[PD] communicating with the shell

[patrick]

another solution is with pyext.
in pdmtl abstractions it's under linux.process.pd (but i think it should 
work on windows and mac (not tested)).

import sys, os, time, signal, subprocess
try:
    import pyext
except:
    print "ERROR: This script must be loaded by the PD pyext external"
    sys.exit()

class sub(pyext._class):
    """A simple script to start and stop process"""

    # number of inlets and outlets
    _inlets=1
    _outlets=1
   
    def __init__(self,*args):
        pass
   
    def start_1(self,a):
        global process
        process = subprocess.Popen(str(a))
        self._outlet(1, 'opening '+str(a))
       
    def stop_1(self,*a):
        os.kill(process.pid, signal.SIGTERM)
        self._outlet(1, 'stopping process '+str(process.pid))