#include <sys/socket.h>
#include <sys/un.h>
#include <fcntl.h>
#include <stdarg.h>
#include <stdio.h>
#include <unistd.h>

#include "unix_lock.h"

int UnixSocketLock(const char *format,...)
{
	int lockfd = socket(AF_UNIX, SOCK_STREAM, 0);
	if(lockfd >= 0)
	{
		va_list ap;
		struct sockaddr_un addr;
		int len;

		addr.sun_family = AF_UNIX;

		va_start(ap, format);
		vsnprintf(addr.sun_path+1, sizeof(addr.sun_path)-1, format, ap);
		va_end(ap);

		addr.sun_path[0] = '@';
		len = SUN_LEN(&addr);
		addr.sun_path[0] = '\0';
		if(bind(lockfd, (struct sockaddr *)&addr, len) == 0)
			fcntl(lockfd, F_SETFD, FD_CLOEXEC);
		else {
			close(lockfd);
			lockfd = -1;
		}
	}
	return lockfd;
}