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UsingES
How to use the ES operating system.
Introduction
If you turn on the PC installed with the ES operating system, the following screen appears on your SVGA monitor.
esjs file/shell.js alloc count: 2400 yypase() ok. %
Once the ES operating system kernel gets executing, it will start the event manger (eventManager.elf) and the canvas service (console.elf) in userland. The event manager is a user process that records the inputs from the keyboard and from the mouse as events so that the other processes can get the events. The canvas service repeatedly reads the events from the event manager converting the keyboard input events into a stream of characters; The canvas service also accepts the requests from the yet other processes to draw graphics and texts in the screen.
The kernel then starts the ECMAScript interpreter (esjs.elf), which execute the command line shell program written in ECMAScript (shell.js). The command line shell provides the interactive environment to the user using the canvas service.
Using commands
From the command line shell, you can use the programs like below. Most of the commands are written in ECMAScript:
| Command Name | Description |
| cat [file ...] | Prints the contents of files to the screen |
| cd [dir] | Sets the current directory to dir |
| clear | Clears the canvas for drawing graphics |
| date [-u] | Displays the current date and time. |
| echo [arg ...] | Prints the arguments to the screen |
| edit [file] | Edits text files |
| exit | Exits the command line shell |
| figure | Draws chars using the CanvasRenderingContext2D interface (A demo script) |
| ls [dir ...] | Lists names of objects in the directory |
| rm [file ...] | Removes the files |
| squeak | Squeak - a Smalltalk programming environment |
Namespace
You can list the objects in the current directory by executing the ls command without specifying any arguments:
% ls device network class interface file %
You can change the current directory to any place in the namespace using the cd command. Initially, the current directory is set to the root of the namespace. In the following example, names of device objects in the device directory are shown:
% cd device % ls rtc cga beep framebuffer cursor keyboard mouse ata floppy loopback soundInput soundOutput ethernet event console %
The event and console device objects are dynamically registered objects by the event manager and the canvas service, respectively. In the ES operating system, you can dynamically extend the system features that can be used from the other programs by executing userland programs like this way.
To set the current directory back to the root, invoke the cd comand without any arguments:
% cd % ls device network class interface file %
Your local disk drive is mounted in the file object. To display the names of files in your disk, invoke the ls command with an argument file:
% ls file es.ldr es.img eventManager.elf console.elf esjs.elf shell.js cat.js cd.js date.js echo.js edit.js ls.js %
You can draw graphics on the screen: type figure in the command line and hit enter:
figure is another ECMAScript program that invokes the canvas service. You might want to read the program by typing
% cat file/figure.js
The APIs used in figure.js are basically same as the ones defined in the CanvasRenderingContext2D interface in the HTML5 specification.
To shut down the computer, just invoke the exit command. It will automatically turn off your computer.
% exit
Programming in the ES operating system
To extend the operating system features, you still need to write the programs like the event manger or the canvas service in C or in C++. However, you can easily write your program using those services in ECMAScript. For example, let's take a look into the date program:
% cat file/date.js var date = new Date(); var str = date.toString(); stdout.write(str + '\n', str.length + 1); %
It's just three lines of code. In this script, you see a non-standard ECMAScript object is used: stdout. In ECMAScript programs invoked from the command line shell - shell.js - you can use the following objects:
| Object | Interface | Description |
| System | ICurrentProcess | The current process |
| stdin | IStream | The standard input |
| stdout | IStream | The standard output |
| stderr | IStream | The standard error output |
| root | IContext | The root namespace |
| cwd | IContext | The current directory |
| classStore | IClassStore | The class store |
| path | Array | Array of pathnames in which programs are looked up by the shell |
The ECMAScript interpreter esjs is implemented in a way that it can invoke any programming interfaces defined in the standard interface definition language (IDL). For example, you can invoke any method provided by the ICurrentProcess interface using the System object.
To obtain a different interface of an object, just write as below:
unknown = iter.next(); file = IFile(unknown); // get IFile interface for unknown.
The second line can also be written as below:
file = new IFile(unknown);
// or
file = unknown.queryInterface("0325f4e6-25db-11db-9c02-0009bf000001");If you want to edit a tiny script program, you may use the edit command:
% edit file/date.js 3 1,$p var date = new Date(); var str = date.toString(); stdout.write(str + '\n', str.length + 1); q %
The edit program is originally introduced by Kernighan and Plauger [1, 2]. It was written in Ratfor and then in Pascal at that time. In ES, edit is another ECMAScript script. ECMAScript is actually a powerful language with the support for exception, regular expression, and more. In the ES operating system, you can easily write a command line shell program or a text editor in ECMAScript; those programs are usually written in C or in C++ in the other operating systems.
References
[1] B. W. Kernighan and P. J. Plauger, Software Tools, Addison-Wesley, 1976.
[2] B. W. Kernighan and P. J. Plauger, Software Tools in Pascal, Addison-Wesley, 1981.
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yes i can finaly go to somethig new
ok, where can I find a "HOWTO" in order to get started TRYING the "ES" operating system? Does it install natively on it's own partition? or can it run somehow virtually inside VMware or Virtual PC? Or even cooperatively within Linux or Windows XP? This page is very incomplete. Where can I find more information? And could "ES" be considered as the "Future" Operating System (within a browser) of the XUL platform by Mozilla?
--ProphetPX
Thank you very much for taking a look into this page. There are links to the how-to pages in the Project Home page, and we are working on improving the how-to pages. The ES operating system runs on qemu and on actual PCs. We've tested with the following configurations so far:
Your last question is a really interesting point. Our approach is probably more like, "What if a XULRunner like environment is the actual operating system kernel." Is this an answer to your question?
Best,
Shiki
very interesting, I think what is more interesting is that this could easily be a full blown os. Is it an XUL environment? I currently employ a team of developers creating a linux based XUL OS. but I can imagine that ES is very quick to render and light on ram... hmm..
maybe you should drop me an email. I cannot find a way to contact you. Hope you read it soon.
Anthony Dillavou
Hi Anthony,
Please feel free to send me an email to Shiki.Okasaka at gmail.com.
Best,
Shiki
Has there been any attempts to run ES under any other virtualization environments? (I.e. VirtualBox? or VMWare)
We've been testing ES only on QEMU and actual PCs so far. But supporting other virtualization environments sounds a good idea.
Thanks,
Shiki