#!/usr/bin/env python3

import locale
import os
import subprocess

if __name__ == "__main__":
    print("*" * 100)
    print(locale.getpreferredencoding())

    print("*" * 100)
    result = subprocess.run(
        ['env'],
        capture_output=True,
    )
    result.check_returncode()
    print('return code:', result.returncode)
    print(result.stdout)
    print("*" * 100)
    result = subprocess.run(
        ['env'],
        capture_output=True,
        text=True,
        encoding='utf-8',
    )
    result.check_returncode()
    print('return code:', result.returncode)
    print(f"{result.stdout[:100]}******")

    print("*" * 100)
    subprocess.run(
        ['env'],
        env={"NAME": "hatter"},
    )

    print("*" * 100)
    my_env = os.environ.copy()
    my_env["NAME"] = "hatter"
    subprocess.run(
        ['sleep', '5'],
        env=my_env,
        check=True,  # 非 0 返回时抛出异常
    )

    print("*" * 100)
    subprocess.Popen(
        ['sleep', '50'],
        stdout=subprocess.DEVNULL,
        stderr=subprocess.DEVNULL,
        preexec_fn=os.setpgrp  # 让子进程独立，即使当前脚本挂了它也继续运行
    )

    print("*" * 100)