XX_DIR_LEN
char longname[XX_DIR_LEN + 1];
memset(longname, 'x', XX_DIR_LEN - 1);
longname[XX_DIR_LEN - 1] = '/';
longname[XX_DIR_LEN] = '\0';
count = (PATH_MAX - 3 - strlen(cwd)) / XX_DIR_LEN;
len = (PATH_MAX - 3 - strlen(cwd)) - (count * XX_DIR_LEN);