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HTTP Addressing
With an access code of http:, a protocol introduced for the WWW
initiative is used to acquire data from a server. This is the "Hypertext
Transfer protocol", HTTP , a simple search and retrieve (S and R)
protocol.
The syntax of an http address is, with [] indicating optional parts
(see BNF description ),
<![CDATA[ http : // hostname [ : port ] / path [ ? searchwords ]
]]>
for example, the following are valid addresses:
<![CDATA[ http://info.cern.ch/hypertext/WWW/TheProject.html
http://crnvmc.cern.ch/FIND?sgml+examples
]]>
HTTP addresses conform to the WWW conventions, including the possibility
of using the search format . The significance of the items in the
path part of the document name is completely up to the server. Different
paths may be used to select different databases, different views of
the same database, etc.
- hostname
- This is the name of the server in internet form. A numeric
form (e.g. 128.141.201.74) may be used, by the domain name form (e.g.
info.cern.ch) is preferred. The hostname is mandatory.
- port
- This is a numeric port number. If a non-numeric string is used,
it must be a defined service name. Note that as there is no central
repository for service names (they are defined locaaly for each host),
a service name is NOT an appropriate way to specify a port number
for a hypertext address. If the port number is omitted the preceding
colon must also be omitted. In this case, port number 2784 is assumed
[This may change!].
See also: WWW addressing in general , HTTP protocol .
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Tim BL
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