原文地址：https://www.cnblogs.com/codetime/p/7066557.html
top: show running processes, memory usage and similar stats | 查看运行的进程
iostat: show I/O per terminal, device and SPU summery statistics |查看io状态
vm_stat: show Mach virtual memory statistics | 查看虚拟机运行内存统计
df and diskutil list: report on drive space used and free | 查看设备存储
fs_usage: show file activity for both disk and network | 查看网络和磁盘的活动
nettop: display updated information about the network (a bit like top for net I/O) | 查看网络信息
w: display who is logged in, what they are doing and system load | 查看 登录用户是谁，做了什么，和系统加载
ifconfig and ipconfig: network interface and IP protocol details | 查看ip