[WEB4LIB] IE 5.x's automatic configuration script issues

[Debra Lords]

William Moore wrote:
> 
> Hoping someone may have some insight on this. We have some resources offered
> to the students and staff that are restricted by IP address. As some of the
> students and staff work from home, we have setup a proxy server that they
> can use to gain access to these resources. The server of course prompts them
> for a login id and password before allowing them to use it.
> 
> Specifically we have two sets of documents that are IP restricted, one set
> is for resources not maintained on our network (external links) and the
> other is for resources within our network. An automatic proxy configuration
> script had been created which performs two checks on a url to determine if
> the proxy server is needed or not. The one test checks the host value to see
> if it is one of the external sites which will require the proxy server, if
> it fails that test it then checks to see if the url contains a specific file
> or path and if it does then tells the browser to use the proxy server. If it
> fails both tests it tells the browser to connect directly and not through
> the proxy.
> 
> In all browsers the host check works flawlessly, however the url check only
> works correctly in Netscape and IE 4.x. For IE 5 and later it would appear
> that the browsers caches the response from the script for the given host
> value and not the url. (perhaps an example shall help)
> 
> Given the following function in the proxy.pac file:
> function FindProxyForURL(url, host)
> {
>   if (shExpMatch(url, "*webspirs.cgi*")) {
>     return 'PROXY proxy:5555';
>   } else {
>     return 'DIRECT';
>   }
> }
> 
> 1. In IE 5.x if you go to http://www.umanitoba.ca the script will check the
> url and not find webspirs.cgi in the path. It will fail on the test and tell
> the browser to connect directly. (which is correct of course)
> 2. If you then go to
> http://www.umanitoba.ca/cgi-bin/libraries/ws/webspirs.cgi IE 5.x does not
> use the proxy although it should as it contains webspirs.cgi in the url
> 
> Now if you were to go to
> http://www.umanitoba.ca/cgi-bin/libraries/ws/webspirs.cgi first, the script
> will find webspirs.cgi, direct you to the proxy and ask for an id and
> password. If you then go to http://www.umanitoba.ca the browser will still
> use the proxy server even though it is not required.
> 
> Now the questions I have are:
> 1. Has anyone encountered this as well?
> 2. Is there a possible fix for this, within the realms of the proxy.pac
> config file?
> 3. Are there any good sites for proxy script creation? (I've been to the
> Netscape and Microsoft one)
> 
> ~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=
> ~=~=
>     William Moore                          mailto:william_moore at umanitoba.ca
>     LETS Web Developer                                        (204) 474-6523
>                   http://www.umanitoba.ca/libraries/units/lets
>       486f6d6f 73756d3a 68756d616e69 6e696c 61 6d65 616c69656e756d 7075746f

When you do your return of either PROXY:5555 or DIRECT, you set a
value somewhere outside of this function.  What calls this
function?  Be sure to clear that value PRIOR to this call on each
iteration and that may solve it.  Another option is to clear the
value immediately following the use of it, virtually garbage
clean-up.  Seeing only this function and not what calls it does
not help because the problem lies outside of your function.  


Hope this helps.

-- 

Debbie

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Debra Lords			Experience is what you
dlords at library.utah.edu		have just right after 
ACLIS Labs			you need it.
585-9810