bind: invalid arguments AF_UNIX

server.c

#include <stdio.h>
#include <sys/socket.h>
#include <string.h> 
#include <myhead.h>
#include <unistd.h>
int main() {
  int unix_socket = socket(AF_UNIX,SOCK_STREAM,0);
  perror("");
  struct sockaddr_un behS;
  memset(&behS,0,sizeof(struct sockaddr_un));
  behS.sun_family= AF_UNIX;
  perror("");
  strlcpy(behS.sun_path,"hello_c",1024);
  perror("");
  printf("%i\n",unix_socket);
  perror("");
  int wth = bind(unix_socket,
    (struct sockaddr *)&behS,
    sizeof(behS));
  perror("");
  return 0;
}

myhead.h

struct sockaddr_un {
  short sun_family;
  char sun_path[1024];
};

output

Success
Success
Success
3
Success
Invalid argument

the code is pretty straightforward why is it not working edit: I updated the code to what I have right now and fixed myhead.c to myhead.h (mistyped)

From the man page for bind a possible error in the call bind(sockfd, const addr, addrlen) is...

EINVAL addrlen is wrong, or addr is not a valid address for this socket's domain.

Your struct sockaddr_un definition is...

struct sockaddr_un {
  short sun_family;
  char sun_path[1024];
};

Whereas the typical definition (again, from the relevant man page) will be something like...

struct sockaddr_un {
  sa_family_t sun_family;               /* AF_UNIX */
  char        sun_path[108];            /* Pathname */
};

That being the case, sizeof(behS) in your own code will almost certainly not return the expected value and you get an EINVAL.

The solution is to simply use the definition of struct sockaddr_un provided in sys/un.h.