title: about PHP configure:--with-zlib=DIR and --with-zlib-dir=DIR
body: <p>from ./configure --help:</p>
  <blockquote>
  <p>--with-zlib=DIR    Include ZLIB support (requires zlib &gt;= 1.0.9)</p>
  <p>--with-zlib-dir=<code>&lt;DIR&gt;</code>    Define the location of zlib install directory</p>
  </blockquote>
  <p>first one: Why &quot;--with-zlib&quot; need a DIR ?</p>
  <p>second one: does &quot;Define the location of zlib install directory
  &quot; mean &quot;Define the location of directory of zlib which you have already installed in system&quot; ?</p>
  <p>what's the difference between &quot;--with-zlib&quot; and &quot;--with-zlib-dir&quot; ?</p>