Installing and using crontab in CentOS

Installing and using crontab in CentOS

Install crontab in CentOS:

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1	Yuminstallcrontabs

Start or close this service:

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1234567

/Sbin/servicecrond start // start the service/sbin/servicecrond stop // close the service/sbin/servicecrond restart // restart the service/sbin/servicecrond reload // reload the configuration

View the crontab Service Status:

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1	Service crond status

Start the crontab service manually:

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1	Service crond start

Run the following command to check whether the crontab service is set to start at startup:

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Ntsysv

Add boot auto start:

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1	Chkconfig -- level 35 crond on

Crontab command:

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1234	Crontab [-u <用户名称> ] [Configuration file] or crontab [-u <用户名称> ] [-Elr] crontab-u root-e // edit the root timer settings. Crontab-u root-l // list the root timer settings. Crontab-u root-r // delete the root timer settings.

The configuration file format is as follows:

Minute Hour Day Month DayOFWeek Command

* *** Command
Hour, day, month, and Week commands

The 1st column indicates minute 1 ~ 59. each minute is represented by * or */1.
The first column indicates the hour 1 ~ 23 (0 indicates 0 points)
The 3rd column indicates the date 1 ~ 31
The 4th column indicates the month 1 ~ 12
The identification number of column 5th is from day of the week to day ~ 6 (0 indicates Sunday)
6th columns of commands to run

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123	40 23 ***/usr/bin/php/var/www/html/. php // execute 40, 20 **/usr/bin/php/var/www/html/a at every day. php // execute 40 ***,/usr/bin/php/var/www/html/a at every month. php // Run on Saturday at on Sunday