IF_INDEXTONAME(3P)

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 .