A implement of linux ls command

linux ls命令的一种实现方式
Revert "A implement of linux ls command"

This reverts commit 9c833ad0694bb3ad3c833895b949937587bb95d0.
Revert "Revert "A implement of linux ls command""

This reverts commit 4c3cde551c6aa8c60845b7c5b5698701d97d80d1.
Revert "Revert "Revert "A implement of linux ls command"""

This reverts commit e9657919a813094437d0eedd2aa89f66a18cb3da.
a program to copy data on stdio

在标准io设备上复制数据的程序