Sangfor Proxy

On smartphones, when a proxy is turned on, the corresponding indicator (the "VPN" icon) appears in the status bar. In Windows you have to go to "Settings", open "Network and Internet". Under "Proxy Server", if the item "Manual" is activated, it means that the proxy is engaged right now.

Sending large files over UDP can be a bit tricky because UDP does not guarantee delivery, order, or even that packets won't be duplicated. However, it is possible to send large files using UDP by breaking the file into smaller chunks and sending each chunk separately. Here's a step-by-step guide on how to do it in Python:

1. Import necessary libraries:

import os
import socket
import pickle

2. Define a function to serialize the file data:

def serialize_file_data(file_data):
    return pickle.dumps(file_data)

3. Create a UDP socket:

def create_udp_socket(host, port):
    sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    sock.bind((host, port))
    return sock

4. Send the file data over UDP:

def send_file(sock, file_data, host, port):
    serialized_file_data = serialize_file_data(file_data)
    sock.sendto(serialized_file_data, (host, port))

5. Define a function to deserialize the file data:

def deserialize_file_data(file_data):
    return pickle.loads(file_data)

6. Create a function to receive the file data:

def receive_file(sock, host, port):
    while True:
        data, addr = sock.recvfrom(4096)
        file_data = deserialize_file_data(data)
        yield file_data

7. Putting it all together:

if __name__ == "__main__":
    file_path = "large_file.txt"
    host, port = "127.0.0.1", 12345
    sock = create_udp_socket(host, port)
    send_file(sock, file_path, host, port)

On the receiving side, you will need to collect all the received file data and save it to a file.

If you want to close an application running in the background while using PyQt5 and Selenium in Python, you can use the pyautogui library to simulate keyboard shortcuts or mouse clicks that trigger the application's exit action.

Here's an example using PyQt5 for the GUI and Selenium for web automation, along with pyautogui to close the application:

from PyQt5.QtWidgets import QApplication, QMainWindow, QPushButton
from selenium import webdriver
import pyautogui
import sys
import time

class MyMainWindow(QMainWindow):
    def __init__(self):
        super(MyMainWindow, self).__init__()

        # Create a button to close the application
        self.close_button = QPushButton("Close Application", self)
        self.close_button.clicked.connect(self.close_application)

    def close_application(self):
        # Add code here to close the application or trigger the exit action
        print("Closing application")

if __name__ == '__main__':
    # Create the PyQt application
    app = QApplication(sys.argv)
    main_window = MyMainWindow()
    main_window.show()

    # Start the Selenium WebDriver
    driver = webdriver.Chrome()

    try:
        # Navigate to a webpage (you can replace this with your Selenium code)
        driver.get("https://example.com")

        # Simulate a user interacting with the application
        # ...

        # Simulate closing the application using pyautogui
        time.sleep(2)  # Wait for the application to be in focus
        pyautogui.hotkey('alt', 'f4')  # Simulate pressing Alt+F4 to close the active window

    finally:
        # Close the Selenium WebDriver
        driver.quit()

    # Start the PyQt application event loop
    sys.exit(app.exec_())

- The MyMainWindow class is a basic PyQt5 window with a button.
- The close_application method is connected to the button's click event and prints a message.
- After starting the Selenium WebDriver, you can simulate user interactions with the application.
- pyautogui.hotkey('alt', 'f4') simulates pressing Alt+F4, a common keyboard shortcut to close the active window.

A proxy server acts as an intermediary between client and server parts of distributed network applications. The role of a transit node provides a logical break in the direct connection between the server and the client. A proxy server can also act as a firewall if the traffic it controls does not go through a workaround.

If your proxy gives you a 504 error, it means the server failed to complete the request within the time period you specified. Refreshing the page may help. Another option is to switch to another browser. You can also use the incognito mode, pre-clearing the browser cache. Pay attention to plug-ins that can also cause this error.