Undocumented behavior: mosh drops exit code of command executed on target, returns overall session success instead

[andres-erbsen]

I would expect mosh --local 127.0.0.1 "sh -c 'exit 42'" ; echo $? to exit with code 42 as does ssh, but it exits with 0. Is this behavior intentional?

[cgull]

It's intentional. Since Mosh is a virtual terminal usually used for interactive sessions, I decided (after some discussion) to make the exit status reflect the success of the terminal session, rather than the commands run within it. That is to say, if Mosh successfully establishes a session and terminates it normally, it exits with status 0, otherwise !0. This isn't documented in the man pages and should be. We could also consider adding a new feature and command-line option to return the remote command's exit status instead, but that doesn't exist in Mosh today and wouldn't work with older servers.

[ryran]

Thanks @cgull for the explanation. I was wondering the same thing. An option to tweak this behavior would be so awesome..