查看centos版本：cat /etc/redhat-release
设置时区：timedatectl set-timezone Asia/Shanghai
启动时间：date -d "$(awk -F. '{print $1}' /proc/uptime) second ago" +"system boot:%Y-%m-%d %H:%M:%S"
运行时间：cat /proc/uptime | awk -F. '{run_days = $1 / 86400; run_hour = ($1 % 86400) / 3600; run_minute = ($1 % 3600) / 60; run_second = $1 % 60; printf("系统已运行：%d天%d时%d分%d秒\n", run_days, run_hour, run_minute, run_second)}'
切换至上次目录：cd -
清空至行首：Ctrl+U
清空至行尾：Ctrl+K
移动至行首：Ctrl+A
移动至行尾：Ctrl+E