I’ve been annoyed by a message when scripting my rsync backups for some time now.

“stdin: is not a tty”

which I spent a while trying to sort out today.

Turns out that it is associated with the setup of the shell on the servers where I manage some hosted sites.

In my rsync commands I have embedded the ssh commands and adding -q(quiet) to make the messages go away makes no difference. Adding a -t for tty setting makes no difference and adding -T is ineffective as well.

Hmm, according to the SSH syntax, repeating the -t may work.  Yep, it does.

ssh -qtt will suppress the message about the tty!

Except, that I now get an error “tcgetattr: Invalid argument” which is triggered apparently by the second ‘t’.

I’ve left it. I now get my logs of the rsync transactions that I was not getting with the tty error message and the other error does not impact anything that I can see.