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<a href="#id2561532" class="shortcut">Description</a></nobr></td></tr>
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<div class="refentry" lang="en">
<a name="libidn-punycode"></a><div class="titlepage"></div>
<div class="refnamediv"><table width="100%"><tr>
<td valign="top">
<h2>
<a name="id2558276"></a><span class="refentrytitle">punycode</span>
</h2>
<p>punycode</p>
</td>
<td valign="top" align="right"></td>
</tr></table></div>
<div class="refsynopsisdiv">
<h2>Synopsis</h2>
<pre class="synopsis">
enum <a href="libidn-punycode.html#Punycode-status">Punycode_status</a>;
const char* <a href="libidn-punycode.html#punycode-strerror">punycode_strerror</a> (<a href="libidn-punycode.html#Punycode-status">Punycode_status</a> rc);
typedef <a href="libidn-punycode.html#punycode-uint">punycode_uint</a>;
int <a href="libidn-punycode.html#punycode-encode">punycode_encode</a> (size_t input_length,
const <a href="libidn-punycode.html#punycode-uint">punycode_uint</a> input[],
unsigned char case_flags[],
size_t *output_length,
char output[]);
int <a href="libidn-punycode.html#punycode-decode">punycode_decode</a> (size_t input_length,
const char input[],
size_t *output_length,
<a href="libidn-punycode.html#punycode-uint">punycode_uint</a> output[],
unsigned char case_flags[]);
</pre>
</div>
<div class="refsect1" lang="en">
<a name="id2561532"></a><h2>Description</h2>
<p>
</p>
</div>
<div class="refsect1" lang="en">
<a name="id2561547"></a><h2>Details</h2>
<div class="refsect2" lang="en">
<a name="id2561558"></a><h3>
<a name="Punycode-status"></a>enum Punycode_status</h3>
<a class="indexterm" name="id2561571"></a><pre class="programlisting"> typedef enum
{
PUNYCODE_SUCCESS = punycode_success,
PUNYCODE_BAD_INPUT = punycode_bad_input,
PUNYCODE_BIG_OUTPUT = punycode_big_output,
PUNYCODE_OVERFLOW = punycode_overflow
} Punycode_status;
</pre>
<p>
Enumerated return codes of <a href="libidn-punycode.html#punycode-encode"><code class="function">punycode_encode()</code></a> and <a href="libidn-punycode.html#punycode-decode"><code class="function">punycode_decode()</code></a>.
The value 0 is guaranteed to always correspond to success.</p>
<p>
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><span class="term"><a name="PUNYCODE-SUCCESS:CAPS"></a><code class="literal">PUNYCODE_SUCCESS</code></span></td>
<td> Successful operation. This value is guaranteed
to always be zero, the remaining ones are only guaranteed to hold
non-zero values, for logical comparison purposes.
</td>
</tr>
<tr>
<td><span class="term"><a name="PUNYCODE-BAD-INPUT:CAPS"></a><code class="literal">PUNYCODE_BAD_INPUT</code></span></td>
<td> Input is invalid.
</td>
</tr>
<tr>
<td><span class="term"><a name="PUNYCODE-BIG-OUTPUT:CAPS"></a><code class="literal">PUNYCODE_BIG_OUTPUT</code></span></td>
<td> Output would exceed the space provided.
</td>
</tr>
<tr>
<td><span class="term"><a name="PUNYCODE-OVERFLOW:CAPS"></a><code class="literal">PUNYCODE_OVERFLOW</code></span></td>
<td> Input needs wider integers to process.
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2568510"></a><h3>
<a name="punycode-strerror"></a>punycode_strerror ()</h3>
<a class="indexterm" name="id2568522"></a><pre class="programlisting">const char* punycode_strerror (<a href="libidn-punycode.html#Punycode-status">Punycode_status</a> rc);</pre>
<p>
Convert a return code integer to a text string. This string can be
used to output a diagnostic message to the user.
</p>
<p>
PUNYCODE_SUCCESS: Successful operation. This value is guaranteed
to always be zero, the remaining ones are only guaranteed to hold
non-zero values, for logical comparison purposes.
PUNYCODE_BAD_INPUT: Input is invalid.
PUNYCODE_BIG_OUTPUT: Output would exceed the space provided.
PUNYCODE_OVERFLOW: Input needs wider integers to process.</p>
<p>
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><span class="term"><em class="parameter"><code>rc</code></em> :</span></td>
<td> an <a href="libidn-punycode.html#Punycode-status"><span class="type">Punycode_status</span></a> return code.
</td>
</tr>
<tr>
<td><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td>
<td> Returns a pointer to a statically allocated string
containing a description of the error with the return code <em class="parameter"><code>rc</code></em>.
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2568609"></a><h3>
<a name="punycode-uint"></a>punycode_uint</h3>
<a class="indexterm" name="id2568621"></a><pre class="programlisting"> typedef uint32_t punycode_uint;
</pre>
<p>
Unicode code point data type, this is always a 32 bit unsigned
integer.</p>
<p>
</p>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2568642"></a><h3>
<a name="punycode-encode"></a>punycode_encode ()</h3>
<a class="indexterm" name="id2568654"></a><pre class="programlisting">int punycode_encode (size_t input_length,
const <a href="libidn-punycode.html#punycode-uint">punycode_uint</a> input[],
unsigned char case_flags[],
size_t *output_length,
char output[]);</pre>
<p>
Converts a sequence of code points (presumed to be Unicode code
points) to Punycode.</p>
<p>
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><span class="term"><em class="parameter"><code>input_length</code></em> :</span></td>
<td> The number of code points in the <em class="parameter"><code>input</code></em> array and
the number of flags in the <em class="parameter"><code>case_flags</code></em> array.
</td>
</tr>
<tr>
<td><span class="term"><em class="parameter"><code>input</code></em> :</span></td>
<td> An array of code points. They are presumed to be Unicode
code points, but that is not strictly REQUIRED. The array
contains code points, not code units. UTF-16 uses code units
D800 through DFFF to refer to code points 10000..10FFFF. The
code points D800..DFFF do not occur in any valid Unicode string.
The code points that can occur in Unicode strings (0..D7FF and
E000..10FFFF) are also called Unicode scalar values.
</td>
</tr>
<tr>
<td><span class="term"><em class="parameter"><code>case_flags</code></em> :</span></td>
<td> A <code class="literal">NULL</code> pointer or an array of boolean values parallel
to the <em class="parameter"><code>input</code></em> array. Nonzero (true, flagged) suggests that the
corresponding Unicode character be forced to uppercase after
being decoded (if possible), and zero (false, unflagged) suggests
that it be forced to lowercase (if possible). ASCII code points
(0..7F) are encoded literally, except that ASCII letters are
forced to uppercase or lowercase according to the corresponding
case flags. If <em class="parameter"><code>case_flags</code></em> is a <code class="literal">NULL</code> pointer then ASCII letters
are left as they are, and other code points are treated as
unflagged.
</td>
</tr>
<tr>
<td><span class="term"><em class="parameter"><code>output_length</code></em> :</span></td>
<td> The caller passes in the maximum number of ASCII
code points that it can receive. On successful return it will
contain the number of ASCII code points actually output.
</td>
</tr>
<tr>
<td><span class="term"><em class="parameter"><code>output</code></em> :</span></td>
<td> An array of ASCII code points. It is *not*
null-terminated; it will contain zeros if and only if the <em class="parameter"><code>input</code></em>
contains zeros. (Of course the caller can leave room for a
terminator and add one if needed.)
</td>
</tr>
<tr>
<td><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td>
<td> The return value can be any of the <a href="libidn-punycode.html#Punycode-status"><span class="type">Punycode_status</span></a>
values defined above except <a href="libidn-punycode.html#PUNYCODE-BAD-INPUT:CAPS"><code class="literal">PUNYCODE_BAD_INPUT</code></a>. If not
<a href="libidn-punycode.html#PUNYCODE-SUCCESS:CAPS"><code class="literal">PUNYCODE_SUCCESS</code></a>, then <em class="parameter"><code>output_size</code></em> and <em class="parameter"><code>output</code></em> might contain
garbage.
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2592950"></a><h3>
<a name="punycode-decode"></a>punycode_decode ()</h3>
<a class="indexterm" name="id2592963"></a><pre class="programlisting">int punycode_decode (size_t input_length,
const char input[],
size_t *output_length,
<a href="libidn-punycode.html#punycode-uint">punycode_uint</a> output[],
unsigned char case_flags[]);</pre>
<p>
Converts Punycode to a sequence of code points (presumed to be
Unicode code points).</p>
<p>
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><span class="term"><em class="parameter"><code>input_length</code></em> :</span></td>
<td> The number of ASCII code points in the <em class="parameter"><code>input</code></em> array.
</td>
</tr>
<tr>
<td><span class="term"><em class="parameter"><code>input</code></em> :</span></td>
<td> An array of ASCII code points (0..7F).
</td>
</tr>
<tr>
<td><span class="term"><em class="parameter"><code>output_length</code></em> :</span></td>
<td> The caller passes in the maximum number of code
points that it can receive into the <em class="parameter"><code>output</code></em> array (which is also
the maximum number of flags that it can receive into the
<em class="parameter"><code>case_flags</code></em> array, if <em class="parameter"><code>case_flags</code></em> is not a <code class="literal">NULL</code> pointer). On
successful return it will contain the number of code points
actually output (which is also the number of flags actually
output, if case_flags is not a null pointer). The decoder will
never need to output more code points than the number of ASCII
code points in the input, because of the way the encoding is
defined. The number of code points output cannot exceed the
maximum possible value of a punycode_uint, even if the supplied
<em class="parameter"><code>output_length</code></em> is greater than that.
</td>
</tr>
<tr>
<td><span class="term"><em class="parameter"><code>output</code></em> :</span></td>
<td> An array of code points like the input argument of
<a href="libidn-punycode.html#punycode-encode"><code class="function">punycode_encode()</code></a> (see above).
</td>
</tr>
<tr>
<td><span class="term"><em class="parameter"><code>case_flags</code></em> :</span></td>
<td> A <code class="literal">NULL</code> pointer (if the flags are not needed by the
caller) or an array of boolean values parallel to the <em class="parameter"><code>output</code></em>
array. Nonzero (true, flagged) suggests that the corresponding
Unicode character be forced to uppercase by the caller (if
possible), and zero (false, unflagged) suggests that it be forced
to lowercase (if possible). ASCII code points (0..7F) are output
already in the proper case, but their flags will be set
appropriately so that applying the flags would be harmless.
</td>
</tr>
<tr>
<td><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td>
<td> The return value can be any of the <a href="libidn-punycode.html#Punycode-status"><span class="type">Punycode_status</span></a>
values defined above. If not <a href="libidn-punycode.html#PUNYCODE-SUCCESS:CAPS"><code class="literal">PUNYCODE_SUCCESS</code></a>, then
<em class="parameter"><code>output_length</code></em>, <em class="parameter"><code>output</code></em>, and <em class="parameter"><code>case_flags</code></em> might contain garbage.
</td>
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</tbody>
</table></div>
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