How to restart ES from a script?

[meleu]

@cyperghost @TMNTturtlguy
Some background I would like to share with you guys:

• when you type emulationstation in the shell, it executes /usr/bin/emulationstation

• the /usr/bin/emulationstation is a shell script that calls /opt/retropie/supplementary/emulationstation/emulationstation.sh.

• the /opt/retropie/supplementary/emulationstation/emulationstation.sh calls the /opt/retropie/supplementary/emulationstation/emulationstation and this is the real emulationstation binary.

• the /opt/retropie/supplementary/emulationstation/emulationstation.sh has a logic to restart ES, restart system and shutdown system based on the existence of some specific files in /tmp. The code of this script can be seen here.

• in my failed attempt to restart ES from commandline, I was trying create the /tmp/es-restart and kill only the ES binary. According to the emulationstation.sh it's enough to restart ES. But as we saw, my approach is killing the emulationstation.sh too, and that is what is "crashing".

I'll try something more concise this evening, but if @cyperghost has some free time now and would like to investigate more, my suggestion is to find a way to kill only that very specific binary: /opt/retropie/supplementary/emulationstation/emulationstation.

I used those metacharacters on my pkill regex to try to match some edge cases (like running a custom branch ES or launching ES with some parameter).

P.S.: now that I see @BuZz is aboard, I'm sure that the elegant solution is coming. :)

[BuZz]

@cyperghost I think the problem is just the emulationstation.sh is being killed (which handles the restarting). Should be simple enough to avoid killing that. eg specifying the process name exactly rather than pattern matching.

[cyperghost]

@BuZz Please go on.... I think it is not as easy
Because I manually lauched /opt.../ emulationstation.sh and that did not workd.
@TMNTturtlguy discovered the /tmp thing today +1 for him

[BuZz]

@cyperghost It should be. I would guess at something like

touch /tmp/es-restart; killall -e "/opt/retropie/supplementary/emulationstation/emulationstation"

should be fine.

[cyperghost]

let me test...

[BuZz]

or to work with emulationstation running from any path. (eg with emulationstation-kids etc).

touch /tmp/es-restart; pkill -f "/emulationstation$"

[cyperghost]

Works fine

touch /tmp/es-restart; killall -e "/opt/retropie/supplementary/emulationstation/emulationstation"

[cyperghost]

@BuZz said in How to restart ES from a script?:

pkill -f "/emulationstation$"

That let's restart just 2 PIDs... Does not work!

touch /tmp/es-restart; killall -e "/opt/retropie/supplementary/emulationstation/emulationstation"

runs fine all 3 PIDs are up to date

---

Man ... I even wrote use the tty1 outputs. So indeed the relauch script was killed

[BuZz]

@cyperghost said in How to restart ES from a script?:

pkill -f "/emulationstation$"

Worked here when I just tested.

[cyperghost]

@BuZz Wait I post output in a few minutes...

pi@retropie:~ $ ls /tmp
es-restart  omxplayerdbus.root  omxplayerdbus.root.pid
pi@retropie:~ $ ps -a
  PID TTY          TIME CMD
  862 tty1     00:00:00 bash
  867 tty1     00:00:00 bash
  868 tty1     00:00:00 emulationstatio
  874 tty1     00:00:00 emulationstatio
  877 tty1     00:00:13 emulationstatio
  990 pts/0    00:00:00 ps

The command pkill

pi@retropie:~ $ pkill -f -e "/emulationstation$"
emulationstatio killed (pid 868)
emulationstatio killed (pid 877)

check with ps -a

pi@retropie:~ $ ps -a
  PID TTY          TIME CMD
  862 tty1     00:00:00 bash
  874 tty1     00:00:00 emulationstatio
 1001 tty1     00:00:08 emulationstatio
 1071 pts/0    00:00:00 ps

worked now... sorry... but 2 PIDs alive
If PID 874 in my current setup will be killed than ES is wrecked.

Thank you

[BuZz]

@cyperghost use ps -fa as you can't tell what they are from that. probably parent bash scripts (which is correct - they shouldn't be killed).

[TMNTturtlguy]

@BuZz @cyperghost

touch /tmp/es-restart; killall -e "/opt/retropie/supplementary/emulationstation/emulationstation"

runs fine all 3 PIDs are up to date

When i use this in my script, it runs the first time. The second time i try to run it, the script crashes with error "cant remove /tmp/es-restart

[cyperghost]

@BuZz
Thank you I will remember that command!
Very usefull :)

[cyperghost]

@TMNTturtlguy I will check....
I tested all scripts 2 two 3 times... all runing fine

[BuZz]

@TMNTturtlguy said in How to restart ES from a script?:

@BuZz @cyperghost

touch /tmp/es-restart; killall -e "/opt/retropie/supplementary/emulationstation/emulationstation"

When i use this in my script, it runs the first time. The second time i try to run it, the script crashes with error "cant remove /tmp/es-restart

because custom retropie scripts are actually run as root - ill change that I think, but just make sure you create it owned by pi for now.

sudo -u pi touch /tmp/es-restart
pkill -f "/emulationstation$"

[cyperghost]

@BuZz Solid work!
Thank you

[cyperghost]

@BuZz What is your prefered method?
pkill or killall? I think pkill offers more room for changes.

[BuZz]

I have updated retropie-setup so user scripts will now be launched as a normal user without elevated permissions (can use sudo in a script if needed).

[BuZz]

@cyperghost pkill so it can kill emulationstation running from any path.

[cyperghost]

@BuZz
Ufff... that was hard stuff!