问题
I'm trying to connect to machine one with ssh and then connect to another machine two with ssh. But get this error:
ssh user@computerone.com 'ssh otheruser@computertwo.com'
stdin: is not a tty
回答1:
When logging into a shell, the remote host assumes that the connection is done by a human user. Therefore, it is reasonable to expect that they have control over the standard in on the client. That is to say, the user is giving input on a terminal through the keyboard. If the remote host detects that the user is not human (because the input is not a terminal - tty, but another process), it may warn the user about this unexpected condition.
A demonstration of the discussed misbehavior and how to avoid it (man ssh and look for -t for a more thorough explanation).
$ ssh -t genja.org 'ssh raptor.lan hostname\; uptime'
host: genja.lan
raptor
21:17:27 up 3 days, 15 min, 1 user, load average: 0.00, 0.00, 0.00
Connection to genja.org closed.
$ ssh genja.org uptime
host: genja.lan
21:17:43 up 12 days, 17:40, 1 user, load average: 0.30, 0.08, 0.02
...and the error:
$ ssh genja.org 'ssh raptor.lan hostname\; uptime'
host: genja.lan
Permission denied (publickey,keyboard-interactive).
You may want to make a tunnel instead:
ssh -L 4444:raptor.lan:22 genja.org
Then, on a different terminal:
ssh -p 4444 localhost will give you a conenction straight to "raptor.lan"
Use IP addresses such as 192.168.0.11 if DNS aliases are not configured on the remote end.
来源：https://stackoverflow.com/questions/12480284/ssh-error-when-executing-a-remote-command-stdin-is-not-a-tty