The if_nameindex() function shall return an array of if_nameindex
structures, one structure per interface. The end
of the array is indicated by a structure with an if_index field
of zero and an if_name field of NULL.
Applications should call if_freenameindex() to release the memory
may be dynamically allocated by this function, after they have finished
An array of structures identifying local interfaces. A NULL pointer
is returned upon an error, with errno set to indicate
The if_nameindex() function may fail if:
Insufficient resources are available to complete the function.
The following sections are informative.
getsockopt() , if_freenameindex() , if_indextoname()
, if_nametoindex() , setsockopt() , the Base Definitions
volume of IEEE Std 1003.1-2001, <net/if.h>
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 6, Copyright (C) 2001-2003 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