如何在仍在运行的标准输入中写入进程标准输入并从其标准输出中读取？

编辑：在python的subprocess.PIPE上签出非阻塞读取

我当时正在与一个非常相似的问题作斗争，我花了3天的时间才能全部解决。subprocess.communicate的问题在于您只能调用一次，而子进程终止后似乎只能给出输出（根据我的经验，很可能是错误的）。

我所遇到的问题（您的问题imho可以归结为该问题）：如何在仍在运行的标准输入中写入标准输入并从标准输出中读取？

我最终使用了Pipes。请注意，如果您编写的内容小于BUFSIZE（在我的情况下为0x1000），则必须对它们进行冲洗。请参阅man pipe以获取更多信息。

无论如何，下面是我的代码。

import time
import pty
import os
import subprocess
PIPE_BUFSIZE = 4096
_control = False


class Pipe:

    def __init__(self, flags=None, terminal=True):
        """Creates a Pipe you can easily write to and read from. Default is to open up a pseudo-terminal.
            If you supply flags, pipe2 is used."""

        if flags or not terminal:
            self._readfd, self._writefd = os.pipe2(flags)
        else:   # default
            self._readfd, self._writefd = pty.openpty()

        self.readobj = open(self._readfd, "rb", 0)  
        self.writeobj = open(self._writefd, "wb", 0)

    def write(self, text):
        if isinstance(text, str):
            text = text.encode()

        result = self.writeobj.write(text)
        self.writeobj.flush()
        return result

    def read(self, n):
        if _control:    # im not using this anymore since the flush seems to be reliable
            controlstr = b"this_was_flushed"
            controllen = len(controlstr)

            self.writeobj.write(controlstr)
            time.sleep(.001)
            self.writeobj.flush()

            result = self.readobj.read(n+controllen)
            assert result[-controllen:] == controlstr
            return result[:-controllen]
        else:
            self.writeobj.flush()
            return self.readobj.read(n)


class ProcessIOWrapper:
    """Provides an easy way to redirect stdout and stderr using pipes. Write to the processes STDIN and read from STDOUT at any time! """

    def __init__(self, args, inittext=None, redirect=True):

        #create three pseudo terminals
        self.in_pipe = Pipe()
        self.out_pipe = Pipe()
        self.err_pipe = Pipe()

        # if we want to redirect, tell the subprocess to write to our pipe, else it will print to normal stdout
        if redirect:
            stdout_arg= self.out_pipe.writeobj
            stderr_arg= self.err_pipe.writeobj
        else:
            stdout_arg=None
            stderr_arg= None

        self.process = subprocess.Popen(args, stdin=self.in_pipe.readobj, stdout=stdout_arg, stderr=stderr_arg)


    def write(self, text):
        return self.in_pipe.write(text)

    def read(self, n, start=None):
        return self.out_pipe.read(n)

我用于测试的小型C程序（也用于其他程序）

#include <stdio.h>


int main(){
    puts("start\n");
    char buf[100]="bufbufbuf";
    while(1){

        gets(buf);
        for (int i=0; i<strlen(buf); i++)
            if (i%2==0) buf[i]+=1;

        puts(buf);
    }
}