getnetent_r(3) - Linux manual page (original) (raw)
getnetentr(3) Library Functions Manual getnetentr(3)
NAME top
getnetent_r, getnetbyname_r, getnetbyaddr_r - get network entry
(reentrant)LIBRARY top
Standard C library (_libc_, _-lc_)SYNOPSIS top
**#include <netdb.h>**
**int getnetent_r(struct netent *restrict** _resultbuf_**,**
**char** _buf_**[restrict .**_size_**], size_t** _size_**,**
**struct netent restrict** _result_**,**
**int *restrict** _herrnop_**);**
**int getnetbyname_r(const char *restrict** _name_**,**
**struct netent *restrict** _resultbuf_**,**
**char** _buf_**[restrict .**_size_**], size_t** _size_**,**
**struct netent restrict** _result_**,**
**int *restrict** _herrnop_**);**
**int getnetbyaddr_r(uint32_t** _net_**, int** _type_**,**
**struct netent *restrict** _resultbuf_**,**
**char** _buf_**[restrict .**_size_**], size_t** _size_**,**
**struct netent restrict** _result_**,**
**int *restrict** _herrnop_**);**Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
**getnetent_r**(), **getnetbyname_r**(), **getnetbyaddr_r**():
Since glibc 2.19:
_DEFAULT_SOURCE
glibc 2.19 and earlier:
_BSD_SOURCE || _SVID_SOURCEDESCRIPTION top
The **getnetent_r**(), **getnetbyname_r**(), and **getnetbyaddr_r**()
functions are the reentrant equivalents of, respectively,
[getnetent(3)](../man3/getnetent.3.html), [getnetbyname(3)](../man3/getnetbyname.3.html), 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 _resultbuf_.
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 _size_. 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 size 1024 bytes should be sufficient for most
applications.)
If the function call successfully obtains a network record, then
_*result_ is set pointing to _resultbuf_; otherwise, _*result_ is set
to NULL.
The buffer pointed to by _herrnop_ is used to return the value that
would be stored in the global variable _herrno_ by the nonreentrant
versions of these functions.RETURN VALUE top
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 top
**ENOENT** (**getnetent_r**()) No more records in database.
**ERANGE** _buf_ is too small. Try again with a larger buffer (and
increased _size_).ATTRIBUTES top
For an explanation of the terms used in this section, see
[attributes(7)](../man7/attributes.7.html).
┌───────────────────────────────┬───────────────┬────────────────┐
│ **Interface** │ **Attribute** │ **Value** │
├───────────────────────────────┼───────────────┼────────────────┤
│ **getnetent_r**(), │ Thread safety │ MT-Safe locale │
│ **getnetbyname_r**(), │ │ │
│ **getnetbyaddr_r**() │ │ │
└───────────────────────────────┴───────────────┴────────────────┘VERSIONS top
Functions with similar names exist on some other systems, though
typically with different calling signatures.STANDARDS top
GNU.SEE ALSO top
[getnetent(3)](../man3/getnetent.3.html), [networks(5)](../man5/networks.5.html)COLOPHON top
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man-pages@man7.orgLinux man-pages 6.10 2024-12-24 getnetentr(3)
Pages that refer to this page:getnetent(3)