using an interactive program (e.g. python) under conch

[holtzermann17]

This seems related to #10, but as a specific example I wonder whether this can be made to work properly. I repeat the example from the docs to show that cat is working, but python behaves differently. Can an interactive program be made to work with Conch?

flowrweb.core=> (def p (sh/proc "cat"))
#'flowrweb.core/p
flowrweb.core=> (future (sh/stream-to-out p :out))
#future[{:status :pending, :val nil} 0x6e1e2ba]
flowrweb.core=> (sh/feed-from-string p "foo\n")
foo
nil
flowrweb.core=> (def py (sh/proc "python"))
#'flowrweb.core/py
flowrweb.core=> (future (sh/stream-to-out py :out))
#future[{:status :pending, :val nil} 0x5645b83]
flowrweb.core=> (sh/feed-from-string py "1+1\n")
nil
flowrweb.core=> (future (sh/stream-to-out py :err))
#future[{:status :pending, :val nil} 0x455548ec]
flowrweb.core=> (sh/feed-from-string py "1+1\n")
nil
flowrweb.core=> 

[holtzermann17]

Mainly, python needs to be called with the -i flag.

And there's at least one further confusing point, starting with (*) below.

(def sh-python (sh/proc "python" "-i"))
;=> #'flowrweb.core/sh-python
(future (sh/stream-to-out sh-python :out))      
#future[{:status :pending, :val nil} 0x24cf71f]
(sh/feed-from-string sh-python "1+1\n")
;=> 2
;=> nil
(def sh-python (sh/proc "python" "-i"))
;=> #'flowrweb.core/sh-python
(future (sh/stream-to-out sh-python :out))           ;;; (*) for e.g. numeric output
;=> #future[{:status :pending, :val nil} 0x24cf71f]
(future (sh/stream-to-out sh-python :err))           ;;; (*) for >>> decorations etc.
;=> Python 2.7.9 (default, Apr  2 2015, 15:33:21) 
;=> [GCC 4.9.2] on linux2
;=> Type "help", "copyright", "credits" or "license" for more information.
;=> >>>
;=> #future[{:status :pending, :val nil} 0x2aea9bf0]
(sh/feed-from-string sh-python "1+1\n")
;=> >>> 2
;=> nil

Note in that output from both *err* and *out* is redirected to the *nrepl-server* buffer under CIDER; cf #1588 in the CIDER issue queue.

I think this may be helped on the Conch side from #31.

Closing.