Subject: From: Date:

RE: [ECS] CGI advice needed Martin Terry Sun, 30 Jan 2000 12:26:07 -0800

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Mark,

As far as a OS independant web server goes, I imagine there is source code
available for many of the GNU type servers, and some of these have already
been coded for "platform independance". I believe apache has source code
available for many platforms? In ECS's case you would probably want to find
a minimal implementation of a web server.

Not being much of a programmer, this process makes me think in somewhat of a
grey area. Starting at the basic traditional level, a web server fetches
static pages stored on disk and gives them to the client at the client's
request. Pretty basic. Adding CGI lets the client start a process on the
server that changes a web page, then serves that up to the client.

In ECS's case this is probably OK, because unlike a traditional web server,
ECS will have few concurrent client connections. If you start to scale to
hundreds of concurrent connections, traditional CGI starts to create a huge
overhead because of the number of processes that are spawned for each
connection, but again ECS should be able to handle this due to low client
connections.

ECS would probably build web pages "on the fly" so to speak, or at least
static web pages on disk would have references to ECS items that would then
have their current state inserted as the page is fetched. I'm not sure how
this kind of "state reference" is handled in html, but it sounds fairly
trivial, much like CGI can show the state of environmental variables of a
windows machine. On the input side, a client browser would submit a form
that changes the state of an item, which ECS would process.

I'm guessing that most of these internal states are kept just that -
internal in most web servers, instead of keeping a file of all the current
states on disk then refering to the file when necessary.


Actually, this project follows the lines of most embedded web servers that
are being implemented today. For example, most of the new networked printers
you buy today have a built in webserver in the firmware. Once the unit has
been assigned or learned it's IP address, you can point a web browser to
that address and get a "configuration page" that let's you setup all the
internal configuration items - a process that used to be done with a
specialized network application or via the front panel of the printer.

All the web pages and server process are implemented in firmware and RAM,
most of these units don't have disks.

You might want to check out the comp.arch.embedded newsgroup. They may have
some information on embedded web servers as this is a fairly common practice
these days. Before you know it your toaster WILL have an embedded web server
for selecting color. :)








-----Original Message-----
From: Mark Gilmore [mailto:omnip@usit.net]
Sent: Sunday, January 30, 2000 8:46 AM
To: ecs-list@netbloc.com
Subject: Re: [ECS] CGI advice needed


Per helpful inputs from SCOTT/MARTIN/KENT, I am strongly
leaning towards making ECS a web server.

I have already added test code in ECS to generate a
web page listing all Items and State-dropdowns for each
(generating any required web pages will be trivial).

Any thoughts on how to best make ECS a web server ?
MS VC++ has support for this, but I would like to find
a system-independent solution (if possible).

I don't mind AT ALL if you call today (collect).

Thanks,
-- 
Mark Gilmore
Omnipotence (ECS home automation software)
http://www.usit.com/omnip
423-745-0026

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