Zsh completion for ssh confuses hostnames with local files

autocompletezsh

suppose I have following entry in my /etc/hosts

192.168.1.10      server1.mydomain.com

and I have a directory SERVER-FILES in current dir. I want to scp the directory SERVER-FILES somewhere. I type SE and use autocompletion to complete the directory name:

$ scp -rp SE<TAB>

This completion should be totally unambiguous. But zsh autocomplletion tries to be too smart, and treats hostnames case-insensitive, and thus attempts to match SE to hostnames:

$ scp -rp SE<TAB>
SERVER-FILES/
server1.mydomain.com

How can I disable this annoying feature, where zsh is trying to match hostnames case-insensitive, and therefore completes SE<TAB> to server1.mydomain.com` ?

UPDATE:

Based on suggestions from @zeppelin, I have changed the following line in the ssh completion file Unix/_ssh:

- compadd -M 'm:{a-zA-Z}={A-Za-z} r:|.=* r:|=*' "$@" $config_hosts
+ compadd "$@" $config_hosts

but that did not help. It has absolutely no effect.

And I don't understand the answer from @Tomasz Pala. My zsh completion is not case-insensitive.

Please sopmebody just tell me what I need to change in /usr/share/zsh/functions/Completion/Unix/_foo to change this behaviour.

UPDATE 2

I have finally narrowed the problem down, and found out why the solution from @Tomasz Pala did work for him, but not for me:

When I change the Unix/_hosts file on a newly setup machine/user account, the solution works.

scp -r SE<TAB>

The above command ignores server1.mydomain.com in /etc/hosts, and only offers local directory SERVER-FILES for completion.

But this does not work for me on my existing user account, because I have
server.mydomain.com in my ~/.ssh/config. When I remove the entry, then everything works as desired.

But how can I make this hack work even with my current ~/.ssh/config ?

Best Answer

Second answer tries to explain that you need to do two things:

1_ make sure your general matching rules are not case-insensitive (matcher-list) - from the updated question it's not,

2_ change Unix/(Type/)_hosts (the actual location might vary, but not the Unix/_ssh - this one handles ~/.ssh/config hosts, see below) last 2 lines to:

_wanted hosts expl host \
   compadd -M 'm:{a-z}={A-Z} r:|.=* r:|=*' -a "$@" - _hosts

All of this was already summarized in my answer, so simply try doing this without reading all the rationale before. Also, since your global config is not case-insensitive, the @zeppelin's answer should also work, although it doesn't use $fpath and removes also small->CAPS matching of the hosts.

I did test this with your settings from the update and it works as expected.

Update: remember that zsh keeps it's functions loaded, so after modifying the _hosts you need to reload it either by logging in fresh, or:

unfunction _hosts
autoload -Uz _hosts

Also remember that zsh can have the scripts 'compiled' in zwc form (zcompile [file]) and if such file exists and is newer than the source it would be used instead.

Ad. update 2:

Handling the ~/.ssh/config defined hosts is actually pretty much the same as for _hosts - depending on your zsh version in either Unix/(Command/)_ssh or Unix/(Type/)_ssh_hosts change the

compadd -M 'm:{a-zA-Z}={A-Za-z} r:|.=* r:|=*' "$@" $config_hosts

line to

compadd -M 'm:{a-z}={A-Z} r:|.=* r:|=*' "$@" $config_hosts

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