计划任务at的使用

计划任务
at #只能执行一次
语法
at 时间
服务atd 必须开启
[root@ZQ ~]# systemctl status atd.service #查看atd服务状态
● atd.service - Job spooling tools
   Loaded: loaded (/usr/lib/systemd/system/atd.service; enabled; vendor preset: enabled)
   Active: active (running) since Mon 2017-06-05 13:00:27 CST; 7min ago
 Main PID: 1166 (atd)
   CGroup: /system.slice/atd.service
           └─1166 /usr/sbin/atd -f

Jun 05 13:00:27 ZQ systemd[1]: Started Job spooling tools.
Jun 05 13:00:27 ZQ systemd[1]: Starting Job spooling tools...
[root@ZQ ~]# date
Mon Jun  5 13:08:34 CST 2017
[root@ZQ ~]# at 13:11
at> echo `data` > /tmp/date.ext
at> <EOT>
job 1 at Mon Jun  5 13:11:00 2017
[root@ZQ ~]# date
Mon Jun  5 13:10:36 CST 2017
[root@ZQ ~]# ls /tmp/
CVU_12.1.0.2.0_oracle                                                   systemd-private-7b32fa1bbfa14092932ffe412d0d528d-rtkit-daemon.service-ivM7Ax
date.ext                                                                systemd-private-7b32fa1bbfa14092932ffe412d0d528d-vmtoolsd.service-HhtqSh
hogsuspend                                                              systemd-private-f05972506cf74169b213ca382fbf0af5-colord.service-coCDy6
linuxamd64_12102_database_2of2.zip                                      systemd-private-f05972506cf74169b213ca382fbf0af5-cups.service-MIl1vE
ssh-uaeT8B8iT7oQ                                                        systemd-private-f05972506cf74169b213ca382fbf0af5-rtkit-daemon.service-3DbcmZ
systemd-private-7b32fa1bbfa14092932ffe412d0d528d-colord.service-zVDfng  systemd-private-f05972506cf74169b213ca382fbf0af5-vmtoolsd.service-agCWo2
systemd-private-7b32fa1bbfa14092932ffe412d0d528d-cups.service-CkpC5p    tracker-extract-files.1000
[root@ZQ ~]# at 1:30 2017-6-5
at: refusing to create job destined in the past
[root@ZQ ~]# at 13:30 2017-6-5
at> echo aaa > /tmp/a.txt
at> <EOT>
job 2 at Mon Jun  5 13:30:00 2017
[root@ZQ ~]# at now+10min
at> echo bbb > /tmp/b.txt
at> <EOT>
job 3 at Mon Jun  5 13:30:00 2017
[root@ZQ ~]# at -l     #查询计划任务
2    Mon Jun  5 13:30:00 2017 a root
3    Mon Jun  5 13:30:00 2017 a root
[root@ZQ ~]# ll /var/spool/at/*    
-rwx------  1 root   root   2951 Jun  5 13:19 /var/spool/at/a00002017c9d8a
-rwx------  1 root   root   2951 Jun  5 13:20 /var/spool/at/a00003017c9d8a

/var/spool/at/spool:
total 0


计划任务创建成功后都会在一下目录创建脚本文件
[root@ZQ ~]# vim /var/spool/at/a00002017c9d8a



at删除

[root@ZQ ~]# at -l
2    Mon Jun  5 13:30:00 2017 a root
3    Mon Jun  5 13:30:00 2017 a root
[root@ZQ ~]# atrm 3
[root@ZQ ~]# at -l
2    Mon Jun  5 13:30:00 2017 a root
[root@ZQ ~]# ll /var/spool/at/*
-rwx------  1 root   root   2951 Jun  5 13:19 /var/spool/at/a00002017c9d8a

/var/spool/at/spool:
total 0