Debugging pipe IPC

[Jim B. Wilson]

Ian Clark wrote:

 > import os
 > os.system("netcat -l -p 1234 localhost")
 >
 > HTH,

Nope, but the network theme got me thinking about how one might run 
Python on a remote host.  After a few false starts, Googling "remote 
python shell" led me to Guido's "ripshell.py" (not *that* Guido, a 
different one).  Peeking inside, I discovered the module I'm looking for 
was "code".  Remember, in my case, communication on stdin and stdout
was all handled by a Pyrex extension.  I'm unsure the code below will 
work in a pure Python application.

For posterity, here is itest.py, the solution to my problem:

###	itest.py - allows interactive debugging of a "filter"
#
#  If stdin and stdout are dedicated to your filter script, but you
#  want to interactively check a few things, try something like this:

from code import interact
import sys

sys.stdout = open("/dev/tty", "w")	# Rebind Python's lips
sys.stdin  = open("/dev/tty", "r")	#  and Python's ears.

foo = "This is a test"		# Lay down some history
interact(			# Convenience function from code.
   "At your service, Sir!",	#   BUG: could be "Madam" or "Miss"
   local = locals())		#   Teach interpreter some history
print "Thank you, Sir!"		# BUG: ibid.

To check this works:

$ python itest.py </dev/null >/dev/full # mother is a deafmute
At your service, Sir!
 >>> foo
'This is a test'
 >>> ^D (not shown)
Thank you, Sir!
$