docs/manual/mod/mod_env.xml

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<modulesynopsis metafile="mod_env.xml.meta">

<name>mod_env</name>
<description>Modifies the environment which is passed to CGI scripts and
SSI pages</description>
<status>Base</status>
<sourcefile>mod_env.c</sourcefile>
<identifier>env_module</identifier>
<summary>
    <p>This module allows for control of internal environment variables that
    are used by various Apache HTTP Server modules. These variables are also
    provided to CGI scripts as native system environment variables, and available
    for use in SSI pages. Environment variables may be passed from the shell
    which invoked the <program>httpd</program> process. Alternatively,
    environment variables may be set or unset within the configuration process.</p>
</summary>
<seealso><a href="../env.html">Environment Variables</a></seealso>
<seealso><directive module="mod_setenvif">SetEnvIf</directive></seealso>

<directivesynopsis>
<name>PassEnv</name>
<description>Passes environment variables from the shell</description>
<syntax>PassEnv <var>env-variable</var> [<var>env-variable</var>]
...</syntax>
<contextlist><context>server config</context><context>virtual host</context>
<context>directory</context><context>.htaccess</context></contextlist>
<override>FileInfo</override>

<usage>
    <p>Specifies one or more native system environment variables to make available
    as internal environment variables, which are available to Apache HTTP Server modules
    as well as propagated to CGI scripts and SSI pages. Values come from the
    native OS environment of the shell which invoked the
    <program>httpd</program> process.</p>

    <example><title>Example</title>
    <highlight language="config">
      PassEnv LD_LIBRARY_PATH
      </highlight>
    </example>
</usage>
</directivesynopsis>

<directivesynopsis>
<name>SetEnv</name>
<description>Sets environment variables</description>
<syntax>SetEnv <var>env-variable</var> [<var>value</var>]</syntax>
<contextlist><context>server config</context><context>virtual host</context>
<context>directory</context><context>.htaccess</context></contextlist>
<override>FileInfo</override>

<usage>
    <p>Sets an internal environment variable, which is then available to Apache
    HTTP Server modules, and passed on to CGI scripts and SSI pages.</p>

    <example><title>Example</title>
    <highlight language="config">
      SetEnv SPECIAL_PATH /foo/bin
      </highlight>
    </example>

    <p> If you omit the <var>value</var> argument, the variable is set to
    an empty string.</p>

    <note><p>The internal environment variables set by this directive are set
    <em>after</em> most early request processing directives are run, such as access
    control and URI-to-filename mapping.  If the environment variable you're
    setting is meant as input into this early phase of processing such as the
    <directive module="mod_rewrite">RewriteRule</directive> directive, you should
    instead set the environment variable with
    <directive module="mod_setenvif">SetEnvIf</directive>.</p>
    </note>

</usage>
<seealso><a href="../env.html">Environment Variables</a></seealso>
</directivesynopsis>

<directivesynopsis>
<name>UnsetEnv</name>
<description>Removes variables from the environment</description>
<syntax>UnsetEnv <var>env-variable</var> [<var>env-variable</var>]
...</syntax>
<contextlist><context>server config</context><context>virtual host</context>
<context>directory</context><context>.htaccess</context></contextlist>
<override>FileInfo</override>

<usage>
    <p>Removes one or more internal environment variables from those passed
    on to CGI scripts and SSI pages.</p>

    <example><title>Example</title>
    <highlight language="config">
      UnsetEnv LD_LIBRARY_PATH
      </highlight>
    </example>
</usage>
</directivesynopsis>

<directivesynopsis>
<name>SetEnvFromFile</name>
<description>Sets environment variables from a file</description>
<syntax>SetEnvFromFile <var>file-path</var></syntax>
<contextlist><context>server config</context><context>virtual host</context>
<context>directory</context></contextlist>
<compatibility>Available in version 2.5.1 and later.</compatibility>

<usage>
    <p>Sets internal environment variables read from a file, which are then
    available to Apache HTTP Server modules, and passed on to CGI scripts and
    SSI pages. This is equivalent to a series of <directive
    module="mod_env">SetEnv</directive> directives, one per variable, but keeps
    the values in a separate file.</p>

    <p>The <var>file-path</var> is either an absolute path or a path relative
    to the <directive module="core">ServerRoot</directive>. The file is read
    once when the configuration is parsed; changes to it take effect only after
    the server is restarted.</p>

    <p>Each line of the file has the form <code>name=value</code>. Blank lines
    and lines beginning with <code>#</code> are ignored, and leading and
    trailing whitespace is stripped. If a line contains no <code>=</code>, the
    variable is set to an empty string. A line ending in a backslash
    (<code>\</code>) is continued on the following line, just as in the main
    configuration files.</p>

    <example><title>Example</title>
    <highlight language="config">
      SetEnvFromFile conf/app.env
      </highlight>
    </example>

    <example><title>Example file (<code>conf/app.env</code>)</title>
    <highlight language="config">
      # Application settings
      APP_MODE=production
      SPECIAL_PATH=/foo/bin
      </highlight>
    </example>

    <note><p>As with <directive module="mod_env">SetEnv</directive>, the
    variables are set <em>after</em> most early request processing directives
    are run, such as access control and URI-to-filename mapping.</p>
    </note>

    <note type="warning"><title>Security</title>
    <p>Unlike <directive module="mod_env">SetEnv</directive>, this directive
    reads the <em>contents</em> of a file into the internal environment, where
    they may be exposed through CGI, SSI, logging and other consumers. To
    prevent an untrusted author from disclosing the contents of any file
    readable by the server (for example configuration or credential files
    elsewhere on the host), <directive>SetEnvFromFile</directive> is
    <strong>not</strong> permitted in <code>.htaccess</code> files; it may only
    be used in the main server configuration.</p>
    </note>
</usage>
<seealso><a href="../env.html">Environment Variables</a></seealso>
<seealso><directive module="mod_env">SetEnv</directive></seealso>
</directivesynopsis>

</modulesynopsis>