Re: reading an environment variable from screen

[Neal Fultz]

There is not a getenv command to match setenv iirc.

There's a -Q flag for query - z=$(screen -S $STY -Q echo '$SSH_AUTH_SOCK')

Getting the shell quoting correct will probably be pretty fiddly though.

On Wed, Dec 16, 2020 at 7:09 AM Michael Grant <mgrant@grant.org> wrote:
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> When I reattach to screen, the SSH_AUTH_SOCK is wrong.
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> I often ssh in and run screen simultaneously on a laptop and desktop.  So I 
> can’t use the trick of symlinking something to /tmp/ssh-xxxxxxxxxx.
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> Is there some way to interrogate screen to tell me what the contents of an 
> environment variable are?
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> Running this in a shell inside of screen:
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> screen -S $STY -X colon 'exec |echo $SSH_AUTH_SOCK\r'
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> gives me the info I’m looking for, but it pushes it out to the display.  I’m 
> so close!  How can I capture this output?
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> My goal here is to create a sort of ssh/scp pre-command as a shell alias that 
> probes screen each time and sets the SSH_AUTH_SOCK variable correctly.