#include <stddef.h>
#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#include <sys/socket.h>
#include <sys/un.h>

int 
make_named_socket (const char *filename)
@{
  struct sockaddr_un name;
  int sock;
  size_t size;

  /* @r{Create the socket.} */
  
  sock = socket (PF_UNIX, SOCK_DGRAM, 0);
  if (sock < 0)
    @{
      perror ("socket");
      exit (EXIT_FAILURE);
    @}

  /* @r{Bind a name to the socket.} */

  name.sun_family = AF_FILE;
  strcpy (name.sun_path, filename);

  /* @r{The size of the address is
     the offset of the start of the filename,
     plus its length,
     plus one for the terminating null byte.} */
  size = (offsetof (struct sockaddr_un, sun_path)
          + strlen (name.sun_path) + 1);

  if (bind (sock, (struct sockaddr *) &name, size) < 0)
    @{
      perror ("bind");
      exit (EXIT_FAILURE);
    @}

  return sock;
@}
