python - 如何在不阻塞的情况下在 python 中读取 unix 管道？

Question

我想通过这样的管道读取进程的输出：

./backup.sh | my-python_program.py

我的 python 程序当前从标准输入读取：

buff =  sys.stdin.read()

虽然这看起来很幼稚，并且似乎阻碍了需要很长时间才能执行的脚本。有没有更好的办法？

Answer 1

不知道 python 是如何包装它的，但你会想要使用具有较小超时值的select() 。

Answer 2

Pipes are set up explicitly to block and for most purposes it makes sense -- does your program have other stuff that it could be doing when not reading the input?

If so, then you can look into asynchronous I/O, and if you're going to be doing this in python, I'd recommend using [gevent[(http://www.gevent.org/) which will let you use lightweight threads that do efficient asynchronous I/O:

import gevent
from gevent import monkey; monkey.patch_all()

def read_from_stdin():
    buff = sys.stdin.read()
    # Whatever you're going to do with it

def some_other_stuff_to_do():
    # ...
    pass

gevent.Greenlet(read_from_stdin).run()
gevent.Greenlet(some_other_stuff_to_do).run()