bzero

#define bcopy(b1,b2,len) memmove(b2, b1, (size_t)(len))
#define bzero(b,len) memset(b, 0, (size_t)(len))
#define bcmp(b1,b2,len) memcmp(b1, b2, (size_t)(len))

bzero is not an ANSI C function. It is derived from early Berkeley networking code. Nevertheless, we use it throughout the text, instead of the ANSI C memset function, because bzero is easier to remember (with only two arguments) than memset (with three arguments). Almost every vendor that supports the sockets API also provides bzero, and if not, we provide a macro definition of it in our unp.h header.