[Python] port number script to avoid port number conflicts

1. Idea

When using like socketmodules, when the port number needs to be bound, if the port number is occupied, it will cause a port number conflict.

For frequently used port numbers that cause port number conflicts, the solution can be to automatically obtain a non-conflicted port number and bind this port number.

The idea is as follows:

1. Write a get_port.pyscript that encapsulates a function inside get_port(). Each time the function is called, a new port number will be obtained, and the port number will increase by one.
2. get_port()The obtained port number is given a range [initPort, endPort]. In order to avoid port number conflicts, this range does not include the existing port numbers on the machine.
3. After walking from initPortto to endPort, reset the port number to initPort, and reuse the port number to avoid infinite increment of the obtained port number.

2. Code implementation

Create a new get_port.pyfile with the following content:

import os

portFile = 'port.txt' # 端口号文件
initPort = '10001' # 初始端口号
endPort = '10010' # 结束端口号

# 创建端口号文件，并写入初始端口号
def create_port_file():
    with open(portFile, 'w') as f:
        f.write(initPort)

# 获取端口号
def get_port():
    if not os.path.exists(portFile): # 端口号文件不存在则创建
        create_port_file()
    with open(portFile, 'r') as f:
        port = f.read()
    update_port(port)
    if port == endPort: # 重置端口号
        create_port_file()
    print("The current port number: {}".format(port))
    return int(port)

# 更新端口号
def update_port(oldPort):
    newPort = int(oldPort) + 1
    with open(portFile,'w') as f:
        port = f.write(str(newPort))

if __name__ == "__main__":
    for i in range(15):
        get_port()  
        

The result of the operation is as follows:

The current port number: 10001
The current port number: 10002
The current port number: 10003
The current port number: 10004
The current port number: 10005
The current port number: 10006
The current port number: 10007
The current port number: 10008
The current port number: 10009
The current port number: 10010
The current port number: 10001
The current port number: 10002
The current port number: 10003
The current port number: 10004
The current port number: 10005

3. Port number usage

Create a new one in get_port.pythe same directory test.py, import the get_portmodule, and use get_port()the function.

test.pyThe content of the file is as follows:

import socket      
from get_port import get_port # 导入get_port模块

s = socket.socket() # 创建socket对象
host = socket.gethostname() # 获取本地主机名
port = get_port() # 使用get_port模块的get_port()函数    
s.bind((host, port)) # 绑定端口