1. 57×57 – iPod touch, iPhone, iPhone 3G, iPhone 3GS main screen
2. 29×29 – iPod touch, iPhone, iPhone 3G, iPhone 3GS app settings and Spotlight, iPad settings
3. 72×72 – iPad main screen
4. 50×50 – iPad Spotlight
5. 72×72 – iPad main screen
6. 114×114 – iPhone 4 main screen
7. 58×58 – iPhone 4 settings and Spotlight
8. 320×320 – iOS documents
9. 64×64 – iOS documents

You may wish to customize your document icons (e.g., by overlaying your icon on a page icon or somesuch). And of course, iTunes requires that you submit a 512×512 image to be used in the App Store and elsewhere. This is often customized but will likely be similar in style to your primary app icon.

If you’re like me, you don’t have a graphic designer operating at the pixel level to produce sharp, snazzy icons at all those sizes. So instead of tooling around in Photoshop every time you tweak your 512×512 master icon (Image -> Image Size… -> 57px -> Save As… -> Undo -> ad infinitum), why not automate the process?

I’ve put together a small (tiny) XCode project that uses AppKit to output all the icon sizes mentioned above. And it’ll be easy to tweak when the iPad with Retina Display (*fingers crossed*) debuts and needs 96px and 144 px versions of your icon. Throw it into your build system and get freshly-resized icons every time you compile. Grab it here:

Unfortunately, in OS X, aliases are treated differently by the command line than symlinks. In particular, they won’t be followed by the “cd” command, leading to your present frustration. Fortunately, with a little elbow grease, you can patch up your shell and be on your merry way.

This is a two-part process requiring a little familiarity with gcc and bash, but I’ll try to make it as simple as possible. Firstly, you need this file: getTrueName.c. This file was created by Thos Davis and is licensed under the GPLv2. Save it anywhere, then compile it with the following command:

gcc -o getTrueName -framework Carbon getTrueName.c

This will create the ‘getTrueName’ executable in the same directory as the source. You can add it to your PATH, or just copy it directly to /usr/bin so it’s easy to access.

Interestingly, when Terminal opens a new shell, .bashrc is not executed as you might expect. Instead, under the login shell, .bash_profile is executed. So, add the following to .bash_profile in your Home directory. You might need to create it first; it isn’t there by default.

function cd {
  if [ ${#1} == 0 ]; then
    builtin cd
  elif [ -d "${1}" ]; then
    builtin cd "${1}"
  elif [[ -f "${1}" || -L "${1}" ]]; then
    path=$(getTrueName "$1")
    builtin cd "$path"
  else
    builtin cd "${1}"
  fi
}

Effectively, this looks for Finder aliases and resolves them before deferring to the builtin cd command. Append it to your .bash_profile, then either execute it or restart Terminal for the changes to take effect. Now you can cd to Finder aliases within Terminal and have them treated just like symlinks. Just like it should be.