PROLOG

       This  manual  page  is part of the POSIX Programmer's Manual.  The Linux implementation of
       this interface may differ (consult the corresponding Linux  manual  page  for  details  of
       Linux behavior), or the interface may not be implemented on Linux.

NAME

       if_nameindex — return all network interface names and indexes

SYNOPSIS

       #include <net/if.h>

       struct if_nameindex *if_nameindex(void);

DESCRIPTION

       The  if_nameindex()  function  shall  return  an  array  of  if_nameindex  structures, one
       structure per interface. The end of the array is indicated by a structure with an if_index
       field of zero and an if_name field of NULL.

       Applications  should call if_freenameindex() to release the memory that may be dynamically
       allocated by this function, after they have finished using it.

RETURN VALUE

       An array of structures identifying local interfaces. A null pointer is  returned  upon  an
       error, with errno set to indicate the error.

ERRORS

       The if_nameindex() function may fail if:

       ENOBUFS
              Insufficient resources are available to complete the function.

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

       None.

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       getsockopt(), if_freenameindex(), if_indextoname(), if_nametoindex(), setsockopt()

       The Base Definitions volume of POSIX.1‐2008, <net_if.h>

COPYRIGHT

       Portions  of  this  text  are  reprinted  and  reproduced in electronic form from IEEE Std
       1003.1, 2013 Edition, Standard for Information Technology  --  Portable  Operating  System
       Interface  (POSIX),  The Open Group Base Specifications Issue 7, Copyright (C) 2013 by the
       Institute of Electrical and Electronics Engineers, Inc  and  The  Open  Group.   (This  is
       POSIX.1-2008  with  the  2013  Technical  Corrigendum  1  applied.)  In  the  event of any
       discrepancy between this version and the original IEEE and The Open  Group  Standard,  the
       original  IEEE  and The Open Group Standard is the referee document. The original Standard
       can be obtained online at http://www.unix.org/online.html .

       Any typographical or formatting errors that appear in this page are most  likely  to  have
       been  introduced  during  the conversion of the source files to man page format. To report
       such errors, see https://www.kernel.org/doc/man-pages/reporting_bugs.html .