The <net/if.h> header shall define the if_nameindex structure that includes at least the following members:
unsigned if_index Numeric index of the interface. char *if_name Null-terminated name of the interface.
The <net/if.h> header shall define the following macro for the length of a buffer containing an interface name (including the terminating NULL character):
Interface name length.
The following shall be declared as functions and may also be defined as macros. Function prototypes shall be provided.
unsigned if_nametoindex(const char *); char *if_indextoname(unsigned, char *); struct if_nameindex *if_nameindex(void); void if_freenameindex(struct if_nameindex *);
The following sections are informative.
COPYRIGHTPortions 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 http://www.opengroup.org/unix/online.html .