相关链接
运行示例（加下划线的为输入）：
DIR: /etc
DIR: /etc/sudoers.d
reg: /etc/sudoers.d/README
...............
reglar files = 1593, 59.89 %
directories = 306, 11.50 %
block special = 0, 0.00 %
char special = 0, 0.00 %
FIFOs = 0, 0.00 %
symbolic links = 761, 28.61 %
sockets = 0, 0.00 %