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<manualpage metafile="install.xml.meta">

  <title>Compiling and Installing</title>

<summary>

    <p>This document covers compilation and installation of Apache
    on Unix and Unix-like systems only. For compiling and
    installation on Windows, see <a
    href="platform/windows.html">Using Apache with Microsoft
    Windows</a>. For other platforms, see the <a
    href="platform/">platform</a> documentation.</p>

    <p>Apache 2.0's configuration and installation environment has
    changed completely from Apache 1.3. Apache 1.3 used a custom
    set of scripts to achieve easy installation. Apache 2.0 now
    uses <code>libtool</code> and <code>autoconf</code>
    to create an environment that looks like many other Open Source
    projects.</p>

    <p>If you are upgrading from one minor version to the next (for
    example, 2.0.50 to 2.0.51), please skip down to the <a
    href="#upgrading">upgrading</a> section.</p>

</summary>

<seealso><a href="programs/configure.html">Configure the source tree</a></seealso>
<seealso><a href="invoking.html">Starting Apache</a></seealso>
<seealso><a href="stopping.html">Stopping and Restarting</a></seealso>

<section id="overview"><title>Overview for the
    impatient</title>

    <table>
      <columnspec><column width=".13"/><column width=".80"/></columnspec>
      <tr>
        <td><a href="#download">Download</a></td>

        <td><code>$ lynx http://httpd.apache.org/download.cgi</code>
        </td>
      </tr>

      <tr>
        <td><a href="#extract">Extract</a></td>

        <td><code>$ gzip -d httpd-2_1_<em>NN</em>.tar.gz<br />
         $ tar xvf httpd-2_1_<em>NN</em>.tar</code> </td>
      </tr>

      <tr>
        <td><a href="#configure">Configure</a></td>

        <td><code>$ ./configure --prefix=<em>PREFIX</em></code>
        </td>
      </tr>

      <tr>
        <td><a href="#compile">Compile</a></td>

        <td><code>$ make</code> </td>
      </tr>

      <tr>
        <td><a href="#install">Install</a></td>

        <td><code>$ make install</code> </td>
      </tr>

      <tr>
        <td><a href="#customize">Customize</a></td>

        <td><code>$ vi <em>PREFIX</em>/conf/httpd.conf</code> </td>
      </tr>

      <tr>
        <td><a href="#test">Test</a></td>

        <td><code>$ <em>PREFIX</em>/bin/apachectl start</code>
        </td>
      </tr>
    </table>

    <p><em>NN</em> must be replaced with the current minor version
    number, and <em>PREFIX</em> must be replaced with the
    filesystem path under which the server should be installed. If
    <em>PREFIX</em> is not specified, it defaults to
    <code>/usr/local/apache2</code>.</p>

    <p>Each section of the compilation and installation process is
    described in more detail below, beginning with the requirements
    for compiling and installing Apache HTTPD.</p>
</section>

<section id="requirements"><title>Requirements</title>

    <p>The following requirements exist for building Apache:</p>

    <dl>
      <dt>Disk Space</dt>
      <dd>Make sure you have at least 50 MB of temporary free disk
      space available. After installation Apache occupies
      approximately 10 MB of disk space. The actual disk space
      requirements will vary considerably based on your chosen
      configuration options and any third-party modules.</dd>

      <dt>ANSI-C Compiler and Build System</dt>
      <dd>Make sure you have an ANSI-C compiler installed. The <a
      href="http://www.gnu.org/software/gcc/gcc.html">GNU C
      compiler (GCC)</a> from the <a
      href="http://www.gnu.org/">Free Software Foundation (FSF)</a>
      is recommended (version 2.7.2 is fine). If you don't have GCC
      then at least make sure your vendor's compiler is ANSI
      compliant. In addition, your <code>PATH</code> must contain
      basic build tools such as <code>make</code>.</dd>

      <dt>Accurate time keeping</dt>
      <dd>Elements of the HTTP protocol are expressed as the time of
      day. So, it's time to investigate setting some time
      synchronization facility on your system. Usually the
      <code>ntpdate</code> or <code>xntpd</code> programs are used for
      this purpose which are based on the Network Time Protocol (NTP).
      See the Usenet newsgroup <a
      href="news:comp.protocols.time.ntp">comp.protocols.time.ntp</a>
      and the <a href="http://www.ntp.org">NTP
      homepage</a> for more details about NTP software and public
      time servers.</dd>

      <dt><a href="http://www.perl.org/">Perl 5</a>
      [OPTIONAL]</dt>
      <dd>For some of the support scripts like <program>
      apxs</program> or <program>dbmmanage</program> (which are
      written in Perl) the Perl 5 interpreter is required (versions
      5.003 or newer are sufficient). If you have multiple Perl 
      interpreters (for example, a systemwide install of Perl 4, and 
      your own install of Perl 5), you are advised to use the 
      <code>--with-perl</code> option (see below) to make sure the 
      correct one is used by <program>configure</program>.
      If no Perl 5 interpreter is found by the 
      <program>configure</program> script, you will not be able to use 
      the affected support scripts. Of course, you will still be able to 
      build and use Apache 2.0.</dd>
    </dl>
</section>

<section id="download"><title>Download</title>

    <p>Apache can be downloaded from the <a
    href="http://httpd.apache.org/download.cgi">Apache HTTP Server
    download site</a> which lists several mirrors.  Most users of
    Apache on unix-like systems will be better off downloading and
    compiling a source version.  The build process (described below) is
    easy, and it allows you to customize your server to suit your needs.
    In addition, binary releases are often not up to date with the latest
    source releases.  If you do download a binary, follow the instructions
    in the <code>INSTALL.bindist</code> file inside the distribution.</p>

    <p>After downloading, it is important to verify that you have a
    complete and unmodified version of the Apache HTTP Server. This
    can be accomplished by testing the downloaded tarball against the
    PGP signature.  Details on how to do this are available on the <a
    href="http://httpd.apache.org/download.cgi#verify">download
    page</a> and an extended example is available describing the <a
    href="http://httpd.apache.org/dev/verification.html">use of
    PGP</a>.</p>

</section>

<section id="extract"><title>Extract</title>

    <p>Extracting the source from the Apache HTTPD tarball is a
    simple matter of uncompressing, and then untarring:</p>

<example>
$ gzip -d httpd-2_1_<em>NN</em>.tar.gz<br />
$ tar xvf httpd-2_1_<em>NN</em>.tar
</example>

    <p>This will create a new directory under the current directory
    containing the source code for the distribution. You should
    <code>cd</code> into that directory before proceeding with
    compiling the server.</p>
</section>

<section id="configure"><title>Configuring the source tree</title>

    <p>The next step is to configure the Apache source tree for your
    particular platform and personal requirements. This is done using
    the script <program>configure</program> included in
    the root directory of the distribution. (Developers downloading
    the CVS version of the Apache source tree will need to have
    <code>autoconf</code> and <code>libtool</code> installed and will
    need to run <code>buildconf</code> before proceeding with the next
    steps. This is not necessary for official releases.)</p>

    <p>To configure the source tree using all the default options,
    simply type <code>./configure</code>. To change the default
    options, <program>configure</program> accepts a variety of variables
    and command line options.</p>

    <p>The most important option is the location <code>--prefix</code>
    where Apache is to be installed later, because Apache has to be
    configured for this location to work correctly.  More fine-tuned
    control of the location of files is possible with additional <a
    href="programs/configure.html#installationdirectories">configure
    options</a>.</p>

    <p>Also at this point, you can specify which <a
    href="programs/configure.html#optionalfeatures">features</a> you
    want included in Apache by enabling and disabling <a
    href="mod/">modules</a>.  Apache comes with a <a
    href="mod/module-dict.html#Status">Base</a> set of modules included by
    default.  Other modules are enabled using the
    <code>--enable-<var>module</var></code> option, where
    <var>module</var> is the name of the module with the
    <code>mod_</code> string removed and with any underscore converted
    to a dash.  You can also choose to compile modules as <a
    href="dso.html">shared objects (DSOs)</a> -- which can be loaded
    or unloaded at runtime -- by using the option
    <code>--enable-<var>module</var>=shared</code>.  Similarly, you can
    disable Base modules with the
    <code>--disable-<var>module</var></code> option.  Be careful when
    using these options, since <program>configure</program> cannot warn you
    if the module you specify does not exist; it will simply ignore the
    option.</p>

    <p>In addition, it is sometimes necessary to provide the
    <program>configure</program> script with extra information about the
    location of your compiler, libraries, or header files.  This is
    done by passing either environment variables or command line
    options to <program>configure</program>.  For more information, see the
    <program>configure</program> manual page.</p>

    <p>For a short impression of what possibilities you have, here
    is a typical example which compiles Apache for the installation
    tree <code>/sw/pkg/apache</code> with a particular compiler and flags
    plus the two additional modules <module>mod_rewrite</module> and
    <module>mod_speling</module> for
    later loading through the DSO mechanism:</p>

<example>
      $ CC="pgcc" CFLAGS="-O2" \<br />
       ./configure --prefix=/sw/pkg/apache \<br />
       --enable-rewrite=shared \<br />
       --enable-speling=shared
</example>

    <p>When <program>configure</program> is run it will take several minutes to
    test for the availability of features on your system and build
    Makefiles which will later be used to compile the server.</p>

    <p>Details on all the different <program>configure</program> options are
    available on the <program>configure</program> manual page.</p>
</section>

<section id="compile"><title>Build</title>

    <p>Now you can build the various parts which form the Apache
    package by simply running the command:</p>

<example>$ make</example>

    <p>Please be patient here, since a base configuration takes
    approximately 3 minutes to compile under a Pentium III/Linux
    2.2 system, but this will vary widely depending on your
    hardware and the number of modules which you have enabled.</p>
</section>

<section id="install"><title>Install</title>

    <p>Now it's time to install the package under the configured
    installation <em>PREFIX</em> (see <code>--prefix</code> option
    above) by running:</p>

<example>$ make install</example>

    <p>If you are upgrading, the installation will not overwrite
    your configuration files or documents.</p>
</section>

<section id="customize"><title>Customize</title>

    <p>Next, you can customize your Apache HTTP server by editing
    the <a href="configuring.html">configuration files</a> under
    <code><em>PREFIX</em>/conf/</code>.</p>

<example>$ vi <em>PREFIX</em>/conf/httpd.conf</example>

    <p>Have a look at the Apache manual under <a
    href="./">docs/manual/</a> or consult <a
    href="http://httpd.apache.org/docs/&httpd.docs;/"
    >http://httpd.apache.org/docs/&httpd.docs;/</a> for the most recent
    version of this manual and a complete reference of available <a
    href="mod/directives.html">configuration directives</a>.</p>
</section>

<section id="test"><title>Test</title>

    <p>Now you can <a href="invoking.html">start</a> your Apache
    HTTP server by immediately running:</p>

<example>$ <em>PREFIX</em>/bin/apachectl start</example>

    <p>and then you should be able to request your first document
    via URL <code>http://localhost/</code>. The web page you see is located
    under the <directive module="core">DocumentRoot</directive>
    which will usually be <code><em>PREFIX</em>/htdocs/</code>.
    Then <a href="stopping.html">stop</a> the server again by
    running:</p>

<example>$ <em>PREFIX</em>/bin/apachectl stop</example>
</section>
<section id="upgrading"><title>Upgrading</title>

    <p>The first step in upgrading is to read the release announcement
    and the file <code>CHANGES</code> in the source distribution to
    find any changes that may affect your site.  When changing between
    major releases (for example, from 1.3 to 2.0 or from 2.0 to 2.2),
    there will likely be major differences in the compile-time and
    run-time configuration that will require manual adjustments.  All
    modules will also need to be upgraded to accomodate changes in the
    module API.</p>

    <p>Upgrading from one minor version to the next (for example, from
    2.0.55 to 2.0.57) is easier.  The <code>make install</code>
    process will not overwrite any of your existing documents, log
    files, or configuration files.  In addition, the developers make
    every effort to avoid incompatible changes in the
    <program>configure</program> options, run-time configuration, or the
    module API between minor versions.  In most cases you should be able to
    use an identical <program>configure</program> command line, an identical
    configuration file, and all of your modules should continue to
    work.  (This is only valid for versions after 2.0.41; earlier
    versions have incompatible changes.)</p>

    <p>To upgrade across minor versions, start by finding the file
    <code>config.nice</code> in the <code>build</code> directory of
    your installed server or at the root of the source tree for your
    old install.  This will contain the exact
    <program>configure</program> command line that you used to
    configure the source tree.  Then to upgrade from one version to
    the next, you need only copy the <code>config.nice</code> file to
    the source tree of the new version, edit it to make any desired
    changes, and then run:</p>

    <example>
    $ ./config.nice<br />
    $ make<br />
    $ make install<br />
    $ <em>PREFIX</em>/bin/apachectl stop<br />
    $ <em>PREFIX</em>/bin/apachectl start<br />
    </example>

    <note type="warning">You should always test any new version in your
    environment before putting it into production.  For example, you
    can install and run the new version along side the old one by
    using a different <code>--prefix</code> and a
    different port (by adjusting the <directive
    module="mpm_common">Listen</directive> directive) to test for any
    incompatibilities before doing the final upgrade.</note>
</section>
</manualpage>