)
Synopsis
#include <netdb.h>
int
getnetent_r( |
struct netent *result_buf, |
| char *buf, | |
| size_t buflen, | |
| struct netent **result, | |
int *h_errnop); |
int
getnetbyname_r( |
const char *name, |
| struct netent *result_buf, | |
| char *buf, | |
| size_t buflen, | |
| struct netent **result, | |
int *h_errnop); |
int
getnetbyaddr_r( |
uint32_t net, |
| int type, | |
| struct netent *result_buf, | |
| char *buf, | |
| size_t buflen, | |
| struct netent **result, | |
int *h_errnop); |
![[Note]](../stylesheet/note.png) |
Note | ||
|---|---|---|---|
|
DESCRIPTION
The getnetent_r(),
getnetbyname_r(), and
getnetbyaddr_r() functions are
the reentrant equivalents of, respectively, getnetent(3), getnetbyname(3), and
getnetbynumber(3). They differ
in the way that the netent
structure is returned, and in the function calling signature
and return value. This manual page describes just the
differences from the nonreentrant functions.
Instead of returning a pointer to a statically allocated
netent structure as the
function result, these functions copy the structure into the
location pointed to by result_buf.
The buf array is
used to store the string fields pointed to by the returned
netent structure. (The
nonreentrant functions allocate these strings in static
storage.) The size of this array is specified in buflen. If buf is too small, the call
fails with the error ERANGE,
and the caller must try again with a larger buffer. (A buffer
of length 1024 bytes should be sufficient for most
applications.)
If the function call successfully obtains a network
record, then *result
is set pointing to result_buf; otherwise,
*result is set to
NULL.
The buffer pointed to by h_errnop is used to return the
value that would be stored in the global variable
h_errno by the nonreentrant
versions of these functions.
RETURN VALUE
On success, these functions return 0. On error, they return one of the positive error numbers listed in ERRORS.
On error, record not found (getnetbyname_r(), getnetbyaddr_r()), or end of input
(getnetent_r()) result is set to NULL.
ERRORS
- ENOENT
-
(
getnetent_r()) No more records in database. - ERANGE
-
bufis too small. Try again with a larger buffer (and increasedbuflen).
CONFORMING TO
These functions are GNU extensions. Functions with similar names exist on some other systems, though typically with different calling signatures.
COLOPHON
This page is part of release 3.52 of the Linux man-pages project. A
description of the project, and information about reporting
bugs, can be found at
http://www.kernel.org/doc/man−pages/.
|
Copyright 2008, Linux Foundation, written by Michael Kerrisk <mtk.manpagesgmail.com> %%%LICENSE_START(VERBATIM) Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Since the Linux kernel and libraries are constantly changing, this manual page may be incorrect or out-of-date. The author(s) assume no responsibility for errors or omissions, or for damages resulting from the use of the information contained herein. The author(s) may not have taken the same level of care in the production of this manual, which is licensed free of charge, as they might when working professionally. Formatted or processed versions of this manual, if unaccompanied by the source, must acknowledge the copyright and authors of this work. %%%LICENSE_END |