if_nametoindex, if_indextoname - mappings between network interface names and indexes
#include <net/if.h>
unsigned int if_nametoindex(const char *ifname);
char *if_indextoname(unsigned int ifindex, char *ifname);
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.
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.
if_nametoindex() may fail and set errno
if:
No interface found with given name.
if_indextoname() may fail and set errno
if:
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).
For an explanation of the terms used in this section, see attributes(7).
Interface | Attribute | Value |
if_nametoindex(), if_indextoname() | Thread safety | MT-Safe |
POSIX.1-2001, POSIX.1-2008, RFC 3493.
This function first appeared in BSDi.
getifaddrs(3), if_nameindex(3), ifconfig(8)
This page is part of release 5.10 of the Linux man-pages
project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.