Why do some ssh sessions offer autocomplete and some not?

Question

Very newbie question!

I'm sshing to two different servers, both part of the same Amazon AWS cluster. They're not run by me.

On one ssh session, the terminal lets me autocomplete. On the other session, it doesn't - I wish it did.

Why is this - is it an option set by the server administrator?

And can I do anything about it?

thanks!

Answer 1

This isn't really a programming question, but it has to do with your shell. You can try starting the bash shell (by typing bash at the prompt) and see if you can autocomplete.

If that works you can use which bash to verify it's location and then chsh -s /bin/bash to set your shell permanently.

A list of available shells can also be found in /etc/shells.

Answer 2

It is a combination of the shell that is being used in your ssh session as well as it's configuration.

While your shell may support autocompletion it may not be configured for it. If you're using the bash shell, you can edit your local .bashrc file for the following to provide autocomplete.

# enable bash completion in interactive shells
if [ -f /etc/bash_completion ]; then
    . /etc/bash_completion
fi

Answer 3

IIRC it could also be an issue that ssh hashes the hostnames in ~/.ssh/known_hosts

most installations I know use ~/.ssh/known_hosts as source for the list of available hosts for completion but some systems also started to set "HashKnownHosts yes", which prohibits using known_hosts as a source....

if your known hosts lines start with something like

|1|BWO5qDxk/cFH0wa05JLdHn+j6xQ=|rXQvIxh5cDD3C4

then hashing is activated.