计划任务cron
2013年3月9日 星期六
cron
1、查询是否安装软件包
[root@desktop4 ~]# rpm -e cronie-1.4.4-7.el6.x86_64 --nodeps
[root@desktop4 ~]# yum -y -d 0 install cronie-1.4.4-7.el6.x86_64
Warning: RPMDB altered outside of yum.
** Found 3 pre-existing rpmdb problem(s), 'yum check' output follows:
cronie-anacron-1.4.4-7.el6.x86_64 has missing requires of cronie = ('0', '1.4.4', '7.el6')
crontabs-1.10-33.el6.noarch has missing requires of /etc/cron.d
sysstat-9.0.4-18.el6.x86_64 has missing requires of /etc/cron.d
[root@desktop4 ~]#
2、查询服务是否开启
[root@desktop4 ~]# service crond status
crond is stopped
[root@desktop4 ~]# service crond start
Starting crond: [ OK ]
[root@desktop4 ~]# service crond status
crond (pid 8228) is running...
[root@desktop4 ~]#
3、设置服务永久生效
[root@desktop4 ~]# chkconfig --list cron
error reading information on service cron: No such file or directory
[root@desktop4 ~]# chkconfig --list crond
crond 0:off 1:off 2:on 3:on 4:on 5:on 6:off
[root@desktop4 ~]# chkconfig --level 35 crond off
[root@desktop4 ~]# chkconfig --list crond
crond 0:off 1:off 2:on 3:off 4:on 5:off 6:off
[root@desktop4 ~]# chkconfig --level 35 crond on
[root@desktop4 ~]# chkconfig --list crond
crond 0:off 1:off 2:on 3:on 4:on 5:on 6:off
4、查看配置文件
[root@desktop4 ~]# cat /etc/crontab
SHELL=/bin/bash
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MAILTO=root
HOME=/
# For details see man 4 crontabs
# Example of job definition:
# .---------------- minute (0 - 59)
# | .------------- hour (0 - 23)
# | | .---------- day of month (1 - 31)
# | | | .------- month (1 - 12) OR jan,feb,mar,apr ...
# | | | | .---- day of week (0 - 6) (Sunday=0 or 7) OR sun,mon,tue,wed,thu,fri,sat
# | | | | |
# * * * * * user-name command to be executed
5、管理cron数据文件
（1）设置任务
[root@desktop4 ~]# crontab -e
no crontab for root - using an empty one
crontab: installing new crontab
（2）查询设置情况
[root@desktop4 ~]# crontab -l
50 07 * * * /sbin/service sshd start
50 22 * * * /sbin/service sshd stop
* * */5 * * /bin/rm -rf /var/ftp/pub/*
30 7 * * 6 /sbin/service httpd restart
30 17 * * 1,3,5 /bin/tar jcvf httpdconf.tar.bz2 /etc/httpd
[root@desktop4 ~]#
（3）为其他用户设置计划任务
[root@desktop4 ~]# crontab -e -u chenglong
crontab: installing new crontab
[root@desktop4 ~]#
（4）查询设置情况
[root@desktop4 ~]# crontab -l -u chenglong
55 23 * * 0 /bin/cp /etc/passwd /home/chenglong/pwd.txt
[root@desktop4 ~]#
[root@desktop4 ~]# ls -l /var/spool/cron/chenglong
-rw-------. 1 root root 56 Mar 10 09:35 /var/spool/cron/chenglong
[root@desktop4 ~]#
（5）删除用户计划任务
[root@desktop4 ~]# crontab -r -u chenglong
[root@desktop4 ~]# crontab -l -u chenglong
no crontab for chenglong
[root@desktop4 ~]#
[root@desktop4 cron]# cat /var/spool/cron/chenglong
cat: /var/spool/cron/chenglong: No such file or directory
[root@desktop4 cron]#
（6）删除系统（超级管理员的）计划任务
[root@desktop4 ~]# crontab -l
50 07 * * * /sbin/service sshd start
50 22 * * * /sbin/service sshd stop
* * */5 * * /bin/rm -rf /var/ftp/pub/*
30 7 * * 6 /sbin/service httpd restart
30 17 * * 1,3,5 /bin/tar jcvf httpdconf.tar.bz2 /etc/httpd
[root@desktop4 ~]#
[root@desktop4 ~]# crontab -r
[root@desktop4 ~]# crontab -l
no crontab for root
[root@desktop4 ~]#
[root@desktop4 ~]# vim /etc/cron.weekly/
[root@desktop4 ~]# vim /etc/cron.hourly
[root@desktop4 ~]# vim /etc/cron.daily
[root@desktop4 ~]# vim /etc/cron.monthly/
[root@desktop4 ~]#