Hello,
On Wednesday, 12 February 2014 20:14:25 UTC+11, Victor Stinner wrote:
>
> Hi,
>
> Tulip now has multiple examples showing how to interact with stdin and
> stdout:
> - examples/child_process.py (low-level API, as you did)
> - examples/shell.py
> - examples/subprocess_shell.py
Maybe I'm misunderstanding - all of these examples demonstrate communicating
with stdin/stdout of a subprocess - I am looking to communicate over
stdin/stdout in the current running process, communicating with a parent
process, e.g. a terminal.
> It looks like you are using an old version, please try the latest
> version (0.3.1).
Thank you! I've done this now. I feel much better having gotten rid of that.
>
>
> It's hard to tell you what is the problem. First, what is the program
> you are running (the one which reads stdin and writes stdout)?
I am running the given example in a terminal, interacting with it directly
myself.
>
>
> I don't think that _set_nonblocking() is needed. It's done by
> connect_read/write_pipe() if I remember correctly. Where does
> _set_nonblocking() come from? asyncio.unix_events? If yes, please
> don't use private methods.
Indeed, it would appear that _set_nonblocking is not needed. For the record,
I know that private methods shouldn't be used - I just thought it would help
clarify that blocking vs non-blocking wasn't the issue. Sorry for the
confusion.
>
>
> >> writer = StreamWriter(transport, protocol, reader, EVENT_LOOP)
>
> Here you connect stdin to stdout with the reader parameter. In the
> latest version you can pass None for the reader. But it should not be
> an issue.
Yep, it doesn't seem to be an issue - I have tried both versions to
completeness.
>
> If you would like to make sure that all data are written, you may add:
> yield from writer.drain()
Okay, so calling this meant changing that placeholder Stdio class to inherit
from asyncio.streams.FlowControlMixin, because the drain method assumes the
protocol has a _make_drain_waiter method.
After reading from stdin, I get a ConnectionResetError.
test
b'test\n'
Traceback (most recent call last):
File "stdio.py", line 31, in <module>
EVENT_LOOP.run_until_complete(stdio())
File
"/home/nathan/.local/lib/python3.3/site-packages/asyncio/base_events.py",
line 177, in run_until_complete
return future.result()
File "/home/nathan/.local/lib/python3.3/site-packages/asyncio/futures.py",
line 236, in result
raise self._exception
File "/home/nathan/.local/lib/python3.3/site-packages/asyncio/tasks.py",
line 279, in _step
result = coro.send(value)
File "stdio.py", line 28, in stdio
yield from writer.drain()
File "/home/nathan/.local/lib/python3.3/site-packages/asyncio/streams.py",
line 247, in drain
raise ConnectionResetError('Connection lost')
ConnectionResetError: Connection lost
But if I don't read from stdin, then no error occurs:
b'test line\n'
data received test line
b'test line\n'
data received test line
b'test line\n'
data received test line
b'test line\n'
data received test line
b'test line\n'
data received test line
b'test line\n'
data received test line
b'test line\n'
data received test line
b'test line\n'
data received test line
b'test line\n'
data received test line
b'test line\n'
data received test line
Thank you,
Nathan.
