Understand cron concepts
The cron daemon is a small subsystem composed of utilities and configuration files. cron of a certain style can be found in almost all UNIX-like systems. CronComponents include the daemon itself, a set of system-wide
Author:North SouthFrom:Linuxsir. orgAbstract:In a Linux operating system, scheduled tasks are usually undertaken by cron. Understanding or understanding cron can help us manage servers more conveniently and save more time. This article also provides
Most of the content below is translated according to Cron Help Guide, and some parts are added by yourself.
The full text is as follows:
Cron comes from the Greek word chronos (meaning "time"). It is the next program in linux to automatically
Cron is a daemon that can be used to schedule the execution of repeated tasks based on the combination of time, date, month, and week. Cron assumes that the system continues to run. If the system does not run when a task is scheduled, the task will
Name: crontab
Permission: All Users
Usage:
Crontab file [-u user]-replace the current crontab with the specified file.
Crontab-[-u user]-replace the current crontab with the standard input.
Crontab-1 [user]-list the current crontab of the
In RedHat
Linux Cron configuration file:
/Etc/crontab records environment variables (shell, path, mailto, home) and pre-defined cron tasks (cron. Hourly/daily/weekly/monthly ).
(When the cron task cannot be executed, check the environment variables
Name: crontab
Use Rights: All users
How to use:
crontab file [-u user]-replaces the current crontab with the specified files.
Crontab-[-u user]-replaces the current crontab with standard input.
crontab-1[user]-lists the user's current crontab.
Cron is a Linux scheduled execution tool that can run jobs without human intervention. Since cron is a built-in service in Linux, but it does not automatically get up, you can use the following methods to start and close this service:
Name: CrontabUsage rights: All usersHow to use:crontab file [-u user]-replaces the current crontab with the specified files.Crontab-[-u user]-replaces the current crontab with standard input.crontab-1[user]-lists the user's current crontab.crontab-e[
Linux scheduled task system cron entry
Cron is a Linux scheduled execution tool that can run jobs without human intervention.1. Start and close the service:
Since cron is a built-in service in Linux, but it does not automatically get up, you can use
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