Default documents, directory browsing, and error messages
Describe the concepts of default documents, directory browsing, and error messages.
Default Documents, Directory Browsing
When a server receives a request for a URL that refers to a directory rather than to a specified document, the server may operate in one of the following ways, depending on how it is configured:
It may return a default document present in that directory.
It may generate an error and refuse the request.
It may return a directory listing.
The first option listed is the most common. You can configure any Web server, whether it is IIS, Lotus Go Webserver, or Apache Server, to refer to a default document automatically if the user does not specify a document.
For example, a request for the URL http://www.ewebprogrammer.com/ usually returns the default document, or home page, from the server resource root directory on the machine http://www.ewebprogrammer.com.
You can name your default document anything you wish, as long as you configure the server to recognize this name.
Common default document names include index.htm, index.html, default.htm, and welcome.html. IIS defaults to default.htm, and Apache Server defaults to index.html. You can change this name at any time by customizing the configuration files.
Common HTTP error messages
Below is a partial list of common HTTP error messages:
All Web servers have a directory listing feature. This involves setting the server's permissions so that the server automatically formats the directory's contents in HTML, then reports the contents to the browser.
This HTML page represents each file as an HTML link in alphabetical order. By clicking on the corresponding link, the browser user may read and/or download the listed file.
It is generally not a good idea to allow this option, because it may reveal too much information about the workings of your server. You will learn more about security issues in a later module.
In the next lesson, Web site development software will be discussed.