diff options
Diffstat (limited to 'cmd2/utils.py')
| -rw-r--r-- | cmd2/utils.py | 20 |
1 files changed, 14 insertions, 6 deletions
diff --git a/cmd2/utils.py b/cmd2/utils.py index a0026eba..45c7ca6a 100644 --- a/cmd2/utils.py +++ b/cmd2/utils.py @@ -371,7 +371,7 @@ class ByteBuf(object): class ProcReader(object): - """Used to read stdout and stderr from a Popen process whose stdout and stderr are set to binary pipes""" + """Used to read stdout and stderr from a Popen process if any of those were set to subprocess.PIPE""" def __init__(self, proc: subprocess.Popen, stdout: Union[StdSim, BinaryIO, TextIO], stderr: Union[StdSim, BinaryIO, TextIO]) -> None: """ @@ -390,9 +390,11 @@ class ProcReader(object): self._err_thread = threading.Thread(name='out_thread', target=self._reader_thread_func, kwargs={'read_stdout': False}) - # Start reading from the process - self._out_thread.start() - self._err_thread.start() + # Start the reader threads for pipes only + if self._proc.stdout is not None: + self._out_thread.start() + if self._proc.stderr is not None: + self._err_thread.start() def terminate(self) -> None: """Terminates the process being run""" @@ -400,10 +402,13 @@ class ProcReader(object): def wait(self) -> None: """Wait for the process to finish""" - self._out_thread.join() - self._err_thread.join() + if self._out_thread.is_alive(): + self._out_thread.join() + if self._err_thread.is_alive(): + self._err_thread.join() # Handle case where the process ended before the last read could be done + # This will return None for the streams that weren't pipes so it is safe. out, err = self._proc.communicate() if out: self._write_bytes(self._stdout, out) @@ -422,6 +427,9 @@ class ProcReader(object): read_stream = self._proc.stderr write_stream = self._stderr + # The thread should have been started only if this stream was a pipe + assert read_stream is not None + # Run until process completes while self._proc.poll() is None: # noinspection PyUnresolvedReferences |