OS X File Sharing — The Basics - Enabling File Sharing

One of the great things about computers these days is that it's so easy to share things among them.  Text documents, music files, photos... anything that lives on your computer can be moved to another device.  Whereas this used to be a semi-complicated procedure for the novice, it's now as easy as finding a checkbox and clicking it.  Mostly.


The procedure goes like this:
•  Enable File Sharing
•  Tell OS X who can file share with your computer
•  Tell OS X what kind of permissions those people have


The important thing to remember when file sharing with OS X (or any computer really), is that there are two distinct devices: the server and the client.  If you are connecting to a computer to take files off of it, you are the client.  If someone else is connecting to your computer, your computer is acting as a server.  Makes sense.


However, if you connect to a computer through file sharing, you can not only take files from that computer, but you can also put files onto that computer.  As long as you have the proper credentials, you can move files, delete files and copy files from the computer you connect to.


So how do you do it?


Well, let's start by setting your computer up to share files, so that you can gain a better understanding of what's involved in the process.


First, head over to the System Preferences, and click the Sharing preference, as seen here:

Once opened, you will see the following screen:

On the left side of this screen, you will see different "sharing" services that you can turn on and off, simply by checking the box next to it.  In the above picture, File Sharing is highlighted and enabled.  


You will see that over to the right of the screen, there is a list of users.  This panel is where you select the people that are allowed to connect to your computer, and what they are allowed to do.


You can allow anyone to connect to your computer, a group of people or individual users, and assign each of them different permissions.  They will be able to either:


1)  Read Only - not only see things on your computer, but also copy things from it.  Others will not be able to modify files on your computer, however.  This is the safest option if you want to share files with others, but you want to make sure that they don't change things by mistake.  If you are at work, your administrator is probably giving you "read-only access" so that you can't mess anything up.
2)  Write Only - copy things to your computer, AND modify items/files/etc.  Other users can leave files for you, but they won't be able to see anything on your computer.  This is handy if you want to provide a simple folder for others to drop files into.  They won't be able to access any other parts of your system.  A write-only folder is often times called a dropbox.
3)  Read & Write - copy things to and from your computer, as well as see files and modify them.  This should be used only if you completely trust the person on the other end, as they will have full access to whatever it is you are giving them permission to (in this case, your whole computer).


So, as you can see, there are many different options to choose from.  For now, we are only going to concern ourselves with one user (you) and one kind of permission (Read & Write).  The beauty of doing things this way is that you are only trusting yourself with the files on your computer.  If you want to add more people in the future, you can just follow these instructions, substituting other accounts for yours.


Let's enable file sharing for your User Account.  To do so, make sure File Sharing is enabled, and then click the "+" sign underneath the list of users.  You will be presented with a new drop-down menu:

As you can see, my user is greyed-out because my user account is already setup for file sharing.

Click on your user account (probably your name), click the Select button, and your user account will be added to the list of accepted users on the right.


Next, it's time to set what permissions your account can have.  Next to your name (which has now been added to the right side pane), click the black arrows.  You will see the following:

Select "Read & Write", and you're done!


Once you've set this up once, you don't need to do it again.  You can enable and disable File Sharing by clicking the checkbox, and OS X will remember who has access to your system.  If you need to remove a user from File Sharing, simply highlight their name on the right, and click the "-" symbol below it.


You will now be able to see your computer on a network, and you can connect to this computer by using your User Account name and password.  Once connected, you will be able to see all of the files on your computer, as well as copy files to your computer and modify things.