How ASP connects with IIS

The ASP itself contains a DLL file, named ASP.DLL, which is installed by default in the Winntsystem32inetsrv directory. This DLL file is responsible for getting an ASP page (by file name extension). ASP identification), and then analyze it to look for server-side script content. This script is routed to the appropriate script engine, and the results of the script are combined with the HTML and template text in the ASP page. The full page is sent to the Web server from where it was sent to the client who originally made the request.
About the application mapping
To better understand this process, you need to look at how application mapping works in Windows 2000. For each Web site that is set up under IIS, there is a root directory on the server. When you install IIS, the default Web site is usually c:inetpubwwwroot, unless you change the path during installation. For this directory and the subdirectories (which we'll discuss later), there's a set of definitions that define how the directory fits into the IIS properties.
Opening Internet Services Manger from Administrative Tools in the Start menu will run the Microsoft Management Console (Microsoft Management CONSOLE,MMC) to show IIS.
Right-click the default Web Site, select Properties, and the Home Directory tab appears, as shown in Figure 1-4.
You can see that the default site is set up as a virtual application. There are applicationname, Execute permissions, and Application protection options in the lower half of the tab. IIS uses a virtual application to isolate the page set and instances of the components that are used, affecting the prevention of Web servers with failure. As has been seen earlier, this is done through the execution of page and out-of-process components in a separate memory space. We will discuss this issue later in this chapter.
Click the Configuration button to open the Application Configuration dialog box, as shown in Figure 1-5. In the App Mappings tab, you can see that IIS is linked to various files using a specific DLL. Any file containing the extended filename. ASP's Web pages are sent to ASP.DLL for processing; pages with unmapped extension filenames, such as. html and. htm and XML files for HTML pages, simply upload them from disk and send them directly to the client.
Readers may want to know more about the other file types on this tab. Ida,. IDC and. idq file extensions are used by IDC template files and query files, so an IDC query page (. idc) will be sent directly to the dynamic link library httpodbc. DLL for processing. It can also be guessed from the file name, which uses ODBC to execute the SQL statement and returns a set of data records contained in the page. Similarly, the. shtm,. shtml and. stm file extensions correspond to dynamic-link libraries with file names of Ssinc.DLL, which are generally used to request files that are processed by the server side (Server-sideinclude,ssi). We will give some relevant examples in the following sections of this book.