[Solved] How to write variable value to file?

---

Hello,
i am trying to write the value of a variable to a file.

I am trying to use a shell sensor for it where the command is
echo $target_temperature > /home/pi/Projects/temp_controller.input

However, this only creates a file with one new line character. Seems the variable is not parsed.

Any ideas?

Probably i could do it via the REST api if there is no other easy way.

@gunknown said in How to write variable value to file?:

However, this only creates a file with one new line character. Seems the variable is not parsed.

Yes. The Shell Sensor currently only handles environment variables. Possible work-around: write shell script which pulls the variable value using the REST-API and write the result to a file.

@mwittig would it be possible to have something like a simple export function, something like an opposite logreader?
maybe an enhancement on the logwatcher plugin that implements an export to the action handler so you are able to use a rule like when $temperatur changes then export $temperatur to "/home/pi/temp.log" ?

@gunknown

you could add a new line in temp_controller.input with

... then execute "sudo sed -i '\$ a sometext $target_temperature' /home/pi/Projects/temp_controller.input" 

https://forum.pimatic.org/topic/1744/monthly-logging-in-external-file

Thank you xCite86, this is a way to go …

Sorry for warming, i still dont get it. I have a string variable in pimatic, it’s name is $teamsoll

And when I hit a button, i want to write that variable into a textfile, e.g. /home/foo/scripts/football/team.txt

I tried many ways, including the above, either with a rule or with a shellbuttondevice, i failed. Can somebody help me?

@suchalaugh said in [Solved] How to write variable value to file?:

Sorry for warming, i still dont get it. I have a string variable in pimatic, it’s name is $teamsoll

And when I hit a button, i want to write that variable into a textfile, e.g. /home/foo/scripts/football/team.txt

I tried many ways, including the above, either with a rule or with a shellbuttondevice, i failed. Can somebody help me?

It is all about the “quotes”…

When yourbutton is pressed then
execute "echo '$teamsoll' > /home/foo/scripts/football/team.txt"

Everytime the button is pressed, it will replace the first line in team.txt with the variable.

If you want it like this:
Team1
Team2
Team3
Then, add another > so it becomes echo '$teamsoll' >> /home/foo/scripts/football/team.txt

Thanks for the hint. Yeah, i just want it to be overwritten, so one > is just fine for me.
Thing is, it just doesn’t work, it can’t even create the file when it’s not existing. Also, if i create it in ssh, it overwrites nothing, it just stays that way. Path and name of variable both are correct. Also tried it with sudo execute…

@suchalaugh you cant create the file?

Hm, permission issue?
sudo nano /home/foo/scripts/football/team.txt

CTRL + X / Y / ENTER

Sorry for my misleading words. I myself can create the file very well, pimatic just can’t…

@suchalaugh said in [Solved] How to write variable value to file?:

I myself can create the file very well, pimatic just can’t…

Do you run pimatic as a service using the service template as described in the documentation? If yes, it should not be a permission issue as pimatic will have root privileges. If you pimatic with a non-privileged user account, make sure this account as the write privileges on the directory where the file is created.

I any case make sure the directory path exists! For example, if you want to dump to file /home/foo/scripts/football/team.txtmake sure the path /home/foo/scripts/footballexists.