man/zip_set_file_compression.html

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  <title>ZIP_SET_FILE_COMPRESSION(3)</title>
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<table class="head">
  <tr>
    <td class="head-ltitle">ZIP_SET_FILE_COMPRESSION(3)</td>
    <td class="head-vol">Library Functions Manual</td>
    <td class="head-rtitle">ZIP_SET_FILE_COMPRESSION(3)</td>
  </tr>
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<div class="manual-text">
<section class="Sh">
<h1 class="Sh" id="NAME"><a class="permalink" href="#NAME">NAME</a></h1>
<code class="Nm">zip_set_file_compression</code> &#x2014;
<div class="Nd">set compression method 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">int</var>
  <br/>
  <code class="Fn">zip_set_file_compression</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_int32_t
    comp</var>, <var class="Fa" style="white-space: nowrap;">zip_uint32_t
    comp_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_set_file_compression</code>() function sets the
  compression method for the file at position <var class="Ar">index</var> in the
  zip archive to <var class="Ar">comp</var> with the compression method specific
  <var class="Ar">comp_flags</var>. The <var class="Ar">comp</var> is the same
  as returned by <a class="Xr" href="zip_stat.html">zip_stat(3)</a>. For the
  <var class="Ar">comp</var> argument, currently only the following values are
  supported:
<dl class="Bl-tag">
  <dt><a class="permalink" href="#ZIP_CM_DEFAULT"><code class="Dv" id="ZIP_CM_DEFAULT">ZIP_CM_DEFAULT</code></a></dt>
  <dd>default compression; currently the same as
      <code class="Dv">ZIP_CM_DEFLATE</code>, but <var class="Ar">flags</var>
      are ignored.</dd>
  <dt><a class="permalink" href="#ZIP_CM_STORE"><code class="Dv" id="ZIP_CM_STORE">ZIP_CM_STORE</code></a></dt>
  <dd>Store the file uncompressed.</dd>
  <dt><a class="permalink" href="#ZIP_CM_BZIP2"><code class="Dv" id="ZIP_CM_BZIP2">ZIP_CM_BZIP2</code></a></dt>
  <dd>Compress the file using the <a class="Xr" href="http://pubs.opengroup.org/onlinepubs/9699919799/functions/bzip2.html">bzip2(1)</a>
      algorithm.</dd>
  <dt><a class="permalink" href="#ZIP_CM_DEFLATE"><code class="Dv" id="ZIP_CM_DEFLATE">ZIP_CM_DEFLATE</code></a></dt>
  <dd>Deflate the file with the <a class="Xr" href="http://pubs.opengroup.org/onlinepubs/9699919799/functions/zlib.html">zlib(3)</a>
      algorithm and default options.</dd>
  <dt><a class="permalink" href="#ZIP_CM_XZ"><code class="Dv" id="ZIP_CM_XZ">ZIP_CM_XZ</code></a></dt>
  <dd>Use the <a class="Xr" href="http://pubs.opengroup.org/onlinepubs/9699919799/functions/xz.html">xz(1)</a> algorithm for
    compression</dd>
  <dt><a class="permalink" href="#ZIP_CM_ZSTD"><code class="Dv" id="ZIP_CM_ZSTD">ZIP_CM_ZSTD</code></a></dt>
  <dd>Use the <a class="Xr" href="http://pubs.opengroup.org/onlinepubs/9699919799/functions/zstd.html">zstd(1)</a> algorithm for
      compression</dd>
</dl>
<p class="Pp"><i class="Em">NOTE</i>: Only the deflate and store methods can be
    assumed to be universally supported.</p>
<p class="Pp">The <var class="Ar">comp_flags</var> argument defines the
    compression level. This value is dependent on the compression algorithm. In
    general, lower numbers mean faster de/compression and higher numbers mean
    slower de/compression. For <code class="Dv">ZIP_CM_BZIP</code>,
    <code class="Dv">ZIP_CM_DEFLATE</code>, and
    <code class="Dv">ZIP_CM_XZ</code> 1 is the fastest compression and 9 the
    best, 0 chooses the default. For <code class="Dv">ZIP_CM_ZSTD</code>
    possible values are
    <a class="Xr" href="http://pubs.opengroup.org/onlinepubs/9699919799/functions/ZSTD_minCLevel.html">ZSTD_minCLevel(3)</a> to
    <a class="Xr" href="http://pubs.opengroup.org/onlinepubs/9699919799/functions/ZSTD_maxCLevel.html">ZSTD_maxCLevel(3)</a>.</p>
<p class="Pp">Further compression method specific flags might be added over
    time.</p>
<p class="Pp">The current compression method for a file in a zip archive can be
    determined using <a class="Xr" href="zip_stat.html">zip_stat(3)</a>.</p>
</section>
<section class="Sh">
<h1 class="Sh" id="RETURN_VALUES"><a class="permalink" href="#RETURN_VALUES">RETURN
  VALUES</a></h1>
Upon successful completion 0 is returned. Otherwise, -1 is returned and the
  error information 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_set_file_compression</code>() fails if:
<dl class="Bl-tag">
  <dt>[<a class="permalink" href="#ZIP_ER_COMPNOTSUPP"><code class="Er" id="ZIP_ER_COMPNOTSUPP">ZIP_ER_COMPNOTSUPP</code></a>]</dt>
  <dd>Unsupported compression method requested.</dd>
  <dt>[<a class="permalink" href="#ZIP_ER_INVAL"><code class="Er" id="ZIP_ER_INVAL">ZIP_ER_INVAL</code></a>]</dt>
  <dd><var class="Ar">index</var> is not a valid file index in
      <var class="Ar">archive</var>, or the argument combination is
    invalid.</dd>
  <dt>[<a class="permalink" href="#ZIP_ER_RDONLY"><code class="Er" id="ZIP_ER_RDONLY">ZIP_ER_RDONLY</code></a>]</dt>
  <dd>Read-only zip file, no changes allowed.</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_compression_method_supported.html">zip_compression_method_supported(3)</a>,
  <a class="Xr" href="zip_stat.html">zip_stat(3)</a>
</section>
<section class="Sh">
<h1 class="Sh" id="HISTORY"><a class="permalink" href="#HISTORY">HISTORY</a></h1>
<code class="Fn">zip_set_file_compression</code>() was 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>
</div>
<table class="foot">
  <tr>
    <td class="foot-date">June 18, 2021</td>
    <td class="foot-os">NiH</td>
  </tr>
</table>
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