Example #1
0
def popen(cmd, args, mode, capture_err=1):
    if sys.platform == "win32":
        command = win32popen.CommandLine(cmd, args)

        if mode.find('r') >= 0:
            hStdIn = None

            if debug.SHOW_CHILD_PROCESSES:
                dbgIn, dbgOut = None, StringIO.StringIO()

                handle, hStdOut = win32popen.MakeSpyPipe(0, 1, (dbgOut, ))

                if capture_err:
                    hStdErr = hStdOut
                    dbgErr = dbgOut
                else:
                    dbgErr = StringIO.StringIO()
                    x, hStdErr = win32popen.MakeSpyPipe(None, 1, (dbgErr, ))
            else:
                handle, hStdOut = win32popen.CreatePipe(0, 1)
                if capture_err:
                    hStdErr = hStdOut
                else:
                    hStdErr = win32popen.NullFile(1)

        else:
            if debug.SHOW_CHILD_PROCESSES:
                dbgIn, dbgOut, dbgErr = StringIO.StringIO(), StringIO.StringIO(
                ), StringIO.StringIO()
                hStdIn, handle = win32popen.MakeSpyPipe(1, 0, (dbgIn, ))
                x, hStdOut = win32popen.MakeSpyPipe(None, 1, (dbgOut, ))
                x, hStdErr = win32popen.MakeSpyPipe(None, 1, (dbgErr, ))
            else:
                hStdIn, handle = win32popen.CreatePipe(0, 1)
                hStdOut = None
                hStdErr = None

        phandle, pid, thandle, tid = win32popen.CreateProcess(
            command, hStdIn, hStdOut, hStdErr)

        if debug.SHOW_CHILD_PROCESSES:
            debug.Process(command, dbgIn, dbgOut, dbgErr)

        return _pipe(win32popen.File2FileObject(handle, mode), phandle)

    # flush the stdio buffers since we are about to change the FD under them
    sys.stdout.flush()
    sys.stderr.flush()

    r, w = os.pipe()
    pid = os.fork()
    if pid:
        # in the parent

        # close the descriptor that we don't need and return the other one.
        if mode.find('r') >= 0:
            os.close(w)
            return _pipe(os.fdopen(r, mode), pid)
        os.close(r)
        return _pipe(os.fdopen(w, mode), pid)

    # in the child

    # we'll need /dev/null for the discarded I/O
    null = os.open('/dev/null', os.O_RDWR)

    if mode.find('r') >= 0:
        # hook stdout/stderr to the "write" channel
        os.dup2(w, 1)
        # "close" stdin; the child shouldn't use it
        ### this isn't quite right... we may want the child to read from stdin
        os.dup2(null, 0)
        # what to do with errors?
        if capture_err:
            os.dup2(w, 2)
        else:
            os.dup2(null, 2)
    else:
        # hook stdin to the "read" channel
        os.dup2(r, 0)
        # "close" stdout/stderr; the child shouldn't use them
        ### this isn't quite right... we may want the child to write to these
        os.dup2(null, 1)
        os.dup2(null, 2)

    # don't need these FDs any more
    os.close(null)
    os.close(r)
    os.close(w)

    # the stdin/stdout/stderr are all set up. exec the target
    try:
        os.execvp(cmd, (cmd, ) + tuple(args))
    except:
        # aid debugging, if the os.execvp above fails for some reason:
        print "<h2>exec failed:</h2><pre>", cmd, ' '.join(args), "</pre>"
        raise

    # crap. shouldn't be here.
    sys.exit(127)
Example #2
0
def pipe_cmds(cmds, out=None):
  """Executes a sequence of commands. The output of each command is directed to
  the input of the next command. A _pipe object is returned for writing to the
  first command's input. The output of the last command is directed to the
  "out" file object or the standard output if "out" is None. If "out" is not an
  OS file descriptor, a separate thread will be spawned to send data to its
  write() method."""

  if out is None:
    out = sys.stdout

  if sys.platform == "win32":
    ### FIXME: windows implementation ignores "out" argument, always
    ### writing last command's output to standard out

    if debug.SHOW_CHILD_PROCESSES:
      dbgIn = StringIO.StringIO()
      hStdIn, handle = win32popen.MakeSpyPipe(1, 0, (dbgIn,))

      i = 0
      for cmd in cmds:
        i = i + 1

        dbgOut, dbgErr = StringIO.StringIO(), StringIO.StringIO()

        if i < len(cmds):
          nextStdIn, hStdOut = win32popen.MakeSpyPipe(1, 1, (dbgOut,))
          x, hStdErr = win32popen.MakeSpyPipe(None, 1, (dbgErr,))
        else:
          ehandle = win32event.CreateEvent(None, 1, 0, None)
          nextStdIn, hStdOut = win32popen.MakeSpyPipe(None, 1, (dbgOut, sapi.server.file()), ehandle)
          x, hStdErr = win32popen.MakeSpyPipe(None, 1, (dbgErr,))

        command = win32popen.CommandLine(cmd[0], cmd[1:])
        phandle, pid, thandle, tid = win32popen.CreateProcess(command, hStdIn, hStdOut, hStdErr)
        if debug.SHOW_CHILD_PROCESSES:
          debug.Process(command, dbgIn, dbgOut, dbgErr)

        dbgIn = dbgOut
        hStdIn = nextStdIn


    else:

      hStdIn, handle = win32popen.CreatePipe(1, 0)
      spool = None

      i = 0
      for cmd in cmds:
        i = i + 1
        if i < len(cmds):
          nextStdIn, hStdOut = win32popen.CreatePipe(1, 1)
        else:
          # very last process
          nextStdIn = None

          if sapi.server.inheritableOut:
            # send child output to standard out
            hStdOut = win32popen.MakeInheritedHandle(win32popen.FileObject2File(sys.stdout),0)
            ehandle = None
          else:
            ehandle = win32event.CreateEvent(None, 1, 0, None)
            x, hStdOut = win32popen.MakeSpyPipe(None, 1, (sapi.server.file(),), ehandle)

        command = win32popen.CommandLine(cmd[0], cmd[1:])
        phandle, pid, thandle, tid = win32popen.CreateProcess(command, hStdIn, hStdOut, None)
        hStdIn = nextStdIn

    return _pipe(win32popen.File2FileObject(handle, 'wb'), phandle, ehandle)

  # flush the stdio buffers since we are about to change the FD under them
  sys.stdout.flush()
  sys.stderr.flush()

  prev_r, parent_w = os.pipe()

  null = os.open('/dev/null', os.O_RDWR)

  child_pids = []

  for cmd in cmds[:-1]:
    r, w = os.pipe()
    pid = os.fork()
    if not pid:
      # in the child

      # hook up stdin to the "read" channel
      os.dup2(prev_r, 0)

      # hook up stdout to the output channel
      os.dup2(w, 1)

      # toss errors
      os.dup2(null, 2)

      # close these extra descriptors
      os.close(prev_r)
      os.close(parent_w)
      os.close(null)
      os.close(r)
      os.close(w)

      # time to run the command
      try:
        os.execvp(cmd[0], cmd)
      except:
        pass

      sys.exit(127)

    # in the parent
    child_pids.append(pid)

    # we don't need these any more
    os.close(prev_r)
    os.close(w)

    # the read channel of this pipe will feed into to the next command
    prev_r = r

  # no longer needed
  os.close(null)

  # done with most of the commands. set up the last command to write to "out"
  if not hasattr(out, 'fileno'):
    r, w = os.pipe()

  pid = os.fork()
  if not pid:
    # in the child (the last command)

    # hook up stdin to the "read" channel
    os.dup2(prev_r, 0)

    # hook up stdout to "out"
    if hasattr(out, 'fileno'):
      if out.fileno() != 1:
        os.dup2(out.fileno(), 1)
        out.close()

    else:
      # "out" can't be hooked up directly, so use a pipe and a thread
      os.dup2(w, 1)
      os.close(r)
      os.close(w)

    # close these extra descriptors
    os.close(prev_r)
    os.close(parent_w)

    # run the last command
    try:
      os.execvp(cmds[-1][0], cmds[-1])
    except:
      pass

    sys.exit(127)

  child_pids.append(pid)
  # not needed any more
  os.close(prev_r)

  if not hasattr(out, 'fileno'):
    os.close(w)
    thread = _copy(r, out)
    thread.start()
  else:
    thread = None

  # write into the first pipe, wait on the final process
  return _pipe(os.fdopen(parent_w, 'w'), child_pids, thread=thread)