GETNETENT_R(3)		   Linux Programmer's Manual		GETNETENT_R(3)



NAME
       getnetent_r,  getnetbyname_r, getnetbyaddr_r - get network entry (reen-
       trant)

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);

   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_SOURCE

DESCRIPTION
       The getnetent_r(), getnetbyname_r(), and getnetbyaddr_r() functions are
       the  reentrant  equivalents  of,	 respectively, getnetent(3), getnetby-
       name(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  non-
       reentrant functions.

       Instead	of returning a pointer to a statically allocated netent struc-
       ture 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 ver-
       sions 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 buf is too small.	 Try again with a larger buffer (and increased
	      buflen).

ATTRIBUTES
       For   an	  explanation	of   the  terms	 used  in  this	 section,  see
       attributes(7).

       +------------------+---------------+----------------+
       |Interface	  | Attribute	  | Value	   |
       +------------------+---------------+----------------+
       |getnetent_r(),	  | Thread safety | MT-Safe locale |
       |getnetbyname_r(), |		  |		   |
       |getnetbyaddr_r()  |		  |		   |
       +------------------+---------------+----------------+
CONFORMING TO
       These functions are GNU extensions.  Functions with similar names exist
       on  some	 other systems, though typically with different calling signa-
       tures.

SEE ALSO
       getnetent(3), networks(5)

COLOPHON
       This page is part of release 4.10 of the Linux  man-pages  project.   A
       description  of	the project, information about reporting bugs, and the
       latest	 version    of	  this	  page,	   can	   be	  found	    at
       https://www.kernel.org/doc/man-pages/.



GNU				  2016-03-15			GETNETENT_R(3)