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What tool does Dropbox use to zip folders for download?
Summary:
I’m trying to figure out how to create a usable zip file out of files that have non-ASCII filenames, so I’d like to find out what zip tool Dropbox uses when I download a folder from Dropbox.
Background:
It turns out that most zip-file-creation tools cause problems when you try to zip a file that has a non-ASCII filename.
But when I download a folder from Dropbox that contains files with non-ASCII filenames, the folder arrives on my computer in the form of a zip file that correctly includes those files.
So whatever tool Dropbox is using (internally) to automatically create zip files for download is doing exactly what I want to do.
Workaround:
If I want to zip a folder, I can upload it to Dropbox and then download it. That works, but it takes a lot of bandwidth and time.
Question:
So I’d like to find out what zip-file-creation tool Dropbox is using to create zip files for download, in hopes that I can use that same tool (or something similar) on my local computer, to be able to correctly zip non-ASCII filenames without having to upload and download to and from Dropbox.
So do any of you know what Dropbox uses to create zip files for download?
thanks,
—Jed
Hi JedHartman, thanks for your patience on this matter.
Regarding your query, we've checked with our team and can provide the following information:
- Dropbox supports a subset of UTF-8 characters in filenames internally
- We set the EFS / 11th bit when zipping files with UTF-8 characters in their filename
- The zip is created on a Linux-based OS, which could come into play
- Files are zipped using zipfile from the Python standard library
I believe the last bullet point should help answer your main question.While it is possible to install Python on a personal machine, we can't be certain that it would have the same effect when using the zipfile program given the differences in how files are stored on Dropbox servers.
Great—thank you! That’s all very helpful.
—Jed
- Walter
Dropbox Staff
Hey JedHartman - thanks for showing your interest in this.
We're trying to find this out for you internally with the team and see if this is a piece of information we can share.
We'll keep you posted anyhow, Jed.
Great—thank you!
Side note: I’ve seen info pages elsewhere that talk about setting bit 11 (the “EFS flag”) of a zip file to indicate a UTF-8 character encoding, but I don’t know whether that’s what Dropbox does.(In case you’re curious, this is all for the Hugo Awards Voter Packet. Dropbox is an important part of an earlier stage of the process of creating the Packet, which is how we found out that it does exactly what we need when it zips a folder for download.)
- Jay
Hi JedHartman, thanks for your patience on this matter.
Regarding your query, we've checked with our team and can provide the following information:
- Dropbox supports a subset of UTF-8 characters in filenames internally
- We set the EFS / 11th bit when zipping files with UTF-8 characters in their filename
- The zip is created on a Linux-based OS, which could come into play
- Files are zipped using zipfile from the Python standard library
I believe the last bullet point should help answer your main question.While it is possible to install Python on a personal machine, we can't be certain that it would have the same effect when using the zipfile program given the differences in how files are stored on Dropbox servers.
