Programming

We are calling the bind system call as below

Code:

bind(sfd, (struct sockaddr *) &addr, sizeof(struct sockaddr_un));

Why there is difference in third parameter getting the sizeof as "struct sockaddr_un", wherein the 2nd parametere we are passing it as "(struct sockaddr *)"?

Regards,
Sajjan

Code:

#include <sys/types.h>        
#include <sys/socket.h>

int bind(int sockfd, const struct sockaddr *addr,
         socklen_t addrlen);

This is the man page definition of the bind system call. I believe when BSD first came out with sockets different platforms had different sized versions of struct sockaddr. To my knowledge this is still true. Anybody else know positively?

BSD sockets is usually considered the origin of modern socket implementations. Even Windows referred to winsock as "based on BSD sockets" way back when. Circa Windows 95.

bind() supports many different kinds of sockets. They will not all have the same structure, and are not guaranteed to be the same size.