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ActiveTcl User Guide
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uri(n) 1.1.2 "Tcl Uniform Resource Identifier Management"
uri - URI utilities
package require Tcl 8.2
package require uri ?1.1.2?
This package contains two parts. First it provides regular
expressions for a number of url/uri schemes. Second it provides a
number of commands for manipulating urls/uris and fetching data
specified by them. For the latter this package analyses the
requested url/uri and then dispatches it to the appropriate package
(http, ftp, ...) for actual fetching.
The package currently does not conform to RFC 2396 (http://www.rfc-editor.org/rfc/rfc2396.txt),
but quite likely should be. Patches and other help are welcome.
- uri::split url ?defaultscheme?
- uri::split takes an url,
decodes it and then returns a list of key/value pairs suitable for
array set containing the constituents of the url. If the scheme is missing from the url it
defaults to the value of defaultscheme if it was
specified, or http else.
Currently only the schemes http , ftp , mailto , urn, news , and file are supported by the package
itself. See section EXTENDING on how to
expand that range.
- uri::join ?key value?...
- uri::join takes a list of key/value pairs
(generated by uri::split, for example) and
returns the canonical url they represent. Currently only the
schemes http , ftp , mailto , urn, news , and file are supported. See section EXTENDING on how to expand that range.
- uri::resolve base url
- uri::resolve resolves the specified url relative to base. In other
words: A non-relative url is returned unchanged,
whereas for a relative url the missing parts are
taken from base and prepended to it. The result
of this operation is returned. For an empty url
the result is base.
- uri::isrelative url
- uri::isrelative determines whether the
specified url is absolute or relative.
- uri::geturl url ?options...?
- uri::geturl decodes the specified url and then dispatches the request to the package
appropriate for the scheme found in the url. The command assumes
that the package to handle the given scheme either has the same
name as the scheme itself (including possible capitalization)
followed by ::geturl, or, in case of this
failing, has the same name as the scheme itself (including possible
capitalization). It further assumes that whatever package was
loaded provides a geturl-command in the
namespace of the same name as the package itself. This command is
called with the given url and all given options. Currently geturl does
not handle any options itself.
Note: file
-urls are an exception to the rule described above. They are
handled internally.
It is not possible to specify results of the command. They depend
on the geturl-command for the scheme the request
was dispatched to.
- uri::canonicalize uri
- uri::canonicalize returns the canonical form
of a URI. The canonical form of a URI is one where relative path
specifications, ie. . and .., have been resolved.
- uri::register schemeList script
- uri::register registers the first element of
schemeList as a new scheme and the remaining
elements as aliases for this scheme. It creates the namespace for
the scheme and executes the script in the new
namespace. The script has to declare variables containing the
regular expressions relevant to the scheme. At least the variable
schemepart has to be declared as that one is used
to extend the variables keeping track of the registered
schemes.
In addition to the commands mentioned above this package
provides regular expression to recognize urls for a number of url
schemes.
For each supported scheme a namespace of the same name as the
scheme itself is provided inside of the namespace uri
containing the variable url whose contents are a
regular expression to recognize urls of that scheme. Additional
variables may contain regular expressions for parts of urls for
that scheme.
The variable uri::schemes contains a list of
all supported schemes. Currently these are ftp , file , http , gopher , mailto , news , wais and prospero .
Extending the range of schemes supported by uri::split and uri::join is easy
because both commands do not handle the request by themselves but
dispatch it to another command in the uri namespace using
the scheme of the url as criterion.
uri::split and uri::join
call Split[string totitle <scheme>] and Join[string totitle <scheme>]
respectively.
Original code (regular expressions) by Andreas Kupries.
Modularisation by Steve Ball, also the split/join/resolve
functionality.
fetching information , file , ftp , gopher , http , mailto , news , prospero , rfc 2396 , uri , url , wais , www