高效解析Nmap扫描报告：处理可选主机名与IP地址的正则表达式教程

Nmap scan report fors+(?P<first_part>[^()s]+)(?:s+((?P<ip_in_parens>d{1,3}.d{1,3}.d{1,3}.d{1,3})))?

package main

import (
    "fmt"
    "regexp"
)

func parseNmapReport(line string) (hostname string, ipAddress string, err error) {
    // 定义正则表达式，使用命名捕获组
    // first_part: 捕获主机名或IP
    // ip_in_parens: 捕获括号中的IP（如果存在）
    re := regexp.MustCompile(`Nmap scan report fors+(?P<first_part>[^()s]+)(?:s+((?P<ip_in_parens>d{1,3}.d{1,3}.d{1,3}.d{1,3})))?`)

    matches := re.FindStringSubmatch(line)
    if matches == nil {
        return "", "", fmt.Errorf("no match found for line: %s", line)
    }

    // 获取命名捕获组的索引
    firstPartIndex := re.SubexpIndex("first_part")
    ipInParensIndex := re.SubexpIndex("ip_in_parens")

    // 提取捕获到的值
    potentialHostnameOrIP := matches[firstPartIndex]
    actualIPFromParens := matches[ipInParensIndex] // 如果没有匹配，此值为""

    // 根据捕获结果进行逻辑判断
    if actualIPFromParens != "" {
        // 格式1: Hostname (IP)
        hostname = potentialHostnameOrIP
        ipAddress = actualIPFromParens
    } else {
        // 格式2: 只有IP
        hostname = potentialHostnameOrIP // 此时 potentialHostnameOrIP 就是IP
        ipAddress = potentialHostnameOrIP
    }

    return hostname, ipAddress, nil
}

func main() {
    // 示例Nmap输出
    line1 := "Nmap scan report for 2u4n32t-n4 (192.168.2.168)"
    line2 := "Nmap scan report for 192.168.2.1"
    line3 := "Nmap scan report for another-host (10.0.0.5)"
    line4 := "Nmap scan report for 172.16.0.100"
    line5 := "Nmap scan report for host-without-ip-in-parens" // 这是一个不符合预期的格式，会报错

    fmt.Println("--- Parsing Nmap Report Lines ---")

    // 测试第一种格式
    h1, ip1, err1 := parseNmapReport(line1)
    if err1 != nil {
        fmt.Printf("Error parsing '%s': %v
", line1, err1)
    } else {
        fmt.Printf("Line: '%s'
  Hostname: %s, IP Address: %s
", line1, h1, ip1)
    }

    // 测试第二种格式
    h2, ip2, err2 := parseNmapReport(line2)
    if err2 != nil {
        fmt.Printf("Error parsing '%s': %v
", line2, err2)
    } else {
        fmt.Printf("Line: '%s'
  Hostname: %s, IP Address: %s
", line2, h2, ip2)
    }

    // 更多测试
    h3, ip3, err3 := parseNmapReport(line3)
    if err3 != nil {
        fmt.Printf("Error parsing '%s': %v
", line3, err3)
    } else {
        fmt.Printf("Line: '%s'
  Hostname: %s, IP Address: %s
", line3, h3, ip3)
    }

    h4, ip4, err4 := parseNmapReport(line4)
    if err4 != nil {
        fmt.Printf("Error parsing '%s': %v
", line4, err4)
    } else {
        fmt.Printf("Line: '%s'
  Hostname: %s, IP Address: %s
", line4, h4, ip4)
    }

    // 测试不匹配的行
    h5, ip5, err5 := parseNmapReport(line5)
    if err5 != nil {
        fmt.Printf("Error parsing '%s': %v
", line5, err5)
    } else {
        fmt.Printf("Line: '%s'
  Hostname: %s, IP Address: %s
", line5, h5, ip5)
    }
}

--- Parsing Nmap Report Lines ---
Line: 'Nmap scan report for 2u4n32t-n4 (192.168.2.168)'
  Hostname: 2u4n32t-n4, IP Address: 192.168.2.168
Line: 'Nmap scan report for 192.168.2.1'
  Hostname: 192.168.2.1, IP Address: 192.168.2.1
Line: 'Nmap scan report for another-host (10.0.0.5)'
  Hostname: another-host, IP Address: 10.0.0.5
Line: 'Nmap scan report for 172.16.0.100'
  Hostname: 172.16.0.100, IP Address: 172.16.0.100
Error parsing 'Nmap scan report for host-without-ip-in-parens': no match found for line: Nmap scan report for host-without-ip-in-parens