IF_INDEXTONAME(3P)                                  POSIX Programmer's Manual                                 IF_INDEXTONAME(3P)



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

NAME
       if_indextoname - map a network interface index to its corresponding name

SYNOPSIS
       #include <net/if.h>

       char *if_indextoname(unsigned ifindex, char *ifname);


DESCRIPTION
       The if_indextoname() function shall map an interface index to its corresponding name.

       When this function is called, ifname shall point to a buffer of at least {IF_NAMESIZE} bytes. The function shall place in
       this buffer the name of the interface with index ifindex.

RETURN VALUE
       If ifindex is an interface index, then the function shall return the value supplied in ifname, which points to  a  buffer
       now  containing  the  interface  name.  Otherwise, the function shall return a NULL pointer and set errno to indicate the
       error.

ERRORS
       The if_indextoname() function shall fail if:

       ENXIO  The interface does not exist.


       The following sections are informative.

EXAMPLES
       None.

APPLICATION USAGE
       None.

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       getsockopt(),  if_freenameindex(),  if_nameindex(),  if_nametoindex(),  setsockopt(),  the  Base  Definitions  volume  of
       IEEE Std 1003.1-2001, <net/if.h>

COPYRIGHT
       Portions  of  this  text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for
       Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6,  Copy-
       right (C) 2001-2003 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.open-
       group.org/unix/online.html .



IEEE/The Open Group                                           2003                                            IF_INDEXTONAME(3P)