是否可以将图像从FTP客户端的内存发送到FTP服务器，而不是在C ++ libcurl中发送文件？当然，图像最终应该作为FTP服务器上的文件。
目前我正在使用此示例：https://curl.haxx.se/libcurl/c/ftpupload.html。我首先将图片存储到文件中，然后上传它，但这对我的应用来说太慢了。
我需要的是给我的记忆中的图像地址卷曲。有没有人有这方面的经验？
这是代码：
static size_t read_callback(void *ptr, size_t size, size_t nmemb, void *stream)
{
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 */
size_t 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(void)
{
CURL *curl;
CURLcode res;
FILE *hd_src;
struct stat file_info;
curl_off_t fsize;
struct curl_slist *headerlist=NULL;
static const char buf_1 [] = "RNFR " UPLOAD_FILE_AS;
static const char buf_2 [] = "RNTO " RENAME_FILE_TO;
/* get the file size of the local file */
if(stat(LOCAL_FILE, &file_info)) {
printf("Couldnt open '%s': %s\n", LOCAL_FILE, strerror(errno));
return 1;
}
fsize = (curl_off_t)file_info.st_size;
printf("Local file size: %" CURL_FORMAT_CURL_OFF_T " bytes.\n", fsize);
/* get a FILE * of the same file */
hd_src = fopen(LOCAL_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) {
/* build a list of commands to pass to libcurl */
headerlist = curl_slist_append(headerlist, buf_1);
headerlist = curl_slist_append(headerlist, buf_2);
/* 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);
/* specify target */
curl_easy_setopt(curl, CURLOPT_URL, REMOTE_URL);
/* pass in that last of FTP commands to run after the transfer */
curl_easy_setopt(curl, CURLOPT_POSTQUOTE, headerlist);
/* now specify which file to upload */
curl_easy_setopt(curl, CURLOPT_READDATA, hd_src);
/* Set the size of the file to upload (optional). If you give a *_LARGE
option you MUST make sure that the type of the passed-in argument is a
curl_off_t. If you use CURLOPT_INFILESIZE (without _LARGE) you must
make sure that to pass in a type 'long' argument. */
curl_easy_setopt(curl, CURLOPT_INFILESIZE_LARGE,
(curl_off_t)fsize);
/* 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));
/* clean up the FTP commands list */
curl_slist_free_all(headerlist);
/* always cleanup */
curl_easy_cleanup(curl);
}
fclose(hd_src); /* close the local file */
curl_global_cleanup();
return 0;
}