| socket_getifidx(3) | Library Functions Manual | socket_getifidx(3) |
socket_getifidx - get interface number
#include <socket.h>
int socket_getifidx(const char* ifname);
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.