Name

if_nametoindex, if_indextoname — mappings between network interface names and indexes

Synopsis

#include <net/if.h>
unsigned int if_nametoindex( const char *ifname);
 
char *if_indextoname( unsigned int ifindex,
  char *ifname);
 

DESCRIPTION

The if_nametoindex() function returns the index of the network interface corresponding to the name ifname.

The if_indextoname() function returns the name of the network interface corresponding to the interface index ifindex. The name is placed in the buffer pointed to by ifname. The buffer must allow for the storage of at least IF_NAMESIZE bytes.

RETURN VALUE

On success, if_nametoindex() returns the index number of the network interface; on error, 0 is returned and errno is set appropriately.

On success, if_indextoname() returns ifname; on error, NULL is returned and errno is set appropriately.

ERRORS

if_indextoname() may fail and set errno if:

ENXIO

No interface found for the index.

if_nametoindex() and if_indextoname() may also fail for any of the errors specified for socket(2) or ioctl(2).

CONFORMING TO

RFC 3493, POSIX.1-2001.

This function first appeared in BSDi.

SEE ALSO

getifaddrs(3), if_nameindex(3), ifconfig(8)

COLOPHON

This page is part of release 3.52 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man−pages/.


  Copyright (c) 2012 YOSHIFUJI Hideaki <yoshfujilinux-ipv6.org>

%%%LICENSE_START(VERBATIM)
Permission is granted to make and distribute verbatim copies of this
manual provided the copyright notice and this permission notice are
preserved on all copies.

Permission is granted to copy and distribute modified versions of
this manual under the conditions for verbatim copying, provided that
the entire resulting derived work is distributed under the terms of
a permission notice identical to this one.

Since the Linux kernel and libraries are constantly changing, this
manual page may be incorrect or out-of-date.  The author(s) assume
no responsibility for errors or omissions, or for damages resulting
from the use of the information contained herein.  The author(s) may
not have taken the same level of care in the production of this
manual, which is licensed free of charge, as they might when working
professionally.

Formatted or processed versions of this manual, if unaccompanied by
the source, must acknowledge the copyright and authors of this work.
%%%LICENSE_END