.. Licensed to the Apache Software Foundation (ASF) under one
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   regarding copyright ownership.  The ASF licenses this file
   to you under the Apache License, Version 2.0 (the
   "License"); you may not use this file except in compliance
   with the License.  You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing,
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   "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
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.. include:: ../../../common.defs

.. default-domain:: c

TSUrlPercentEncode
******************

Traffic Server URL percent encoding API.

Synopsis
========

.. code-block:: cpp

    #include <ts/ts.h>

.. function:: TSReturnCode TSUrlPercentEncode(TSMBuffer bufp, TSMLoc offset, char * dst, size_t dst_size, size_t * length, const unsigned char * map)
.. function:: TSReturnCode TSStringPercentEncode(const char * str, int str_len, char * dst, size_t dst_size, size_t * length, const unsigned char * map)
.. function:: TSReturnCode TSStringPercentDecode(const char * str, size_t str_len, char * dst, size_t dst_size, size_t * length)

Description
===========

The URL data structure is a parsed version of a standard internet URL. The
Traffic Server URL API provides access to URL data stored in marshal
buffers. The URL functions can create, copy, retrieve or delete entire URLs,
and retrieve or modify parts of URLs, such as their host, port or scheme
information.

:func:`TSUrlPercentEncode` performs percent-encoding of the URL object,
storing the new string in the :arg:`dst` buffer. The :arg:`length` parameter
will be set to the new (encoded) string length, or :literal:`0` if the encoding
failed.  :func:`TSStringPercentEncode` is similar but operates on a string. If
the optional :arg:`map` parameter is provided (not :literal:`nullptr`) , it should
be a map of characters to encode.

:func:`TSStringPercentDecode` perform percent-decoding of the string in the :arg:`str` buffer,
writing to the :arg:`dst` buffer. The source and destination can be the same, in which case the
decoded string is written on top of the source string. The decoded string is guaranteed to be
no longer than the source string, but will include a terminating null which, if there are no
escapes, makes the destination one longer than the source. In practice this means the destination
length needs to be bumped up by one to account for the null, and a string can't be decoded in place
if it's not already null terminated with the length of the destination including the null, but the
length of the source *not* including the null. E.g. ::

   static char const ORIGINAL[] = "A string without escapes, but null terminated";
   char * source = TSstrdup(ORIGINAL); // make it writeable.
   size_t length; // return value.
   // sizeof(ORIGINAL) includes the null, so don't include that in the input.
   static const size_t N_CHARS = sizeof(ORIGINAL) - 1;
   TSReturnCode result = TSStringPercentDecode(source, N_CHARS, source, N_CHARS + 1, &length);
   ink_assert(length == N_CHARS);

Return Values
=============

All these APIs returns a :type:`TSReturnCode`, indicating success (:data:`TS_SUCCESS`) or failure
(:data:`TS_ERROR`) of the operation.

See Also
========

:manpage:`TSAPI(3ts)`,
:manpage:`TSUrlCreate(3ts)`,
:manpage:`TSUrlHostGet(3ts)`,
:manpage:`TSUrlHostSet(3ts)`,
:manpage:`TSUrlStringGet(3ts)`