| NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | CONFORMING TO | SEE ALSO | COLOPHON | The Linux Programming Interface |
GETNETENT_R(3) Linux Programmer's Manual GETNETENT_R(3)
getnetent_r, getnetbyname_r, getnetbyaddr_r - get network entry (reentrant)
#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);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
getnetent_r(), getnetbyname_r(), getnetbyaddr_r():
_BSD_SOURCE || _SVID_SOURCE
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.
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.
ENOENT (getnetent_r()) No more records in database.
ERANGE buf is too small. Try again with a larger buffer (and increased
buflen).
These functions are GNU extensions. Functions with similar names exist on
some other systems, though typically with different calling signatures.
getnetent(3), networks(5)
This page is part of release 3.32 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/.
GNU 2010-09-10 GETNETENT_R(3)
HTML rendering created 2010-12-03 by Michael Kerrisk, author of The Linux Programming Interface