Shell Programming and Scripting

No, it's not. I used what came into my mind first. But I will fix that. Is there anything else I should make better?

date is correctly executed, yes. The logs contain the correct date/time for every line and the if branches are triggered, the corresponding log lines are present.

jq works as well, I logged the variables and they are all set. $RETURN contains json and I need the unit-/systemcodes from different senders to identify which one was used. That works, too. The log contains every line it should contain.

Did you print all the variables JUST before the tests are done?

Sorry, I don't understand. Do you mean print the variables in the line directly preceeding the if-condition?

---------- Post updated at 03:42 PM ---------- Previous update was at 03:34 PM ----------

Well, it was the working directory.
Adding "cd /home/pi" solved it. But I was using absolute paths, could anybody explain what was wrong with that?

And thank you guys! That was really kind, I appreciate your help. Hope I can give sth in return some day.

Sourcing means executing with dot . your env file you use in your profile, can be .profile, .kshrc .bashrc etc...
Let's say you just modified your environment like you just added an alias:
alias='ls -la' #this is for most sh and ksh, the syntax may differ for her and is for csh...
Now you want to test lets say you modified .kshrc, to test there is no need to log out and connect again, you can also:

Code:

 . ./.kshrc

Now you can also add the above to be executed at the beginning of your script, the only problem is your environment is done to meet interactive mode e.g standard input/output etc... are set, which is of no use and more gererates error when being set as for instance you dont have a display...
So either you accept all the errors hoping it will continue anyway ( because you are testing - you want to see there is something there missing for batchmode... ) you see it works so you are then left to find out what... Either you test if batchmode or interactive and use an if to skip what is set for interactive in your .profile

I was also puzzled by your if test as it looked as you were comparing a char with a char or numeric ( -lt ) "$value" is to me a char ( or could be seen as a string of one or more characters... ) so it cant be less than as less than means you are dealing with numbers
To be sure I have a num in a variable affection I use e.g.

Code:

 let RING=0

So here

Code:

 if [ "$RING" -eq 1 ]

I really have a doubt but I am not a bash user and so maybe that can pass...
Only here is where things get tricky, on a true UNIX system init uses /bin/sh and its path is very.very limited: /bin:/usr/bin... And you dont know where you are: if it needs to write in current directory. depending where, you find yourself ( as user is pi..) with no permissions....
And I am not sure that a real Bourne shell would like the above if test... and so it will never execute what you expected
All that to say it may work for you but it may very well in that case, be portable, so complying to old standards have an advantage, old guys like some of us will very easily point out the errors or issues, using fancy last versions of shells that we may not use makes things far more difficult to read, understand and test...

All the best and welcome here