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
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
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
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
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
After more than a decade of development in Linux, many users are familiar with Linux. Here we will introduce cron's understanding in Linux and discuss it with you. Cron is a Linux scheduled execution tool that runs jobs without manual intervention.
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
From: http://blog.chinaunix.net/u3/111961/showart_2359262.html
Cron is a Linux scheduled execution tool that can run jobs without human intervention.
1. About crontab
In ubuntu server 9.10, cron is installed and started by default. The/etc/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:
Linux cron and crontab croncrond are located in/etc/rc. d/init. d/crond or/etc/init. d or/etc/rc. d/rc5.d/S90crond, always reference/var/lock/subsys/crond. Cron is a scheduled execution tool in linux (equivalent to cron and crontab cron crond in
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