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Re: ssh password-less cmds to Windows 2003 don't return any output

On Wed, 21 Jun 2006, John McNulty wrote:

> Hello,
> I've been testing executing command via password-less SSH (public key)
> logins from  MacOSX and OpenVMS clients to a Redhat EL AS 4 server,
> and a WinXP Home system (with Cygwin's OpenSSH).  All works ok and I
> can issue test commands like:
> $  ssh administrator@host ipconfig
> and see the output from ipconfig on the client.
> However I've just installed and configured Cygwin OpenSSH on a Windows
> 2003 server, and setup password-less logins (via public keys) as
> before. But when I try and issue a command via ssh from the client I
> get no command output back at all.  The remote command just completes
> silently.  The password-less login is working just fine.
> Does anyone else see this and have any idea why I'm getting this
> behavior?

Cygwin ssh (and basically all terminals except the Windows console) use
pipes to emulate ttys (so-called "ptys").  Some Windows applications don't
like these ptys and won't write data to them (and they will certainly not
detect them as a console, so any console-specific functions won't work

> I followed the instructions in ssh-host-config and opted to use the
> sshd_server account (which kind of caught me by surprise).  Obviously
> this changes the way ssh works on Cygwin a little.

On Windows 2003, SYSTEM does not have the appropriate privileges to switch
user contexts, so ssh-host-config needs to create an account that does.
Read <> for

> Ultimately the object of the exercise here is to drive a CLI app on
> Windows 2003 from batch jobs on OpenVMS.  Cygwin OpenSSH is the only
> way I've been able to think of to solve this problem.  The other
> clients and servers are only being used to test my methodology is
> correct, and it works flawlessly on WinXP Home.

You are not guaranteed that the program you want to drive will work with a
pty.  The easiest way to check is to run the application in rxvt.  If that
works, your app will probably work over ssh as well.  If it doesn't, don't
even bother to set up ssh.  Whether or not this works is specific to the
application you intend to run.
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