Re: Prompt expansion, multi-job for

[Peter Stephenson <pws@pwstephenson.fsnet.co.uk>]

Andre Pang wrote:
> Hiya guys,
> 
>     I've got two completely separate questions about zsh.
> 
>     1) Let's say I'm in the /usr/local/src path at the moment.  Normally, if
> you use the %~ prompt expansion, it will expand to /usr/local/src - no
> surprises there.  What I'd like to do is trim each path element to one
> character unless it's the last path element, in which case it should be
> displayed to a maximum of, say, 15 characters.  eg, /usr/local/src should be
> displayed as "/u/l/src", /usr/local/src/linux would be displayed as
> "/u/l/s/linux", and /usr/local/src/linux-2.2.14+reiserfs+raid+ide might be
> displayed as "/u/l/s/linux-2.2.14...".  Is this possible with the current
> prompt expansion codes, or will I have to write up a function to do it, if
> it's possible to do at all?

Without ~ backsubstitution (i.e. full paths with no insertion of ~'s), you
can do it with the latest code as follows --- it won't work even with
3.1.6, because of the use of backreferences, as you've already discovered,
so you'll need to get zsh-3.1.6-dev-14 from the development directory on
the standard archives (if they're up to date).

setopt extendedglob promptsubst
PS1='${${PWD:h}//(#b)(\\/[^\\/])[^\\/]#/$match[1]}${${PWD:t}:+/}%15>...>${PWD:t}'

I'll explain it if you like, but that would take a good deal longer than
inventing it.  I can't think of a way of getting the ~'s back just using
parameter code, sorry (anyone else?).  If you can live with just $HOME put
back, you can replace PWD both times with ${PWD/$HOME/~}.

-- 
Peter Stephenson <pws@pwstephenson.fsnet.co.uk>