相关疑难解决方法(0)

像这样:

if (fcntl(fd, F_SETFD, FD_CLOEXEC) == -1) {
...

虽然我读过man fcntl,但我无法弄清楚它的作用.

我有点难以理解解决这个简单问题的python方法是什么.

我的问题很简单.如果您使用以下代码,它将挂起.这在子流程模块doc中有详细记载.

import subprocess

proc = subprocess.Popen(['cat','-'],
                        stdin=subprocess.PIPE,
                        stdout=subprocess.PIPE,
                        )
for i in range(100000):
    proc.stdin.write('%d\n' % i)
output = proc.communicate()[0]
print output

寻找一个解决方案(有一个非常有洞察力的线程,但我现在已经丢失了)我发现这个解决方案(以及其他)使用了一个显式的fork:

import os
import sys
from subprocess import Popen, PIPE

def produce(to_sed):
    for i in range(100000):
        to_sed.write("%d\n" % i)
        to_sed.flush()
    #this would happen implicitly, anyway, but is here for the example
    to_sed.close()

def consume(from_sed):
    while 1:
        res = from_sed.readline()
        if not res:
            sys.exit(0)
            #sys.exit(proc.poll())
        print 'received: ', [res]

def main():
    proc = Popen(['cat','-'],stdin=PIPE,stdout=PIPE)
    to_sed = proc.stdin
    from_sed = …