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_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 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 .