crontab command

Cron is a daemon that can be used to schedule execution of repetitive tasks based on a combination of time, date, month, and week. Cron assumes that the system is running continuously. If the system is not running when a task is scheduled, the task is not executed. To use the Cron service, you must install the Vixie-cron RPM package and must be running the Crond service. To determine if the package is installed, use the Rpm-q vixie-cron command. To de

Linux provides a very powerful and useful command [crontab]Crontab is used by UNIX and Linux to set up periodic instructions, is a very common Internet technology, many tasks will be set in the crontab loop execution,If I want Linux timed to execute a script or timed an HTTP request, you can use

A simple instance used by crontab 1) create a file in any directory of ubuntu # Touch cronfile01 2) EDIT crontab file01 [note]: If the root user uses crontab-e to write the root file in the/etc/spool/cron/crontabs directory, this file is written by default, after you log on with the root user and use crontab file01, th

CronTab Common Errors and crontab Common Errors Environment Variable When using environment variables, crontab may fail to normally access the environment variables in bashrc. Therefore, you should be very careful when using crontab to access environment variables. Between the third and fifth are "or" operations ("da

Explore Linux mdash; CRONTAB scheduled task cron is a scheduled execution tool in linux that can run jobs without manual intervention. Since Crond is a built-in service in Linux, it is automatically started with the system by default. of course, you can manage and maintain con... explore Linux-CRONTAB scheduled task cron is a linux scheduled execution tool that can run jobs without manual intervention. Sin

Original address: http://edu.codepub.com/2011/0104/28518.phpToday I made a backup script of the database, and by the way the system had to learn the settings of the timed execution script under Linux. Linux scheduled execution is mainly used in the crontab file to add a custom plan to execute, the setup is slightly more complicated than Windows (because there is no graphical interface), but it is not very complex, basically used once to remember, the

Original address:http://edu.codepub.com/2011/0104/28518.php Today I made a backup script of the database, and by the way the system had to learn the settings of the timed execution script under Linux. Linux scheduled execution is mainly used in the crontab file to add a custom plan to execute, the setup is slightly more complicated than Windows (because there is no graphical interface), but it is not very complex, basically used once to remember, the

. specify to execute the ls command at on January 1, June 8 each year.30 5 8 6 * ls 5. specify to execute the ls command at every Sunday.30 6 ** 0 lsNote: 0 indicates Sunday, 1 indicates Monday, and so on. sun indicates Sunday, mon indicates Monday, and so on. 6. execute the ls command at on the 10th and 20th every month.30 3 10, 20 ** lsNote: "," is used to conn

. For example, if you want to create a backup of some files or folders during your nightly sleep, you can use cron to move from execution. start and stop of services The cron service is a built-in service for Linux, but it does not boot automatically. You can start and stop a service with the following command: /sbin/service Crond Start /sbin/service Crond Stop /sbin/service Crond Restart /sbin/service Crond Reload The above 1-4 lines are start, s

Use crontab to regularly execute php Code, for example, once every 10 minutes: /10 ***** wget-q -- sqider http ://****** 1. Use PHP to execute scripts in CrontabJust like calling a common shell script in Crontab (specific Crontab usage), you can use a PHP program to call the PHP script. Execute myscript. php every hour as follows: Copy codeThe Code is as follows

Crontab scheduled task instance and crontab task instance Instance 1: Execute myCommand once every minute * *** MyCommand Instance 2: 3rd and 15th minutes per hour 3, 15 * myCommand Instance 3: Run at 3rd and 15th minutes from eight o'clock A.M. 3, 15 8-11 *** myCommand Instance 4: runs every two days, from eight o'clock A.M. to, at 3rd and 15th minutes. 3, 15 8-11 */2 ** myCommand Instance 5: runs every 3r

The common user crontab task is not executed, and the common user crontab Today, in linux, the crontab task of common users is not executed. I have searched a lot on the Internet. I 'd like to add the following content before the executed script. If [-f ~ /. Bash_profile];Then.~ /. Bash_profileFi It does not work after being added. I don't know if it works o

Original address: http://blog.chinaunix.net/uid-7552018-id-182133.htmlToday I made a backup script of the database, and by the way the system had to learn the settings of the timed execution script under Linux. Linux scheduled execution is mainly used in the crontab file to add a custom plan to execute, the setup is slightly more complicated than Windows (because there is no graphical interface), but it is not very complex, basically used once to reme

CronTab task schedule format: ***** command score (0-59), hour (0-23), Day (1-31), month (1-12) week (0-6) Description: 1. asterisks can match all characters 2, an integer, must be exact match 3, two integers separated by a short line, they match the value range. 4. Add a diagonal slice and a step value after the time range. 1-10/2 general user process: crontab-e

detailed usage of CRONTAB commands in Linux systems: If you do not see this command in your system, install the following two packages. Vixie-cron Crontabs Crontab is used to allow the user to execute a program at a fixed time or at a fixed interval, in other words, a user-like schedule. -u user is the time table that specifies the user, as long as you have per

To create a cron service for the current user1. Type CRONTAB-E edit crontab service fileFor example, the contents of the file are:*/2 * * * */bin/sh/home/admin/jiaoben/buy/deletefile.shSave the file and exit*/2 * * * */bin/sh/home/admin/jiaoben/buy/deletefile.sh*/2 * * * * This field allows you to set when to execute the script/bin/sh/home/admin/jiaoben/buy/deletefile.sh This field can set the script you wa

To create a cron service for the current user1. Type CRONTAB-E edit crontab service fileFor example, the contents of the file are:*/2 * * * */bin/sh/home/admin/jiaoben/buy/deletefile.shSave the file and exit*/2 * * * */bin/sh/home/admin/jiaoben/buy/deletefile.sh*/2 * * * * This field allows you to set when to execute the script/bin/sh/home/admin/jiaoben/buy/deletefile.sh This field can set the script you wa