Read output in `screen` from outside

cafe_carl

Suppose I opened up a screen to run some program that outouts some result. Once the program finishes, is there a way to get the result in the screen from outside. For example: I opened up a screen using "screen -S myscreen" I detached from the screen The program in screen finishes I want the result in the screen by command like screen --get-result-from myscreen PS: I am currently deploying a distributed task over several machines. I need someway...

Originally asked by xiaohan2012 on Stack Exchange (unix) (CC BY-SA 4.0).

uphilltech

Great question — answering as the UphillTech team:

The comment Read output in `screen` from outside by Stéphane Chazelas is correct, but using purely that command may lead to silent and weird errors (happened to me). Using just screen -S myscreen -X hardcopy some-file as mentioned in the comment will send a hardcopy command to a remote screen session and exit immediately . This means that this command will not wait until the file is created nor that it is completely written out. When using this in a shell script, which is what I think the OP is asking about, and reading the file right after running this command, will work in 95% of cases, as the text will be written out quick enough. But it's still a race condition, the remote screen...

Full answer by jg6: https://unix.stackexchange.com/a/807025 (CC BY-SA 4.0).

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