How to determine whether a file is still being transferred via ftp

Question

I have a directory with files that need processing in a batch with PHP. The files are copied on the server via FTP. Some of the files are very big and take a long time to co

Answer 1

Some FTP servers allow running commands when certain event occurs. So if your FTP server allows this, then you can build a simple signalling scheme to let your application know that the file has been uploaded more or less successfully (more or less is because you don't know if the user intended to upload the file completely or in parts). The signalling scheme can be as simple as creation of "uploaded_file_name.ext.complete" file, and you will monitor existence of files with ".complete" extension.

Now, you can check if you can open file for writing. Most FTP servers won't let you do this if the file is being uploaded.

One more approach mentioned by Mat is using system-specific techniques to check if the file is opened by other process.