Paths - file name, URLs, and URIs

A Path is the name of a file or some other resource.

Type: path

A general path, which can be a filename or a URI. It can be either a filename or a URI. Represented using the abstract Java class java.text.Path.

Coercing a value to a Path is equivalent to calling the path constructor documented below.

Constructor: path arg

Coerces the arg to a path. If arg is already a path, it is returned unchanged. If arg is a java.net.URI, or a java.net.URL then a URI value is returned. If arg is a java.io.File, a filepath value is returned. Otherwise, arg can be a Scheme string or a java.lang.String. A URI value is returns if the string starts with a URI scheme (such as "http:"), and a filepath value is returned otherwisw.

Predicate: path? arg

True if arg is a path - i.e. an instance of a gnu.text.Path.

Type: filepath

The name of a local file. Represented using the Java class gnu.text.FilePath, which is a wrapper around java.io.File.

Predicate: filepath? arg

True if arg is a filepath - i.e. an instance of a gnu.text.FilePath.

Type: URI

A Uniform Resource Indicator, which is a generalization of the more familiar URL. The general format is specified by RFC 2396: Uniform Resource Identifiers (URI): Generic Syntax. Represented using the Java class gnu.text.URIPath, which is a wrapper around java.net.URI. A URI can be a URL, or it be a relative URI.

Predicate: URI? arg

True if arg is a URI - i.e. an instance of a gnu.text.URIPath.

Extracting Path components

Function: path-scheme arg

Returns the “URI scheme” of arg (coerced to a path) if it is defined, or #f otherwise. The URI scheme of a filepath is "file" if the filepath is absolute, and #f otherwise.
(path-scheme "http://gnu.org/") ⇒ "http"

Function: path-authority arg

Returns the authority part of arg (coerced to a path) if it is defined, or #f otherwise. The “authority” is usually the hostname, but may also include user-info or a port-number.
(path-authority "http://me@localhost:8000/home") ⇒ "me@localhost:8000"

Function: path-host arg

Returns the name name part of arg (coerced to a path) if it is defined, or #f otherwise.
(path-host "http://me@localhost:8000/home") ⇒ "localhost"

Function: path-user-info arg

Returns the “user info” of arg (coerced to a path) if it is specified, or #f otherwise.
(path-host "http://me@localhost:8000/home") ⇒ "me"

Function: path-port arg

Returns the port number of arg (coerced to a path) if it is specified, or -1 otherwise. Even if there is a default port associated with a URI scheme (such as 80 for http), the value -1 is returned unless the port number is explictly specified.
(path-host "http://me@localhost:8000/home") ⇒ 8000
(path-host "http://me@localhost/home") ⇒ -1

Function: path-file arg

Returns the “path component” of the arg (coerced to a path). (The name path-path might be more logical, but it is obviously a bit awkward.) The path component of a file name is the file name itself. For a URI, it is the main hierarchical part of the URI, without schema, authority, query, or fragment.
(path-file "http://gnu.org/home/me.html?add-bug#body") ⇒ "me.html"

Function: path-directory arg

If arg (coerced to a path) is directory, return arg; otherwise return the “parent” path, without the final component.
(path-directory "http://gnu.org/home/me/index.html#body")
  ⇒ (path "http://gnu.org/home/me/")
(path-directory "http://gnu.org/home/me/")
  ⇒ (path "http://gnu.org/home/me/")
(path-directory "./dir") ⇒ (path "./dir") if dir is a directory, and (path ".") otherwise.

Function: path-parent arg

Returns the “parent directory” of arg (coerced to a path). If arg is not a directory, same as path-directory arg.
(path-parent "a/b/c") ⇒ (path "a/b")
(path-parent "file:/a/b/c") ⇒ (path "file:/a/b/c")
(path-parent "file:/a/b/c/") ⇒ (path "file:/a/b/")

Function: path-last arg

The last component of path component of arg (coerced to a path). Returns a substring of (path-file arg). If that string ends with ‘/’ or the path separator, that last character is ignored. Returns the tail of the path-string, following the last (non-final) ‘/’ or path separator.
(path-last "http:/a/b/c") ⇒ "c"
(path-last "http:/a/b/c/") ⇒ "c"
(path-last "a/b/c") ⇒ "c"

Function: path-extension arg

Returns the “extension” of the arg (coerced to a path).
(path-extension "http://gnu.org/home/me.html?add-bug#body") ⇒ "html"
(path-extension "/home/.init") ⇒ #f

Function: path-query arg

Returns the query part of arg (coerced to a path) if it is defined, or #f otherwise. The query of a URI is the part of after ‘?’.
(path-query "http://gnu.org/home?add-bug") ⇒ "add-bug"

Function: path-fragment arg

Returns the fragment part of arg (coerced to a path) if it is defined, or #f otherwise. The fragment of a URI is the part of after ‘#’.
(path-query "http://gnu.org/home#top") ⇒ "top"

Kawa

Paths - file name, URLs, and URIs

Extracting Path components