@background and @start

[g105b]

Linux crontab supports replacing the date/time columns with @reboot to indicate that the script should be run once on reboot.

As a new feature, @background can be used to indicate that the script should be run forever in the background (waiting for the process to finish before starting again).

@start can be used to indicate that the script should be run once at the start of the server starting.

[g105b]

.crontab.lock should be introduced to track the process execution here.

@start should create an entry once, and when it's in there, any future @start commands will not run. When running the dev server, this can be reset when the server starts, before the cron runner begins. On a server, the log entry can be removed on boot (using the @boot syntax!).

@background should use the lockfile to record the PID. On the minute, the cron bin executes, and if there is no PID (or the PID does is not running any more) it starts an endless loop to call the process.

[g105b]

This may require implementation of our own parsing mechanism. Currently a third party is depended on.