A JS entry to https://gist.github.com/1029706

kvs.js

/*
 * Save this file as "kvs.js".
 *
 * Usage:
 *
 * node kvs.js set foo bar
 *
 *   ... sets the "foo" entry to bar, and overwrites the kvs.js script with the updated data.
 * 
 * node kvs.js set foo bar
 *
 *   ... sets the "foo" entry to bar, and overwrites the kvs.js script with the updated data.
 * 
 */
App = {
  //
  // This must be this file's name, unless we are testing: the file in _filename
  // will be overwritten by this file's operation.
  _filename: "kvs.js",                
  
  //
  // Run the command, as passed in from the command line, and
  // dump the entire app into _filename.
  _run: function() {
    process.argv.shift();
    var binary = process.argv.shift();
    var cmd = process.argv.shift();
    if(!cmd || cmd.substr(0,1) === "_" || App[cmd] === undefined) cmd = "usage";
    if(!App[cmd].apply(this, process.argv)) return;
    App._dump();
  },
  
  // Dump both App and Data into _filename
  _dump: function() {
    function dump(name, obj) {
      var r = [];
      for(var key in obj) {
        if(obj.hasOwnProperty(key)) {
          var v = obj[key];
          v = typeof(v) === "function" ? "" + v : JSON.stringify(v);
          r.push('  "' + key + '": ' + v);
        }
      }
      
      var s = "/* ---- " + name + " ---- */\n" + 
        name + " = {\n" + r.join(",\n") + "\n};\n\n";

      return s;
    };

    var js = dump("App", App) + dump("Data", Data) + "App._run();\n";
      
    require("fs").writeFileSync(App._filename, js, "utf8");
  },
  
  // -- Application commands: must return true, if the application should be dumped.
  
  usage: function() {
    process.stderr.write("A simple key value store. Usage:\n\n");
    process.stderr.write("  node " + App._filename + " set key value\n");
    process.stderr.write("  node " + App._filename + " get key\n");
    process.stderr.write("  node " + App._filename + " delete key\n");
    process.stderr.write("  node " + App._filename + " list\n\n");
    process.exit(1);
  },

  set: function(key, value) { 
    Data[key] = value; 
    return true;
  },
  "delete": function(key) {
    delete Data[key];
    return true;
  },
  get: function(key) { 
    if(!Data.hasOwnProperty(key)) 
    process.exit(1);

    process.stdout.write(Data[key] + "\n"); 
  },
  list: function(key) { 
    for(var key in Data) {
      if(Data.hasOwnProperty(key)) 
        process.stdout.write(key + "\n"); 
    }
  }
};

Data = {};

App._run();