if_nametoindex man page


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.

if_nametoindex — map a network interface name to its corresponding index


#include <net/if.h>

unsigned if_nametoindex(const char *ifname);


The if_nametoindex() function shall return the interface index corresponding to name ifname.

Return Value

The corresponding index if ifname is the name of an interface; otherwise, zero.


No errors are defined.

The following sections are informative.

See Also

getsockopt(), if_freenameindex(), if_indextoname(), if_nameindex(), setsockopt()

The Base Definitions volume of POSIX.1‐2008, <net_if.h>


2013 IEEE/The Open Group POSIX Programmer's Manual