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Comment by ryanprichard | Hacker News Reader

Will this OpenSSH server be able to run interactive console programs (like cmd.exe or python.exe), or will it be limited to (say) PowerShell?

Windows doesn't have a good API for hosting a console--it's not like Unix, where a pty has a master end and a slave end. Trying to run a console program in mintty.exe (https://github.com/mintty/mintty/issues/56) or Cygwin SSHD fails for this reason. I wrote a tool, winpty, that makes a best-effort attempt to emulate a Unix pty master by scraping the console buffer, but it has some limitations, so I'm not sure Microsoft would want to use it. Maybe they would expand the console API?

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I too was very skeptical. Something about posts from "The Powershell Team" about porting sshd makes me deeply cynical that they would get the integration right from a layering perspective, i.e. as if they would make it support powershell and nothing else.

Fortunately this example shows it going straight into cmd and then they invoke powershell as a next step:

    C:\Master>ssh.exe -l user@127.0.0.1
    user@127.0.0.1's password: **********
    Microsoft Windows [Version 10.0.10566]
    (c) 2016 Microsoft Corporation. All rights reserved.
    user@DEV-10566-829 C:\Users\user>powershell -File -

- https://github.com/PowerShell/Win32-OpenSSH/wiki/ssh.exe-exa...

That gives me some hope that it's being done right.

There are these two interesting commits, "Add pty mode support code":

https://github.com/PowerShell/Win32-OpenSSH/commit/55f2ec682...

and "Add ANSI parsing engine and console draw support to SSH client":

https://github.com/PowerShell/Win32-OpenSSH/commit/7aac59e52...

Something about this reminds me of ANSI.SYS.

you could run ANSI.sys in modern cmd.exe, sadly there's no ANSI.sys in Win7 anymore.

https://groups.google.com/forum/#!topic/alt.msdos.batch.nt/Y...

Cool. Looks like that is essentially listing DEVICE=ANSI.SYS in config.nt? Google results imply some things about 16-bit emulation here -- was that post about running actual DOS ANSI.SYS in a VDM running actual DOS COMMAND.COM, within a native Windows terminal?

IIRC, the command.com only bootstrap the ANSI coloring, after that you can run anything in cmd.exe

> Will this OpenSSH server be able to run interactive console programs

I would think so. Anything less would not be a real SSH server.

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