Using Curllib to rename file after transfer (sftp) - libcurl

Question

There is a similar question to this already but the answer given does not solve my problem. Here is my code
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struct curl_slist *slist = NULL;
curl_easy_setopt( Curl, CURLOPT_UPLOAD, 1L);
curl_easy_setopt( Curl, CURLOPT_URL, "sftp://user:user#blah.blah.net:22/my_temp_file.txt");
curl_easy_setopt( Curl, CURLOPT_READFUNCTION, my_read_func));
curl_easy_setopt( Curl, CURLOPT_READDATA, &my_read_data);
slist = curl_slist_append( slist, "RNFR my_temp_file.txt");
slist = curl_slist_append( slist, "RNTO my_file.txt");
curl_easy_setopt( Curl, CURLOPT_POSTQUOTE, slist);
rc = curl_easy_perform(Curl);
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When I run the above I get a CURLE_QUOTE_ERROR (the file transfer actually occurs but the rename doesn't happen). If I leave out the post quote option then all works (as before) with no error.
I've tried all the different formats for the from/to names but to no avail. Any ideas ?

Answer 1

The documentation says:
The valid SFTP commands are: chgrp, chmod, chown, ln, mkdir, pwd,
rename, rm, rmdir, symlink (see curl (1))
So you'd use "rename" to rename a file.
The RNFR/RNTO you've used are FTP commands and despite the similarities in names, SFTP is very different compared to FTP.

Answer 2

This SFTP version of the FTP cURL example works fine for me:
/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 1998 - 2017, 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 https://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.
*
***************************************************************************/
/* <DESC>
* Gets a file using an SFTP URL.
* compile me:
* gcc sftpup.c -lcurl -o sftpup.exe
* </DESC>
*/
#include <stdio.h>
#include <string.h>
#include <curl/curl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#ifdef WIN32
#include <io.h>
#else
#include <unistd.h>
#endif
/* <DESC>
* Performs an FTP upload and renames the file just after a successful
* transfer.
* </DESC>
*/
#define LOCAL_FILE "/tmp/uploadthis.txt"
#define UPLOAD_FILE_AS "while-uploading.txt"
#define REMOTE_URL "sftp://sftpuser#123.1.1.1:/data/upload/" UPLOAD_FILE_AS
#define RENAME_FILE_TO "renamed-and-fine.txt"
/* NOTE: if you want this example to work on Windows with libcurl as a
DLL, you MUST also provide a read callback with CURLOPT_READFUNCTION.
Failing to do so will give you a crash since a DLL may not use the
variable's memory when passed in to it from an app like this. */
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 [] = "rename /data/upload/" UPLOAD_FILE_AS " /data/upload/" 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);
/* 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;
}