Mac Geekery

As an admin, sometimes you want to tweak the dock a bit when you can’t sit at the Mac or VNC in to it. Luckily, the Dock is governed by a plist that’s a bit cryptic, but is otherwise fairly easy to tweak. I used this quite a bit, back in the day, but when a friend asked me for it recently, I had to dig around quite a bit to find the darn thing.

The Basics

The com.apple.dock.plist file is binary, but responds to defaults as you would expect. At first, the CFURLAliasData field looks a bit intimidating, but luckily we don’t really have to worry about it. In _persistent-apps, a typical Docked item looks about like this:

        {
            GUID = 1883183727; 
            "tile-data" = {
                "file-data" = {
                    "_CFURLAliasData" = <00000000 00b40003 00010000 c107bb6f 0000482b 00000000 0000013d 00000a22 0000bfee 53de0000 00000920 fffe0000 00000000 0000ffff ffff0001 00080000 013d0000 013c000e 001a000c 00540065 0072006d 0069006e 0061006c 002e0061 00700070 000f001a 000c004d 00610063 0069006e 0074006f 00730068 00200048 00440012 00234170 706c6963 6174696f 6e732f55 74696c69 74696573 2f546572 6d696e61 6c2e6170 70000013 00012f00 ffff0000 >; 
                    "_CFURLString" = "/Applications/Utilities/Terminal.app/"; 
                    "_CFURLStringType" = 0; 
                }; 
                "file-label" = Terminal; 
                "file-mod-date" = 3220067294; 
                "file-type" = 41; 
                "parent-mod-date" = 3250793941; 
            }; 
            "tile-type" = "file-tile"; 
        }, 

Thankfully, we don’t care about roughly half of that. We just need to build something that looks like this:

        {
            "tile-data" = {
                "file-data" = {"_CFURLString" = "/Applications/Terminal.app/"; "_CFURLStringType" = 0; }; 
            }; 
        }

It’s a little much to have to type in every time, what with matching brackets and escaping chars here and there, but the basic command to accomplish this is as follows:

defaults write com.apple.dock persistent-apps -array-add "<dict><key>tile-data</key><dict><key>file-data</key><dict><key>_CFURLString</key><string>/Applications/Terminal.app/</string><key>_CFURLStringType</key><integer>0</integer></dict></dict></dict>";

The Dock doesn’t have any notifications set looking for external changes to this file, so it’ll ignore what you do until you logout or kill the Dock.

Getting Funky

All that nested XML is a pain in the ass to type in repeatedly, so I made a bash funct in my profile to handle both the defaults and the (sane) killing of the Dock. Sadly, bash aliases won’t take args like csh does, but since we have functs, we don’t really care too much. The following creates a bash function called “dockadd” that adds the first argument to the Dock, then uses osascript to quit (not kill) the Dock. This is done because killing the Dock will prevent it from writing out any changes the user has made on their own. Lossy techniques suck.

dockadd () {
        defaults write com.apple.dock persistent-apps -array-add "<dict><key>tile-data</key><dict><key>file-data</key><dict><key>_CFURLString</key><string>$1</string><key>_CFURLStringType</key><integer>0</integer></dict></dict></dict>";
        osascript -e "tell application \"Dock\" to quit"
}

If you really want to, $1 can be changed to $* and it’ll take multiple arguments. There’s no sanity checking by the Dock, so you can violate typical usage here. Say, adding a document to the application side of the dock, or visa versa. Once you open a new bash (or reload your profile file), usage is quite simple.

$ dockadd /Application/Foo.app

When the Dock comes back up, your new item should be on the Dock.