A few weeks ago here on TMO, I posted an article called How to Locate & Manage Your "Stuff" in OS X. In that article, I glossed over a special User Folder called Shared. The time has come to take a closer look.
You may be thinking that knowing about the Shared Folder is important only if you have more than one user/logon account on your Mac. If you only use your one user account, read-on, because you'll see why it you might want to create one or two other logon accounts on your machine.
Let me approach the "why" by relating to you how I use multiple user accounts on my own Mac. Hopefully, this will inspire you to think of ways this can be useful in your workflow.
The Users & Groups System Settings panel is where User Accounts are created and managed.
First, of course, I have my regular every-day working user account. Additionally, I have an account with Administrator privileges that I logon to strictly for troubleshooting purposes. Of course, since I run a lean, clean and mean machine, I rarely find myself shooting any trouble! But, if I need to, I can do so easily with this additional user account.
For example, there may be something odd happening in my working account – perhaps with a certain errant System Preferences setting, or a user font, or even an attached printer or other peripherals. With a "clean" user account that has the default System Preferences configured, I am better able to note how something should behave. Troubleshooting personal computer problems is all about "process of elimination." Having this extra user account aids in this approach.
I teach several courses in technology, digital photography and horror cinema at local higher-education schools. For each class, which involves special configurations, demos, and Keynote presentations, I have a separate user account.
Overkill? Perhaps. But, it really makes my work simple, safe and organized.
On my MacBook Pro, I also have a user account for my wife to use in the event it's needed. She has her own Mac mini in our home office, so when we travel, being able to have her own logon on my MacBook Pro is important. If I had children, they might have their own user accounts as well. My two goldfish have expressed a desire to have their own logons, but I feel strangely reluctant to accommodate them on this one request.
Finally, I keep a user account with Administrator privileges (configured with a different password, of course) specifically for use by Apple Genii or other service providers. I use this just in case I have to take the machine in for service – keeping my other accounts out-of-sight-out-of-mind. Yes, I know that depending on certain settings, they may be able to circumvent this, but I am not overly concerned about it, and I maintain a strict backup regimen. This just makes things easier for them and for me.
OK, so hopefully, you get the idea. If you are not now using multiple user accounts, hopefully I've given you some food for thought. If you take anything away from this article, it should be the value of the additional "clean" user accounts for troubleshooting and/or for use by the Apple Genius Bar.
At this point, you may be asking, "What's the best way to share files between these user accounts?" I'm glad you asked, because you may find many good reasons to maintain separate accounts for various uses.
In my own teaching scenario described above, I utilize my main working account to prep for my Keynote presentations, Pages-based class handouts, and demo image files. Once I have all class materials ready, I make use of the Shared Users Folder to easily copy the files to the corresponding class user account. When I get to class, I log onto the User Account for that class and present the students with a clean desktop and perhaps even a custom desktop background.
The User Folder is located at the root level of the system drive and contains all User Account Home Folders plus the Shared Folder.
In my article referenced back in the first paragraph, I talked about the Users Folder located at the root directory of your Mac's system drive. This folder contains all the data created by each of the Mac's logon accounts – whether just your one logon account or a hundred accounts on the machine. The Users Folder contains a Home Folder for each account, identified by account name. Your Home Folder is additionally identified by an icon of a house. You will also find the Shared Folder within the Users Folder.
Since, by default, each user's Home Folder is inaccessible by any other account, the Shared Folder is there for all the local user accounts to use freely when files need to be shared. Remember that the Shared Folder is for intra-account sharing on the one Mac. It is not intended for sharing files between machines – and people – on a network, as there are better mechanisms and methods for that type of activity.
I am constantly exploiting the Shared Folder, finding it enormously useful in my work. As I create my presentations and handouts, I stick copies of them into the Shared Folder. I usually organize the Shared Folder by creating additional folders – one for each user account. Any files commonly needed by all user accounts are placed at the root of the Shared Folder.
To streamline my workflow, I create an alias of the Shared Folder in the Favorites section of the Finder window's sidebar. You do this by first selecting GO > COMPUTER in Finder, then going into the System drive (typically named "Macintosh HD"), and finally into the Users Folder. Locate the Shared Folder, and drag it's icon to the Finder window's sidebar anywhere within the Favorites section at the top. This makes an alias to the Shared Folder easily accessible from anywhere – even in standard open/close file dialog boxes.
Drag the Shared Folder into the Finder window sidebar to create an alias there.
By the way, you can also place an alias of the Shared Folder on your Dock by dragging it's icon just to the left of the trash can. (Now remember, if you've had one-too-many, your lack of accuracy here may be detrimental to your happiness).
Without going into technical detail in this article, you need to understand that, no matter which user account you are logged in as, files and folders you create while in that account are owned by you, i.e.; by that account. This is all about the concept of file permissions, which governs who can open, modify, delete, or even see your files.
Because the Shared Folder can be potentially used by every user account, this folder can contain any number of files and folders with differing ownership and therefore, differing permissions.
There are a couple of important implications regarding file ownership and permissions:
If a file is "owned" by another user account, you and others are typically not allowed to make changes to or delete the file. By the Shared Folder's very nature, you are allowed to open and use files created by other accounts. When you open a file directly from within the Shared Folder, and it's owned by another account, you will be directed to duplicate the file first, or you may be asked to authenticate. As soon as the file is duplicated, you now become the owner of that duplicated file. If you are asked to authenticate, and you do so successfully, the ownership of that original file is now assigned to you.
If you are the owner of a file in the Shared Folder, and you drag it out and onto your desktop, the file is MOVED out of the Shared Folder.
If you drag a file that is owned by another user account from the Shared Folder to your desktop or another location within your own Home Folder, a COPY of the file is made, and the original is kept intact. In general, I prefer this method for sharing a file between user accounts, as leaving the original file as-is in the Shared Folder assures the retrieval of an original copy if the need arises.
This GET INFO panel for a selected Keynote file shows its Sharing and Permissions settings.
The best way to learn all this is to experiment with some throw-away files belonging to the various user accounts on your Mac. While logged into the different account, drag the files in and out, attempt to edit and delete them. Do a Get Info on the files (via FILE > GET INFO in Finder), and look at the Sharing & Permissions section at the very bottom. But, be careful! Don't get too cocky and go around changing permissions on things outside the Shared Folder without a better understanding. There is rarely any reason to do so.
In conclusion, multiple secure user accounts feature in OS X is undoubtedly a powerful tool for enhancing security and organization. File sharing between single machine user accounts via the Shared Folder makes secure collaboration a snap.