non-blocking named pipe comms (Python)

Because I want to use this for work on Monday and I don’t feel like writing myself an email atm.

Optionally blocking writer (sender) and reader (receiver) via a named pipe in Python.

Feel free to use it – it’s hereby CC0-licensed.

import os
from time import sleep
import sys

Q_NAME = "a_q"
BLOCKING = sys.argv[1] == "-b" if len(sys.argv) > 1 else False
OPEN_FLAGS = os.O_WRONLY
if not BLOCKING:
    OPEN_FLAGS |= os.O_NONBLOCK
print("writer start")

if not os.path.exists(Q_NAME):
    os.mkfifo(Q_NAME)

for i in range(9999999999):
    try:
        q = os.open(Q_NAME, OPEN_FLAGS)
        print(f"sending {i}")
        os.write(q, f"test {i}\n".encode())
    except OSError as e:
        print(f"no listener, discarding {i}")
    sleep(1)

import os
import sys
import select
from time import sleep

Q_NAME = "a_q"
BLOCKING = sys.argv[1] == "-b" if len(sys.argv) > 1 else False
OPEN_FLAGS = os.O_RDONLY
if not BLOCKING:
    OPEN_FLAGS |= os.O_NONBLOCK
print("reader start")

if not os.path.exists(Q_NAME):
    os.mkfifo(Q_NAME)

while True:
    q = os.open(Q_NAME, OPEN_FLAGS)
    while True:
        rlist, _, _ = select.select([q], [], [], 2)
        if rlist:
            data = os.read(q, 1024).decode().strip()
            if len(data) == 0:
                print("stream closed")
                break
            else:
                print(data)
        else:
            print("no input")
            sleep(1)