SFTP files not showing upload date as last modification time

Question

Some of the files we receive on our Redhat server are showing date different from upload date as the last modification time. For us the modification time is important as we classify files depending on date we receive it. Some of these file show earlier timestamps, maybe that of files original creation/modification date on client machine.

Answer 1

*nix filesystems provide 3 distinct timestamps:

• mtime is the time the file's contents was last modified
• ctime is the time the file's attributes were last changed
• atime is the time the file was last accessed

The timestamp usually shown in directory listings is the mtime, because it is the most useful; however, many FTP servers will upload a file to a temporary filename and then rename the file once complete, to avoid exposing incomplete files to the OS.

This causes the mtime and ctime to differ for newly-created (uploaded) files; the ctime will show the time the file finished uploading and was renamed, while the mtime will show file creation time.

If you can show some samples of what you're talking about, perhaps additional help can be offered.