gistfile1.txt

    var commandList = ["a", "b", "c"];
    var commandFuncs = [];
    
    for(var i = 0; i < commandList.length; i++){
        var cmd = commandList[i];
        commandFuncs.push( function(callback){
                setTimeout(function(){
                    console.log(cmd);
                    callback(null);
                }, 500);
            }
        );
    }
    
    for(var i = 0; i < commandList.length; i++){
      commandFuncs[i](null);
    }