#include "apue.h"
#include <sys/socket.h>
#include <sys/un.h>
#include <errno.h>

#define QLEN	10

/*
 * Create a server endpoint of a connection.
 * Returns fd if all OK, <0 on error.
 */
int
serv_listen(const char *name)
{
	int					fd, len, err, rval;
	struct sockaddr_un	un;

	/* create a UNIX domain stream socket */
	if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) < 0)
		return(-1);

	unlink(name);	/* in case it already exists */

	/* fill in socket address structure */
	memset(&un, 0, sizeof(un));
	un.sun_family = AF_UNIX;
	strcpy(un.sun_path, name);
	len = offsetof(struct sockaddr_un, sun_path) + strlen(name);

	/* bind the name to the descriptor */
	if (bind(fd, (struct sockaddr *)&un, len) < 0) {
		rval = -2;
		goto errout;
	}

	if (listen(fd, QLEN) < 0) {	/* tell kernel we're a server */
		rval = -3;
		goto errout;
	}
	return(fd);

errout:
	err = errno;
	close(fd);
	errno = err;
	return(rval);
}