@code{(require 'uri)}
@ftindex uri

@noindent Implements @dfn{Uniform Resource Identifiers} (URI) as
@cindex Uniform Resource Identifiers
described in RFC 2396.


@defun make-uri


@defunx make-uri fragment

@defunx make-uri query fragment

@defunx make-uri path query fragment

@defunx make-uri authority path query fragment

@defunx make-uri scheme authority path query fragment

Returns a Uniform Resource Identifier string from component arguments.
@end defun


@defun uri:make-path path

Returns a URI string combining the components of list @var{path}.
@end defun


@defun html:anchor name
Returns a string which defines this location in the (HTML) file
as @var{name}.  The hypertext @samp{<A HREF="#@var{name}">} will link to this point.

@example
(html:anchor "(section 7)")
@result{}
"<A NAME=\"(section%207)\"></A>"
@end example
@end defun


@defun html:link uri highlighted
Returns a string which links the @var{highlighted} text to @var{uri}.

@example
(html:link (make-uri "(section 7)") "section 7")
@result{}
"<A HREF=\"#(section%207)\">section 7</A>"
@end example
@end defun


@defun html:base uri
Returns a string specifying the @dfn{base} @var{uri} of a document, for
@cindex base
inclusion in the HEAD of the document (@pxref{HTML, head}).
@end defun


@defun html:isindex prompt
Returns a string specifying the search @var{prompt} of a document, for
inclusion in the HEAD of the document (@pxref{HTML, head}).
@end defun


@defun uri->tree uri-reference base-tree


@defunx uri->tree uri-reference

Returns a list of 5 elements corresponding to the parts
(@var{scheme} @var{authority} @var{path} @var{query} @var{fragment})
of string @var{uri-reference}.  Elements corresponding to absent parts are #f.

The @var{path} is a list of strings.  If the first string is empty,
then the path is absolute; otherwise relative.  The optional @var{base-tree} is a
tree as returned by @code{uri->tree}; and is used as the base address for relative
URIs.

If the @var{authority} component is a
@dfn{Server-based Naming Authority}, then it is a list of the
@cindex Server-based Naming Authority
@var{userinfo}, @var{host}, and @var{port} strings (or #f).  For other
types of @var{authority} components the @var{authority} will be a
string.

@example
(uri->tree "http://www.ics.uci.edu/pub/ietf/uri/#Related")
@result{}
(http "www.ics.uci.edu" ("" "pub" "ietf" "uri" "") #f "Related")
@end example
@end defun


@defun uri:split-fields txt chr

Returns a list of @var{txt} split at each occurrence of @var{chr}.  @var{chr} does not
appear in the returned list of strings.
@end defun


@defun uri:decode-query query-string
Converts a @dfn{URI} encoded @var{query-string} to a query-alist.
@cindex URI
@end defun


@noindent @code{uric:} prefixes indicate procedures dealing with
URI-components.


@defun uric:encode uri-component allows
Returns a copy of the string @var{uri-component} in which all @dfn{unsafe} octets
@cindex unsafe
(as defined in RFC 2396) have been @samp{%} @dfn{escaped}.
@cindex escaped
@code{uric:decode} decodes strings encoded by @code{uric:encode}.
@end defun


@defun uric:decode uri-component
Returns a copy of the string @var{uri-component} in which each @samp{%} escaped
characters in @var{uri-component} is replaced with the character it encodes.  This
routine is useful for showing URI contents on error pages.
@end defun


@defun uri:path->keys path-list ptypes
@var{path-list} is a path-list as returned by @code{uri:split-fields}.  @code{uri:path->keys}
returns a list of items returned by @code{uri:decode-path}, coerced
to types @var{ptypes}.
@end defun

@subheading File-system Locators and Predicates


@defun path->uri path
Returns a URI-string for @var{path} on the local host.
@end defun


@defun absolute-uri? str
Returns #t if @var{str} is an absolute-URI as indicated by a
syntactically valid (per RFC 2396) @dfn{scheme}; otherwise returns
@cindex scheme
#f.
@end defun


@defun absolute-path? file-name
Returns #t if @var{file-name} is a fully specified pathname (does not
depend on the current working directory); otherwise returns #f.
@end defun


@defun null-directory? str
Returns #t if changing directory to @var{str} would leave the current
directory unchanged; otherwise returns #f.
@end defun


@defun glob-pattern? str
Returns #t if the string @var{str} contains characters used for
specifying glob patterns, namely @samp{*}, @samp{?}, or @samp{[}.
@end defun

@noindent
Before RFC 2396, the @dfn{File Transfer Protocol} (FTP) served a
@cindex File Transfer Protocol
similar purpose.


@defun parse-ftp-address uri

Returns a list of the decoded FTP @var{uri}; or #f if indecipherable.  FTP
@dfn{Uniform Resource Locator}, @dfn{ange-ftp}, and @dfn{getit}
@cindex Uniform Resource Locator
@cindex ange-ftp
@cindex getit
formats are handled.  The returned list has four elements which are
strings or #f:

@enumerate 0
@item
username
@item
password
@item
remote-site
@item
remote-directory
@end enumerate
@end defun