Web Pages

HTTP Status Codes explained for web servers

As a web administrator I encounter quite a few instances where a weird HTTP status is returned to a browser.Even using them often it’s hard to remember the codes 100% and what they all mean. Sure, a 404 means the file doesn’t exist and a 200 is a good response… but what about the harder more obscure ones? Generally the toughest to resolve revolve around permissions and the HTTP 401.x status, here is a good article explaining the HTTP 401 sub status codes for IIS (The general idea will flow over to other web servers like apache as well).

As a  added bonus here is a great article that explains a vast variety of other HTTP Status codes.

Using Internet Explorer objects to scrape links from web pages.

 Recently, I needed to write a tool that would scrape the links from a page. To accomplish this I used the Internet Explorer object “InternetExplorer.Application“.  We’ll explain it a bit more in a later entry but for now, take a look at the code below:

URL = “http://itknowledgeexchange.techtarget.com/itblogs/“

With CreateObject(”InternetExplorer.Application”)
  .Navigate URL
  Do Until .ReadyState = 4
    Wscript.sleep 10
  Loop
  for each link in .document.links
    Wscript.echo link, link.InnerText
  next

‘ Uncomment the three lines below to scrape references to images
‘  for each pix in .document.images
‘  Wscript.echo pix.src
‘  Next
 
  .Quit
End With

Consuming and using a web service from within VBScript to create a WHOIS tool

Recently I posted a list of web services at a site that were public web services, in the article entitled A Great list of FREE publicly available Web Services. In looking through them I noticed one that would be useful- a WHOIS web service!

Please keep in mind that this script uses a PUBLIC and FREE web service to preform the heart of it’s work… it might not be always available and that is out of both our control. However, the code will work, with minor changes where noted for any other web service.

First some background on a web service. When you consume (use) a web service, you call it like you would any other class or function, with a .functionname after the object is created as an instance.

The MSSOAP.SOAPClient line below creates a SOAP object, and the .MSSOAPINIT creates an instance of your web service in that object. Then, in this case the .whois  call actually makes it preform the functions on the remote system. The remote system then returns back the value from the function to you just as if a local function were called.

Pretty cool stuff! So, here is the code to call a web service from VBScript!
dim SOAPClient, Response
‘create the SOAP object
Set SOAPClient = createobject(”MSSOAP.SOAPClient”)
on error resume Next
‘create a instance of the WHIOIS web service
SOAPClient.mssoapinit(”http://www.ecubicle.net/whois_service.asmx?WSDL“)
  ‘ check for errors… deal with them if they occur by reporting them
  if err Then
    wscript.echo SOAPClient.faultString
    wscript.echo SOAPClient.detail
  end If

‘this next line is where we actually CALL the web service
Response = SOAPClient.Whois(”whois.networksolutions.com”, 43, “networksolutions.com”)

‘fix up network solutions’ HTML responses to whois queries. why do they have to be difficult?
Response = replace(Response,”<br/>”,VbCrLf)
Response = replace(Response,”<BR/>”,VbCrLf)

‘ echo the response recieved (since it’s a string)
wscript.echo Response

‘ check for errors… deal with them if they occur by reporting them
  if err Then
    wscript.echo SOAPClient.faultString
    wscript.echo SOAPClient.detail
  End If

A Great list of FREE publicly available Web Services

As an IIS Administrator I have spent quite a bit of time administering web sites and web services in my role where I work. Recently, I have been doing some work with Web Services in IIS to actually monitor them since we needed to do more than just simply monitor the Web Service Definition Language (WSDL) page.

For those of you who do this sort of work, you know this is a real challenge sometimes, since the web service can actually be broken– but the WSDL page shows up. So, I had to create something to actually consume the web service so that we could truely test the web service.

Web Services are basically (yes, I’m boiling it down to the bare minimum here…) web sites that accept input via the HTTP protocol, preform work based on those parameters, and return back some value via HTTP. Just like a FUNCTION! This is an exciting technology, becasue it essentially is distributed computing.

This caused me to look for public web services, again, because I was interested in the concept since I first heard about it 4 or 5 years back. I found a decent site that had a list of web services that were available on the internet at Xmethods.net. While they all aren’t free (and they all didn’t appear to be operational) — it did seem like a decent list of sometimes useful stuff to have handy.

Having found this, I can now share the consumption of web services from VBScript with you in another blog posting– Consuming and using a web service from within VBScript to create a WHOIS tool.

How to retrieve HTML web pages with VBScript via the Microsoft.XmlHttp object

Recently, I had a situation where I had to pull down a HTML page to compare it to a known copy of the page. Certainly, IE or FireFox– or Google’s Chrome would have done the trick and I could have viewed the source. But that would require me to do work every time we needed to check the page against the known good source.

 Instead I wrote a script to pull the HTML source and echo the response to the console (or a messag box if you are not using cscript to execute the script). While not a full blown HTTP QA script it does do the job of getting the HTTP responses from the server and is certainly a core part of any QA script anyone would write.

Basically the script uses the Microsoft.XMLHTTP object to preform all the HTTP calls and retrieve the HTML page. It sounds scary, but if you look at the script below I think you’ll find that it really is quite easy to accomplish.  So, here is the script’s code:

URL=”http://www.gamersigs.net/“
Set WshShell = WScript.CreateObject(”WScript.Shell”)
Set http = CreateObject(”Microsoft.XmlHttp”)

On Error Resume Next
http.open “GET”, URL, False
http.send “”
if err.Number = 0 Then
     WScript.Echo http.responseText
Else
     Wscript.Echo “error ” & Err.Number & “: ” & Err.Description
End If
set WshShell = Nothing
Set http = Nothing

Enjoy!