[DSF Extension] Exec On MCode (was: Shutdown SBC)

Greg_the_maker

What is it i need to be looking for?

PCR

@PCR said in [DSF Extension] Exec On MCode (was: Shutdown SBC):

made a little videos how to install it. Mainly for my own reference later

How to install and test

How to make it as a systemservice

Here you go

Greg_the_maker

thank you

wilriker

@Greg_the_maker Thanks for pointing that out. I will point the download instructions towards the GitHub Releases page. For there it should be clear what is meant by renaming also.

Greg_the_maker

Is tehre a way to get terminal messages displayed in the console?

For example I need to see a list of usb devices with lsusb, is it possible to have that list returned as an M117 message or similar?

wilriker

@Greg_the_maker In theory this is possible. Right now successful execution will discard the application output and error in execution results in an error being sent to DCS what failed (e.g. file not found but still not the output of the application).

I could add that but I am not sure how it will deal with line-breaks.

Greg_the_maker

@wilriker Ahh ok. was just a thought. would be a nice feature to have though

wilriker

@Greg_the_maker I have to correct myself. In case of an error it will indeed return the output of stdout and stderr combined as an error message. But since we are in short-lived world things can be changed quickly and thus:

Release v5.1.2

This release adds a new flag -returnOutput to be able to send the collected output of a successful run back to DCS. Prior this was only the case if the execution of the command failed.
Note that this cannot be combined with -execAsync.

Download

As usual get it from GitHub Releases page.

Greg_the_maker

@wilriker Fantastic! Works exactly as desired. Have my upvote!

oozeBot

@wilriker Could you please provide a simple example of using the -returnOutput flag? Thanks

wilriker

@oozeBot said in [DSF Extension] Exec On MCode (was: Shutdown SBC):

@wilriker Could you please provide a simple example of using the -returnOutput flag? Thanks

Simple example:

execonmode -mCode 7777 -command "whoami" -returnOutput

will not just confirm successful completion of the command but as part of this return the output of whoami (that returns the user execonmcode is started as, so probably root) so you can see it e.g. in DWC.

oozeBot

@wilriker Thanks. So the return is echo'ed in DWC, correct? Could the return value be evaluated within conditional gCode?

garethky

@oozeBot said in [DSF Extension] Exec On MCode (was: Shutdown SBC):

@wilriker Thanks. So the return is echo'ed in DWC, correct? Could the return value be evaluated within conditional gCode?

I was thinking about this today. Currently there are no variables so there is nothing to write the result back to. (there is a result int from the last code but it can't contain other data types) I think we might have to wait for variables and then we could write the value back to a global.

When that happens... it should be possible to set up an MCode that stores and retrieves values from a file on the SD card. So we could do what M500 does but with key/value semantics of M409:

M7500 K"some.key" V"The value"
M7500 K"some.other.key" V0.05

and then get them back in a global with:

M7500 K"some.key"
echo {global.M7500_value}    ; or whatever you want to name it!

and stored on disk as JSON:

"some": {
    "key": "The Value"
    "other": {
        "key": 0.05
    }
}

EMRosa

Great work! This is incredibly useful and appreciated!

Is there a way to pass quotes through the -command argument?
For example:

execonmcode --command "sudo pkill -fx "blah, blah, blah"" -mCode 7720 -execAsync

I've tried single quotes, escape characters, and changing it to an argument passed through the m-code command;

execonmcode --command "sudo pkill -fx %F" -mCode 7720 -execAsync

and then tried from DWC:

M7720 F"python3 script.py"

but the full argument gets lost. I foolishly tried double quotes and DSF crashed. haha.

Please, forgive my inexperience. There is probably a simple answer to this, but it seems to escape my googling ability.

wilriker

@EMRosa Quick answer is: this is currently not implemented.
I'll think about adding it, though.

ukwebb

followed your video and got it installed and working in 5 minutes - superb work - thanks

EMRosa

@wilriker thanks for the quick reply! No worries; at least it wasn’t something related to my Linux-literacy (or lack thereof). Haha. Your work and efforts on this implementation are inspirational.

wilriker

@EMRosa said in [DSF Extension] Exec On MCode (was: Shutdown SBC):

I've tried single quotes, escape characters, and changing it to an argument passed through the m-code command;
execonmcode --command "sudo pkill -fx %F" -mCode 7720 -execAsync

I thought about this some more and actually the above should work. Though probably as you use -fx on pkill this has to match the full commandline, i.e. you also have to specify the path to python3, so you will probably need use the following command:

M7720 F"/usr/bin/python3 script.py"

EDIT: to find the full commandline while your script.py is running use

$ pgrep -fa "python3 script.py"

This should give you the PID as well as the full command-line of your process.

EMRosa

Thanks so much for the assist! I’ll try that, but I was using the exact process as listed from

ps -aux | grep python3

This lists the process as “python3 location/to/script/script.py”.

In my case, I was able to put the command line call in another python script and just call it that way. I just wasn’t sure if it would be helpful (or necessary) for execonmcode to be able to send quoted arguments. (Or more likely, if I was doing it wrong. Haha)

I’ll let you know if adding the path to python helps.

wilriker

@EMRosa Since you are using pkill you need to use pgrep to find the required command line (it's the same binary that acts different based on which name it is called with but shares common features otherwise). ps is a different tool that uses (and prints) a different format usually dropping the path to the executable. I think there is a flag to ps to add it but I don't know that off-hand.

Also quotes are not necessary for execonmcode. Quotes are a concept of shells (sh, bash, zsh, fish, etc.) to provide means to human users to provide command arguments containing spaces. If an application runs another application they usually can provide arguments containing spaces without the need for quotes.