写C++代码 实现从指定网页中抓取中文写作素材

抓取网页内容需要用到网络编程和HTML解析技术，这里给出一个基于C++的示例代码，使用了libcurl和libxml2库：

#include <curl/curl.h>
#include <libxml/HTMLparser.h>
#include <iostream>
#include <string>
#include <vector>

// 回调函数，处理libcurl返回的网页内容
static size_t WriteCallback(void* contents, size_t size, size_t nmemb, void* userp) {
    size_t realsize = size * nmemb;
    std::string* str = (std::string*)userp;
    str->append((char*)contents, realsize);
    return realsize;
}

// 解析HTML内容，提取中文文本
static void ParseHtml(const std::string& html, std::vector<std::string>& result) {
    htmlDocPtr doc = htmlReadDoc((xmlChar*)(html.c_str()), NULL, NULL, HTML_PARSE_NOERROR | HTML_PARSE_NOWARNING);
    if (!doc) {
        std::cerr << "Failed to parse HTML" << std::endl;
        return;
    }
    xmlNodePtr cur = xmlDocGetRootElement(doc);
    while (cur && cur->type != XML_ELEMENT_NODE) {
        cur = cur->next;
    }
    while (cur) {
        if (cur->type == XML_ELEMENT_NODE) {
            if (xmlStrcmp(cur->name, (const xmlChar*)"script") == 0 ||
                xmlStrcmp(cur->name, (const xmlChar*)"style") == 0) { // 忽略脚本和样式标签
                cur = cur->next;
                continue;
            }
            xmlChar* text = xmlNodeGetContent(cur);
            if (text) {
                std::string str = (char*)text;
                int len = str.length();
                for (int i = 0; i < len; i++) {
                    if (str[i] >= 0x4e00 && str[i] <= 0x9fa5) { // 只保留中文字符
                        result.push_back(str.substr(i, 1));
                    }
                }
                xmlFree(text);
            }
        }
        cur = cur->next;
    }
    xmlFreeDoc(doc);
}

int main(int argc, char** argv) {
    if (argc < 2) {
        std::cerr << "Usage: " << argv[0] << " url" << std::endl;
        return 1;
    }
    CURL* curl = curl_easy_init();
    if (!curl) {
        std::cerr << "Failed to initialize libcurl" << std::endl;
        return 1;
    }
    std::string html;
    std::vector<std::string> result;
    curl_easy_setopt(curl, CURLOPT_URL, argv[1]);
    curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, WriteCallback);
    curl_easy_setopt(curl, CURLOPT_WRITEDATA, &html);
    CURLcode res = curl_easy_perform(curl);
    if (res != CURLE_OK) {
        std::cerr << "Failed to fetch URL: " << curl_easy_strerror(res) << std::endl;
        curl_easy_cleanup(curl);
        return 1;
    }
    ParseHtml(html, result);
    for (const auto& str : result) {
        std::cout << str;
    }
    std::cout << std::endl;
    curl_easy_cleanup(curl);
    return 0;
}

这个代码可以从命令行接收一个网页链接作为参数，抓取网页内容并解析出中文文本，输出到标准输出。你可以根据自己的需求修改代码，比如改为从文件中读取链接列表，抓取多个网页的内容等。