您不应使用 CURLOPT_CONNECT_ONLY 选项或 curl_easy_send() 函数，它们旨在用于自定义的非 HTTP 协议。
有关如何使用 libcurl 执行 PUT 请求的示例，请参阅 this page。基本上，您希望启用 CURLOPT_UPLOAD 和 CURLOPT_PUT 选项来表示您正在执行 PUT 请求并启用使用请求上传正文，然后设置 CURLOPT_READDATA 和 CURLOPT_INFILESIZE_LARGE 选项来告诉libcurl 如何读取你上传的数据以及数据有多大。
在你的情况下，如果你已经在内存中有数据，那么你不需要从文件中读取它，你可以在你的读取回调中memcpy()它。
下面复制的示例代码：
/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 1998 - 2012, Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
* are also available at http://curl.haxx.se/docs/copyright.html.
*
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
* copies of the Software, and permit persons to whom the Software is
* furnished to do so, under the terms of the COPYING file.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
***************************************************************************/
#include <stdio.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <curl/curl.h>
/*
* This example shows a HTTP PUT operation. PUTs a file given as a command
* line argument to the URL also given on the command line.
*
* This example also uses its own read callback.
*
* Here's an article on how to setup a PUT handler for Apache:
* http://www.apacheweek.com/features/put
*/
static size_t read_callback(void *ptr, size_t size, size_t nmemb, void *stream)
{
size_t retcode;
curl_off_t nread;
/* in real-world cases, this would probably get this data differently
as this fread() stuff is exactly what the library already would do
by default internally */
retcode = fread(ptr, size, nmemb, stream);
nread = (curl_off_t)retcode;
fprintf(stderr, "*** We read %" CURL_FORMAT_CURL_OFF_T
" bytes from file\n", nread);
return retcode;
}
int main(int argc, char **argv)
{
CURL *curl;
CURLcode res;
FILE * hd_src ;
struct stat file_info;
char *file;
char *url;
if(argc < 3)
return 1;
file= argv[1];
url = argv[2];
/* get the file size of the local file */
stat(file, &file_info);
/* get a FILE * of the same file, could also be made with
fdopen() from the previous descriptor, but hey this is just
an example! */
hd_src = fopen(file, "rb");
/* In windows, this will init the winsock stuff */
curl_global_init(CURL_GLOBAL_ALL);
/* get a curl handle */
curl = curl_easy_init();
if(curl) {
/* we want to use our own read function */
curl_easy_setopt(curl, CURLOPT_READFUNCTION, read_callback);
/* enable uploading */
curl_easy_setopt(curl, CURLOPT_UPLOAD, 1L);
/* HTTP PUT please */
curl_easy_setopt(curl, CURLOPT_PUT, 1L);
/* specify target URL, and note that this URL should include a file
name, not only a directory */
curl_easy_setopt(curl, CURLOPT_URL, url);
/* now specify which file to upload */
curl_easy_setopt(curl, CURLOPT_READDATA, hd_src);
/* provide the size of the upload, we specicially typecast the value
to curl_off_t since we must be sure to use the correct data size */
curl_easy_setopt(curl, CURLOPT_INFILESIZE_LARGE,
(curl_off_t)file_info.st_size);
/* Now run off and do what you've been told! */
res = curl_easy_perform(curl);
/* Check for errors */
if(res != CURLE_OK)
fprintf(stderr, "curl_easy_perform() failed: %s\n",
curl_easy_strerror(res));
/* always cleanup */
curl_easy_cleanup(curl);
}
fclose(hd_src); /* close the local file */
curl_global_cleanup();
return 0;
}