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The TCP/IP Guide  9  TCP/IP Application Layer Protocols, Services and Applications (OSI Layers 5, 6 and 7)       9  TCP/IP Key Applications and Application Protocols            9  TCP/IP Application Layer Addressing: Uniform Resource Identifiers, Locators and Names (URIs, URLs and URNs)                 9  Uniform Resource Locators (URLs)

URL General Syntax 1 2 3 4 5 URL Relative Syntax and Base URLs

Uniform Resource Locators (URLs) use a general syntax that describes the location and method for accessing a TCP/IP resource. Each access method, called a scheme, has its own specific URL syntax, including the various pieces of information required by the method to identify a resource. RFC 1738 includes a description of the specific syntaxes used by several popular URL schemes. Others have been defined in subsequent RFCs using the procedure established for URL scheme registration.

Several of the URL schemes use the common Internet pattern given in my overview of URL syntax. Other schemes use entirely different (usually simpler) structures based on their needs. For reference, I will repeat the general syntax again here, as it will help you understand the rest of the topic:

<scheme>://<user>:<password>@<host>:<port>/<url-path>;<params>?<query>#<fragment>

The following are the most common URL schemes and the scheme-specific syntaxes they use.

URL General Syntax 1 2 3 4 5 URL Relative Syntax and Base URLs