Implicit declaration of function ' Ether_ntoa ' is invalid in C99

error code:strcpy (temp, ( char * ) Ether_ntoa (LLADDR (SDL) )); Workaround: Import these three header files, #include<sys/types.h>#include<sys/socket.h>#include<net/ethernet.h>then the above line of code will have a warning:"incompatible pointer types passing ' caddr_t ' (aka ' char * ') to parameter of type ' const struct ETHER_ADDR * '"; can be added in front of the LLADDR (Const structETHER_ADDR *This is also true:
strcpy (temp, ( char *) ETHER_NTOA ((const struct ETHER_ADDR *)lladdr (SDL));
so there's no warning. 

Implicit declaration of function ' Ether_ntoa ' is invalid in C99