Prevent shutdown when tvheadend recording / KDE session is active

Question

I am searching for a way to prevent shutdown/standby when tvheadend (or vdr) is currently recording.

What I found so far:

Prevent shutdown when rsnapshot is running: Which I don't like because it requires tvheadend to have root privileges and the link referenced seems to provide variants which do not work any more.
TVHeadend Wakup: Setting Wake up time works fine. But pm-suspend does not check if a KDE session is active but instantly suspends.
How can I make shutdown not require admin password?: works only for a very special case: checks if users are logged in

I see two solutions:

Either TVHeadend script calls some KDE functions to ask for KDE state (screen locked, user logged in etc) and issues shutdown/suspend calls as seen in the above example.
or modify the shutdown behavior of KDE so it checks if any TVH recording is currently active.

I cannot find any docs about these two variants.

score 1 · Accepted Answer · edited Jul 30 '17 at 14:20

Found a really easy solution!
Create a file /etc/pm/sleep.d/70-check-recordings.

In this file check if a recording currently is active. If yes, just return exit 1. That's it. Suspend will be aborted.

My script looks like this, it is based on this at tvheadend.

$ cat /etc/pm/sleep.d/00-check-recordings
#!/bin/bash
#
# this script sets ACPI Wakeup alarm and stops standby if a recording is active
# safe_margin - minutes to start up system before the earliest timer

# bootup system x sec. before timer
safe_margin=60

# modify if different location for tvheadend dvr/log path
cd ~hts/.hts/tvheadend/dvr/log

######################

start_date=0
stop_date=0

current_date=`date +%s`

for i in $( ls ); do
        tmp_start=`cat $i | grep '"start":' | cut -f 2 -d " " | cut -f 1 -d ","`
        tmp_stop=`cat $i | grep '"stop":' | cut -f 2 -d " " | cut -f 1 -d ","`
#       logger "$0: $i from $(date -d @$tmp_start) to $(date -d @$tmp_stop)"

        start_extra=`cat $i | grep '"start_extra":' | cut -f 2 -d " " | cut -f 1 -d ","`
        stop_extra=`cat $i | grep '"stop_extra":' | cut -f 2 -d " " | cut -f 1 -d ","`

        let tmp_start=$tmp_start-$start_extra*60
        let tmp_stop=$tmp_stop+$stop_extra*60
#       logger "$0: $i from $(date -d @$tmp_start) to $(date -d @$tmp_stop)"

        # if recording is active, immediately stop suspend 
        # tmp_stop > now and tmp_start < now 
        if [ $((tmp_stop)) -gt $((current_date)) -a $((tmp_start)) -lt $((current_date)) ]; then
                name=`grep -h -A 1 title $i | grep -v  title | sed 's/.*: "\(.*\)"$/\1/'`
                logger "$0: Currently RECORDING $name. No Suspend until $(date -d @$tmp_stop!)"
                exit 1;
        fi

        # only check future recordings
        # tmp_stop > now and tmp_start > now 
        if [ $((tmp_stop)) -gt $((current_date)) -a $((tmp_start)) -gt $((current_date)) ]; then

                # take lower value (tmp_start or start_date)
                # (start_date = 0) or  (tmp_start < start_date)
                if [ $((start_date)) -eq 0 -o $((tmp_start)) -lt $((start_date)) ]; then
                        start_date=$tmp_start
                        stop_date=$tmp_stop
                        name=`grep -h -A 1 title $i | grep -v  title | sed 's/.*: "\(.*\)"$/\1/'`
                fi
        fi
done

wake_date=$((start_date-safe_margin))

# set up wakeup alarm
if [ $((start_date)) -ne 0 ]; then
        logger "$0: Set Wakealarm for $name to $(date -d @$wake_date)"
        echo 0 > /sys/class/rtc/rtc0/wakealarm
        echo $wake_date > /sys/class/rtc/rtc0/wakealarm
fi

Now set up KDE to handle standby after time-out. If a recording is active, KDE standby is aborted by the above script.

See also this in the MythTV documentation.

score 0 · Answer 2 · edited Mar 28 '15 at 18:59

0

Use kaffeinety. It is an application that prevents power management actions from triggering when certain applications are running. You can then go into system settings -> power management and add the application to the list.

edited Mar 28 '15 at 18:59

JPT

369

answered Mar 27 '15 at 13:07

TheBlackCat

208

Thanks, I will try it soon, but not now. I fear that "add the application to the list" is not what I want, since tvheadend always runs. It only raises number of processes from 10 to 16 when recording. – JPT Mar 28 '15 at 18:40

score 0 · Answer 3 · answered Sep 23 '16 at 08:27

0

I wrote a script to shutdown and wakeup the system based on Tvheadend activity. It does not suspend your system while Tvheadend is active. You can find it on GitHub.

answered Sep 23 '16 at 08:27

Christian

1

That's awesome, but we do like it if you can post the script here in case of link-rot, or at least give some more details... – Zanna Sep 23 '16 at 08:35

Prevent shutdown when tvheadend recording / KDE session is active

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