Re: Mysterious completion of variables

[Hannu Koivisto <azure@iki.fi>]

Ian Langworth <ian.langworth@gmail.com> writes:

> I have a few variables for hosts that I shell into frequently:
>
>   aspen='me@aspen.mydomain.com'
>   alias aspen="ssh $aspen"
>
> Thus, I'm usually able to do the following:
>
>   scp $aspen:temp .

Since Peter explained that a more complex form is required, I would
like to suggest another approach that avoids such a variable to
begin with.

Add...

Host aspen
Hostname aspen.mydomain.com
User me

...to your ~/.ssh/config file.  This allows you to write 
'scp aspen:temp .' and 'ssh aspen'.

You might also want to replace _ssh_hosts in _ssh with the function
I provided in a mail sent earlier to this list.  I reproduce it
here in order to save you the trouble of finding it from the
archives:

-----8<------------------------------------------------------------
I modified ssh completion to dig host aliases from the
configuration file.  I don't use wildcards in host patterns or give
multiple patterns, so this doesn't attempt to handle such cases.  I
also have no idea whether this modification is otherwise well
written or not; I'm still a beginner in completion hacking.  All
comments appreciated.

I think that a well written version (one that handles multiple
patterns and patterns with wildcards, among the other issues) of
the same subject would be nice as a standard feature.  One might
also want to utilize hosts from the known_hosts file.

_ssh_hosts () {
  if [[ "$IPREFIX" == *@ ]]; then
    _combination -s '[:@]' my-accounts users-hosts "users=${IPREFIX/@}" hosts "$@"
  else
    _combination -s '[:@]' my-accounts users-hosts \
      ${opt_args[-l]:+"users=${opt_args[-l]:q}"} hosts "$@"
  fi
  if [[ -r "$HOME/.ssh/config" ]]; then
      local IFS=" 	" key host
      while read key host; do
          if [[ "$key" == (#i)host ]]; then
              _wanted hosts expl host \
                  compadd -M 'm:{a-zA-Z}={A-Za-z} r:|.=* r:|=*' "$@" "$host"
          fi
      done < "$HOME/.ssh/config"
  fi
}
-----8<------------------------------------------------------------

This allows you to say 'scp a<tab>' and get 'scp aspen:' assuming
you don't have other hosts beginning with 'a'.  I hope it works
with _ssh of recent zsh versions, I haven't tested; I made a copy
of _ssh from an older version to a personal function directory with
higher priority and modified that.

-- 
Hannu