How to Share Folders in Mountain Lion - dummies

How to Share Folders in Mountain Lion

Suppose you have a folder you want to share on your Mac running OS X Mountain Lion, but it has slightly different rules than those set up for the Public folder, for the Drop Box folder within the Public folder, or for your personal folders. These rules are permissions, and they tell you how much access someone has to your stuff.

Actually, the rules governing Shared and Public folders are permissions, too, but they’re set up for you when OS X is installed.

Share only folders located in your Home folder (or a folder within it). Because of the way Unix works, the Unix permissions of the enclosing folder can prevent access to a folder for which you do have permissions. If you share only the folders in your Home folder, you’ll never go wrong.

If you don’t take this advice, you could wind up having folders that other users can’t access, even though you gave them the appropriate permissions.

By the way, you can set permissions for folders within your Public folder (like the Drop Box folder) that are different from those for the rest of the folder.

Sharing a folder, also applies to sharing disks — and disk partitions other than your startup disk (which you just can’t share, period). Though you can’t explicitly share your startup disk, anyone with administrator access can mount it for sharing from across the network (or Internet).

To share a folder with another user, follow these steps:

  1. Choose Apple→System Preferences (or click the System Preferences icon in the Dock).

    The System Preferences window appears.

  2. In the System Preferences window, click the Sharing icon.

    The Sharing System Preferences pane appears.

  3. Click File Sharing in the list of services on the left.

    The lists of shared folders and their users appear on the right.

    If an entry in, for example, the Shared Folders list is too long for you to make out the folder name, hover your pointer over it, and a tooltip will appear, giving you the full name.


  4. Click the + (plus) button under the Shared Folders column to add the folder you wish to share.

    If you select the Shared Folder check box in a folder’s Get Info window, that folder already appears in the list of Shared Folders, so you won’t have to bother with Step 4.

    Alas, while checking the Shared Folder check box in a folder’s Get Info window causes it to appear in the Sharing System Preferences pane’s Shared Folders list, you still have to complete the steps that follow to assign that folder’s users and privileges.

  5. Click the + (plus) button under the Users column to add a user or group if the user or group you desire isn’t already showing in the Users column.

  6. Click the double-headed arrow to the right of a user or group name and change its privileges.

    You can choose among three types of access (in addition to no access) for each user or group, as shown in the following table. If you’re the folder’s owner (or have administrator access), you can click the padlock icon and change the owner and/or group for the file or folder.

Permission What It Allows
Read & Write A user with Read & Write access can see, add, delete, move,
and edit files just as though they were stored on her own
Read Only A Read Only user can see and use files that are stored in a
Shared folder but can’t add, delete, move, or edit them.
Write Only (Drop Box) Users can add files to this folder but can’t see
what’s in it. The user must have read access to the folder
containing a Write Only folder.
No Access With no permissions, a user can neither see nor use your Shared
folders or drives.