openssh unix dev - Apr 2015 - Is ssh supposed to run commands in terminal?

I noticed that this command returns NO through ssh:
 > $ ssh user at host "if [ -t 1 ]; then echo YES; else echo NO;
fi"
 > NO
and YES when run locally (of course):
 > $ if [ -t 1 ]; then echo YES; else echo NO; fi
 > YES

I can't find any command line option related to running command remotely 
in terminal. I think users intuitively expect commands to be run in 
terminal.
Is something broken with my ssh setup?

ssh on FreeBSD 10.1

Yuri

On 04/15/2015 08:48 AM, Yuri wrote:
> I noticed that this command returns NO through ssh:
>  > $ ssh user at host "if [ -t 1 ]; then echo YES; else echo NO;
fi"
>  > NO
> and YES when run locally (of course):
>  > $ if [ -t 1 ]; then echo YES; else echo NO; fi
>  > YES
>
> I can't find any command line option related to running command
remotely
> in terminal.
-o RequestTTY=yes

I think users intuitively expect commands to be run in
> terminal.
> Is something broken with my ssh setup?
>
> ssh on FreeBSD 10.1
>
> Yuri
> _______________________________________________
> openssh-unix-dev mailing list
> openssh-unix-dev at mindrot.org
> https://lists.mindrot.org/mailman/listinfo/openssh-unix-dev

On 2015-04-15, Yuri <yuri at rawbw.com> wrote:
> I can't find any command line option related to running command
remotely
> in terminal.
-t, -T
The term you are looking for is "tty".
> I think users intuitively expect commands to be run in 
> terminal.
Historically, the idea was that users expect ssh(1) to behave like
rsh(1), which did not allocate a tty.

-- 
Christian "naddy" Weisgerber                          naddy at
mips.inka.de

On 04/15/2015 00:49, Christian Kandeler wrote:
>
> -o RequestTTY=yes

Thanks, this works.

However, with this option ssh alters the output of all commands: it adds 
CR=0x0d in front of every NL=0x0a. This doesn't happen without this option.
Why is sshd adding CR?

I think the only effect of running in the terminal is the term flag that 
the process sees on the stdin and stdout (in shell it is [ -t 1 ]). The 
process is supposed to detect the terminal caps and print the output 
accordingly.

I even verified that this is sshd is doing it and not the cat command by 
writing the C program printing newlines.

Yuri