我调用方法send_message写入标准输出之后,read_thread_func 并不能读取到标准输出中的信息。
#!/usr/bin/env python
# Copyright (c) 2012 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
# A simple native messaging host. Shows a tkinter dialog with incoming messages
# that also allows to send message back to the webapp.
import struct
import sys
import threading
import queue
try:
import tkinter
import tkMessageBox
except ImportError:
Tkinter = None
# On Windows, the default I/O mode is O_TEXT. Set this to O_BINARY
# to avoid unwanted modifications of the input/output streams.
if sys.platform == "win32":
import os, msvcrt
msvcrt.setmode(sys.stdin.fileno(), os.O_BINARY)
msvcrt.setmode(sys.stdout.fileno(), os.O_BINARY)
# Helper function that sends a message to the webapp.
def send_message(message):
# Write message size.
sys.stdout.write(struct.pack("I", len(message)).decode('utf-8'))
# Write the message itself.
sys.stdout.write(message)
sys.stdout.flush()
# Thread that reads messages from the webapp.
def read_thread_func(queue):
message_number = 0
print('-------------------')
while 1:
# Read the message length (first 4 bytes).
text_length_bytes = sys.stdin.read(4).encode()
if len(text_length_bytes) == 0:
if queue:
queue.put(None)
#os.system("pause")
sys.exit(0)
# Unpack message length as 4 byte integer.
text_length = struct.unpack('i', text_length_bytes)[0]
# Read the text (JSON object) of the message.
text = sys.stdin.read(10)
if queue:
queue.put(text)
else:
# In headless mode just send an echo message back.
send_message('{"echo": %s}' % text)
if tkinter:
class NativeMessagingWindow(tkinter.Frame):
def __init__(self, queue):
self.queue = queue
tkinter.Frame.__init__(self)
self.pack()
self.text = tkinter.Text(self)
self.text.grid(row=0, column=0, padx=10, pady=10, columnspan=2)
self.text.config(state=tkinter.DISABLED, height=10, width=40)
self.messageContent = tkinter.StringVar()
self.sendEntry = tkinter.Entry(self, textvariable=self.messageContent)
self.sendEntry.grid(row=1, column=0, padx=10, pady=10)
self.sendButton = tkinter.Button(self, text="Send", command=self.onSend)
self.sendButton.grid(row=1, column=1, padx=10, pady=10)
self.after(100, self.processMessages)
def processMessages(self):
while not self.queue.empty():
message = self.queue.get_nowait()
if message == None:
self.quit()
return
self.log("Received %s" % message)
self.after(100, self.processMessages)
def onSend(self):
text = '{"text": "' + self.messageContent.get() + '"}'
self.log('~~~~~Sending %s' % text)
try:
send_message(text)
except IOError:
tkMessageBox.showinfo('Native Messaging Example',
'Failed to send message.')
sys.exit(1)
def log(self, message):
self.text.config(state=tkinter.NORMAL)
self.text.insert(tkinter.END, message + "\n")
self.text.config(state=tkinter.DISABLED)
def Main():
if not tkinter:
send_message('"tkinter python module was not found. Running in headless ' +
'mode. Please consider installing Tkinter."')
read_thread_func(None)
sys.exit(0)
Queue = queue.Queue()
main_window = NativeMessagingWindow(Queue)
main_window.master.title('Native Messaging Example')
thread = threading.Thread(target=read_thread_func, args=(Queue,))
thread.daemon = True
thread.start()
main_window.mainloop()
#os.system("pause")
sys.exit(0)
if __name__ == '__main__':
Main()
运行结果就是发送信息以后,read_thread_func并不能读取标准输出中的信息
我尝试在send_message中写入标准输出时加入换行回车,并没用
我希望read_thread_func可以接收到信息,非常感谢。
sys.stdin是标准输入啊,你需要从键盘输入内容才行,你自己输出的东西还想自己再读回来?
题主,你需要深入了解
sys.stdout和sys.stderr
1、标准输出和标准错误(通常缩写为 stdout 和 stderr)是建立在每个UNIX系统内的管道(pipe)。
当你 print 某东西时,结果输出到 stdout 管道中;当你的程序崩溃并打印出调试信息时(象Python中的错误跟踪),结果输出到 stderr 管道中。
2、通常这两个管道只与你正在工作的终端窗口相联,所以当一个程序打印输出时,你可以看到输出,并且当一个程序崩溃时,你可以看到调试信息。(如果你在一个基于窗口的Python IDE系统上工作,stdout 和 stderr 缺省为“交互窗口”。)
3、stdout 和 stderr 都是类文件对象,就象我们在提取输入源中所讨论的一样,但它们都是只写的。它们没有 read 方法,只有 write。