最近有个需求，需要用c++请求下我自己的服务器，周末看了一下怎么发起http请求。
官方文档见：

https://curl.se/libcurl/c/example.html

官网的demo是基于c的，我用的时候报错了。下面是我写的get/post的方法，同步执行。

namespace yeshen_http
{struct MemoryStruct{char *memory;size_t size;};static size_tWriteMemoryCallback(void *contents, size_t size, size_t nmemb, void *userp){size_t realsize = size * nmemb;struct MemoryStruct *mem = (struct MemoryStruct *)userp;void *ptr = realloc(mem->memory, mem->size + realsize + 1);if (!ptr){std::cout << "not enough memory (realloc returned NULL)" << std::endl;return 0;}mem->memory = (char *)ptr;memcpy(&(mem->memory[mem->size]), contents, realsize);mem->size += realsize;mem->memory[mem->size] = 0;return realsize;}static const char *get_url = "https://yeshen.org";
}int HTTP::get(const char *url, std::string &response)
{CURL *curl = curl_easy_init();struct yeshen_http::MemoryStruct chunk;chunk.memory = (char *)malloc(1);chunk.size = 0;if (curl){curl_easy_setopt(curl, CURLOPT_URL, url);curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, yeshen_http::WriteMemoryCallback);curl_easy_setopt(curl, CURLOPT_WRITEDATA, (void *)&chunk);CURLcode res = curl_easy_perform(curl);int retCode = -1;if (res != CURLE_OK){std::cerr << "curl_easy_perform() failed:" << curl << curl_easy_strerror(res) << std::endl;}else if (chunk.size == 0){std::cout << (unsigned long)chunk.size << " bytes retrieved" << std::endl;}else{std::cout << (unsigned long)chunk.size << " bytes retrieved" << std::endl;response = chunk.memory;retCode = 0;}free(chunk.memory);curl_easy_cleanup(curl);return retCode;}return -1;
}int HTTP::post(const char *url, const std::string &data)
{CURL *curl = curl_easy_init();if (curl){const char *data_str = data.c_str();curl_easy_setopt(curl, CURLOPT_URL, url);curl_easy_setopt(curl, CURLOPT_POSTFIELDS, data_str);curl_easy_setopt(curl, CURLOPT_POSTFIELDSIZE, (long)strlen(data_str));CURLcode res = curl_easy_perform(curl);if (res != CURLE_OK){std::cerr << "curl_easy_perform() failed:" << curl_easy_strerror(res) << std::endl;return -1;}curl_easy_cleanup(curl);return 0;}return -1;
}

cmake部分的处理

target_link_libraries(${YESHEN_TARGET_NAME} PRIVATE libcurl.so
)