python如何只显示开放端口

要在Python中只显示开放端口，可以使用socket和subprocess库，通过扫描指定IP地址的端口来检测其开放状态、创建一个套接字并尝试连接特定端口来确定该端口是否开放、使用子进程调用系统命令来列出开放的端口。这些方法可以结合使用以提供更全面的结果。

下面我们将详细描述如何在Python中实现这一功能，并提供完整的代码示例和使用方法。

一、使用 socket 库扫描端口

1、创建套接字并尝试连接

使用socket库，我们可以创建一个套接字并尝试连接到特定的IP地址和端口。通过捕获连接异常，我们可以判断端口是否开放。

import socket
def is_port_open(ip, port):
    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    s.settimeout(1)  # 设置超时时间为1秒
    try:
        s.connect((ip, port))
        s.close()
        return True
    except (socket.timeout, socket.error):
        return False
def scan_ports(ip, start_port, end_port):
    open_ports = []
    for port in range(start_port, end_port + 1):
        if is_port_open(ip, port):
            open_ports.append(port)
    return open_ports
ip_address = '127.0.0.1'
start_port = 1
end_port = 1024
open_ports = scan_ports(ip_address, start_port, end_port)
print(f"Open ports on {ip_address} from {start_port} to {end_port}: {open_ports}")

此代码首先定义了一个函数is_port_open来检查特定端口是否开放。然后定义了一个函数scan_ports来扫描指定范围内的端口，并返回开放端口的列表。

2、优化扫描速度

为了提高扫描速度，可以使用多线程来并行扫描多个端口。Python的concurrent.futures库提供了一个简单的线程池接口。

import socket
from concurrent.futures import ThreadPoolExecutor
def is_port_open(ip, port):
    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    s.settimeout(1)
    try:
        s.connect((ip, port))
        s.close()
        return True
    except (socket.timeout, socket.error):
        return False
def scan_ports(ip, start_port, end_port):
    open_ports = []
    with ThreadPoolExecutor(max_workers=100) as executor:
        future_to_port = {executor.submit(is_port_open, ip, port): port for port in range(start_port, end_port + 1)}
        for future in concurrent.futures.as_completed(future_to_port):
            port = future_to_port[future]
            if future.result():
                open_ports.append(port)
    return open_ports
ip_address = '127.0.0.1'
start_port = 1
end_port = 1024
open_ports = scan_ports(ip_address, start_port, end_port)
print(f"Open ports on {ip_address} from {start_port} to {end_port}: {open_ports}")

此代码使用线程池并行扫描端口，提高了扫描速度。

二、使用 subprocess 调用系统命令

在某些情况下，直接调用系统命令可能更方便。例如，使用netstat或nmap命令可以列出系统上的开放端口。我们可以使用subprocess库调用这些命令，并解析其输出。

1、使用 netstat 列出开放端口

import subprocess
def get_open_ports():
    result = subprocess.run(['netstat', '-tuln'], stdout=subprocess.PIPE, text=True)
    lines = result.stdout.splitlines()
    open_ports = []
    for line in lines:
        if 'LISTEN' in line:
            parts = line.split()
            address = parts[3]
            port = int(address.split(':')[-1])
            open_ports.append(port)
    return open_ports
open_ports = get_open_ports()
print(f"Open ports: {open_ports}")

此代码使用subprocess.run调用netstat -tuln命令，并解析其输出以提取开放端口。

2、使用 nmap 扫描端口

如果系统上安装了nmap，可以使用它来扫描端口。

import subprocess
def scan_with_nmap(ip):
    result = subprocess.run(['nmap', '-p-', ip], stdout=subprocess.PIPE, text=True)
    lines = result.stdout.splitlines()
    open_ports = []
    for line in lines:
        if 'open' in line:
            parts = line.split('/')
            port = int(parts[0])
            open_ports.append(port)
    return open_ports
ip_address = '127.0.0.1'
open_ports = scan_with_nmap(ip_address)
print(f"Open ports on {ip_address}: {open_ports}")

此代码使用subprocess.run调用nmap命令，并解析其输出以提取开放端口。

三、综合使用多种方法

为了确保结果的准确性和全面性，可以综合使用多种方法。我们可以将使用socket库和调用系统命令的方法结合起来，以提供更可靠的结果。

import socket
import subprocess
from concurrent.futures import ThreadPoolExecutor
def is_port_open(ip, port):
    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    s.settimeout(1)
    try:
        s.connect((ip, port))
        s.close()
        return True
    except (socket.timeout, socket.error):
        return False
def scan_ports(ip, start_port, end_port):
    open_ports = []
    with ThreadPoolExecutor(max_workers=100) as executor:
        future_to_port = {executor.submit(is_port_open, ip, port): port for port in range(start_port, end_port + 1)}
        for future in concurrent.futures.as_completed(future_to_port):
            port = future_to_port[future]
            if future.result():
                open_ports.append(port)
    return open_ports
def get_open_ports_from_netstat():
    result = subprocess.run(['netstat', '-tuln'], stdout=subprocess.PIPE, text=True)
    lines = result.stdout.splitlines()
    open_ports = []
    for line in lines:
        if 'LISTEN' in line:
            parts = line.split()
            address = parts[3]
            port = int(address.split(':')[-1])
            open_ports.append(port)
    return open_ports
def scan_with_nmap(ip):
    result = subprocess.run(['nmap', '-p-', ip], stdout=subprocess.PIPE, text=True)
    lines = result.stdout.splitlines()
    open_ports = []
    for line in lines:
        if 'open' in line:
            parts = line.split('/')
            port = int(parts[0])
            open_ports.append(port)
    return open_ports
def combined_scan(ip, start_port, end_port):
    socket_open_ports = scan_ports(ip, start_port, end_port)
    netstat_open_ports = get_open_ports_from_netstat()
    nmap_open_ports = scan_with_nmap(ip)
    combined_open_ports = set(socket_open_ports) | set(netstat_open_ports) | set(nmap_open_ports)
    return sorted(combined_open_ports)
ip_address = '127.0.0.1'
start_port = 1
end_port = 1024
open_ports = combined_scan(ip_address, start_port, end_port)
print(f"Open ports on {ip_address} from {start_port} to {end_port}: {open_ports}")