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[javascript] How to access server environment variables

I'm looking for a way to access server specific http environment info using javascript. To explain, I help administer two redundant mirrors of the web site of a prominent souhern university. The main site is hosted on an IBM mainframe where CGI scripts are not allowed (otherwise, I'd just write some perl/php/C code and be done with it). I'm currently in the process of documenting our mirroring strategy and ways to update the web pages when they are being hosted on one of the mirrors, which requires a brain dead way to determine which server the site is currently running on. I say brain dead because this has to be doable by operators who are not knowledgeable in http theory. I need a snippet of javascript that can display the server_signature and other server environment information.

I'm not at all familiar with javascript and all my searching has turned up many ways to access client data (browser type, etc), but nothing on the server type. Does anyone know a way to access server data in javascript (or plain old html)?

You didn't say which variables you want to access, but document.domain and document.referrer are both accessible to JavaScript. If your mirrors are in different domains, you should be able to tell where a page is being served up from with the document.domain variable.

In addition to the document properties named above, the location object has host and hostname properties that would presumably hold the IP address and hostname of the server respectively. I haven't tried these to see what they do, but you could write a simple script to test them:

PHP Code:


		
			
<script type="text/javascript">

  alert(location.hostname);

</script>

As I mentioned in the opening post, I'm looking for something like the server_signature that apache defines which gives machine hostname (not webserver name) and software level. This is easily accessible under php, perl or python, but I haven't had any success finding a javascript analogue.

Gotcha. I really doubt you can access that stuff through JavaScript. It's a platform-neutral client-side environment that works with the HTML Document Object Model. It doesn't concern itself with the way in which the HTML document is delivered.

Incidentally, the location.host and location.hostname properties hold the same value as document.domain, which makes them rather redundant and pointless if you ask me.

I'd use a Server-Side Include for that.

You can add variables to the environment in the Apache config file. Then use an SSI to echo that variable into the page.

Quote:

Originally posted by ratbastid
I'd use a Server-Side Include for that.

You can add variables to the environment in the Apache config file. Then use an SSI to echo that variable into the page.

I inferred from the author's statements that, since he is not allowed to run CGIs, he probably doesn't have permission to edit apache.conf either. Although if SSI is available, he could use it to echo existing server variables.