[IPython-user] ipython -p sh questions

[Ville M. Vainio]

On Tue, Mar 4, 2008 at 7:28 PM, Ville M. Vainio <vivainio@gmail.com> wrote:

>  > > What does !$ do? If there in no equivalent yes, we can do it ;-)
>
>  > !$ designates the last argument of the preceding command.  (!!:n
>  >  designates the n-th argument of the preceding command).  I thought about
>  >  adding it to my config files but I'm always loathe to hack things in
>  >  when someone might've already done it better. :-)
>
>  Ah, such a thing does not exist but it could be useful. Hell, we could
>  add it to jobctrl as well. $! does not sit well in IPython due to Itpl
>  interpolation (even if it could be done with prefilters), but $LA
>  could be handy for this purpose. I.e. in jobctrl shell hook we could
>  set global variable LA in user_ns to have the last arg, and $LA will
>  naturally work.

This has now been added to the sh profile (in bzr). That is, you can
use $LA in system and magic commands (and LA() in normal python code):

[C:opt/Console2]|2> hello world
------------------------------------------------------------
   File "<ipython console>", line 1
     hello world
               ^
SyntaxError: invalid syntax

[C:opt/Console2]|3> echo $LA
world
[C:opt/Console2]|4> LA()
                <4> 'world'

The implementation is simple:
http://bazaar.launchpad.net/~ipython/ipython/stable-dev/revision/38

It is a bit of a 'hack', but it's a nondisruptive one; if you assign
to the LA variable, $LA will stop working but that's "safer" than
disallowing the users the use of variable named 'LA'...

-- 
Ville M. Vainio - vivainio.googlepages.com
blog=360.yahoo.com/villevainio - g[mail | talk]='vivainio'