<?xml version="1.0" encoding="iso-8859-1"?>
<!-- $Revision: 1.91 $ -->
 <reference id="ref.info">
  <title>PHP Options&amp;Information</title>
  <titleabbrev>PHP Options/Info</titleabbrev>

  <refentry id="function.assert">
   <refnamediv>
    <refname>assert</refname>
    <refpurpose>Checks if assertion is &false;</refpurpose>
   </refnamediv>
   <refsect1>
    <title>Description</title>
     <methodsynopsis>
      <type>int</type><methodname>assert</methodname>
      <methodparam><type>string|bool</type><parameter>assertion</parameter></methodparam>
     </methodsynopsis>
    <para>
     <function>assert</function> will check the given
     <parameter>assertion</parameter> and take appropriate action if
     its result is &false;.
    </para>
    <para>
     If the <parameter>assertion</parameter> is given as a string it
     will be evaluated as PHP code by <function>assert</function>.
     The advantages of a string <parameter>assertion</parameter> are
     less overhead when assertion checking is off and messages
     containing the <parameter>assertion</parameter> expression when
     an assertion fails.
    </para>
    <para>
     Assertions should be used as a debugging feature only. You may
     use them for sanity-checks that test for conditions that should
     always be &true; and that indicate some programming errors if not
     or to check for the presence of certain features like extension
     functions or certain system limits and features.
    </para>
    <para>
     Assertions should not be used for normal runtime operations like
     input parameter checks. As a rule of thumb your code should
     always be able to work correctly if assertion checking is not
     activated.
    </para>
    <para>
     The behavior of <function>assert</function> may be configured by
     <function>assert_options</function> or by .ini-settings described
     in that functions manual page.
    </para>
    <para>
     The <function>assert_options</function> function and/or
     ASSERT_CALLBACK configuration directive allow a callback function
     to be set to handle failed assertions.
    </para>
    <para>
     <function>assert</function> callbacks are particularly useful for
     building automated test suites because they allow you to easily
     capture the code passed to the assertion, along with information
     on where the assertion was made. While this information can be
     captured via other methods, using assertions makes it much faster
     and easier!
    </para>
    <para>
     The callback function should accept three arguments. The first
     argument will contain the file the assertion failed in. The
     second argument will contain the line the assertion failed on and
     the third argument will contain the expression that failed (if
     any - literal values such as 1 or "two" will not be passed via
     this argument)
    </para>
    <para>
     <example>
      <title>Handle a failed assertion with a custom handler</title>
      <programlisting role="php">
<![CDATA[
<?php
// Active assert and make it quiet
assert_options (ASSERT_ACTIVE, 1);
assert_options (ASSERT_WARNING, 0);
assert_options (ASSERT_QUIET_EVAL, 1);

// Create a handler function
function my_assert_handler ($file, $line, $code) {
    echo "<hr>Assertion Failed:
        File '$file'<br>
        Line '$line'<br>
        Code '$code'<br><hr>";
}

// Set up the callback
assert_options (ASSERT_CALLBACK, 'my_assert_handler');

// Make an assertion that should fail
assert ('mysql_query ("")');
?>
]]>
      </programlisting>
     </example>
    </para>
   </refsect1>
  </refentry>

  <refentry id="function.assert-options">
   <refnamediv>
    <refname>assert_options</refname>
    <refpurpose>Set/get the various assert flags</refpurpose>
   </refnamediv>
   <refsect1>
    <title>Description</title>
     <methodsynopsis>
      <type>mixed</type><methodname>assert_options</methodname>
      <methodparam><type>int</type><parameter>what</parameter></methodparam>
      <methodparam choice="opt"><type>mixed</type><parameter>value</parameter></methodparam>
     </methodsynopsis>
    <para>
     Using <function>assert_options</function> you may set the various
     <function>assert</function> control options or just query their
     current settings.
    </para>
    <table>
     <title>Assert Options</title>
     <tgroup cols="4">
      <thead>
       <row>
        <entry>option</entry>
        <entry>ini-parameter</entry>
        <entry>default</entry>
        <entry>description</entry>
       </row>
      </thead>
      <tbody>
       <row>
        <entry>ASSERT_ACTIVE</entry>
        <entry>assert.active</entry>
        <entry>1</entry>
        <entry>enable <function>assert</function> evaluation</entry>
       </row>
       <row>
        <entry>ASSERT_WARNING</entry>
        <entry>assert.warning</entry>
        <entry>1</entry>
        <entry>issue a PHP warning for each failed assertion</entry>
       </row>
       <row>
        <entry>ASSERT_BAIL</entry>
        <entry>assert.bail</entry>
        <entry>0</entry>
        <entry>terminate execution on failed assertions</entry>
       </row>
       <row>
        <entry>ASSERT_QUIET_EVAL</entry>
        <entry>assert.quiet_eval</entry>
        <entry>0</entry>
        <entry>
         disable error_reporting during assertion expression
         evaluation
        </entry>
       </row>
       <row>
        <entry>ASSERT_CALLBACK</entry>
        <entry>assert_callback</entry>
        <entry>(&null;)</entry>
        <entry>user function to call on failed assertions</entry>
       </row>
      </tbody>
     </tgroup>
    </table>
    <para>
     <function>assert_options</function> will return the original
     setting of any option or &false; on errors.
    </para>
   </refsect1>
  </refentry>

  <refentry id="function.extension-loaded">
   <refnamediv>
    <refname>extension_loaded</refname>
    <refpurpose>Find out whether an extension is loaded</refpurpose>
   </refnamediv>
   <refsect1>
    <title>Description</title>
     <methodsynopsis>
      <type>bool</type><methodname>extension_loaded</methodname>
      <methodparam><type>string</type><parameter>name</parameter></methodparam>
     </methodsynopsis>
    <simpara>
     Returns &true; if the extension identified by
     <parameter>name</parameter> is loaded. You can see the names of
     various extensions by using <function>phpinfo</function>.
    </simpara>
    <para>
     See also <function>phpinfo</function>.
     <note>
      <para>
       This function was added in 3.0.10.
      </para>
     </note>
    </para>
   </refsect1>
  </refentry>

  <refentry id="function.dl">
   <refnamediv>
    <refname>dl</refname>
    <refpurpose>Loads a PHP extension at runtime</refpurpose>
   </refnamediv>
   <refsect1>
    <title>Description</title>
     <methodsynopsis>
      <type>int</type><methodname>dl</methodname>
      <methodparam><type>string</type><parameter>library</parameter></methodparam>
     </methodsynopsis>
    <para>
     Loads the PHP extension defined in
     <parameter>library</parameter>. See also the <link
     linkend="ini.sect.extension">Extension Loading Directives</link>
    </para>
   </refsect1>
  </refentry>

  <refentry id="function.getenv">
   <refnamediv>
    <refname>getenv</refname>
    <refpurpose>Gets the value of an environment variable</refpurpose>
   </refnamediv>
   <refsect1>
    <title>Description</title>
     <methodsynopsis>
      <type>string</type><methodname>getenv</methodname>
      <methodparam><type>string</type><parameter>varname</parameter></methodparam>
     </methodsynopsis>
    <para>
     Returns the value of the environment variable
     <parameter>varname</parameter>, or &false; on an error.
     <informalexample>
      <programlisting>
<![CDATA[
$ip = getenv ("REMOTE_ADDR"); // get the ip number of the user
]]>
      </programlisting>
     </informalexample>
    </para>
    <para>
     You can see a list of all the environmental variables by using
     <function>phpinfo</function>. You can find out what many of them
     mean by taking a look at the <ulink url="&url.cgispecs;">CGI
     specification</ulink>, specifically the <ulink
     url="&url.cgispec;">page on environmental variables</ulink>.
     <note>
      <para>
       This function does not work in ISAPI mode.
      </para>
     </note>
    </para>
    <para>
     See also <function>putenv</function>.
    </para>
   </refsect1>
  </refentry>

  <refentry id="function.get-cfg-var">
   <refnamediv>
    <refname>get_cfg_var</refname>
    <refpurpose>
     Gets the value of a PHP configuration option
    </refpurpose>
   </refnamediv>
   <refsect1>
    <title>Description</title>
     <methodsynopsis>
      <type>string</type><methodname>get_cfg_var</methodname>
      <methodparam><type>string</type><parameter>varname</parameter></methodparam>
     </methodsynopsis>
    <simpara>
     Returns the current value of the PHP configuration variable
     specified by <parameter>varname</parameter>, or &false; if an
     error occurs.
    </simpara>
    <simpara>
     It will not return configuration information set when the PHP was
     compiled, or read from an Apache configuration file (using the
     php3_configuration_option directives).
    </simpara>
    <simpara>
     To check whether the system is using a <link
     linkend="configuration.file">configuration file</link>, try
     retrieving the value of the cfg_file_path configuration
     setting. If this is available, a configuration file is being
     used.
    </simpara>
    <simpara>
     See also <function>ini_get</function>.
    </simpara>
   </refsect1>
  </refentry>

  <refentry id="function.get-current-user">
   <refnamediv>
    <refname>get_current_user</refname>
    <refpurpose>
     Gets the name of the owner of the current PHP script
    </refpurpose>
   </refnamediv>
   <refsect1>
    <title>Description</title>
     <methodsynopsis>
      <type>string</type><methodname>get_current_user</methodname>
      <void/>
     </methodsynopsis>
    <simpara>
     Returns the name of the owner of the current PHP script.
    </simpara>
    <simpara>
     See also <function>getmyuid</function>,
     <function>getmygid</function>, <function>getmypid</function>,
     <function>getmyinode</function>, and
     <function>getlastmod</function>.
    </simpara>
   </refsect1>
  </refentry>

  <refentry id="function.get-defined-constants">
   <refnamediv>
    <refname>get_defined_constants</refname>
    <refpurpose>
     Returns an associative array with the names of all the constants
     and their values
    </refpurpose>
   </refnamediv>
   <refsect1>
    <title>Description</title>
     <methodsynopsis>
      <type>array</type><methodname>get_defined_constants</methodname>
      <void/>
     </methodsynopsis>
    <para>
     This function returns the names and values of all the constants
     currently defined.  This includes those created by extensions as
     well as those created with the <function>define</function>
     function.
    </para>
    <para>
     For example the line below
     <informalexample>
      <programlisting>
<![CDATA[
print_r (get_defined_constants());
]]>
      </programlisting>
     </informalexample>
     will print a list like:
     <informalexample>
      <programlisting>
<![CDATA[
Array
(
    [E_ERROR] => 1
    [E_WARNING] => 2
    [E_PARSE] => 4
    [E_NOTICE] => 8
    [E_CORE_ERROR] => 16
    [E_CORE_WARNING] => 32
    [E_COMPILE_ERROR] => 64
    [E_COMPILE_WARNING] => 128
    [E_USER_ERROR] => 256
    [E_USER_WARNING] => 512
    [E_USER_NOTICE] => 1024
    [E_ALL] => 2047
    [TRUE] => 1
)
]]>
      </programlisting>
     </informalexample>
    </para>
    <para>
     See also <function>get_loaded_extensions</function>,
     <function>get_defined_functions</function> and
     <function>get_defined_vars</function>.
    </para>
   </refsect1>
  </refentry>

  <refentry id="function.get-extension-funcs">
   <refnamediv>
    <refname>get_extension_funcs</refname>
    <refpurpose>
     Returns an array with the names of the functions of a module
    </refpurpose>
   </refnamediv>
   <refsect1>
    <title>Description</title>
     <methodsynopsis>
      <type>array</type><methodname>get_extension_funcs</methodname>
      <methodparam><type>string</type><parameter>module_name</parameter></methodparam>
     </methodsynopsis>
    <para>
     This function returns the names of all the functions defined in
     the module indicated by <parameter>module_name</parameter>.
    </para>
    <para>
     For example the lines below
     <informalexample>
      <programlisting>
<![CDATA[
print_r (get_extension_funcs ("xml"));
print_r (get_extension_funcs ("gd"));
]]>
      </programlisting>
     </informalexample>
     will print a list of the functions in the modules
     <varname>xml</varname> and <varname>gd</varname> respectively.
    </para>
    <para>
     See also: <function>get_loaded_extensions</function>
    </para>
   </refsect1>
  </refentry>

  <refentry id="function.getmygid">
   <refnamediv>
    <refname>getmygid</refname>
    <refpurpose>Get PHP script owner's GID</refpurpose>
   </refnamediv>
   <refsect1>
    <title>Description</title>
     <methodsynopsis>
      <type>int</type><methodname>getmygid</methodname>
      <void/>
     </methodsynopsis>
    <simpara>
     Returns the group ID of the current script, or &false; on error.
    </simpara>
    <simpara>
     See also <function>getmyuid</function>,
     <function>getmypid</function>,
     <function>get_current_user</function>,
     <function>getmyinode</function>, and
     <function>getlastmod</function>.
    </simpara>
   </refsect1>
  </refentry>

  <refentry id="function.get-included-files">
   <refnamediv>
    <refname>get_included_files</refname>
    <refpurpose>
     Returns an array with the names of included or required files
    </refpurpose>
   </refnamediv>
   <refsect1>
    <title>Description</title>
     <methodsynopsis>
      <type>array</type><methodname>get_included_files</methodname>
      <void/>
     </methodsynopsis>
    <para>
     Returns an array of the names of all files that have been
     included using <function>include</function>,
     <function>include_once</function>, <function>require</function>
     or <function>require_once</function>.
    </para>
    <para>
     Files that are included or required multiple times only show up
     once in the returned array.
    </para>
    <note>
     <para>
      Files included using the <literal>auto_prepend_file</literal>
      configuration directive are not included in the returned array.
     </para>
    </note>
    <para>
     <example>
      <title><function>get_included_files</function> Example</title>
      <programlisting role="php">
<![CDATA[
<?php

include("test1.php");
include_once("test2.php");
require("test3.php");
require_once("test4.php");

$included_files = get_included_files();

foreach($included_files as $filename) {
    echo "$filename\n";
}

?>
]]>
      </programlisting>
     </example>
     will generate the following output:
     <informalexample>
      <programlisting>
<![CDATA[
test1.php
test2.php
test3.php
test4.php
]]>
      </programlisting>
     </informalexample>
    </para>
    <note>
     <para>
      In PHP 4.0.1pl2 and previous versions
      <function>get_included_files</function> assumed that the
      required files ended in the extension <literal>.php</literal>;
      other extensions would not be returned.  The array returned by
      <function>get_included_files</function> was an associative array
      and only listed files included by <function>include</function>
      and <function>include_once</function>.
     </para>
    </note>
    <para>
     See also: <function>include</function>,
     <function>include_once</function>, <function>require</function>,
     <function>require_once</function>, and
     <function>get_required_files</function>.
    </para>
   </refsect1>
  </refentry>

  <refentry id="function.get-loaded-extensions">
   <refnamediv>
    <refname>get_loaded_extensions</refname>
    <refpurpose>
     Returns an array with the names of all modules compiled and
     loaded
    </refpurpose>
   </refnamediv>
   <refsect1>
    <title>Description</title>
     <methodsynopsis>
      <type>array</type><methodname>get_loaded_extensions</methodname>
      <void/>
     </methodsynopsis>
    <para>
     This function returns the names of all the modules compiled and
     loaded in the PHP interpreter.
    </para>
    <para>
     For example the line below
     <informalexample>
      <programlisting>
<![CDATA[
print_r (get_loaded_extensions());
]]>
      </programlisting>
     </informalexample>
     will print a list like:
     <informalexample>
      <programlisting>
<![CDATA[
Array
(
   [0] => xml
   [1] => wddx
   [2] => standard
   [3] => session
   [4] => posix
   [5] => pgsql
   [6] => pcre
   [7] => gd
   [8] => ftp
   [9] => db
   [10] => Calendar
   [11] => bcmath
)
]]>
      </programlisting>
     </informalexample>
    </para>
    <para>
     See also: <function>get_extension_funcs</function>.
    </para>
   </refsect1>
  </refentry>

  <refentry id="function.get-magic-quotes-gpc">
   <refnamediv>
    <refname>get_magic_quotes_gpc</refname>
    <refpurpose>
     Gets the current active configuration setting of magic quotes gpc
    </refpurpose>
   </refnamediv>
   <refsect1>
    <title>Description</title>
     <methodsynopsis>
      <type>long</type><methodname>get_magic_quotes_gpc</methodname>
      <void/>
     </methodsynopsis>
    <simpara>
     Returns the current active configuration setting of <link
     linkend="ini.magic-quotes-gpc">magic_quotes_gpc</link> (0 for
     off, 1 for on).
    </simpara>
    <simpara>
     See also <function>get_magic_quotes_runtime</function> and
     <function>set_magic_quotes_runtime</function>.
    </simpara>
   </refsect1>
  </refentry>

  <refentry id="function.get-magic-quotes-runtime">
   <refnamediv>
    <refname>get_magic_quotes_runtime</refname>
    <refpurpose>
     Gets the current active configuration setting of
     magic_quotes_runtime
    </refpurpose>
   </refnamediv>
   <refsect1>
    <title>Description</title>
     <methodsynopsis>
      <type>long</type><methodname>get_magic_quotes_runtime</methodname>
      <void/>
     </methodsynopsis>
    <simpara>
     Returns the current active configuration setting of <link
     linkend="ini.magic-quotes-runtime">magic_quotes_runtime</link>
     (0 for off, 1 for on).
    </simpara>
    <simpara>
     See also <function>get_magic_quotes_gpc</function> and
     <function>set_magic_quotes_runtime</function>.
    </simpara>
   </refsect1>
  </refentry>

  <refentry id="function.getlastmod">
   <refnamediv>
    <refname>getlastmod</refname>
    <refpurpose>Gets time of last page modification</refpurpose>
   </refnamediv>
   <refsect1>
    <title>Description</title>
     <methodsynopsis>
      <type>int</type><methodname>getlastmod</methodname>
      <void/>
     </methodsynopsis>
    <para>
     Returns the time of the last modification of the current
     page. The value returned is a Unix timestamp, suitable for
     feeding to <function>date</function>. Returns &false; on error.
     <example>
      <title>getlastmod() example</title>
      <programlisting role="php">
<![CDATA[
// outputs e.g. 'Last modified: March 04 1998 20:43:59.'
echo "Last modified: " . date ("F d Y H:i:s.", getlastmod());
]]>
      </programlisting>
     </example>
    </para>
    <para>
     See also <function>date</function>,
     <function>getmyuid</function>, <function>getmygid</function>,
     <function>get_current_user</function>,
     <function>getmyinode</function>, and
     <function>getmypid</function>.
    </para>
   </refsect1>
  </refentry>

  <refentry id="function.getmyinode">
   <refnamediv>
    <refname>getmyinode</refname>
    <refpurpose>Gets the inode of the current script</refpurpose>
   </refnamediv>
   <refsect1>
    <title>Description</title>
     <methodsynopsis>
      <type>int</type><methodname>getmyinode</methodname>
      <void/>
     </methodsynopsis>
    <para>
     Returns the current script's inode, or &false; on error.
    </para>
    <para>
     See also <function>getmygid</function>,
     <function>getmyuid</function>,
     <function>get_current_user</function>,
     <function>getmypid</function>, and
     <function>getlastmod</function>.
    </para>
    &note.no-windows;
   </refsect1>
  </refentry>

  <refentry id="function.getmypid">
   <refnamediv>
    <refname>getmypid</refname>
    <refpurpose>Gets PHP's process ID</refpurpose>
   </refnamediv>
   <refsect1>
    <title>Description</title>
     <methodsynopsis>
      <type>int</type><methodname>getmypid</methodname>
      <void/>
     </methodsynopsis>
    <para>
     Returns the current PHP process ID, or &false; on error.
    </para>
    <warning>
     <para>
      Process IDs are not unique, thus they are a weak entropy
      source. We recommend against relying on pids in
      security-dependent contexts.
     </para>
    </warning>
    <para>
     See also <function>getmygid</function>,
     <function>getmyuid</function>,
     <function>get_current_user</function>,
     <function>getmyinode</function>, and
     <function>getlastmod</function>.
    </para>
   </refsect1>
  </refentry>

  <refentry id="function.getmyuid">
   <refnamediv>
    <refname>getmyuid</refname>
    <refpurpose>Gets PHP script owner's UID</refpurpose>
   </refnamediv>
   <refsect1>
    <title>Description</title>
     <methodsynopsis>
      <type>int</type><methodname>getmyuid</methodname>
      <void/>
     </methodsynopsis>
    <simpara>
     Returns the user ID of the current script, or &false; on error.
    </simpara>
    <simpara>
     See also <function>getmygid</function>,
     <function>getmypid</function>,
     <function>get_current_user</function>,
     <function>getmyinode</function>, and
     <function>getlastmod</function>.
    </simpara>
   </refsect1>
  </refentry>

  <refentry id="function.get-required-files">
   <refnamediv>
    <refname>get_required_files</refname>
    <refpurpose>
     Returns an array with the names of included or required files
    </refpurpose>
   </refnamediv>
   <refsect1>
    <title>Description</title>
     <methodsynopsis>
      <type>array</type><methodname>get_required_files</methodname>
      <void/>
     </methodsynopsis>
    <para>
     As of PHP 4.0.4, this function is an alias for
     <function>get_included_files</function>
    </para>
    <para>
     In PHP 4.0.1pl2 and previous versions
     <function>get_required_files</function> assumed that the required
     files ended in the extension <literal>.php</literal>, other
     extensions would not be returned.  The array returned by
     <function>get_required_files</function> was an associative array
     and only listed files included by <function>require</function>
     and <function>require_once</function>.
    </para>
    <para>
     See also: <function>require</function>,
     <function>require_once</function>, <function>include</function>,
     <function>include_once</function>, and
     <function>get_included_files</function>.
    </para>
   </refsect1>
  </refentry>

  <refentry id="function.getrusage">
   <refnamediv>
    <refname>getrusage</refname>
    <refpurpose>Gets the current resource usages</refpurpose>
   </refnamediv>
   <refsect1>
    <title>Description</title>
     <methodsynopsis>
      <type>array</type><methodname>getrusage</methodname>
      <methodparam choice="opt"><type>int</type><parameter>who</parameter></methodparam>
     </methodsynopsis>
    <para>
     This is an interface to getrusage(2). It returns an associative
     array containing the data returned from the system call. If who
     is 1, getrusage will be called with RUSAGE_CHILDREN.
    </para>
    <para>
     All entries are accessible by using their documented field names.
     <example>
      <title>Getrusage Example</title>
      <programlisting role="php">
<![CDATA[
$dat = getrusage();
echo $dat["ru_nswap"];         # number of swaps
echo $dat["ru_majflt"];        # number of page faults
echo $dat["ru_utime.tv_sec"];  # user time used (seconds)
echo $dat["ru_utime.tv_usec"]; # user time used (microseconds)
]]>
      </programlisting>
     </example>
     See your system's man page on getrusage(2) for more details.
    </para>
   </refsect1>
  </refentry>

  <refentry id="function.ini-alter">
   <refnamediv>
    <refname>ini_alter</refname> 
    <refpurpose>
     Changes the value of a configuration option
    </refpurpose>
   </refnamediv>
   <refsect1>
    <title>Description</title>
     <methodsynopsis>
      <type>string</type><methodname>ini_alter</methodname>
      <methodparam><type>string</type><parameter>varname</parameter></methodparam>
      <methodparam><type>string</type><parameter>newvalue</parameter></methodparam>
     </methodsynopsis>
    <para>
     Changes the value of a configuration option, returns &false; on
     failure, and the previous value of the configuration option on
     success.
    </para>
    <note>
     <para>
      This is an alias of <function>ini_set</function>
     </para>
    </note>
    <para>
     See also <function>ini_get</function>,
     <function>ini_get_all</function>,
     <function>ini_restore</function>, and
     <function>ini_set</function>
    </para>
   </refsect1>
  </refentry>

  <refentry id="function.ini-get">
   <refnamediv>
    <refname>ini_get</refname>
    <refpurpose>Gets the value of a configuration option</refpurpose>
   </refnamediv>
   <refsect1>
    <title>Description</title>
     <methodsynopsis>
      <type>string</type><methodname>ini_get</methodname>
      <methodparam><type>string</type><parameter>varname</parameter></methodparam>
     </methodsynopsis>
    <para>
     Returns the value of the configuration option on success, an
     empty string on failure.
    </para>
    <para>
     See also <function>get_cfg_var</function>,
     <function>ini_get_all</function>,
     <function>ini_alter</function>,
     <function>ini_restore</function>, and
     <function>ini_set</function>
    </para>
   </refsect1>
  </refentry>

  <refentry id="function.ini-get-all">
   <refnamediv>
    <refname>ini_get_all</refname>
    <refpurpose>Gets all configuration options</refpurpose>
   </refnamediv>
   <refsect1>
    <title>Description</title>
     <methodsynopsis>
      <type>array</type><methodname>ini_get_all</methodname>
      <methodparam choice="opt"><type>string</type><parameter>extension</parameter></methodparam>
     </methodsynopsis>
    <para>
     Returns all the registered configuration options as an
     associative array.  If optional <parameter>extension</parameter>
     parameter is set, returns only options specific for that
     extension.
    </para>
    <para>
     See also: <function>ini_alter</function>,
     <function>ini_restore</function>, <function>ini_get</function>,
     and <function>ini_set</function>
    </para>
   </refsect1>
  </refentry>

  <refentry id="function.ini-restore">
   <refnamediv>
    <refname>ini_restore</refname>
    <refpurpose>Restores the value of a configuration option</refpurpose>
   </refnamediv>
   <refsect1>
    <title>Description</title>
     <methodsynopsis>
      <type>string</type><methodname>ini_restore</methodname>
      <methodparam><type>string</type><parameter>varname</parameter></methodparam>
     </methodsynopsis>
    <para>
     Restores a given configuration option to its original value.
    </para>
    <para>
     See also: <function>ini_alter</function>,
     <function>ini_get</function>, <function>ini_get_all</function>,
     and <function>ini_set</function>
    </para>
   </refsect1>
  </refentry>

  <refentry id="function.ini-set">
   <refnamediv>
    <refname>ini_set</refname>
    <refpurpose>Sets the value of a configuration option</refpurpose>
   </refnamediv>
   <refsect1>
    <title>Description</title>
     <methodsynopsis>
      <type>string</type><methodname>ini_set</methodname>
      <methodparam><type>string</type><parameter>varname</parameter></methodparam>
      <methodparam><type>string</type><parameter>newvalue</parameter></methodparam>
     </methodsynopsis>
    <para>
     Sets the value of the given configuration option. Returns the old
     value on success, &false; on failure. The configuration option
     will keep this new value during the script's execution, and will
     be restored at the script's ending.
    </para>
    <para>
     Not all the available options can be changed using
     <function>ini_set</function>. Below is a table with a list of all
     PHP options (as of PHP 4.0.5-dev), indicating which ones can be
     changed/set and at what level.
     <table>
      <title><link linkend="configuration">Configuration</link> options</title>
      <tgroup cols="3">
       <thead>
        <row>
         <entry>Name</entry>
         <entry>Default</entry>
         <entry>Changeable</entry>
        </row>
       </thead>
       <tbody>
        <row>
         <entry>define_syslog_variables</entry>
         <entry>"0"</entry>
         <entry>PHP_INI_ALL</entry>
        </row>
        <row>
         <entry>highlight.bg</entry>
         <entry>HL_BG_COLOR</entry>
         <entry>PHP_INI_ALL</entry>
        </row>
        <row>
         <entry>highlight.comment</entry>
         <entry>HL_COMMENT_COLOR</entry>
         <entry>PHP_INI_ALL</entry>
        </row>
        <row>
         <entry>highlight.default</entry>
         <entry>HL_DEFAULT_COLOR</entry>
         <entry>PHP_INI_ALL</entry>
        </row>
        <row>
         <entry>highlight.html</entry>
         <entry>HL_HTML_COLOR</entry>
         <entry>PHP_INI_ALL</entry>
        </row>
        <row>
         <entry>highlight.keyword</entry>
         <entry>HL_KEYWORD_COLOR</entry>
         <entry>PHP_INI_ALL</entry>
        </row>
        <row>
         <entry>highlight.string</entry>
         <entry>HL_STRING_COLOR</entry>
         <entry>PHP_INI_ALL</entry>
        </row>
        <row>
         <entry>allow_call_time_pass_reference</entry>
         <entry>"1"</entry>
         <entry>PHP_INI_SYSTEM|PHP_INI_PERDIR</entry>
        </row>
        <row>
         <entry>asp_tags</entry>
         <entry>"0"</entry>
         <entry>PHP_INI_SYSTEM|PHP_INI_PERDIR</entry>
        </row>
        <row>
         <entry>display_errors</entry>
         <entry>"1"</entry>
         <entry>PHP_INI_ALL</entry>
        </row>
        <row>
         <entry>display_startup_errors</entry>
         <entry>"0"</entry>
         <entry>PHP_INI_ALL</entry>
        </row>
        <row>
         <entry>enable_dl</entry>
         <entry>"1"</entry>
         <entry>PHP_INI_SYSTEM</entry>
        </row>
        <row>
         <entry>error_append_string</entry>
         <entry>&null;</entry>
         <entry>PHP_INI_ALL</entry>
        </row>
        <row>
         <entry>error_prepend_string</entry>
         <entry>&null;</entry>
         <entry>PHP_INI_ALL</entry>
        </row>
        <row>
         <entry>expose_php</entry>
         <entry>"1"</entry>
         <entry>PHP_INI_SYSTEM</entry>
        </row>
        <row>
         <entry>html_errors</entry>
         <entry>"1"</entry>
         <entry>PHP_INI_SYSTEM</entry>
        </row>
        <row>
         <entry>ignore_user_abort</entry>
         <entry>"0"</entry>
         <entry>PHP_INI_ALL</entry>
        </row>
        <row>
         <entry>implicit_flush</entry>
         <entry>"0"</entry>
         <entry>PHP_INI_PERDIR|PHP_INI_SYSTEM</entry>
        </row>
        <row>
         <entry>log_errors</entry>
         <entry>"0"</entry>
         <entry>PHP_INI_ALL</entry>
        </row>
        <row>
         <entry>magic_quotes_gpc</entry>
         <entry>"1"</entry>
         <entry>PHP_INI_PERDIR|PHP_INI_SYSTEM</entry>
        </row>
        <row>
         <entry>magic_quotes_runtime</entry>
         <entry>"0"</entry>
         <entry>PHP_INI_ALL</entry>
        </row>
        <row>
         <entry>magic_quotes_sybase</entry>
         <entry>"0"</entry>
         <entry>PHP_INI_PERDIR|PHP_INI_SYSTEM</entry>
        </row>
        <row>
         <entry>output_buffering</entry>
         <entry>"0"</entry>
         <entry>PHP_INI_PERDIR|PHP_INI_SYSTEM</entry>
        </row>
        <row>
         <entry>output_handler</entry>
         <entry>&null;</entry>
         <entry>PHP_INI_PERDIR|PHP_INI_SYSTEM</entry>
        </row>
        <row>
         <entry>register_argc_argv</entry>
         <entry>"1"</entry>
         <entry>PHP_INI_ALL</entry>
        </row>
        <row>
         <entry>register_globals</entry>
         <entry>"1"</entry>
         <entry>PHP_INI_PERDIR|PHP_INI_SYSTEM</entry>
        </row>
        <row>
         <entry>safe_mode</entry>
         <entry>"0"</entry>
         <entry>PHP_INI_SYSTEM</entry>
        </row>
        <row>
         <entry>short_open_tag</entry>
         <entry>"1"</entry>
         <entry>PHP_INI_SYSTEM|PHP_INI_PERDIR</entry>
        </row>
        <row>
         <entry>sql.safe_mode</entry>
         <entry>"0"</entry>
         <entry>PHP_INI_SYSTEM</entry>
        </row>
        <row>
         <entry>track_errors</entry>
         <entry>"0"</entry>
         <entry>PHP_INI_ALL</entry>
        </row>
        <row>
         <entry>y2k_compliance</entry>
         <entry>"0"</entry>
         <entry>PHP_INI_ALL</entry>
        </row>
        <row>
         <entry>arg_separator</entry>
         <entry>"&amp;"</entry>
         <entry>PHP_INI_ALL</entry>
        </row>
        <row>
         <entry>auto_append_file</entry>
         <entry>&null;</entry>
         <entry>PHP_INI_ALL</entry>
        </row>
        <row>
         <entry>auto_prepend_file</entry>
         <entry>&null;</entry>
         <entry>PHP_INI_ALL</entry>
        </row>
        <row>
         <entry>doc_root</entry>
         <entry>&null;</entry>
         <entry>PHP_INI_SYSTEM</entry>
        </row>
        <row>
         <entry>default_charset</entry>
         <entry>SAPI_DEFAULT_CHARSET</entry>
         <entry>PHP_INI_ALL</entry>
        </row>
        <row>
         <entry>default_mimetype</entry>
         <entry>SAPI_DEFAULT_MIMETYPE</entry>
         <entry>PHP_INI_ALL</entry>
        </row>
        <row>
         <entry>error_log</entry>
         <entry>&null;</entry>
         <entry>PHP_INI_ALL</entry>
        </row>
        <row>
         <entry>extension_dir</entry>
         <entry>PHP_EXTENSION_DIR</entry>
         <entry>PHP_INI_SYSTEM</entry>
        </row>
        <row>
         <entry>gpc_order</entry>
         <entry>"GPC"</entry>
         <entry>PHP_INI_ALL</entry>
        </row>
        <row>
         <entry>include_path</entry>
         <entry>PHP_INCLUDE_PATH</entry>
         <entry>PHP_INI_ALL</entry>
        </row>
        <row>
         <entry>max_execution_time</entry>
         <entry>"30"</entry>
         <entry>PHP_INI_ALL</entry>
        </row>
        <row>
         <entry>open_basedir</entry>
         <entry>&null;</entry>
         <entry>PHP_INI_SYSTEM</entry>
        </row>
        <row>
         <entry>safe_mode_exec_dir</entry>
         <entry>"1"</entry>
         <entry>PHP_INI_SYSTEM</entry>
        </row>
        <row>
         <entry>upload_max_filesize</entry>
         <entry>"2M"</entry>
         <entry>PHP_INI_ALL</entry>
        </row>
        <row>
         <entry>file_uploads</entry>
         <entry>"1"</entry>
         <entry>PHP_INI_ALL</entry>
        </row>
        <row>
         <entry>post_max_size</entry>
         <entry>"8M"</entry>
         <entry>PHP_INI_SYSTEM</entry>
        </row>
        <row>
         <entry>upload_tmp_dir</entry>
         <entry>&null;</entry>
         <entry>PHP_INI_SYSTEM</entry>
        </row>
        <row>
         <entry>user_dir</entry>
         <entry>&null;</entry>
         <entry>PHP_INI_SYSTEM</entry>
        </row>
        <row>
         <entry>variables_order</entry>
         <entry>&null;</entry>
         <entry>PHP_INI_ALL</entry>
        </row>
        <row>
         <entry>SMTP</entry>
         <entry>"localhost"</entry>
         <entry>PHP_INI_ALL</entry>
        </row>
        <row>
         <entry>browscap</entry>
         <entry>&null;</entry>
         <entry>PHP_INI_SYSTEM</entry>
        </row>
        <row>
         <entry>error_reporting</entry>
         <entry>&null;</entry>
         <entry>PHP_INI_ALL</entry>
        </row>
        <row>
         <entry>memory_limit</entry>
         <entry>"8M"</entry>
         <entry>PHP_INI_ALL</entry>
        </row>
        <row>
         <entry>precision</entry>
         <entry>"14"</entry>
         <entry>PHP_INI_ALL</entry>
        </row>
        <row>
         <entry>sendmail_from</entry>
         <entry>&null;</entry>
         <entry>PHP_INI_ALL</entry>
        </row>
        <row>
         <entry>sendmail_path</entry>
         <entry>DEFAULT_SENDMAIL_PATH</entry>
         <entry>PHP_INI_SYSTEM</entry>
        </row>
        <row>
         <entry>disable_functions</entry>
         <entry>""</entry>
         <entry>PHP_INI_SYSTEM</entry>
        </row>
        <row>
         <entry>allow_url_fopen</entry>
         <entry>"1"</entry>
         <entry>PHP_INI_ALL</entry>
        </row>
       </tbody>
      </tgroup>
     </table>
    </para>
    <para>
     <table>
      <title>Definition of PHP_INI_* constants</title>
      <tgroup cols="3">
       <thead>
        <row>
         <entry>Constant</entry>
         <entry>Value</entry>
         <entry>Meaning</entry>
        </row>
       </thead>
       <tbody>
        <row>
         <entry>PHP_INI_USER</entry>
         <entry>1</entry>
         <entry>Entry can be set in user scripts</entry>
        </row>
        <row>
         <entry>PHP_INI_PERDIR</entry>
         <entry>2</entry>
         <entry>
          Entry can be set in <filename>.htaccess</filename>
         </entry>
        </row>
        <row>
         <entry>PHP_INI_SYSTEM</entry>
         <entry>4</entry>
         <entry>
          Entry can be set in <filename>php.ini</filename> or
          <filename>httpd.conf</filename>
         </entry>
        </row>
        <row>
         <entry>PHP_INI_ALL</entry>
         <entry>7</entry>
         <entry>Entry can be set anywhere</entry>
        </row>
       </tbody>
      </tgroup>
     </table>
    </para>
    <para>
     See also: <function>ini_alter</function>,
     <function>ini_get</function>, and
     <function>ini_restore</function>
    </para>
   </refsect1>
  </refentry>

  <refentry id="function.phpcredits">
   <refnamediv>
    <refname>phpcredits</refname>
    <refpurpose>Prints out the credits for PHP</refpurpose>
   </refnamediv>
   <refsect1>
    <title>Description</title>
     <methodsynopsis>
      <type>void</type><methodname>phpcredits</methodname>
      <methodparam><type>int</type><parameter>flag</parameter></methodparam>
     </methodsynopsis>
    <para>
     This function prints out the credits listing the PHP developers,
     modules, etc. It generates the appropriate HTML codes to insert
     the information in a page. A parameter indicating what will be
     printed (a pre-defined constant flag, see table below) needs to
     be passed. For example to print the general credits, you will use
     somewhere in your code:
     <informalexample>
      <programlisting role="php">
<![CDATA[
...
phpcredits(CREDITS_GENERAL);
...
]]>
      </programlisting>
     </informalexample>
     And if you want to print the core developers and the
     documentation group, in a page of its own, you will use:
     <informalexample>
      <programlisting role="php">
<![CDATA[
<?php
phpcredits(CREDITS_GROUP + CREDITS_DOCS + CREDITS_FULLPAGE);
?>
]]>
      </programlisting>
     </informalexample>
     And if you feel like embedding all the credits in your page, then
     code like the one below will do it:
     <informalexample>
      <programlisting role="php">
<![CDATA[
<html>
 <head>
  <title>My credits page</title>
 </head>
 <body>
  <?php
 // some code of your own
 phpcredits(CREDITS_ALL);
 // some more code
 ?>
 </body>
</html>
]]>
      </programlisting>
     </informalexample>
    </para>
    <para>
    </para>
    <para>
     <table>
      <title>Pre-defined <function>phpcredits</function> flags</title>
      <tgroup cols="2">
       <thead>
        <row>
         <entry>name</entry>
         <entry>description</entry>
        </row>
       </thead>
       <tbody>
        <row>
         <entry>CREDITS_ALL</entry>
         <entry>
          All the credits, equivalent to using: CREDITS_DOCS +
          CREDITS_GENERAL + CREDITS_GROUP + CREDITS_MODULES +
          CREDITS_FULLPAGE. It generates a complete stand-alone HTML
          page with the appropriate tags.
         </entry>
        </row>
        <row>
         <entry>CREDITS_DOCS</entry>
         <entry>The credits for the documentation team</entry>
        </row>
        <row>
         <entry>CREDITS_FULLPAGE</entry>
         <entry>
          Usually used in combination with the other flags.  Indicates
          that the a complete stand-alone HTML page needs to be
          printed including the information indicated by the other
          flags.
         </entry>
        </row>
        <row>
         <entry>CREDITS_GENERAL</entry>
         <entry>
          General credits: Language design and concept, PHP 4.0
          authors and SAPI module.
         </entry>
        </row>
        <row>
         <entry>CREDITS_GROUP</entry>
         <entry>A list of the core developers</entry>
        </row>
        <row>
         <entry>CREDITS_MODULES</entry> 
         <entry>
          A list of the extension modules for PHP, and their authors
         </entry>
        </row>
        <row>
         <entry>CREDITS_SAPI</entry>
         <entry>
          A list of the server API modules for PHP, and their authors
         </entry>
        </row>
       </tbody>
      </tgroup>
     </table>
    </para>
    <para>
     See also: <function>phpinfo</function>,
     <function>phpversion</function>, and
     <function>php_logo_guid</function>.
    </para>
   </refsect1>
  </refentry>

  <refentry id="function.phpinfo">
   <refnamediv>
    <refname>phpinfo</refname>
    <refpurpose>Outputs lots of PHP information</refpurpose>
   </refnamediv>
   <refsect1>
    <title>Description</title>
     <methodsynopsis>
     <type>int</type><methodname>phpinfo</methodname>
     <methodparam choice="opt"><type>int</type><parameter>what</parameter></methodparam>
    </methodsynopsis>
    <para>
     Outputs a large amount of information about the current state of
     PHP. This includes information about PHP compilation options and
     extensions, the PHP version, server information and environment
     (if compiled as a module), the PHP environment, OS version
     information, paths, master and local values of configuration
     options, HTTP headers, and the PHP License.
    </para>
    <para>
     Because every system is setup differently,
     <function>phpinfo</function> is commonly used to check <link
     linkend="configuration">configuration settings</link> and for
     available <link
     linkend="language.variables.predefined">predefined
     variables</link> on a given system.  Also,
     <function>phpinfo</function> is a valuable debugging tool as it
     contains all EGPCS (Environment, GET, POST, Cookie, Server) data.
    </para>
    <para>
     The output may be customized by passing one or more of the
     following <emphasis>constants</emphasis> bitwise values summed
     together in the optional <parameter>what</parameter> parameter.
     One can also combine the respective constants or bitwise values
     together with the <link
     linkend="language.operators.bitwise">or</link> operator.

     <table>
      <title><function>phpinfo</function> options</title>
      <tgroup cols="3">
       <thead>
        <row>
         <entry>Name (constant)</entry>
         <entry>Value</entry>
         <entry>Description</entry>
        </row>
       </thead>
       <tbody>
        <row>
         <entry>INFO_GENERAL</entry>
         <entry>1</entry>
         <entry>
          The configuration line, php.ini location, build date, Web
          Server, System and more.
         </entry>
        </row>
        <row>
         <entry>INFO_CREDITS</entry>
         <entry>2</entry>
         <entry>
          PHP 4 Credits.  See also <function>phpcredits</function>.
         </entry>
        </row>
        <row>
         <entry>INFO_CONFIGURATION</entry>
         <entry>4</entry>
         <entry>
          Current Local and Master values for php directives.  See
          also <function>ini_get</function>.
         </entry>
        </row>
        <row>
         <entry>INFO_MODULES</entry>
         <entry>8</entry>
         <entry>
          Loaded modules and there respective settings.
         </entry>
        </row>
        <row>
         <entry>INFO_ENVIRONMENT</entry>
         <entry>16</entry>
         <entry>
          Environment Variable information that's also available in
          <varname>$_ENV</varname>.
         </entry>
        </row>
        <row>
         <entry>INFO_VARIABLES</entry>
         <entry>32</entry>
         <entry>
          Shows all <link linkend="language.variables.predefined">
          predefined variables</link> from EGPCS (Environment, GET,
          POST, Cookie, Server).
         </entry>
        </row>
        <row>
         <entry>INFO_LICENSE</entry>
         <entry>64</entry>
         <entry>
          PHP License information.  See also the <ulink
          url="&url.php.license;">license faq</ulink>.
         </entry>
        </row>
        <row>
         <entry>INFO_ALL</entry>
         <entry>-1</entry>
         <entry>
          Shows all of the above.  This is the default value.
         </entry>
        </row>
       </tbody>
      </tgroup>
     </table>
    </para>
    <para>
     <example>
      <title><function>phpinfo</function> examples</title>
      <programlisting role="php">
<![CDATA[
<?php

// Show all information, defaults to INFO_ALL
phpinfo();

// Show just the module information.
// phpinfo(8) yields identical results.
phpinfo(INFO_MODULES);

?>
]]>
      </programlisting>
     </example>
    </para>
    <note>
     <para>
      Parts of the information displayed are disabled when the
      <literal>expose_php</literal> configuration setting is set to
      <literal>off</literal>. This includes the PHP and Zend logos,
      and the credits.
     </para>
    </note>
    <para>
    See also: <function>phpversion</function>,
    <function>phpcredits</function>,
    <function>php_logo_guid</function>, <function>ini_get</function>,
    <function>ini_set</function>, and the section on <link
    linkend="language.variables.predefined">Predefined
    Variables</link>.
    </para>
   </refsect1>
  </refentry>

  <refentry id="function.phpversion">
   <refnamediv>
    <refname>phpversion</refname>
    <refpurpose>Gets the current PHP version</refpurpose>
   </refnamediv>
   <refsect1>
    <title>Description</title>
     <methodsynopsis>
      <type>string</type><methodname>phpversion</methodname>
      <void/>
     </methodsynopsis>
    <para>
     Returns a string containing the version of the currently running
     PHP parser.
    </para>
    <note>
     <para>
      This information is also available in the predefined constant
      <constant>PHP_VERSION</constant>.
     </para>
    </note>
    <para>
     <example>
      <title><function>phpversion</function> Example</title>
      <programlisting role="php">
<![CDATA[
<?php
// prints e.g. 'Current PHP version: 4.1.1'
echo 'Current PHP version: ' . phpversion();
?>
]]>
      </programlisting>
     </example>
    </para>
    <para>
     See also <function>version_compare</function>,
     <function>phpinfo</function>, <function>phpcredits</function>,
     <function>php_logo_guid</function>, and
     <function>zend_version</function>.
    </para>
   </refsect1>
  </refentry>

  <refentry id="function.php-logo-guid">
   <refnamediv>
    <refname>php_logo_guid</refname>
    <refpurpose>Gets the logo guid</refpurpose>
   </refnamediv>
   <refsect1>
    <title>Description</title>
     <methodsynopsis>
      <type>string</type><methodname>php_logo_guid</methodname>
      <void/>
     </methodsynopsis>
    <note>
     <para>
      This functionality was added in PHP 4.0.0.
     </para>
    </note>
    <para>
     See also: <function>phpinfo</function>,
     <function>phpversion</function>, and
     <function>phpcredits</function>.
    </para>
   </refsect1>
  </refentry>

  <refentry id="function.php-sapi-name">
   <refnamediv>
    <refname>php_sapi_name</refname>
    <refpurpose>
     Returns the type of interface between web server and PHP
    </refpurpose>
   </refnamediv>
   <refsect1>
    <title>Description</title>
     <methodsynopsis>
      <type>string</type><methodname>php_sapi_name</methodname>
      <void/>
     </methodsynopsis>
    <simpara>
     <function>php_sapi_name</function> returns a lowercase string
     which describes the type of interface between web server and PHP
     (Server API, SAPI). In CGI PHP, this string is "cgi", in mod_php
     for Apache, this string is "apache" and so on.
    </simpara>
    <para>
     <example>
      <title><function>php_sapi_name</function> Example</title>
      <programlisting role="php">
<![CDATA[
$sapi_type = php_sapi_name();
if ($sapi_type == "cgi")
    print "You are using CGI PHP\n";
else
    print "You are not using CGI PHP\n";
]]>
      </programlisting>
     </example>
    </para>
   </refsect1>
  </refentry>

  <refentry id="function.php-uname">
   <refnamediv>
    <refname>php_uname</refname>
    <refpurpose>
     Returns information about the operating system PHP was built on
    </refpurpose>
   </refnamediv>
   <refsect1>
    <title>Description</title>
     <methodsynopsis>
      <type>string</type><methodname>php_uname</methodname>
      <void/>
     </methodsynopsis>
    <simpara>
     <function>php_uname</function> returns a string with a
     description of the operating system PHP is built on.
    </simpara>
    <para>
     <example>
      <title><function>php_uname</function> Example</title>
      <programlisting role="php">
<![CDATA[
if (substr(php_uname(), 0, 7) == "Windows") {
   die ("Sorry, this script doesn't run on Windows.\n");
}
]]>
      </programlisting>
     </example>
    </para>
   </refsect1>
  </refentry>

  <refentry id="function.putenv">
   <refnamediv>
    <refname>putenv</refname>
    <refpurpose>Sets the value of an environment variable</refpurpose>
   </refnamediv>
   <refsect1>
    <title>Description</title>
     <methodsynopsis>
      <type>void</type><methodname>putenv</methodname>
      <methodparam><type>string</type><parameter>setting</parameter></methodparam>
     </methodsynopsis>
    <para>
     Adds <parameter>setting</parameter> to the server environment.
     The environment variable will only exist for the duration of the
     current request. At the end of the request the environment is
     restored to its original state.
    </para>
    <para>
     Setting certain environment variables may be a potential security
     breach.  The <literal>safe_mode_allowed_env_vars</literal>
     directive contains a comma-delimited list of prefixes. In Safe
     Mode, the user may only alter environment variables whose names
     begin with the prefixes supplied by this directive. By default,
     users will only be able to set environment variables that begin
     with <literal>PHP_</literal>
     (e.g. <literal>PHP_FOO=BAR</literal>). Note: if this directive is
     empty, PHP will let the user modify ANY environment variable!
    </para>
    <para>
     The <literal>safe_mode_protected_env_vars</literal> directive
     contains a comma-delimited list of environment variables, that
     the end user won't be able to change using
     <function>putenv</function>.  These variables will be protected
     even if <literal>safe_mode_allowed_env_vars</literal> is set to
     allow to change them.
    </para>
    <warning>
     <para>
      These directives have only effect when <link
      linkend="features.safe-mode">safe-mode</link> itself is enabled!
     </para>
    </warning>
    <para>
     <example>
      <title>Setting an Environment Variable</title>
      <programlisting role="php">
<![CDATA[
putenv ("UNIQID=$uniqid");
]]>
      </programlisting>
     </example>
    </para>
    <para>
     See also <function>getenv</function>.
    </para>
   </refsect1>
  </refentry>

  <refentry id="function.set-magic-quotes-runtime">
   <refnamediv>
    <refname>set_magic_quotes_runtime</refname>
    <refpurpose>
     Sets the current active configuration setting of
     magic_quotes_runtime
    </refpurpose>
   </refnamediv>
   <refsect1>
    <title>Description</title>
     <methodsynopsis>
      <type>long</type><methodname>set_magic_quotes_runtime</methodname>
      <methodparam><type>int</type><parameter>new_setting</parameter></methodparam>
     </methodsynopsis>
    <simpara>
     Set the current active configuration setting of <link
     linkend="ini.magic-quotes-runtime">magic_quotes_runtime</link> (0
     for off, 1 for on).
    </simpara>
    <simpara>
     See also: <function>get_magic_quotes_gpc</function> and
     <function>get_magic_quotes_runtime</function>.
    </simpara>
   </refsect1>
  </refentry>

  <refentry id="function.set-time-limit">
   <refnamediv>
    <refname>set_time_limit</refname>
    <refpurpose>Limits the maximum execution time</refpurpose>
   </refnamediv>
   <refsect1>
    <title>Description</title>
     <methodsynopsis>
      <type>void</type><methodname>set_time_limit</methodname>
      <methodparam><type>int</type><parameter>seconds</parameter></methodparam>
     </methodsynopsis>
    <simpara>
     Set the number of seconds a script is allowed to run.  If this is
     reached, the script returns a fatal error.  The default limit is
     30 seconds or, if it exists, the
     <literal>max_execution_time</literal> value defined in the <link
     linkend="ini.max-execution-time">configuration file</link>.  If
     seconds is set to zero, no time limit is imposed.
    </simpara>
    <simpara>
     When called, <function>set_time_limit</function> restarts the
     timeout counter from zero. In other words, if the timeout is the
     default 30 seconds, and 25 seconds into script execution a call
     such as set_time_limit(20) is made, the script will run for a
     total of 45 seconds before timing out.
    </simpara>
    <simpara>
     <function>set_time_limit</function> has no effect when PHP is
     running in safe mode. There is no workaround other than turning
     off safe mode or changing the time limit in the <link
     linkend="ini.max-execution-time">configuration file</link>.
    </simpara>
    <note>
     <para>
      The <function>set_time_limit</function> function and the
      configuration directive <link
      linkend="ini.max-execution-time">max_execution_time</link> only
      affect the execution time of the script itself.  Any time spent
      on activity that happens outside the execution of the script
      such as system calls using <function>system</function>, the
      <function>sleep</function> function, database queries, etc. is
      not included when determining the maximum time that the script
      has been running.
     </para>
    </note>
   </refsect1>
  </refentry>

  <refentry id="function.version-compare">
   <refnamediv>
    <refname>version_compare</refname>
    <refpurpose>
     Compares two "PHP-standardized" version number strings
    </refpurpose>
   </refnamediv>
   <refsect1>
    <title>Description</title>
     <methodsynopsis>
      <type>int</type><methodname>version_compare</methodname>
      <methodparam><type>string</type><parameter>version1</parameter></methodparam>
      <methodparam><type>string</type><parameter>version2</parameter></methodparam>
      <methodparam choice="opt"><type>string</type><parameter>
        operator
       </parameter></methodparam>
     </methodsynopsis>
    <para>
     <function>version_compare</function> compares two
     "PHP-standardized" version number strings. This is useful if you
     would like to write programs working only on some versions of
     PHP.
    </para>
    <para>
     <function>version_compare</function> returns -1 if the first
     version is lower than the second, 0 if they are equal, and +1 if
     the second is lower.
    </para>
    <para>
     If you specify the third optional <parameter>operator</parameter>
     argument, you can test for a particular relationship. The
     possible operators are: <literal>&lt;</literal>,
     <literal>lt</literal>, <literal>&lt;=</literal>,
     <literal>le</literal>, <literal>&gt;</literal>,
     <literal>gt</literal>, <literal>&gt;=</literal>,
     <literal>ge</literal>, <literal>==</literal>,
     <literal>=</literal>, <literal>eq</literal>,
     <literal>!=</literal>, <literal>&lt;&gt;</literal>,
     <literal>ne</literal> respectively. Using this argument, the
     function will return 1 if the relationship is the one specified
     by the operator, 0 otherwise.
    </para>
    <para>
     <example>
      <title><function>version_compare</function> Example</title>
      <programlisting role="php">
<![CDATA[
// prints -1
echo version_compare("4.0.4", "4.0.6");

// these all print 1
echo version_compare("4.0.4", "4.0.6", "<");
echo version_compare("4.0.6", "4.0.6", "eq");
]]>
      </programlisting>
     </example>
    </para>
   </refsect1>
  </refentry>

  <refentry id="function.zend-logo-guid">
   <refnamediv>
    <refname>zend_logo_guid</refname>
    <refpurpose>Gets the zend guid</refpurpose>
   </refnamediv>
   <refsect1>
    <title>Description</title>
     <methodsynopsis>
      <type>string</type><methodname>zend_logo_guid</methodname>
      <void/>
     </methodsynopsis>
    <note>
     <para>
      This functionality was added in PHP 4.0.0.
     </para>
    </note>
   </refsect1>
  </refentry>

  <refentry id="function.zend-version">
   <refnamediv>
    <refname>zend_version</refname>
    <refpurpose>Gets the version of the current Zend engine</refpurpose>
   </refnamediv>
   <refsect1>
    <title>Description</title>
     <methodsynopsis>
      <type>string</type><methodname>zend_version</methodname>
      <void/>
     </methodsynopsis>
    <para>
     Returns a string containing the version of the currently running
     PHP parser.
     <example>
      <title><function>zend_version</function> Example</title>
      <programlisting role="php">
<![CDATA[
// prints e.g. 'Zend engine version: 1.0.4'
echo "Zend engine version: " . zend_version();
]]>
      </programlisting>
     </example>
    </para>
    <para>
     See also <function>phpinfo</function>,
     <function>phpcredits</function>,
     <function>php_logo_guid</function>, and
     <function>phpversion</function>.
    </para>
   </refsect1>
  </refentry>
  
 </reference>

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