bash - Capture stdout of a container in local machine -

i want capture stdout of running script in container on local machine , parse data.

here's scenario:

let's assume have run_on_container triggered locally , runs couple of scripts in container:

run_on_container:

script1.sh script2.sh sleep script3.sh 

i want spawn new process locally after script2 - run on container - finished , before script3 started parse output data > want capture value printed out script2 , use later. (i don not want use ssh/scp)

what thinking run_on_container | tee output.txt , run parser locally in parallel parse output.txt doesn't seems best solution me.

any comments appreciated. thanks