探索网络爬虫，如何编写有效的c语言爬虫源码？

爬虫源码是一种用于自动获取网页内容的程序代码。通过分析网页结构，提取所需信息并保存或处理。

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <curl/curl.h>
struct MemoryStruct {
  char *memory;
  size_t size;
};
static size_t WriteMemoryCallback(void *contents, size_t size, size_t nmemb, void *userp) {
  size_t realsize = size * nmemb;
  struct MemoryStruct *mem = (struct MemoryStruct *)userp;
  char *ptr = realloc(mem>memory, mem>size + realsize + 1);
  if (ptr == NULL) {
    printf("not enough memory (realloc returned NULL)
");
    return 0;
  }
  mem>memory = ptr;
  memcpy(&(mem>memory[mem>size]), contents, realsize);
  mem>size += realsize;
  mem>memory[mem>size] = 0;
  return realsize;
}
int main(void) {
  CURL *curl_handle;
  CURLcode res;
  struct MemoryStruct chunk;
  chunk.memory = malloc(1);
  chunk.size = 0;
  curl_global_init(CURL_GLOBAL_ALL);
  curl_handle = curl_easy_init();
  if (curl_handle) {
    curl_easy_setopt(curl_handle, CURLOPT_URL, "http://example.com");
    curl_easy_setopt(curl_handle, CURLOPT_WRITEFUNCTION, WriteMemoryCallback);
    curl_easy_setopt(curl_handle, CURLOPT_WRITEDATA, (void *)&chunk);
    curl_easy_setopt(curl_handle, CURLOPT_USERAGENT, "libcurlagent/1.0");
    res = curl_easy_perform(curl_handle);
    if (res != CURLE_OK) {
      fprintf(stderr, "curl_easy_perform() failed: %s
", curl_easy_strerror(res));
    } else {
      printf("%lu bytes retrieved
", (unsigned long)chunk.size);
      printf("Content:
%s
", chunk.memory);
    }
    curl_easy_cleanup(curl_handle);
    free(chunk.memory);
  }
  curl_global_cleanup();
  return 0;
}

这个示例程序会抓取"http://example.com"的HTML内容并打印出来，你可以根据需要修改URL和处理逻辑。