How to check the file to download from ftp site exists ?

[wysota]

I think you are adressing the question in the wrong place. If you want to learn how FTP servers work, then learn about FTP. Qt has nothing to do with this. Your "issue" is stricly FTP related from the very beginning.

[nikhilqt]

I think you are adressing the question in the wrong place. If you want to learn how FTP servers work, then learn about FTP. Qt has nothing to do with this. Your "issue" is stricly FTP related from the very beginning.

I checked FTP is working fine. The connection is up and running. I figured out the situation when it stops downloading. I have QTimer setup, which is running in a different thread, when it fires a 'timeout' signal(While QFtp::Get is in progress) the download stops.

Is this because of the thread affinity. Do I need to call moveToThread(..) to initiate the main thread event loop ? Please comment.

Thanks.

[wysota]

I checked FTP is working fine.

What do you consider "fine" when speaking about a protocol? If you know how ftp dictates the servers to manage the connection state, why are you asking those questions? The protocol clearly states how to abort a running command and what the state of the connection is afterwards.

[davethomaspilot]

Read this thread and didn't see anything useful. The problem seems non-trivial, yet the responses suggest it's only difficult if you don't understand ftp. I disagree!

My situation is similar, except I want to do an ftp of a file and create a directory structure on the remote host based on a part of the local file's path. Which means I need to ftp->mkdir to create directories as needed before doing the ftp->put().

For example, I have a file named /la/lb/d/e/f/file.jpg. I want it to end up on the ftp server in something like /ftptop/d/e/f/file.jpg

So, there needs to be a sequence of ftp->mkdir, ftp->cd commands to create the directory structure on the remote host before doing the final ftp->put.

Something like this doesn't work:

QStringList dirs2Make = ftpDir.split("/");
      qDebug()<< dirs2Make;
      foreach (QString d,dirs2Make)
      {
          qDebug() << "making directory " << d;
         ftp->mkdir(d);
         ftp->cd(d);
      }
      ftp->put ftpFile;

QStringList dirs2Make = ftpDir.split("/");
      qDebug()<< dirs2Make;
      foreach (QString d,dirs2Make)
      {
          qDebug() << "making directory " << d;
         ftp->mkdir(d);
         ftp->cd(d);
      }
      ftp->put ftpFile;

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Because if directories already exist in the remote path, the sequence will terminate. So, if a directory exists, cd into it. If not mkdir first, then cd into. Sounds simple, but it's not that easy.

The QFtp commands are asynchronous. Which means you have to schedule a sequence and wait for it to complete or for a command in the sequence to fail. Then create another sequence based on if and how the prior scheduled sequence completed.

Figuring out which command in a sequence failed requires keeping an association of a sequence number to the each of the commands in the sequence.

So, unless I'm missing something, there's more too it than just understanding how ftp works. I'm thinking it would be easier to just shell out to a script that does the ftp commands--that way the ftp commands can more easily be dynamically created based on the pass/fail result of a prior command.

Basically, what I'd need is a way to do everything but the actual put synchronously. Commands like login, cd, mkdir typically complete quickly and often alter what should happen next based on whether they pass or fail.

[wysota]

So don't schedule a sequence of commands but rather schedule the next one only after the previous one completes. What exactly is the problem?