在Python中使用套接字的简单端口扫描器

先决条件： Python中的套接字编程

在开始编程之前，让我们讨论一下端口。在本文中，我们将检查服务器或网站或 localhost 的虚拟端口。每个端口都有一个唯一的编号。从 0 开始，主机中有 65,535 个可用端口。我们可以为任何服务分配端口。

例1：在这个程序中，可以扫描一定范围内的多个端口。

Python3

# Here we import two modules, socket and time
 
import socket
import time
 
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
 
# here we asking for the target website
# or host
target = input('What you want to scan?: ')
 
# next line gives us the ip address
# of the target
target_ip = socket.gethostbyname(target)
print('Starting scan on host:', target_ip)
 
# function for scanning ports
 
 
def port_scan(port):
    try:
        s.connect((target_ip, port))
        return True
    except:
        return False
 
 
start = time.time()
 
# here we are scanning port 0 to 4
for port in range(5):
    if port_scan(port):
        print(f'port {port} is open')
    else:
        print(f'port {port} is closed')
 
end = time.time()
print(f'Time taken {end-start:.2f} seconds')

输出：

What you want to scan?: localhost
Starting scan on host: 127.0.0.1
port 0 is closed
port 1 is closed
port 2 is closed
port 3 is closed
port 4 is closed
Time taken 8.12 seconds

注意：您可以更改 for 循环中的范围以更改要扫描的端口数。扫描网站或主机可能需要一定的时间，所以请耐心等待。

示例 2：如果您想扫描特定端口，请选择此解决方案。

Python3

# importing the sockets module
import socket
 
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
target = input('What you want to scan?: ')
 
# getting the ip address using gethostbyname
# function
t_IP = socket.gethostbyname(target)
print("Starting scan on host: ", t_IP)
 
 
def port_scan(port):
    try:
        s.connect((t_IP, port))
        return True
    except:
        return False
 
 
port = int(input("Enter the port number to be scanned: "))
 
if port_scan(port):
    print('Port', port, 'is open')
else:
    print("port", port, "is closed")

输出：

What you want to scan?: localhost
Starting scan on host:  127.0.0.1
Enter the port number to be scanned: 135
Port 135 is open

注意：这里我们正在扫描本地主机。您可以扫描任何主机或网站。如果您遇到任何错误，则套接字无法连接目标，或者您在代码中犯了一些错误。

警告：未经管理员许可扫描服务器或网站的端口可被视为犯罪。有许多免费网站可供测试，您可以使用它们。