KCron

Informazioni generali

KCron è uno strumento per eseguire automaticamente applicazioni ad intervalli regolari. È un'interfaccia grafica per il comando Cron. KCron è un'applicazione standard negli ambienti KDE.

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

Utilizzo

In KDE 4.4 KCron è un modulo accessibile in Impostazioni di sistema -> Avanzate -> sezione Sistema -> Pianificatore di operazioni. Se non è presente controlla di aver installato il pacchetto kdeadmin. In KDE 4.5 lo troverai in Impostazioni di sistema -> sezione Amministrazione del sistema -> Pianificatore di operazioni. Alcune distro creano un pacchetto separato per KCron, dunque se non lo vedi dovresti cercare questo termine nel tuo repository.

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.

• 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

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

• Enter a brief description of the variable.

Suggerimenti

• Tutti i file che vengono modificati si trovano nella cartella /etc/cron dove ci sono numerosi file da guardare.

• Lo strumento a riga di comando che ti permette di vedere i cron-jobs attualmente definiti è

  crontab -l

  (l'ultima è la lettera L).

More Information

• KDE official documentation
• Cron (Wikipedia)
• Cron (Arch Linux wiki)