This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface

       None.

       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                                      net_if.h(7POSIX)

       The <net/if.h> header shall define the if_nameindex structure, which shall include at least the following
       members:

           unsigned  if_index  Numeric index of the interface.
           char     *if_name   Null-terminated name of the interface.

       The  <net/if.h> header shall define the following symbolic constant for the length of a buffer containing
       an interface name (including the terminating NULL character):

       IF_NAMESIZE Interface name length.

       The following shall be declared as functions and may also be defined as macros. Function prototypes shall
       be provided.

           void                  if_freenameindex(struct if_nameindex *);
           char                 *if_indextoname(unsigned, char *);
           struct if_nameindex  *if_nameindex(void);
           unsigned              if_nametoindex(const char *);

       Thefollowingsectionsareinformative.

       None.

       net/if.h — sockets local interfaces

       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.

       None.

       The System Interfaces  volume  of  POSIX.1‐2017,  if_freenameindex(),  if_indextoname(),  if_nameindex(),
       if_nametoindex()

       #include <net/if.h>