timeout does not work for sys.stdin

[karpetrosyan]

This code hangs until ENTER was not pressed

import sys
import trio

async def main():
    with trio.move_on_after(1):
        file = trio.wrap_file(sys.stdin)
        async for line in file:
            print(line)

trio.run(main)

[njsmith]

Unfortunately, that's expected -- move_on_after will attempt to cancel the operation after 1 second, but wrap_file uses threads, and since Python/operating systems don't provide any way to cancel a thread, the cancellation fails. If you're on macOS/Linux and just want to read arbitrary data off stdin, you can use trio.lowlevel.FdStream(os.dup(sys.stdin)) to get "real" async access to stdin as a trio.abc.Stream. For more general support, we'd need to add terminal support to Trio, which we would love to do but it's a huge project (#174) so it hasn't happened yet.

…

On Thu, Jun 1, 2023 at 11:50 PM Karen Petrosyan ***@***.***> wrote: This code hangs until ENTER was not pressed import sysimport trio async def main(): with trio.move_on_after(1): file = trio.wrap_file(sys.stdin) async for line in file: print(line) trio.run(main) — Reply to this email directly, view it on GitHub <#2660>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAEU42BSMMA5P4YCDKV5J6LXJGEKPANCNFSM6AAAAAAYX4UTMU> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

-- Nathaniel J. Smith -- https://vorpus.org <http://vorpus.org>

[njsmith]

already tracked in #174