date命令详解

时间相关命令 - date

查看时间信息

[root@yunxuanedu ~]# date
Tue Aug 17 11:06:55 CST 2021

特殊格式显示时间

[root@yunxuanedu ~]# date +%F-%T
2021-08-17-11:09:39

[root@yunxuanedu ~]# date "+%F %T"
2021-08-17 11:10:26

[root@yunxuanedu ~]# date "+%y-%m-%d %H:%M:%S"
21-08-17 11:12:00

修改系统时间

date -s "2020-08-08"
date -s "2020-09-01 14:00"

扩展-备份文件

[root@yunxuanedu data]# cp -a admin admin_`date "+%F_%T"`
[root@yunxuanedu data]# cp -a admin admin_$(date "+%F_%T")
[root@yunxuanedu data]# ll
total 12
drwxr-xr-x 2 root root 4096 Aug 16 23:29 admin
drwxr-xr-x 2 root root 4096 Aug 16 23:29 admin_2021-08-17_11:21:21
drwxr-xr-x 2 root root 4096 Aug 16 23:29 admin_2021-08-17_11:21:42

# 备份前一天的文件
cp -a /data/web.log /data/web.log.$(date +%F -d "-1day")

扩展 - 显示未来时间和历史时间

# 未来时间
[root@yunxuanedu data]# date
Tue Aug 17 12:10:34 CST 2021
[root@yunxuanedu data]# date +%F -d "+1day"
2021-08-18
[root@yunxuanedu data]# date +%F -d "+2day"
2021-08-19
[root@yunxuanedu data]# date +%F -d "1day"
2021-08-18
[root@yunxuanedu data]# date +%F -d "2day"
2021-08-19

# 历史时间
[root@yunxuanedu data]# date
Tue Aug 17 12:10:34 CST 2021
[root@yunxuanedu data]# date +%F -d "-1day"
2021-08-16
[root@yunxuanedu data]# date +%F -d "-2day"
2021-08-15
[root@yunxuanedu data]# date +%F -d "1 day ago"
2021-08-16

服务器时间同步

yum install ntpdate -y
ntpdate ntp1.aliyun.com