Mac File Sharing

Reviewed by Wayne Greene 6/29/2012

This article explains how to set up sharing on a Macintosh computer.  You can share entire disks or only folders within a disk.  Sharing an item allows you to give certain users, or groups of users, read and/or write access  privileges to your files.  Note that filesharing of applications can be very slow and problematic, as well as illegal under many license agreements.

All Macs in the Department have the ability to access files on other Macintosh systems that have been made available via AppleShare over the network.  Macs allow personal file sharing:  no server is needed.  File sharing must be turned on in the File Sharing Setup control panel on the remote Mac for anyone to be able to access files on it.  If file sharing is stopped, the Mac will not appear in the Chooser, and nobody can access the Mac's disk from a remote location.

Sharing Files to Yourself

If you are only interested in sharing files with yourself, that is, you need to access your files from another machine in the building or off-site, you DO NOT need to explicitly share anything on your Mac.  You are the owner and as such have full privilege when you connect to your machine from a remote machine.  You DO need to be sure that file sharing is turned on so your Mac will be listed in the Chooser on that remote machine.  See the next section to make sure that you are the owner on your machine.

Turning On File Sharing (Making Your Mac Appear in the Chooser List)

For your machine to appear in the Chooser for remote access, your machine's filesharing must be turned on.  Under MacOS, open the File Sharing control panel.  Goto the Start/Stop tab. To turn file sharing on, click on Start.  If it is already on, that button will read Stop.  Again, you MUST enable the file sharing option or NOBODY, including you, can access any files on your computer from a remote location.  In this window, you should also make sure that your login (or that of whoever is the "owner" of the machine) is entered in the Owner Name field, and whatever password the owner desires in the Owner Password field.

Sharing Files with Others

If you need to share files with others, the following description explains how to create user logins and to set the access permissions on a folder so the user(s) can access it.

Creating Users and Groups:

In order to set up sharing, users and/or groups of users need to first be established.  This is done under the File Sharing control panel, users and groups tab.  If no additional users have yet been added, you should see two icons:  the owner of the computer, and Guest.

Add as many new users as desired, choosing New User for each one.  Double-click on each individual icon to assign a specific password for the user, and to set the options to allow him/her to change his/her password (identity) and to connect (sharing).  For Guest, you can select the "Allow guests to connect" option to make available the Guest connection option in the dialog box that appears when your machine is picked from the Chooser.

To create a new group, choose New Group.  To add users to the group, drag each user's icon on top of the group icon.   To see the list of members of a group, double-click on the group's icon.  To remove a member from a group, drag that user's icon out of the group window to the trash.

Setting Permissions:

Once you have established a user or group, you can share folders with a specified party.  You can share only folders, not files. First, highlight the folder you need to share.  Choose Get Info and then Sharing.... from the pull-down menu beside Show: in the middle of the window. A window will appear that designates privileges for certain users or groups.  You need to click on "Share this item and its contents" first. After that, the sections below become "active" and you can set permissions.   The Owner is usually you.  The owner can grant read, write, or read/write permission to specific people, groups or to everyone (anyone who connects as Guest). It should be the group or user who is responsible for, and thus has the most privilege to, the folder.  This user/group usually has full privileges: He or they can see all folders within this folder; see (and thus copy) all files within this folder; and make changes in this folder, including deleting files/folders, adding files/folders, and modifying files/folders.

The User/Group is a second party (user or group) who can access this folder.  The three permission options are as described above.   Often, this party has read-only privileges.  That is, he/they can see folders and see files, but not make changes.

The permissions you set for Everyone are those applied to anyone who accesses your machine as Guest (through the Chooser option mentioned above).   For most shared folders, all three boxes are Unchecked for Everyone.  Usually you have one folder on your machine, maybe called "Outgoing", that Everyone can read and from which Everyone can copy items.  You have a second folder, maybe called "Incoming", to which Everyone has privilege to make changes.  This is where people will copy items they need to get to you.

There are two other options when sharing a folder, "Can't move, rename, or delete this item" and "Copy these privileges to all enclosed folders".  The first, "Can't move..., " is a bit of protection. Even those who have Make Changes privileges cannot move this folder, rename this folder, or delete this folder. Not even the person sitting at your keyboard can do these things without deselecting this option.  The second, "Copy these privileges...," means that all folders inside this folder will be given identical permissions to identical users/groups as this one.  You may or may not want the permissions to be the same.