Classic ASP Sleep Function or How to Delay a HTTP Response in Classic ASP – Explanation & Alternative Solutions

Is There a Sleep Method in Classic ASP?

First, and sorry, there is no built in sleep method in classic ASP. Probably for good reason though. Keep reading for background on why and I’ll offer some possible alternatives.

VBScript Sleep Function Code Example

Normally, when I think of a sleep function, I think of the built-in VBScript Sleep Function where we can set a delay in seconds to pause some code in a function.

WScript.Echo("5 seconds have passed.")

What is Classic ASP?

Classic ASP is VBScript interpreted rather than compiled on the IIS web server then converted into 100% HTML before it is delivered to the client / web browser in a HTTP call.

I’ll emphasize, with Classic ASP, the client never sees the underlying VBScript, only rendered HTML.

The Refresh Meta Tag / Wait vs. Sleep

An alterative to “Sleep” might be delay or wait. We can use the Meta Tag, “Refresh”, if you just need a web page to wait for a number of seconds before refreshing which includes redirecting the page on refresh to another URL.

You would include the meta refresh tag inside the web page’s head tags as shown in the code example below.

Meta Refresh Tag Example Code

        <title>Meta Tag Refresh Example</title>
        <meta http-equiv="refresh" content="5"; url="Test.html" />  

Custom ASP Sleep Function Alternative

As a prerequisite, I can’t imagine why you would want to delay a Classic ASP page from being served to a user’s web browser for 10 seconds. That’s a long time to make a user wait but you can do anything with code.

I will warn you, if you cause the HTTP Response to delay for a User Agent like Google bot, Google will probably exclude your website from their search indexes so I typically would not do this in practice on a website that needed any kind of Search Engine Optimization (SEO) friendliness.

DIY Classic ASP Sleep Function?

With Classic ASP, since we don’t have a native sleep or delay method, we can just build our own. By default, I’m going to stay with a delay of specific number of seconds as our end goal.

I’m sure we can come up with a few ways to solve for this but this solution is mine.

Building the Sleep Function from Scratch

  • We will set some variables for a start time and a current time.
  • Then start a While Loop that watches for # of seconds we’ve chosen.
  • We update the current time at each iteration of the loop and check it at start of each loop iteration.
  • Once current time increments by 10 seconds, loop completes giving you a delay of specified seconds.

Classic ASP Sleep Function Code

Sub Delay(intSeconds)
	StartTime = Now()
	CurrentTime = Now()
	While DateDiff("s",StartTime,CurrentTime) < intSeconds
		CurrentTime = Now()
End Sub

call Delay(10)
Response.Write("Something 10 seconds later")

Another reason I would not recommend this approach is that we are tying up the CPU while running this loop waiting for the time to change. Making this more of a weapon than a tool.

From a bad guy perspective, if you could get this code loaded and running on multiple pages with lots of traffic you could really degrade the performance of the server.

I hope this helps you if you were looking for a simple Classic ASP HTTP Response delay function but be careful how you use it.

Hope this helps you in your search for a VBScript Sleep Function.

~Cyber Abyss