Mac/Contrib/mpwsystem/mpwsystem.py

   1
   2 """mpwsystem -
   3 A simple example of how to use Apple Events to implement a "system()"
   4 call that invokes ToolServer on the command.
   5
   6 Contributed by Daniel Brotsky <dev@brotsky.com>.
   7
   8 (renamed from aesystem to mpwsystem by Jack)
   9
  10 system(cmd, infile = None, outfile = None, errfile = None)
  11
  12 1. Every call to system sets "lastStatus" and "lastOutput" to the
  13 status and output
  14 produced by the command when executed in ToolServer.  (lastParameters
  15 and lastAttributes
  16 are set to the values of the AppleEvent result.)
  17
  18 2. system returns lastStatus unless the command result indicates a MacOS error,
  19 in which case os.Error is raised with the errnum as associated value.
  20
  21 3. You can specify ToolServer-understandable pathnames for
  22 redirection of input,
  23 output, and error streams.  By default, input is Dev:Null, output is captured
  24 and returned to the caller, diagnostics are captured and returned to
  25 the caller.
  26 (There's a 64K limit to how much can be captured and returned this way.)"""
  27
  28 import os
  29 import aetools
  30
  31 try: server
  32 except NameError: server = aetools.TalkTo("MPSX", 1)
  33
  34 lastStatus = None
  35 lastOutput = None
  36 lastErrorOutput = None
  37 lastScript = None
  38 lastEvent = None
  39 lastReply = None
  40 lastParameters = None
  41 lastAttributes = None
  42
  43 def system(cmd, infile = None, outfile = None, errfile = None):
  44         global lastStatus, lastOutput, lastErrorOutput
  45         global lastScript, lastEvent, lastReply, lastParameters, lastAttributes
  46         cmdline = cmd
  47         if infile: cmdline += " <" + infile
  48         if outfile: cmdline += " >" + outfile
  49         if errfile: cmdline += " " + str(chr(179)) + errfile
  50         lastScript = "set Exit 0\r" + cmdline + "\rexit {Status}"
  51         lastEvent = server.newevent("misc", "dosc", {"----" : lastScript})
  52         (lastReply, lastParameters, lastAttributes) = server.sendevent(lastEvent)
  53         if lastParameters.has_key('stat'): lastStatus = lastParameters['stat']
  54         else: lastStatus = None
  55         if lastParameters.has_key('----'): lastOutput = lastParameters['----']
  56         else: lastOutput = None
  57         if lastParameters.has_key('diag'): lastErrorOutput = lastParameters['diag']
  58         else: lastErrorOutput = None
  59         if lastParameters['errn'] != 0:
  60                 raise os.Error, lastParameters['errn']
  61         return lastStatus
  62
  63 if __name__ == '__main__':
  64         sts = system('alert "Hello World"')
  65         print 'system returned', sts
  66
  67