Provided by: tcllib_1.17-dfsg-1_all 
NAME
uri - URI utilities
SYNOPSIS
package require Tcl 8.2
package require uri ?1.2.5?
uri::split url ?defaultscheme?
uri::join ?key value?...
uri::resolve base url
uri::isrelative url
uri::geturl url ?options...?
uri::canonicalize uri
uri::register schemeList script
________________________________________________________________________________________________________________
DESCRIPTION
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.
COMMANDS
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, ldap and file are supported by the package itself. See section EXTENDING
on how to expand that range.
The set of constituents of an url (= the set of keys in the returned dictionary) is dependent on
the scheme of the url. The only key which is therefore always present is scheme. For the following
schemes the constituents and their keys are known:
ftp user, pwd, host, port, path, type
http(s)
user, pwd, host, port, path, query, fragment. The fragment is optional.
file path, host. The host is optional.
mailto user, host. The host is optional.
news Either message-id or newsgroup-name.
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, ldap 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.
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, ldap, file,
http, gopher, mailto, news, wais and prospero.
EXTENDING
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.
CREDITS
Original code (regular expressions) by Andreas Kupries. Modularisation by Steve Ball, also the
split/join/resolve functionality.
BUGS, IDEAS, FEEDBACK
This document, and the package it describes, will undoubtedly contain bugs and other problems. Please
report such in the category uri of the Tcllib Trackers [http://core.tcl.tk/tcllib/reportlist]. Please
also report any ideas for enhancements you may have for either package and/or documentation.
KEYWORDS
fetching information, file, ftp, gopher, http, ldap, mailto, news, prospero, rfc 2255, rfc 2396, uri,
url, wais, www
CATEGORY
Networking
tcllib 1.2.5 uri(3tcl)