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Updated: 03:01 AM CT Jan 10, 2007 Posted: 10:44 PM CT Jan 09, 2007 Parsing URLs with Regular Expressions and the Regex Object And the Anatomy of a URI (Uniform Resource Identifier) Author: Steve Lautenschlager Snippet Regular Expressions Text and Strings C# .NET Browsers Web     Prev     1    2     Next    Summary While the .NET Framework contains a class call Uri which provides a lot of functionality when dealing with URLs and URIs, it's not always easy to get at the pieces of a URL. I present a technique here using regular expressions to extract the subparts of a URI in one fell swoop. But first let's talk about the parts of a URI. For the code go straight to Page 2. Read on below about the anatomy of a URI.  Anatomy of a URI The following information is taken from the official W3C Network Working Group documents. For the whole kit and kaboodle go here. URI stands for Uniform Resource Identifier and is a "compact sequence of characters which identifies an abstract or physical resource." URL stands for Uniform Resource Locator. URLs are a subset of URIs that "provide a means of locating a resource by describing its primary access mechanism, for example, its network location. Now, let's talk about the syntax of the URI, or the various pieces that combine to form the whole. These consist of the scheme, authority, path, query and fragment.  Components of a URI foo://example.com:8042/over/there?name=ferret#nose \_/ \______________/\_________/\__________/ \__/ | | | | | scheme authority path query fragment  Scheme The scheme of a URL is the first item, such as http, which indicates that this URI uses the hyper-text transport protocol. Examples of other schemes are: http World Wide Web Server. (http://www.w3.com) https Secure World Wide Web Server. (https://www.w3.com) ftp File Transfer Protocol (ftp://www.ftpx.com) gopher The Gopher Protocol. mailto Electronic Mail Address. (mailto:info@cambiaresearch.com) news USENET newsgroups. nntp USENET newsgroups using NNTP access. telnet Interactive sessions on server. wais Wide Area Information Servers. file file on local system. prospero Prospero Directory Services.  Authority In a URL the authority is also called the domain and may include a port number at the end separated by a colon. In the following example, the authority is www.cambiaresearch.com http://www.cambiaresearch.com In the following example, the authority is www.cambiaresearch.com:81 https://www.cambiaresearch.com:81 In the following example, the authority is info@cambiaresearch.com mailto:info@cambiaresearch.com  Path The path component of the URL specifies the specific file (or page) at a particular domain. The path is terminated by the end of the URL, a question mark (?) which signifies the beginning of the query string or the number sign (#) which signifies the beginning of the fragment. The path of the following URL is "/default.htm" http://www.cambiaresearch.com/default.htm The path of the following URL is "/snippets/csharp/regex/uri_regex.aspx" http://www.cambiaresearch.com/snippets/csharp/regex/uri_regex.aspx  Query The query part of the URL is a way to send some information to the path or webpage that will handle the web request. The query begins with a question mark (?) and is terminated by the end of the URL or a number sign (#) which signifies the beginning of the fragment. The query of the following URL is "?id=241" http://www.cambiaresearch.com/default.htm?id=241 The query of the following URL is "?sourceid=navclient&ie=UTF-8&rls=GGLC,GGLC: 1969-53,GGLC:en&q=uri+query" http://www.google.com/search?sourceid=navclient&ie=UTF-8&rls=GGLC,GGLC:1969-53,GGLC:en&q=uri+query  Fragment In a URL the fragment is used to specify a location within the current page. This is often used in a FAQ with a list of links at the top of the page linking to longer descriptions farther down in the page. The fragment of the following URL is "contact" http://www.cambiaresearch.com/default.htm#contact The fragment of the following URL is "scheme" http://www.cambiaresearch.com/snippets/csharp/regex/uri_regex.aspx#scheme     Prev     1    2     Next