File/folder ownership

[DanL]

Pardon the dumb question here (I should know the answer), but in a MacOS, when a file or folder is created by some application, what determines who owns it, and what permissions are associated with it? I know how to change ownership and permissions. I just want to know what determines them in the first place. Yes, I know that the owner owns the file, but when I create a file, how can I default permissions to "group", or "everyone"?

 

[Cory Cooper]

Hello,

Default permissions are set by macOS (UNIX-based files structure), depending on where the file/folder is created. If you want other users to be able to read/write for example, you could create/move the file/folder to the Users > Shared folder. Permissions can automatically change when files/folders are moved to various locations, and are stripped/updated when emailing or uploading to Internet locations, external devices, etc. For example, most external storage drive have Ignore ownership on this volume enabled by default, as long as they do not contain a macOS system install.

Is there a particular need you have?

C

 

[DanL]

Well, not sure about permissions being stripped when moving. I move a file of mind to the Drop Box of someone else, and they can't access it. I guess that's what you mean about having a macOS system install.

No, what I want is BY DEFAULT to have files I produce offer R/W permissions to at least my group.

 

[Cory Cooper]

Hi,

If you have access to a shared folder on their Dropbox account, you should be able to copy a file to it and they will have access. Ignore ownership on this volume only applies to physical external drives connected to your Mac, not cloud or network drives like Dropbox. How are you copying files to their Dropbox?

There isn't any way that I know of to change the default permissions in macOS, and you shouldn't have to in this scenario, if I am understanding it correctly.

C

 

[DanL]

Well, that appears to be not always the case. When I copy to my wife's dropbox, she has access to the document. When she copies to mine, I don't. Something is different between the two (El Cap) systems. If does seem strange that when something gets put in your dropbox, you don't have permission to look at it!

 

[Cory Cooper]

How are you copying the documents to the Dropbox accounts - via a web browser?

C

 

[DanL]

I'm using the MacOS "Network" link.

 

[Cory Cooper]

OK...I think I understand.

It's not actually Dropbox. You are using File Sharing across your network between you and your wife's Macs, correct? Some settings of folders are for Write Only (Drop Box). If so, your User > Public folder is setup to drop files into from another Mac, and not be viewed by anyone other than you. You can simply create a folder somewhere, and in System Preferences... > Sharing > File Sharing > Shared folders, add it and allow read/write for Staff and Everyone.

See if that helps.

C

 

[DanL]

OK, I did a little more experimenting. It's a little more complicated than what I described. It's about FOLDERS.

Individual files are shared with no permission problems.

When my wife puts a document in a folder, the folder on her machine has rw privilege for her, r privilege for staff, and r privilege for everyone. When she puts that folder in my dropbox, it lands there with rw privilege for "nobody", r privilege for staff, and r privilege for everyone. I am unable to copy that folder out of my dropbox without changing permissions.

If I put a document in a folder, the folder on my machine has rw privilege for me, r privilege for staff, and r privilege for everyone. When I put that folder in her dropbox, it lands there with "custom" privilege for her, rw privilege for me, r privilege for staff, and r privilege for everyone. She is able to move it an manipulate it without changing permissions.

So why the asymmetry, and why don't I have permission to manipulate a folder she puts in my dropbox?

Now, it is true that on her machine, I am listed in "sharing". On my machine she presently is not. If I specify on my machine that I want to share her dropbox, and list her as a user, maybe that will fix everything. But why does this have anything to do with dropboxes??? I am not accessing the non-public part of her machine directly, and she is not accessing mine directly.

 

[Cory Cooper]

Ahhh...that may be part of it.

If you have a user account on her Mac and she doesn't on yours, that could cause the issue. The Public folder in a user account is normally setup by default in macOS as a "drop box" and permissions for read/write are only for that user account on the Mac.

Personally, I would create a folder on each Mac, add it to the sharing preference pane as in my screenshot, give the permissions listed, and you should both be able to transfer and read/write to all files in that folder.

See if that works better and more consistently.

C

 

[DanL]

Well, I did that, but with the new "Shared with Wife" folder I created, it only has permissions for me. If she doesn't have an account on my machine, I can't give her permissions for that folder. And, without permissions for that folder, she can Network over to it and SEE IT, but is unable to Network over to it and put anything in it.

So I guess we're saying that if someone doesn't have an account on my machine, anything they want to share with you comes over with the wrong permissions. I could just give her an account on my machine, but it seems like there ought to be a way without it.

 

[Cory Cooper]

Did you change the permissions settings for Staff and Everyone for that folder in the Shared preference pane as in my example? If so, and she still can't, she would need an account on your Mac.

C

 

[Cory Cooper]

Let me test it on two of my Macs and see if I can figure it out.

C

 

[DanL]

Ah, BINGO! That did it. With my new "Shared with wife" folder, she can drop things in it that I can see. Somewhat strangely still, though, if she drops a folder there, I can move the folder out of it only by giving Administrator permission. If I click on the folder in that "Shared with wife" folder, I can pull out the file in it with no such permission from an Administrator. Slightly weird. Thank you!

 

[Cory Cooper]

Yes, it can be a bit tricky.

There is a lot if information in these two articles:

• Set up file sharing on Mac
• Set up users, guests, and groups on Mac

Honestly, it is easiest to make an account for her on your Mac, as permissions are easier when an account with the same short name are on both Macs. Because I have the same account on all Macs at my location, file permissions never come into play.

I did test it real quick, and ran into some of the same issues you were having with an account called test I have on one of my Macs.

C

 

[DanL]

Yes, you're right. Making an account for her on my machine is straightforward and sensible. I just found it rather strange that the dropbox was so finicky. Yes, anyone can drop stuff in the dropbox, but it doesn't really make it yours. If someone drops a package in my mail slot, hey, it's mine! You assistance, as usual, is greatly appreciated.