debian man page for socket_getifidx

socket_getifidx(3)					     Library Functions Manual						socket_getifidx(3)

NAME
       socket_getifidx - get interface number

SYNTAX
       #include <socket.h>

       int socket_getifidx(const char* ifname);

DESCRIPTION
       socket_getifidx returns the interface number for a symbolic network interface name (like "eth0" on Linux, for example).

       The interface number can be used as scope_id for IPv6 communications on link-local addresses.

       If something goes wrong, socket_getifidx returns -1, setting errno appropriately.

SEE ALSO
       socket_getifname(3), socket_connect6(3)

																socket_getifidx(3)