Centos7 Linux tries to use Crontab

First, install the crontab

[email protected] ~]# Yum install Vixie-cron
[email protected] ~]# Yum install Crontabs

Description
Vixie-cron package is the main program of Cron;
The Crontabs package is a program used to install, uninstall, or list tables used to drive the cron daemon.
Cron is a built-in service for Linux, but it does not automatically get up, and you can start and shut down this service in the following ways:
/sbin/service Crond Start//Startup service
/sbin/service Crond stop//Shut down service
/sbin/service crond Restart//Restart service
/sbin/service Crond Reload//Reload Configuration

View crontab Service Status: Crond status

Manually Start crontab services: Service Crond start

Reference: http://os.51cto.com/art/201004/192442.htm

Ii. Use of tasks

1. Direct distribution

#crontab-E

And then come out with an editable file: You can do this by setting the time

For example, the task output date is executed once per hour to the/home/mydatetest file

0 * * * * Date >>/home/mydatetest

Execute once per minute

* * * * * Date >>/home/mydatetest

Here's a complicated notation.

Edit the scheduled task under root crontab-U Root-e appends a string to a text at 6 o ' Day in the morning. 0 6* * * echo"Good morning.">>/tmp/Test.txt appends a string to a text every two hours. 0*/2* * * echo"There is a break now .">>/tmp/test.txt 11 o'clock to 8 a.m., every two hours, eight a.m. .0  at-7/2，8* * * echo"a good dream:)">>/tmp/Test.txt, 4th per month and Monday to Sunday, three a.m. 11 .0  One 4*1-3Command line1 month 1st Morning 4 o ' Day0 4 1 1*command line every hour of the month of the first0Minutes to execute/bin/ls0* * * * */bin/ls in AEvery morning in the month6Point to APoint, every -Minutes to execute/usr/bin/Backup*/ - 6- A* A*/usr/bin/backup Monday to Friday every afternoon5:xxsend a letter to Alex_mail_name:0  -* *1-5Mail-s"Hi"Alex_mail_name </tmp/Maildata Midnight every day of the month0Point -Score of2Point -Score of4Point -Points .... Perform echo"haha" - 0- at/2* * * echo"haha"11 o'clock to 8 a.m., every two hours, 8 a.m., Show time .0  at-7/2，8* * * Date

2. Through the *.sh file

2.1 Establish *.sh to set its permissions to 744:chmod 744 mytask.sh

2.2 Ibid. method Direct * * * * * mytask.sh can be

3. Delete All Tasks Crontab-r

Centos7 Linux tries to use Crontab