无法通过asyncio使用bash命令

Question

我试图做一个简单的命令,我可以调用discord,让我看到目录中有多少文件,但由于某种原因,我的代码一旦运行命令就会一直遇到以下错误:

 `Traceback (most recent call last):
  File "/home/pi/MusicToaster/musicbot/bot.py", line 1995, in on_message
    response = await handler(**handler_kwargs)
  File "/home/pi/MusicToaster/musicbot/bot.py", line 1822, in cmd_audiocache
    stdout=asyncio.subprocess.PIPE)
  File "/usr/local/lib/python3.5/asyncio/subprocess.py", line 212, in create_subprocess_exec
    stderr=stderr, **kwds)
  File "/usr/local/lib/python3.5/asyncio/base_events.py", line 970, in subprocess_exec
    bufsize, **kwargs)
  File "/usr/local/lib/python3.5/asyncio/unix_events.py", line 184, in _make_subprocess_transport
    **kwargs)
  File "/usr/local/lib/python3.5/asyncio/base_subprocess.py", line 40, in __init__
    stderr=stderr, bufsize=bufsize, **kwargs)
  File "/usr/local/lib/python3.5/asyncio/unix_events.py", line 635, in _start
    universal_newlines=False, bufsize=bufsize, **kwargs)
  File "/usr/local/lib/python3.5/subprocess.py", line 950, in __init__
    restore_signals, start_new_session)
  File "/usr/local/lib/python3.5/subprocess.py", line 1540, in _execute_child
    raise child_exception_type(errno_num, err_msg)
FileNotFoundError: [Errno 2] No such file or directory: 'find /home/pi/MusicToaster/audio_cache -type f | wc -l'`

香港专业教育学院检查了我正在运行的命令,我无法找到一个原因,为什么它会有一个错误,当我手动输入它我没有问题:

该值已经增加,因为写入该文件夹的机器人正在运行,而我正在拍摄该截图

以下是该命令的代码:

async def cmd_audiocache(self, channel):
    await self.safe_send_message(channel, "hang on ill check :thinking:")
    process = await asyncio.create_subprocess_exec(
        'find /home/pi/MusicToaster/audio_cache -type f | wc -l',
        stdout=asyncio.subprocess.PIPE)
    stdout, stderr = await process.communicate()
    file_count = stdout.decode().strip()
    file_count = str(file_count)
    file_count = file_count + " songs stored"
    await self.safe_send_message(channel, file_count)
    process = await asyncio.create_subprocess_exec(
        'du /home/pi/MusicToaster/audio_cache -h',
        stdout=asyncio.subprocess.PIPE)
    stdout, stderr = await process.communicate()
    file_size = stdout.decode().strip()
    file_size = str(file_size)
    file_size = "all songs total to" + file_size
    await self.safe_send_message(channel, file_size)

请原谅该代码的混乱,我不知道整理代码,直到我知道它的工作原理.

Answer 1

注意create_subprocess_exec之间的区别:

从一个或多个字符串参数[...]创建子进程,其中第一个字符串指定要执行的程序,其余字符串指定程序的参数.

和create_subprocess_shell:

使用平台的"shell"语法从cmd [...]创建子进程.

例:

# Using exec
process = await asyncio.create_subprocess_exec('ls', '-l')
# Using shell
process = await asyncio.create_subprocess_shell('ls -l')