使用curl往服务器推送图片

测试代码：

#include <stdio.h>
#include <stdlib.h>
#include <curl/curl.h>
#include <stdbool.h>

char *upload_url = "http://192.168.10.111:5071/api/device/upload_img";


bool SendImage(char *upload_url, char *send_path) {
    CURL *curl;
    CURLcode res = CURLE_COULDNT_CONNECT;
    struct curl_httppost *form = NULL;
    struct curl_httppost *lastptr = NULL;

    curl = curl_easy_init();
    if (curl) {
        // 打开要上传的文件
        FILE *upload_file = fopen(send_path, "rb");
        if (!upload_file) {
            perror("Error opening file");
            curl_easy_cleanup(curl);
            return false;
        }

        // 设置POST请求和文件上传参数
        curl_easy_setopt(curl, CURLOPT_URL, upload_url);
        curl_formadd(&form, &lastptr,
                     CURLFORM_COPYNAME, "file",    // 字段名与C#接口参数名一致
                     CURLFORM_FILE, send_path,      // 文件路径
                     CURLFORM_CONTENTTYPE, "image/jpeg", // 明确指定文件类型
                     CURLFORM_END);
        
        curl_easy_setopt(curl, CURLOPT_HTTPPOST, form);

        // 关键修改：设置Content-Type为multipart/form-data
        struct curl_slist *headers = NULL;
        headers = curl_slist_append(headers, "Content-Type: multipart/form-data");
        curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers);

        // 设置超时时间
        curl_easy_setopt(curl, CURLOPT_CONNECTTIMEOUT, 60L);

        // 执行请求
        res = curl_easy_perform(curl);

        // 清理资源
        curl_formfree(form);
        fclose(upload_file);
        curl_slist_free_all(headers);
        curl_easy_cleanup(curl);
    }

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

int main() {
    if (SendImage(upload_url, "stream_chn1_0.jpg")) {
        printf("File uploaded successfully.\n");
    } else {
        printf("File upload failed.\n");
    }
    return 0;
}

编译

gcc main.c -o a -lcurl