presto-docs/src/main/sphinx/functions/url.rst
The URL extraction functions extract components from HTTP URLs
(or any valid URIs conforming to :rfc:2396).
The following syntax is supported:
.. code-block:: none
[protocol:][//host[:port]][path][?query][#fragment]
The extracted components do not contain URI syntax separators
such as : or ?.
.. function:: url_extract_fragment(url) -> varchar
Returns the fragment identifier from ``url``.
.. function:: url_extract_host(url) -> varchar
Returns the host from ``url``.
.. function:: url_extract_parameter(url, name) -> varchar
Returns the value of the first query string parameter named ``name``
from ``url``. Parameter extraction is handled in the typical manner
as specified by :rfc:`1866#section-8.2.1`.
.. function:: url_extract_path(url) -> varchar
Returns the path from ``url``.
.. function:: url_extract_port(url) -> bigint
Returns the port number from ``url``.
.. function:: url_extract_protocol(url) -> varchar
Returns the protocol from ``url``.
.. function:: url_extract_query(url) -> varchar
Returns the query string from ``url``.
.. function:: url_encode(value) -> varchar
Escapes ``value`` by encoding it so that it can be safely included in
URL query parameter names and values:
* Alphanumeric characters are not encoded.
* The characters ``.``, ``-``, ``*`` and ``_`` are not encoded.
* The ASCII space character is encoded as ``+``.
* All other characters are converted to UTF-8 and the bytes are encoded
as the string ``%XX`` where ``XX`` is the uppercase hexadecimal
value of the UTF-8 byte.
.. function:: url_decode(value) -> varchar
Unescapes the URL encoded ``value``.
This function is the inverse of :func:`!url_encode`.