System Settings/Task Scheduler: Difference between revisions

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== General Information == <!--T:1-->
== General Information == <!--T:1-->
<!--T:31-->
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).
<!--T:32-->
[[Image:Kcron-screenshot-de.png|thumb|300px|center|Task Scheduler in Plasma 5]]
[[Image:Kcron-screenshot-de.png|thumb|300px|center|Task Scheduler in Plasma 5]]


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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.</translate>
<translate>
<!--T:33-->
** 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.


<!--T:24-->
* When done, click <menuchoice>OK</menuchoice>. The task will be added and scheduled if enabled.
* When done, click <menuchoice>OK</menuchoice>. The task will be added and scheduled if enabled.


<!--T:25-->
{{Tip|Click <menuchoice>Run Now</menuchoice> to run a task immediately after adding or modifying the task.}}
{{Tip|Click <menuchoice>Run Now</menuchoice> to run a task immediately after adding or modifying the task.}}


=== Removing a task === <!--T:20-->
=== Removing a task === <!--T:20-->


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To completely remove a task, select the task from the list and click the '''Delete''' button. This will permanently remove the 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 == <!--T:21-->
== Environment Variables == <!--T:21-->


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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.
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.


* Enter the name of the variable to use. This name:
<!--T:28-->
** Must consist of letters, digits, and underscore ('_') only
* Enter the name of the variable to use. This name:</translate>
** Must start with a latter
<translate>
<!--T:34-->
** Must consist of letters, digits, and underscore ('_') only</translate>
<translate>
<!--T:35-->
** Must start with a letter</translate>
<translate>
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** Should not be a reserved or commonly used system variable. See https://pubs.opengroup.org/onlinepubs/000095399/basedefs/xbd_chap08.html for more information
** Should not be a reserved or commonly used system variable. See https://pubs.opengroup.org/onlinepubs/000095399/basedefs/xbd_chap08.html for more information


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* The value the variable will contain. This can be a number or string.
* The value the variable will contain. This can be a number or string.


<!--T:30-->
* Enter a brief description of the variable.
* Enter a brief description of the variable.



Latest revision as of 08:22, 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