Do subprocess.PIPE and subprocess.STDOUT sametime

[Horst Koiner]

Using asyncio for this is a good possibility I was not aware of.

My best try with asyncio was:
import asyncio

async def run_command():
    # Create subprocess
    process = await asyncio.create_subprocess_exec(
        './test.sh',
        stdout=asyncio.subprocess.PIPE,  # Redirect stdout to a pipe
        stderr=asyncio.subprocess.PIPE  # Redirect stderr to a pipe
    )

    # Read stdout and stderr asynchronously
    captured_output = b''
    async for line in process.stdout:
        print(line.decode().strip())
        captured_output += line
    async for line in process.stderr:
        print(line.decode().strip())
        captured_output += line

    await process.wait()
    print(captured_output)


# Run the asyncio event loop
asyncio.run(run_command())
########################################

This fulfills all my requirements. A nice to have would that the captured_output has not to be constructed with += 's but with a final seek(0) and read() of process.stdout. But I didn't find anything how to rewind the stream, that i can read the whole output again.
Another question is, if this solution is deadlock proof.

Thank you all for the already very valuable input!

Greetings,
Horst