IF_NAMEINDEX(3)            POSIX Programmer's Manual           IF_NAMEINDEX(3)



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

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.1-2017, <net_if.h>

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1-2017, Standard for Information Technology --
       Portable Operating System Interface (POSIX), The Open Group Base
       Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by the
       Institute of Electrical and Electronics Engineers, Inc and The Open
       Group.  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.opengroup.org/unix/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 .



IEEE/The Open Group                  2017                      IF_NAMEINDEX(3)
