int
ptym_open(char * pts_name)
{
	char *ptr1, *ptr2;
	int fdm;
	
	strcpy(pts_name, "/dev/ptyXY");
	/* array index: 012345689 (for references in following code) */
	for (ptr1 = "pqrstuvwxyzPQRST"; *ptr1 != 0; ptr1++) {
		pts_name[8] = *ptr1;
		for (ptr2 = "0123456789abcdef"; *ptr2 != 0; ptr2++) {
			pts_name[9] = *ptr2;
			/* try to open master */
			fdm = open(pts_name, O_RDWR);
			if (fdm < 0) {
				if (errno == ENOENT) {/* different from EIO */
					return -1;  /* out of pty devices */
				} else {
					continue;  /* try next pty device */
				}
			}
			pts_name[5] = 't'; /* chage "pty" to "tty" */
			return fdm;   /* got it, return fd of master */
		}
	}
	return -1; /* out of pty devices */
}