MobileRead Forums - View Single Post - KindleCron - cron-like task scheduling that survives deep sleep

lennardollesch · 07-24-2026, 10:52 AM

KindleCron v0.2.0 - the binary is now called kron

A new release is up: https://github.com/lennardollesch/Ki...eleases/latest

Thanks to skylarplayz348 for the suggestion behind the rename.

Please note this is not a drop-in replacement. The command, its folder and the
KUAL extension are now called kron instead of kcron. Upgrade steps are at the
bottom of the release notes; existing jobs carry over if you move the jobs.d and
state folders across.

What is new

kron setup symlinks the binary into /usr/bin, so you can type kron from any shell and any other program can call it too. It survives reboots, it finds itself wherever you put the binary, and it deals with the read-only rootfs for you. kron unlink reverses it. There is a Setup entry in KUAL.
New -eips flag prints a command's result onto the screen. This is what makes the KUAL menu usable: previously an action either worked or silently did nothing, now you get a readout for Start, Stop, Setup, purge, kill-jobs and so on. The menu was reorganised, with confirmations on the destructive entries.
Defined exit codes (0 ok, 2 invalid request, 1 other failure), so you can drive kron from a script and check the result instead of parsing its output.
A batch of robustness fixes: logging no longer breaks when KUAL closes stdout, stop no longer trusts a stale lock file from a crashed daemon, job names are validated, and state files are flushed to storage before they are swapped in, so a flat battery cannot corrupt them.
clean-logs is now clear-logs, and $KCRON_DIR is now $KRON_DIR.

Still the same single static binary, still no dependencies on the device, still
sleeping between jobs via the RTC wake-up during readyToSuspend.

Feedback and reports of additional working models are welcome as always.

07-24-2026, 10:52 AM	#2
lennardollesch Junior Member Posts: 4 Karma: 20 Join Date: Mar 2026 Device: KT4	KindleCron v0.2.0 - binary now called kron KindleCron v0.2.0 - the binary is now called kron A new release is up: https://github.com/lennardollesch/Ki...eleases/latest Thanks to skylarplayz348 for the suggestion behind the rename. Please note this is not a drop-in replacement. The command, its folder and the KUAL extension are now called kron instead of kcron. Upgrade steps are at the bottom of the release notes; existing jobs carry over if you move the jobs.d and state folders across. What is new kron setup symlinks the binary into /usr/bin, so you can type kron from any shell and any other program can call it too. It survives reboots, it finds itself wherever you put the binary, and it deals with the read-only rootfs for you. kron unlink reverses it. There is a Setup entry in KUAL. New -eips flag prints a command's result onto the screen. This is what makes the KUAL menu usable: previously an action either worked or silently did nothing, now you get a readout for Start, Stop, Setup, purge, kill-jobs and so on. The menu was reorganised, with confirmations on the destructive entries. Defined exit codes (0 ok, 2 invalid request, 1 other failure), so you can drive kron from a script and check the result instead of parsing its output. A batch of robustness fixes: logging no longer breaks when KUAL closes stdout, stop no longer trusts a stale lock file from a crashed daemon, job names are validated, and state files are flushed to storage before they are swapped in, so a flat battery cannot corrupt them. clean-logs is now clear-logs, and $KCRON_DIR is now $KRON_DIR. Still the same single static binary, still no dependencies on the device, still sleeping between jobs via the RTC wake-up during readyToSuspend. Feedback and reports of additional working models are welcome as always.