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How to compile Javascript console application locally?

I am a beginner in Javascript, I decided to practice Javascript by problem solving using it, I found an online judge that accepts Javascript V8 4.8.0 code.
So, I searched online to get that version of Javascript V8 on my machine, but I couldn't find any easy way, All the pages were explaining how to build it, and it seems to be a process that I don't need to go through.
Is there an easy way to compile and run command line apps written in Javascript on my machine?
Note: I don't want to use node.js because I tried using it's I/O and
as a beginner I think it is complex in some way.
Update: I found that package manager pbox.me which provides a version of V8 JavaScript Engine and I managed to install it.
Yet another problem appeared: whenever I try to run a js file writing d8 myfile.js in command line nothing happens as if it is an empty program, knowing that I tryied to d8.exe file and it is working, and I made sure the PATH is inserted in the environment variables.
What am I doing wrong?

The easiest way to get started with JavaScript is probably to use it in a browser. You can type simple things directly into the browser's JavaScript console (check the menu); or you can embed your code in a simple HTML document.
If you want, you can even pretty easily implement the readline()/print() functions, so you can pretend to be doing stdin/stdout based I/O: just read from an array of strings, and send output to console.log (or create DOM nodes if you want to be fancy and/or learn how to generate dynamic website content by hand).
Side note: V8 4.8 is severely outdated, don't use it to execute code you haven't written yourself.

Azure documentdb how to develop server side?

as a total JavaScript beginner, how do I actually develop for it?
I mean, I've seen https://azure.microsoft.com/en-us/documentation/articles/documentdb-programming/ but there was no mentioning of a development environment.
Is there something like a visual studio project template for server-side javascript?

I use node.js so your mileage may vary if you are developing from .NET, but here's what I do:
First of all, I created an npm package documentdb-utils. It is a wrapper for the DocumentDB node.js package that makes it easier to do a bunch of things.
Then, I created npm package documentdb-mock to write tests for my stored procedures. The source code for documentdb-mock includes 4 example stored procedures along with a test suite for each using nodeunit. You can start with these as they exercise most of the server-side API.
After I have them passing my local unit tests, I write integration tests that exercise my system end-to-end including creating any necessary data for each test run. The only problems that I've found here with sprocs that I didn't see in my mocked testing had to do with reaching certain limits... although, documentdb-mock has been upgraded to simulate many of these now also.
I haven't open sourced this yet, but I have also written a parser/rewriter that will embed any require(d) packages into my sprocs before sending them to DocumentDB. This allows me to write and test in a nicely factored way on node.js even using downloaded packages from within my sprocs, but when they get pushed to DocumentDB any dependencies are automatically embedded inside of the function. I'll open source that at some point (probably adding it to documentdb-utils) but I can share it with you now if you desire.

Here are a few tools that I found helpful for development (especially server-side [by which we mean database-side] scripting):
DocumentDB Studio - https://github.com/mingaliu/DocumentDBStudio/releases
Sample Code - https://github.com/Azure/azure-documentdb-js-server/tree/master/samples/stored-procedures

Here is another nice open source tool for exploring data in documentdb:
documentdb.a7pl.us

Is there a way to read a local netcdf file from a web application?

We are building a web service for data analysis and would like to access netcdf files from the local machine where the browser is running. Javascript offers a file browser, but (for security reasons as I learned) it will automatically upload a file after selection, instead of allowing (read-only) access to it. This presents a show-stopper, because the netcdf files can be HUGE. Note, that the netcdf format and API explicitly allow slicing and extraction of individual variables, which is one reason why the format is so popular.
Now, some research into this issue revealed that the server-client architecture normally doesn't allow access to the local file structure to prevent spying. On the other hand, in HTML5 there is a file API which supports exactly the kind of operations we need -- except that you can access portions of a file by specifying byte ranges, but there is no netcdf API available; hence one would be left again with copying the entire file before being able to slice it on the server.
Of course, the other option are web services such as OpenDAP which are meant to do exactly what we want, i.e. access parts of a netcdf file over the internet. However, this of course requires that every user would have to install the OpenDAP server before they could access their local files from within the web service. (Or, at a minimum they would have to install a web server so that one could access the file via http://localhost/...).
So: does anyone know of a solution to read specific portions of a local netcdf file from a web application? Specifically, are there javascript tools available for this?

Currently you can use netcdfjs, that it's a javascript library that allows to read NetCDF v3 files. Because it's a NodeJS package you can run it server side, and for regular size files you can read it online, here you have an example.

There are no Javascript tools to read NetCDF, but there are Java libraries: http://www.unidata.ucar.edu/downloads/netcdf/index.jsp.
You could deploy a Java Applet to read the NetCDF file locally. From there you could have the Applet try to process the file, or communicate with a backend service, or even try to call on the Applet from Javascript: http://docs.oracle.com/javase/tutorial/deployment/applet/invokingAppletMethodsFromJavaScript.html.

There are no specific Javascript libs for reading NetCDF, as far as I know. But let me drop some thoughts:
As you say, you can install a local webserver, and use a server-side language to execute a program that reads the file in your disk. You could use a command-line software called ncdump-json. I intentionally wrote this software for that purpose.
You say that you don't want to install software like OpenDAP or webservers, but maybe a desktop app, a standalone .exe would be OK for you. Using node.js plus chromium (this is called nw.js) you have a program that is at the same time a nodejs server, and a chromium browser. This way you can write a web application that reads the data (e.g. using the embedded nodejs server and spawning ncdump-json...).
And now the simplest scenario, a 100% client-side solution... I think this can only be achieved using Javascript... or anything that can "compile to" Javascript. We need to have the netCDF libraries in Javascript, is that possible? I guess so. Emscripten is a LLVM-to-Javascript compiler, and netCDF is C so it has to be possible to compile it with clang/LLVM, therefore it has to be possible to use Emscripten to have a netCDF JS library version with almost no effort, without having to write from scratch (and also maintain) a JS port. If I'm not wrong, to random access the files there's the method slice in the html5 file api, so that should not be a problem.
Hope I helped.

Javascript code

I checked some websites source code and JavaScript games. The problem is that everything is readable and understandable except for JavaScript code that is isolated on a file with the extension .js. It looks like this:
{Vargas=void0,h=!0,Ge=null,l=!1,AA=component,BA=Infinity,ca=set Timeout,DA=is Nan,m=Math,ea=deconstructionism;function He(a,b){return a.on-load=b}function IE(a,b){return a.on error=b}function ha(a,b) {return a.name=b}
As you can see, it's hard to read this code because of the stupid indentation. I tried to use Microsoft visual web developer and free JavaScript editors to organize the code, but it was all useless!
How can I make it more readable?

The best place to start is to look at other open source java script libraries/modules/plugins. You must have the original code though, because what you see in the browser is already "compiled" for the web to be small and fast.
For the client you have plenty frameworks. Look for example at the list jsfiddle uses (top-left). You can also use this tool to play with javascript without having to install anything. Search on the web for those projects (that jsfiddle uses as libraries) and look into the code.
There is also a server-side javascript library that allows you to write javascript code also for the server (also web apps, the server side of them). This is called Node.js Ceck this page to find out more. In Node.js you have almost an infinite number of open source and small modules: see the node module registry wehre you find the links also to the individual project.
In any case, you certainly need a Github account to play with other's code because most of these projects are stored on Github.

Javascript for command line utilities

Given a need to write command line utilities to do common tasks like uploading files to a remote FTP site, downloading data from a remote MySQL database etc.
Is it practical to use JavaScript for this sort of thing? I know there are JavaScript interpreters that can be run from the command line, but are there libraries for things like FTP and database access the way there are for e.g. Java? If so, what's the best place to look for them? (Google searches with JavaScript in the keywords always seem to return many pages of browser specific things.)
And is there a way to package a JavaScript program up as a standalone executable on Windows?
Update: I've decided Python is a better tool for this kind of job, but the answers to the original question are still good ones.

Standalone executable?
By the way you ask the question, I'm not sure if you are aware, but the Windows Script Host - included in Windows - allows you to run .js files from the command-line. Your javascript will not be an executable, it will remain a script, a text file. The script runs within cscript.exe, which is provided by WSH. There's no compilation required. Maybe you knew all that.
I use Javascript this way for various utilities on Windows.
I think your instinct is right on the availability of libraries. You are sort of on your own to find all those things. Although, once you find them, it's not hard to package Javascript libraries as COM components and allow re-use from anywhere. See here for an example of packaging the Google Diff/Patch/Match Javascript library in COM.
Addendum: Once a bit of code is available within COM, it can be consumed by any Javascript running on the machine. Some examples of COM objects available to Javascript scripts running in WSH:
MSXML2.XMLHTTP object - used in AJAX, but can be used for any HTTP communication. There also an object for the XSLT engine so you can do transforms from script.
Excel.Application - allows you to open up Excel spreadsheets and automate them from Javascript.
Communicator.UIAutomation - automate MS Communicator (send IM's via script)
COM objects for Google Earth.
SlowAES - an all-Javascript implementation of AES encryption.

You can use Rhino to compile Javascript into Java byte code, and get access to all Java libraries.
Or you could use JScript.net, and get access to the .net libraries. .net includes a jsc.exe that produces exe-files.
Both of these requires the respective framework to be installed to be able to run.

Node.js is by far the best environment for running non-browser JS. I've used Rhino and SpiderMonkey, and there's a pretty huge difference in everything from the basics like how errors are handled to the size of the community using the tool. Node is pitched for "server-side" JS - building server apps in JS. It's great for this. But it works equally well for building command line tools.
The NPM package manager (bundled with Node) provides a nice global directory for finding and installing packages. It works much better than other language equivalents like PECL / Pear / CPAN / etc. Several high quality tools like JSHint, The Jade templating language, and the CoffeeScript compiler are all already available through NPM/Node:
npm install -g jshint, coffee-script, jade
jshint my_code.js
jade < my.jade > my.html
For args parsing, there are packages like commander.js. I currently use a heavily extended version of Commander in my underscore-cli command-line tool.
For messing with JSON or for doing command-line JS work (similar to "perl -pe"), check out underscore-cli - It's a really powerful tool for processing JSON data, processing underscore templates, and running JS expressions from the command-line. I use it for 1001 different things that would otherwise be really annoying to accomplish.

Rhino is bundled with JDK 1.6, jrunscript.exe in the bin directory will allow you to run any Javascript you want. Since it runs under Java you get access to any Java libraries that you may have.
We use it from the command line extensively. It's very good at that.

One way is to write these utilities as AIR applications - They can be written in JavaScript and need not have a UI. They have access to the command line, and there are existing ActionScript 3 libraries that can handle FTP etc. These ActionScript APIs can be called from JS, in AIR applications. AIR applications also have access to a sqlite database.

jslibs is a good standalone JavaScript runtime that support many 3rd party open source libraries like zlib, SQLite, NSPR, libiconv, libTomCrypt, OpenGL, ...