curl sftp libcurl 功能使用

#include <curl/curl.h>

#undef DISABLE_SSH_AGENT

struct FtpFile {
  const char *filename;
  FILE *stream;
};

static size_t my_fwrite(void *buffer, size_t size, size_t nmemb,
                        void *stream)
{
  struct FtpFile *out = (struct FtpFile *)stream;
  if(!out->stream) {
    /* open file for writing */
    out->stream = fopen(out->filename, "wb");
    if(!out->stream)
      return -1; /* failure, can't open file to write */
  }
  return fwrite(buffer, size, nmemb, out->stream);
}

//sftp协议
void fileLoadSftp()
{
  CURL *curl;
  CURLcode res;

  char *filename = ui->lineEdit_path->text().toLatin1().data(); //本地文件名
  QString remote = "sftp://user:password@example.com/etc/issue";
  char *remote_url = remote.toLatin1().data(); //服务器路径

  struct FtpFile ftpfile =
  {
    filename, /* name to store the file as if successful */
    NULL
  };

  curl_global_init(CURL_GLOBAL_DEFAULT);

  curl = curl_easy_init();
  if(curl) {
    /*
     * You better replace the URL with one that works!
     * sftp://user:password@example.com/etc/issue - This specifies the file /etc/issue
     */
    curl_easy_setopt(curl, CURLOPT_URL, remote_url);
    /* Define our callback to get called when there's data to be written */
    curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, my_fwrite);
    /* Set a pointer to our struct to pass to the callback */
    curl_easy_setopt(curl, CURLOPT_WRITEDATA, &ftpfile);

#ifndef DISABLE_SSH_AGENT
    /* We activate ssh agent. For this to work you need
       to have ssh-agent running (type set | grep SSH_AGENT to check) or
       pageant on Windows (there is an icon in systray if so) */
    curl_easy_setopt(curl, CURLOPT_SSH_AUTH_TYPES, CURLSSH_AUTH_PASSWORD);
#endif

    /* Switch on full protocol/debug output */
    curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);

    res = curl_easy_perform(curl);

    /* always cleanup */
    curl_easy_cleanup(curl);

    if(CURLE_OK != res) {
      /* we failed */
      fprintf(stderr, "curl told us %d\n", res);
    }
  }

  if(ftpfile.stream)
    fclose(ftpfile.stream); /* close the local file */

  curl_global_cleanup();
}