Shell Scripting with Objective-C

    #!/bin/bash
    set -eu 
    
    curl -s "https://raw.githubusercontent.com/manbolo/appicon/master/mask.png" >"icon_mask.png"
    
    for app_id in "$@"
    do
        metadata=$(curl -s "http://itunes.apple.com/us/lookup?id=$app_id")
        icon_url=$(echo $metadata | jq -r ".results[0].artworkUrl512")
        name=$(echo $metadata | jq -r ".results[0].trackCensoredName")
    
        icon_base="icon_$name"
        curl -s "$icon_url" >"$icon_base.png"
        convert "$icon_base.png" "icon_mask.png" -compose copy-opacity -composite "$icon_base.png"
        
        for size in 1024 512 120 114 60 57
        do
    	convert "$icon_base.png" -resize "${size}x${size}" "${icon_base}_${size}x${size}.png"
        done
    done
    
    rm icon_mask.png

    ./appicon.bash  400274934 598581396

- didn't replicate the slugify

- dependencies: imagemagick, jq

- here without spaces: http://pastebin.com/yBPwHwdk

- to get the same clarity as the python & Obj-C samples, I'd probably be approaching the same length.

Here is an implementation in Objective-Smalltalk (http://objective.st):

    #!/usr/bin/env stsh
    #-<void>processIconForApp:appId
    framework:AppKit load.
    framework:EGOS_Cocoa load.

    nonChars := NSCharacterSet letterCharacterSet invertedSet.
    str := '_'.
    [ :self  |
       ((self componentsSeparatedByCharactersInSet:nonChars) componentsJoinedByString:str) lowercaseStri
    ] installInClass: NSString  withMethodHeaderString:'slugString'.

    mask := http://raw.githubusercontent.com/manbolo/appicon/master/maskInverted.png.
    appInfo := ref:http://itunes.apple.com/us/lookup  getWithArgs id: appId

    iconURL := var:appInfo/results/0/artworkUrl512.
    name := var:appInfo/results/0/trackCensoredName.
    icon := context evaluateScriptString: iconURL.

    #(1024 512 120 114 60 57 ) do:[ :width  |
      c := MPWCGBitmapContext rgbBitmapContext: width @ width.
      c scale: width / icon pixelsWide.
      c maskedBy:mask draw:[ :aContext | aContext drawImage:icon. ].
      scaled := c image.
      outname := name slugString ,'_', width stringValue, '_', width stringValue , '_.png'.
      file:{outname} := scaled representationUsingType:4 properties:nil.
    ].

(also, the pedant in me would like to point out that this is not "shell scripting" as you're not scripting a shell, but it's super cool regardless)

"You can say that [NSJSONSerialization JSONObjectWithData:resultsData options:0 error:nil]; is more verbose than r.json() but verbosity is an Objective-C convention, for the better or the wors[e]"

For this sort of task, like one of the other commenters, I would almost certainly write something quick and simple (and fairly unstructured) in bash; if it needed to be more maintainable, I'd write it in Ruby. Using a verbose, static typed language just seems wrong here.

Of course, for any given programmer and any given task, using the language with which they are most familiar is often a very good option (obviously only in circumstances where it is possible to perform the task in that language and its specific attributes don't jeopardise the successful running of the task).

So I am not surprised someone is trying to use it as a so-called shell script. The cocoa frameworks really contains a lot of convenient API (ex. when it comes to python, you have to install PIL or something else to process images). But on the other hand the objective-c shell scripting can not be used on platform other than OSX. That is a disadvantage.