man/zip_file_extra_field_get.html

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   zip_file_extra_field_get.mdoc -- get extra field for file in zip
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  <title>ZIP_FILE_EXTRA_FIELD_GET(3)</title>
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<table class="head">
  <tr>
    <td class="head-ltitle">ZIP_FILE_EXTRA_FIELD_GET(3)</td>
    <td class="head-vol">Library Functions Manual</td>
    <td class="head-rtitle">ZIP_FILE_EXTRA_FIELD_GET(3)</td>
  </tr>
</table>
<div class="manual-text">
<section class="Sh">
<h1 class="Sh" id="NAME"><a class="permalink" href="#NAME">NAME</a></h1>
<code class="Nm">zip_file_extra_field_get</code>,
  <code class="Nm">zip_file_extra_field_get_by_id</code> &#x2014;
<div class="Nd">get extra field for file in zip</div>
</section>
<section class="Sh">
<h1 class="Sh" id="LIBRARY"><a class="permalink" href="#LIBRARY">LIBRARY</a></h1>
libzip (-lzip)
</section>
<section class="Sh">
<h1 class="Sh" id="SYNOPSIS"><a class="permalink" href="#SYNOPSIS">SYNOPSIS</a></h1>
<code class="In">#include &lt;<a class="In">zip.h</a>&gt;</code>
<p class="Pp"><var class="Ft">const zip_uint8_t *</var>
  <br/>
  <code class="Fn">zip_file_extra_field_get</code>(<var class="Fa" style="white-space: nowrap;">zip_t
    *archive</var>, <var class="Fa" style="white-space: nowrap;">zip_uint64_t
    index</var>, <var class="Fa" style="white-space: nowrap;">zip_uint16_t
    extra_field_index</var>,
    <var class="Fa" style="white-space: nowrap;">zip_uint16_t *idp</var>,
    <var class="Fa" style="white-space: nowrap;">zip_uint16_t *lenp</var>,
    <var class="Fa" style="white-space: nowrap;">zip_flags_t flags</var>);</p>
<p class="Pp"><var class="Ft">const zip_uint8_t *</var>
  <br/>
  <code class="Fn">zip_file_extra_field_get_by_id</code>(<var class="Fa" style="white-space: nowrap;">zip_t
    *archive</var>, <var class="Fa" style="white-space: nowrap;">zip_uint64_t
    index</var>, <var class="Fa" style="white-space: nowrap;">zip_uint16_t
    extra_field_id</var>,
    <var class="Fa" style="white-space: nowrap;">zip_uint16_t
    extra_field_index</var>,
    <var class="Fa" style="white-space: nowrap;">zip_uint16_t *lenp</var>,
    <var class="Fa" style="white-space: nowrap;">zip_flags_t flags</var>);</p>
</section>
<section class="Sh">
<h1 class="Sh" id="DESCRIPTION"><a class="permalink" href="#DESCRIPTION">DESCRIPTION</a></h1>
The <code class="Fn">zip_file_extra_field_get</code>() function returns the
  extra field with index <var class="Ar">extra_field_index</var> for the file at
  position <var class="Ar">index</var> in the zip archive. This pointer should
  not be modified or <a class="Xr" href="http://pubs.opengroup.org/onlinepubs/9699919799/functions/free.html">free(3)</a>'d, and becomes
  invalid when <var class="Ar">archive</var> is closed. If
  <var class="Ar">idp</var> is not <code class="Dv">NULL</code>, the integer to
  which it points will be set to the ID (two-byte signature) of the selected
  extra field. If <var class="Ar">lenp</var> is not
  <code class="Dv">NULL</code>, the integer to which it points will be set to
  the length of the extra field. Generally speaking, <var class="Ar">lenp</var>
  and <var class="Ar">idp</var> should be passed since only the extra field data
  is returned (i.e., neither the ID nor the length, if the
  <var class="Ar">idp</var> and <var class="Ar">lenp</var> arguments are not
  provided).
<p class="Pp">The following <var class="Ar">flags</var> are supported:</p>
<div class="Bd-indent">
<dl class="Bl-tag">
  <dt><a class="permalink" href="#ZIP_FL_CENTRAL"><code class="Dv" id="ZIP_FL_CENTRAL">ZIP_FL_CENTRAL</code></a></dt>
  <dd>Return extra fields from the archive's central directory.</dd>
  <dt><a class="permalink" href="#ZIP_FL_LOCAL"><code class="Dv" id="ZIP_FL_LOCAL">ZIP_FL_LOCAL</code></a></dt>
  <dd>Return extra fields from the local file headers.</dd>
  <dt><a class="permalink" href="#ZIP_FL_UNCHANGED"><code class="Dv" id="ZIP_FL_UNCHANGED">ZIP_FL_UNCHANGED</code></a></dt>
  <dd>Return the original unchanged extra fields, ignoring any changes
    made.</dd>
</dl>
</div>
<p class="Pp">The <code class="Fn">zip_file_extra_field_get_by_id</code>()
    function returns the extra field with ID (two-byte signature)
    <var class="Ar">extra_field_id</var> and index
    <var class="Ar">extra_field_index</var> (in other words, the
    <var class="Ar">extra_field_index</var><span class="No">'th</span> extra
    field with ID <var class="Ar">extra_field_id</var>) The other arguments are
    the same as for <code class="Fn">zip_file_extra_field_get</code>().</p>
</section>
<section class="Sh">
<h1 class="Sh" id="RETURN_VALUES"><a class="permalink" href="#RETURN_VALUES">RETURN
  VALUES</a></h1>
Upon successful completion, a pointer to an extra field is returned, or
  <code class="Dv">NULL</code> if there is no extra field with that
  <var class="Ar">extra_field_index</var> for the file with index
  <var class="Ar">index</var>. In case of an error, <code class="Dv">NULL</code>
  is returned and the error code in <var class="Ar">archive</var> is set to
  indicate the error.
</section>
<section class="Sh">
<h1 class="Sh" id="ERRORS"><a class="permalink" href="#ERRORS">ERRORS</a></h1>
<code class="Fn">zip_file_extra_field_get</code>() and
  <code class="Fn">zip_file_extra_field_get_by_id</code>() fail if:
<dl class="Bl-tag">
  <dt>[<a class="permalink" href="#ZIP_ER_NOENT"><code class="Er" id="ZIP_ER_NOENT">ZIP_ER_NOENT</code></a>]</dt>
  <dd><var class="Ar">index</var> is not a valid file index in
      <var class="Ar">archive</var>, or <var class="Ar">extra_field_index</var>
      is not a valid extra file index (for ID
      <var class="Ar">extra_field_id</var>).</dd>
</dl>
</section>
<section class="Sh">
<h1 class="Sh" id="SEE_ALSO"><a class="permalink" href="#SEE_ALSO">SEE
  ALSO</a></h1>
<a class="Xr" href="libzip.html">libzip(3)</a>,
  <a class="Xr" href="zip_file_extra_field_delete.html">zip_file_extra_field_delete(3)</a>,
  <a class="Xr" href="zip_file_extra_field_set.html">zip_file_extra_field_set(3)</a>,
  <a class="Xr" href="zip_file_extra_fields_count.html">zip_file_extra_fields_count(3)</a>
</section>
<section class="Sh">
<h1 class="Sh" id="HISTORY"><a class="permalink" href="#HISTORY">HISTORY</a></h1>
<code class="Fn">zip_file_extra_field_get</code>() and
  <code class="Fn">zip_file_extra_field_get_by_id</code>() were added in libzip
  0.11.
</section>
<section class="Sh">
<h1 class="Sh" id="AUTHORS"><a class="permalink" href="#AUTHORS">AUTHORS</a></h1>
<span class="An">Dieter Baron</span>
  &lt;<a class="Mt" href="mailto:dillo@nih.at">dillo@nih.at</a>&gt; and
  <span class="An">Thomas Klausner</span>
  &lt;<a class="Mt" href="mailto:tk@giga.or.at">tk@giga.or.at</a>&gt;
</section>
<section class="Sh">
<h1 class="Sh" id="CAVEATS"><a class="permalink" href="#CAVEATS">CAVEATS</a></h1>
Please note that the extra field IDs 0x0001 (ZIP64 extension), 0x6375 (Infozip
  UTF-8 comment), and 0x7075 (Infozip UTF-8 file name) can not be read using
  <code class="Fn">zip_file_extra_field_get</code>() since they are used by
  <a class="Xr" href="libzip.html">libzip(3)</a> internally.
</section>
</div>
<table class="foot">
  <tr>
    <td class="foot-date">December 18, 2017</td>
    <td class="foot-os">NiH</td>
  </tr>
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