正则表达式教程：IPv4地址与端口匹配

一、正则解释

提供的正则表达式：

/^((\d|[1-9]\d|1\d\d|2[0-4]\d|25[0-5])\.){3}(\d|[1-9]\d|1\d\d|2[0-4]\d|25[0-5])(?::(?:[0-9]|[1-9][0-9]{1,3}|[1-5][0-9]{4}|6[0-4][0-9]{3}|65[0-4][0-9]{2}|655[0-2][0-9]|6553[0-5]))?$/

逐段分析：

• ^：匹配字符串的开始。
• (: 开始一个捕获组，用于捕获IPv4地址。
• (\d|[1-9]\d|1\d\d|2[0-4]\d|25[0-5]): 匹配单个IPv4地址段，范围从0到255。
• .：匹配句点，作为IPv4地址段之间的分隔符。
• ){3}：重复上述模式三次，匹配IPv4地址的所有四个段。
• ): 结束捕获组。
• (?::): 可选地匹配冒号，表示端口部分的开始。
• (?:：开始一个非捕获组，用于匹配端口。
• [0-9]|[1-9][0-9]{1,3}|[1-5][0-9]{4}|6[0-4][0-9]{3}|65[0-4][0-9]{2}|655[0-2][0-9]|6553[0-5]): 匹配端口号，范围从0到65535。
• ): 结束非捕获组。
• $: 匹配字符串的结束。

二、使用场景

此正则表达式可用于：

• 验证IPv4地址的有效性。
• 从字符串中提取IPv4地址和端口号。
• 过滤包含特定IPv4地址和端口号的日志或数据。

三、代码示例

JavaScript

const regex = /^((\d|[1-9]\d|1\d\d|2[0-4]\d|25[0-5])\.){3}(\d|[1-9]\d|1\d\d|2[0-4]\d|25[0-5])(?::(?:[0-9]|[1-9][0-9]{1,3}|[1-5][0-9]{4}|6[0-4][0-9]{3}|65[0-4][0-9]{2}|655[0-2][0-9]|6553[0-5]))?$/;

const input = "172.16.0.0:8080";
const match = regex.exec(input);
if (match) {
  const ipAddress = match[1];
  const port = match[2] || "80";
  console.log(`IPv4 Address: ${ipAddress}, Port: ${port}`);
} else {
  console.log("Invalid IPv4 address or port format.");
}

Java

import java.util.regex.Pattern;

public class IPv4PortMatcher {

    private static final Pattern PATTERN = Pattern.compile("^((\d|[1-9]\\d|1\\d\\d|2[0-4]\\d|25[0-5])\\.){3}(\\d|[1-9]\\d|1\\d\\d|2[0-4]\\d|25[0-5])(?::(?:[0-9]|[1-9][0-9]{1,3}|[1-5][0-9]{4}|6[0-4][0-9]{3}|65[0-4][0-9]{2}|655[0-2][0-9]|6553[0-5]))?
import java.util.regex.Pattern;

public class IPv4PortMatcher {

    private static final Pattern PATTERN = Pattern.compile("^((\d|[1-9]\\d|1\\d\\d|2[0-4]\\d|25[0-5])\\.){3}(\\d|[1-9]\\d|1\\d\\d|2[0-4]\\d|25[0-5])(?::(?:[0-9]|[1-9][0-9]{1,3}|[1-5][0-9]{4}|6[0-4][0-9]{3}|65[0-4][0-9]{2}|655[0-2][0-9]|6553[0-5]))?$");

    public static void main(String[] args) {
        String input = "172.16.0.0:8080";
        Matcher matcher = PATTERN.matcher(input);
        if (matcher.find()) {
            String ipAddress = matcher.group(1);
            String port = matcher.group(2);
            System.out.println("IPv4 Address: " + ipAddress + ", Port: " + port);
        } else {
            System.out.println("Invalid IPv4 address or port format.");
        }
    }
}
quot;);

    public static void main(String[] args) {
        String input = "172.16.0.0:8080";
        Matcher matcher = PATTERN.matcher(input);
        if (matcher.find()) {
            String ipAddress = matcher.group(1);
            String port = matcher.group(2);
            System.out.println("IPv4 Address: " + ipAddress + ", Port: " + port);
        } else {
            System.out.println("Invalid IPv4 address or port format.");
        }
    }
}

PHP

<?php
$regex = "/^((\d|[1-9]\d|1\d\d|2[0-4]\d|25[0-5])\.){3}(\d|[1-9]\d|1\d\d|2[0-4]\d|25[0-5])(?::(?:[0-9]|[1-9][0-9]{1,3}|[1-5][0-9]{4}|6[0-4][0-9]{3}|65[0-4][0-9]{2}|655[0-2][0-9]|6553[0-5]))?$/";

$input = "172.16.0.0:8080";
if (preg_match($regex, $input, $matches)) {
    $ipAddress = $matches[1];
    $port = $matches[2] ?? "80";
    echo "IPv4 Address: $ipAddress, Port: $port\n";
} else {
    echo "Invalid IPv4 address or port format.\n";
}
?>

Python

import re

regex = r"^((\d|[1-9]\d|1\d\d|2[0-4]\d|25[0-5])\.){3}(\d|[1-9]\d|1\d\d|2[0-4]\d|25[0-5])(?::(?:[0-9]|[1-9][0-9]{1,3}|[1-5][0-9]{4}|6[0-4][0-9]{3}|65[0-4][0-9]{2}|655[0-2][0-9]|6553[0-5]))?
import re

regex = r"^((\d|[1-9]\d|1\d\d|2[0-4]\d|25[0-5])\.){3}(\d|[1-9]\d|1\d\d|2[0-4]\d|25[0-5])(?::(?:[0-9]|[1-9][0-9]{1,3}|[1-5][0-9]{4}|6[0-4][0-9]{3}|65[0-4][0-9]{2}|655[0-2][0-9]|6553[0-5]))?$"

input = "172.16.0.0:8080"
match = re.search(regex, input)
if match:
    ipAddress = match.group(1)
    port = match.group(2) or "80"
    print(f"IPv4 Address: {ipAddress}, Port: {port}")
else:
    print("Invalid IPv4 address or port format.")
quot;

input = "172.16.0.0:8080"
match = re.search(regex, input)
if match:
    ipAddress = match.group(1)
    port = match.group(2) or "80"
    print(f"IPv4 Address: {ipAddress}, Port: {port}")
else:
    print("Invalid IPv4 address or port format.")