New submission from Vahid Mardani:
Assume this simple script for reading from stdin:
```python
#! /usr/bin/env python3
import sys
import os
import asyncio
async def main(loop):
done = False
fileno = sys.stdin.fileno()
def _reader():
nonlocal done
chunk = os.read(fileno, 1024)
if not chunk:
loop.remove_reader(fileno)
done = True
return
print(chunk.decode(), end='')
loop.add_reader(fileno, _reader)
while not done:
await asyncio.sleep(1)
if __name__ == '__main__':
main_loop = asyncio.get_event_loop()
main_loop.run_until_complete(main(main_loop))
```
When I run it by:
```bash
$ ./stdin_issue.py <<EOF
> hello
> EOF
```
I get:
```
Traceback (most recent call last):
File "/usr/lib/python3.5/asyncio/selector_events.py", line 234, in add_reader
key = self._selector.get_key(fd)
File "/usr/lib/python3.5/selectors.py", line 191, in get_key
raise KeyError("{!r} is not registered".format(fileobj)) from None
KeyError: '0 is not registered'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "./stdin_issue.py", line 41, in <module>
main_loop.run_until_complete(main(main_loop))
File "/usr/lib/python3.5/asyncio/base_events.py", line 387, in
run_until_complete
return future.result()
File "/usr/lib/python3.5/asyncio/futures.py", line 274, in result
raise self._exception
File "/usr/lib/python3.5/asyncio/tasks.py", line 239, in _step
result = coro.send(None)
File "./stdin_issue.py", line 34, in main
loop.add_reader(fileno, _reader)
File "/usr/lib/python3.5/asyncio/selector_events.py", line 237, in add_reader
(handle, None))
File "/usr/lib/python3.5/selectors.py", line 411, in register
self._epoll.register(key.fd, epoll_events)
PermissionError: [Errno 1] Operation not permitted
```
But the:
```bash
echo "Hello" | ./stdin_issue.py
```
Is working well.
I was already tried this with the `select.select` directly, and it working:
```
def using_select():
files = [sys.stdin.fileno()]
while True:
readables, _, errors = select(files, [], files)
if errors:
print('ERROR:', errors)
return
if readables:
for f in readables:
chunk = os.read(f, 1024)
if not chunk:
return
print(chunk.decode(), end='')
```
----------
components: asyncio
messages: 288941
nosy: gvanrossum, vahid.mardani, yselivanov
priority: normal
severity: normal
status: open
title: `loop.add_reader` and `<<EOF`
versions: Python 3.5
_______________________________________
Python tracker <rep...@bugs.python.org>
<http://bugs.python.org/issue29717>
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