Back up OS X app icons

March 22, 2015

OS X application icons are valuable assets, and it's interesting to see how they evolve over time. This is especially the case when we upgraded to OS X 10.10 Yosemite, when Apple and many design-aware third party developers overhauled (mainly flattened) their icons.

However, we lose all the old icons when we do a major OS upgrade. Technically they still live in Time Machine backups, but those are a pain to pull out. Therefore, I wrote a script just now to back up app icons of all applications living in /Applications (including those symlinked to /Applications, e.g., apps installed through brew cask) and its level-one subdirectories, and /System/Library/CoreServices (for Finder.app and such). Here's the script:

#!/usr/bin/env bash
function app_version
{
    # $1 is the path to the app
    /usr/libexec/PlistBuddy -c "print CFBundleShortVersionString" "$1"/Contents/Info.plist 2>/dev/null || date +%Y%m%d
}

function app_icon_path
{
    # $1 is the path to the app
    filename=$(/usr/libexec/PlistBuddy -c "print CFBundleIconFile" "$1"/Contents/Info.plist 2>/dev/null)
    [[ -n ${filename} ]] || return
    filename=$(basename "${filename}" .icns)
    echo "$1/Contents/Resources/${filename}.icns"
}

function process_app
{
    # $1 is the path to the app
    name=$(basename "$1" .app | tr -d ' ')
    path=$(realpath -e "$1") || { echo "${RED}error: broken link '${path}'${RESET}" >&2; return 1; }
    version=$(app_version "${path}")
    icon_path=$(app_icon_path "${path}")
    [[ -n ${icon_path} ]] || { echo "${YELLOW}warning: '$1' has no app icon${RESET}"; return 1; }
    [[ -f ${icon_path} ]] || { echo "${RED}error: '${icon_path}' does not exist${RESET}" >&2; return 1; }
    cp "${icon_path}" "${name}-${version}.icns"
    echo "${name}-${version}.icns"
}

find /Applications -maxdepth 2 -name '*.app' | while read app; do process_app "${app}"; done
find /System/Library/CoreServices -maxdepth 1 -name '*.app' | while read app; do process_app "${app}"; done

The script is also available as a gist.