libcurl库使用实例

**Libcurl 库使用实例**

Libcurl 是一个著名的 HTTP 客户端库，支持多种协议，如 HTTP、HTTPS、FTP 等。它提供了一个简单易用的 API，让开发者可以轻松地在自己的应用程序中实现网络通信功能。

### 一、Libcurl 的基本概念Libcurl 库提供了以下几个主要的类：

* `CURL`：这是 Libcurl 库的核心类，代表一个 HTTP 会话。
* `CURLOPT`：这是一个枚举类型，用于设置会话选项，如 URL、方法等。

### 二、Libcurl 的基本使用下面是一个简单的例子，演示了如何使用 Libcurl 库发送一个 GET 请求：

c#include <stdio.h>
#include <stdlib.h>
#include <string.h>

// Libcurl 头文件#include <libcurl/curl.h>

int main() {
 CURL *curl;
 CURLcode res;

 // 初始化 curl 会话 curl_global_init(CURL_GLOBAL_DEFAULT);
 curl = curl_easy_init();

 if(curl) {
 // 设置 URL 和方法 struct curl_slist *headers = NULL;
 headers = curl_slist_append(headers, "Accept: */*");
 headers = curl_slist_append(headers, "User-Agent: Mozilla/5.0 (Windows NT10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.3");

 // 发送 GET 请求 curl_easy_setopt(curl, CURLOPT_URL, " /> curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers);
 res = curl_easy_perform(curl);

 if(res != CURLE_OK) {
 fprintf(stderr, "curl_easy_perform() failed: %s
", curl_easy_strerror(res));
 }

 //释放资源 curl_easy_cleanup(curl);
 }

 // 全局资源释放 curl_global_cleanup();

 return0;
}

c#include <stdio.h>
#include <stdlib.h>
#include <string.h>

// Libcurl 头文件#include <libcurl/curl.h>

int main() {
 CURL *curl;
 CURLcode res;

 // 初始化 curl 会话 curl_global_init(CURL_GLOBAL_DEFAULT);
 curl = curl_easy_init();

 if(curl) {
 // 设置 URL 和方法 struct curl_slist *headers = NULL;
 headers = curl_slist_append(headers, "Accept: */*");
 headers = curl_slist_append(headers, "User-Agent: Mozilla/5.0 (Windows NT10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.3");

 // 设置 POST 数据 struct curl_ *post = NULL;
 post = curl_formadd(post, CURLFORM_COPYNAME, "username", strlen("username"), "username", strlen("username"), &username);
 post = curl_formadd(post, CURLFORM_COPYNAME, "password", strlen("password"), "password", strlen("password"), &password);

 // 发送 POST 请求 curl_easy_setopt(curl, CURLOPT_URL, " /> curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers);
 curl_easy_setopt(curl, CURLOPT_POSTFIELDS, post);
 res = curl_easy_perform(curl);

 if(res != CURLE_OK) {
 fprintf(stderr, "curl_easy_perform() failed: %s
", curl_easy_strerror(res));
 }

 //释放资源 curl_formfree(post);
 curl_easy_cleanup(curl);
 }

 // 全局资源释放 curl_global_cleanup();

 return0;
}

c#include <stdio.h>
#include <stdlib.h>
#include <string.h>

// Libcurl 头文件#include <libcurl/curl.h>

int main() {
 CURL *curl;
 CURLcode res;

 // 初始化 curl 会话 curl_global_init(CURL_GLOBAL_DEFAULT);
 curl = curl_easy_init();

 if(curl) {
 // 设置 URL 和方法 struct curl_slist *headers = NULL;
 headers = curl_slist_append(headers, "Accept: */*");
 headers = curl_slist_append(headers, "User-Agent: Mozilla/5.0 (Windows NT10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.3");

 // 设置 FTP 数据 struct curl_slist *ftp_list = NULL;
 ftp_list = curl_slist_append(ftp_list, "username");
 ftp_list = curl_slist_append(ftp_list, "password");

 // 发送 FTP 请求 curl_easy_setopt(curl, CURLOPT_URL, "ftp://example.com");
 curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers);
 curl_easy_setopt(curl, CURLOPT_FTPFILEPTR, ftp_list);
 res = curl_easy_perform(curl);

 if(res != CURLE_OK) {
 fprintf(stderr, "curl_easy_perform() failed: %s
", curl_easy_strerror(res));
 }

 //释放资源 curl_slist_free_all(ftp_list);
 curl_easy_cleanup(curl);
 }

 // 全局资源释放 curl_global_cleanup();

 return0;
}

c#include <stdio.h>
#include <stdlib.h>
#include <string.h>

// Libcurl 头文件#include <libcurl/curl.h>

int main() {
 CURL *curl;
 CURLcode res;

 // 初始化 curl 会话 curl_global_init(CURL_GLOBAL_DEFAULT);
 curl = curl_easy_init();

 if(curl) {
 // 设置 URL 和方法 struct curl_slist *headers = NULL;
 headers = curl_slist_append(headers, "Accept: */*");
 headers = curl_slist_append(headers, "User-Agent: Mozilla/5.0 (Windows NT10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.3");

 // 设置 HTTPS 数据 struct curl_slist * = NULL;
  = curl_slist_append( "username");
  = curl_slist_append( "password");

 // 发送 HTTPS 请求 curl_easy_setopt(curl, CURLOPT_URL, " /> curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers);
 curl_easy_setopt(curl, CURLOPT_FTPFILEPTR,  /> res = curl_easy_perform(curl);

 if(res != CURLE_OK) {
 fprintf(stderr, "curl_easy_perform() failed: %s
", curl_easy_strerror(res));
 }

 //释放资源 curl_slist_free_all( /> curl_easy_cleanup(curl);
 }

 // 全局资源释放 curl_global_cleanup();

 return0;
}

c#include <stdio.h>
#include <stdlib.h>
#include <string.h>

// Libcurl 头文件#include <libcurl/curl.h>

int main() {
 CURL *curl;
 CURLcode res;

 // 初始化 curl 会话 curl_global_init(CURL_GLOBAL_DEFAULT);
 curl = curl_easy_init();

 if(curl) {
 // 设置 URL 和方法 struct curl_slist *headers = NULL;
 headers = curl_slist_append(headers, "Accept: */*");
 headers = curl_slist_append(headers, "User-Agent: Mozilla/5.0 (Windows NT10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.3");

 // 设置 SSL/TLS 数据 struct curl_slist *ssl_list = NULL;
 ssl_list = curl_slist_append(ssl_list, "username");
 ssl_list = curl_slist_append(ssl_list, "password");

 // 配置 SSL/TLS curl_easy_setopt(curl, CURLOPT_URL, " /> curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers);
 curl_easy_setopt(curl, CURLOPT_FTPFILEPTR, ssl_list);
 res = curl_easy_perform(curl);

 if(res != CURLE_OK) {
 fprintf(stderr, "curl_easy_perform() failed: %s
", curl_easy_strerror(res));
 }

 //释放资源 curl_slist_free_all(ssl_list);
 curl_easy_cleanup(curl);
 }

 // 全局资源释放 curl_global_cleanup();

 return0;
}