一本shell的经典书籍，由资深的unix，linux系统管理员描述他们多年的心得-A shell of classic books, from senior unix ，linux system administrator to describe their many years of experience

linux下很实用的shell，有对系统的管理和用户的管理，以及一些实用。-Under linux very practical shell, there is the system management and user management, as well as some practical.