System Settings/Task Scheduler/en: Difference between revisions

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== General Information ==
== General Information ==
Task Scheduler is a graphical front end to the standard "cron" utility. With it, commands (or "tasks") can be run at specific times, on a certain day or date, or at specific intervals (time between execution).
[[Image:Kcron-screenshot-de.png|thumb|300px|center|Task Scheduler in Plasma 5]]


Task Scheduler is a graphical front end to the standard "cron" utility. With it, commands (or "tasks") can be run at specific times, on a certain day or date, or at specific intervals (time between execution).
Task Scheduler is a graphical front end to the standard "cron" utility. With it, commands (or "tasks") can be run at specific times, on a certain day or date, or at specific intervals (time between execution).
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* Using the buttons, choose when the command should be run. Not all parameters are required, those not needed may be left blank.
* Using the buttons, choose when the command should be run. Not all parameters are required, those not needed may be left blank.
** Hours and Minutes are the time of day to run the task, not an interval.
** Hours and Minutes are the time of day to run the task, not an interval.
** Hours and Minutes are the time of day to run the task, not an interval.


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* Enter the name of the variable to use. This name:
* Enter the name of the variable to use. This name:
** Must consist of letters, digits, and underscore ('_') only
** Must start with a letter
** Should not be a reserved or commonly used system variable. See https://pubs.opengroup.org/onlinepubs/000095399/basedefs/xbd_chap08.html for more information
** Must consist of letters, digits, and underscore ('_') only
** Must consist of letters, digits, and underscore ('_') only
** Must start with a letter
** Must start with a letter

Latest revision as of 08:30, 1 June 2019

General Information

Task Scheduler is a graphical front end to the standard "cron" utility. With it, commands (or "tasks") can be run at specific times, on a certain day or date, or at specific intervals (time between execution).

Task Scheduler in Plasma 5

Usage

Task Scheduler can be started by starting the System Settings application. Select Startup and Shutdown follwed by Task Scheduler.

Adding and Modifying tasks

  • Click New Task... to add a new task, or "Modify" to modify an existing task. The Add or modify existing task page will be displayed.
The "Add or modify task" page of SystemSettings
  • Enter the command to be run. Click the folder icon to choose it from a dialog.
  • Enter a comment (optional). This should be descriptive, explaining what the task will do as the command may not always be obvious.
  • Click Enable this task to enable the task to run.
  • Click Run at system bootup to enable the script to run each time the system is booted.
  • Click Run every day to enable the script to run every day. This will automatically select the appropriate options.
  • Using the buttons, choose when the command should be run. Not all parameters are required, those not needed may be left blank.
    • Hours and Minutes are the time of day to run the task, not an interval.
  • When done, click OK. The task will be added and scheduled if enabled.

Tip

Click Run Now to run a task immediately after adding or modifying the task.


Removing a task

To completely remove a task, select the task from the list and click the Delete button. This will permanently remove the task.

Environment Variables

Sometimes a task or multiple tasks need a specific variable set, it must be added in the Environment Variables section. The cron utility uses its own environment, system-wide and user-specific variables are not used. Click New Variable to add a new variable definition, or Modify to change an existing variable.

  • The value the variable will contain. This can be a number or string.
  • Enter a brief description of the variable.

Hints

  • All the files that are modified are located in the /etc/cron directory where there are numerous files to look at.
  • The command-line tool that allows you to have a look at the currently installed cron-jobs is
    crontab -l
    (that's the letter L).

More Information