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



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);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       getnetent_r(), getnetbyname_r(), getnetbyaddr_r(): _BSD_SOURCE || _SVID_SOURCE

DESCRIPTION
       The  getnetent_r(), getnetbyname_r(), and getnetbyaddr_r() functions are the reentrant equivalents of, respectively, get-
       netent(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 func-
       tions 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, a positive error number is returned.

       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).

CONFORMING TO
       These functions are GNU extensions.  Functions with similar names exist on some other systems, though typically with dif-
       ferent calling signatures.

SEE ALSO
       getnetent(3), networks(5)

COLOPHON
       This  page  is  part of release 3.25 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                                                        2009-02-21                                             GETNETENT_R(3)