<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<HTML
><HEAD
><TITLE
>dl</TITLE
><META
NAME="GENERATOR"
CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK
REL="HOME"
TITLE="PHP 手册"
HREF="index.html"><LINK
REL="UP"
TITLE="PHP Options&Information"
HREF="ref.info.html"><LINK
REL="PREVIOUS"
TITLE="assert"
HREF="function.assert.html"><LINK
REL="NEXT"
TITLE="extension_loaded"
HREF="function.extension-loaded.html"><META
HTTP-EQUIV="Content-type"
CONTENT="text/html; charset=UTF-8"></HEAD
><BODY
CLASS="refentry"
BGCOLOR="#FFFFFF"
TEXT="#000000"
LINK="#0000FF"
VLINK="#840084"
ALINK="#0000FF"
><DIV
CLASS="NAVHEADER"
><TABLE
SUMMARY="Header navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TH
COLSPAN="3"
ALIGN="center"
>PHP 手册</TH
></TR
><TR
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="bottom"
><A
HREF="function.assert.html"
ACCESSKEY="P"
>上一页</A
></TD
><TD
WIDTH="80%"
ALIGN="center"
VALIGN="bottom"
></TD
><TD
WIDTH="10%"
ALIGN="right"
VALIGN="bottom"
><A
HREF="function.extension-loaded.html"
ACCESSKEY="N"
>下一页</A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><H1
><A
NAME="function.dl"
></A
>dl</H1
><DIV
CLASS="refnamediv"
><A
NAME="AEN180623"
></A
><P
> (PHP 3, PHP 4, PHP 5)</P
>dl -- Loads a PHP extension at runtime</DIV
><DIV
CLASS="refsect1"
><A
NAME="AEN180626"
></A
><H2
>说明</H2
>int <B
CLASS="methodname"
>dl</B
> ( string library )<BR
></BR
><P
> Loads the PHP extension given by the parameter
<CODE
CLASS="parameter"
>library</CODE
>.
</P
><P
> Use <A
HREF="function.extension-loaded.html"
><B
CLASS="function"
>extension_loaded()</B
></A
> to test whether a given
extension is already available or not. This works on both built-in
extensions and dynamically loaded ones (either through <TT
CLASS="filename"
>php.ini</TT
> or
<B
CLASS="function"
>dl()</B
>).
</P
></DIV
><DIV
CLASS="refsect1"
><A
NAME="AEN180640"
></A
><H2
>参数</H2
><P
> <P
></P
><DIV
CLASS="variablelist"
><DL
><DT
><CODE
CLASS="parameter"
>library</CODE
></DT
><DD
><P
> This parameter is <SPAN
CLASS="emphasis"
><I
CLASS="emphasis"
>only</I
></SPAN
> the filename of the
extension to load which also depends on your platform. For example,
the <A
HREF="ref.sockets.html"
>sockets</A
> extension (if compiled
as a shared module, not the default!) would be called
<TT
CLASS="filename"
>sockets.so</TT
> on Unix platforms whereas it is called
<TT
CLASS="filename"
>php_sockets.dll</TT
> on the Windows platform.
</P
><P
> The directory where the extension is loaded from depends on your
platform:
</P
><P
> Windows - If not explicitly set in the <TT
CLASS="filename"
>php.ini</TT
>, the extension is
loaded from <TT
CLASS="filename"
>c:\php4\extensions\</TT
> by default.
</P
><P
> Unix - If not explicitly set in the <TT
CLASS="filename"
>php.ini</TT
>, the default extension
directory depends on
<P
></P
><UL
><LI
><P
> whether PHP has been built with <TT
CLASS="literal"
>--enable-debug</TT
>
or not
</P
></LI
><LI
><P
> whether PHP has been built with (experimental) ZTS (Zend Thread Safety)
support or not
</P
></LI
><LI
><P
> the current internal <TT
CLASS="literal"
>ZEND_MODULE_API_NO</TT
> (Zend
internal module API number, which is basically the date on which a
major module API change happened, e.g. <TT
CLASS="literal"
>20010901</TT
>)
</P
></LI
></UL
>
Taking into account the above, the directory then defaults to
<TT
CLASS="literal"
><install-dir>/lib/php/extensions/ <debug-or-not>-<zts-or-not>-ZEND_MODULE_API_NO</TT
>,
e.g.
<TT
CLASS="filename"
>/usr/local/php/lib/php/extensions/debug-non-zts-20010901</TT
>
or
<TT
CLASS="filename"
>/usr/local/php/lib/php/extensions/no-debug-zts-20010901</TT
>.
</P
></DD
></DL
></DIV
>
</P
></DIV
><DIV
CLASS="refsect1"
><A
NAME="AEN180672"
></A
><H2
>返回值</H2
><P
> 如果成功则返回 <TT
CLASS="constant"
><B
>TRUE</B
></TT
>，失败则返回 <TT
CLASS="constant"
><B
>FALSE</B
></TT
>。 If the functionality of loading modules is not available
(see Note) or has been disabled (either by turning it off
<TT
CLASS="literal"
>enable_dl</TT
> or by enabling <A
HREF="features.safe-mode.html#ini.safe-mode"
>安全模式</A
>
in <TT
CLASS="filename"
>php.ini</TT
>) an <TT
CLASS="constant"
><B
>E_ERROR</B
></TT
> is emitted
and execution is stopped. If <B
CLASS="function"
>dl()</B
> fails because the
specified library couldn't be loaded, in addition to <TT
CLASS="constant"
><B
>FALSE</B
></TT
> an
<TT
CLASS="constant"
><B
>E_WARNING</B
></TT
> message is emitted.
</P
></DIV
><DIV
CLASS="refsect1"
><A
NAME="AEN180684"
></A
><H2
>范例</H2
><P
> <TABLE
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
CLASS="EXAMPLE"
><TR
><TD
><DIV
CLASS="example"
><A
NAME="AEN180687"
></A
><P
><B
>例 1. <B
CLASS="function"
>dl()</B
> examples</B
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
CELLPADDING="5"
><TR
><TD
><code><font color="#000000">
<font color="#0000BB"><?php<br /></font><font color="#FF8000">// Example loading an extension based on OS<br /></font><font color="#007700">if (!</font><font color="#0000BB">extension_loaded</font><font color="#007700">(</font><font color="#DD0000">'sqlite'</font><font color="#007700">)) {<br /> if (</font><font color="#0000BB">strtoupper</font><font color="#007700">(</font><font color="#0000BB">substr</font><font color="#007700">(</font><font color="#0000BB">PHP_OS</font><font color="#007700">, </font><font color="#0000BB">0</font><font color="#007700">, </font><font color="#0000BB">3</font><font color="#007700">)) === </font><font color="#DD0000">'WIN'</font><font color="#007700">) {<br /> </font><font color="#0000BB">dl</font><font color="#007700">(</font><font color="#DD0000">'php_sqlite.dll'</font><font color="#007700">);<br /> } else {<br /> </font><font color="#0000BB">dl</font><font color="#007700">(</font><font color="#DD0000">'sqlite.so'</font><font color="#007700">);<br /> }<br />}<br /><br /></font><font color="#FF8000">// Or, the PHP_SHLIB_SUFFIX constant is available as of PHP 4.3.0<br /></font><font color="#007700">if (!</font><font color="#0000BB">extension_loaded</font><font color="#007700">(</font><font color="#DD0000">'sqlite'</font><font color="#007700">)) {<br /> </font><font color="#0000BB">$prefix </font><font color="#007700">= (</font><font color="#0000BB">PHP_SHLIB_SUFFIX </font><font color="#007700">=== </font><font color="#DD0000">'dll'</font><font color="#007700">) ? </font><font color="#DD0000">'php_' </font><font color="#007700">: </font><font color="#DD0000">''</font><font color="#007700">;<br /> </font><font color="#0000BB">dl</font><font color="#007700">(</font><font color="#0000BB">$prefix </font><font color="#007700">. </font><font color="#DD0000">'sqlite.' </font><font color="#007700">. </font><font color="#0000BB">PHP_SHLIB_SUFFIX</font><font color="#007700">);<br />}<br /></font><font color="#0000BB">?></font>
</font>
</code></TD
></TR
></TABLE
></DIV
></TD
></TR
></TABLE
>
</P
></DIV
><DIV
CLASS="refsect1"
><A
NAME="AEN180691"
></A
><H2
>注释</H2
><DIV
CLASS="note"
><BLOCKQUOTE
CLASS="note"
><P
><B
>注意: </B
>
<B
CLASS="function"
>dl()</B
> is <SPAN
CLASS="emphasis"
><I
CLASS="emphasis"
>not</I
></SPAN
> supported in
multithreaded Web servers. Use the <TT
CLASS="literal"
>extensions</TT
>
statement in your <TT
CLASS="filename"
>php.ini</TT
> when operating under such
an environment. However, the <TT
CLASS="literal"
>CGI</TT
> and
<TT
CLASS="literal"
>CLI</TT
> build are <SPAN
CLASS="strong"
><B
CLASS="emphasis"
>not</B
></SPAN
>
affected !
</P
></BLOCKQUOTE
></DIV
><DIV
CLASS="note"
><BLOCKQUOTE
CLASS="note"
><P
><B
>注意: </B
>
As of PHP 5, the <B
CLASS="function"
>dl()</B
> function is deprecated in every
SAPI <SPAN
CLASS="emphasis"
><I
CLASS="emphasis"
>except</I
></SPAN
> <ACRONYM
CLASS="acronym"
>CLI</ACRONYM
>.
Use <A
HREF="ini.core.html#ini.extension"
>Extension Loading Directives</A
>
method instead.
</P
></BLOCKQUOTE
></DIV
><DIV
CLASS="note"
><BLOCKQUOTE
CLASS="note"
><P
><B
>注意: </B
>
Since PHP 6 this function is disabled in all SAPIs, except CLI, CGI and
embed.
</P
></BLOCKQUOTE
></DIV
><DIV
CLASS="note"
><BLOCKQUOTE
CLASS="note"
><P
><B
>注意: </B
>
<B
CLASS="function"
>dl()</B
> is case sensitive on Unix platforms.
</P
></BLOCKQUOTE
></DIV
><DIV
CLASS="note"
><BLOCKQUOTE
CLASS="note"
><P
><B
>注意: </B
>本函数在<A
HREF="features.safe-mode.html"
>安全模式</A
>下被禁用。</P
></BLOCKQUOTE
></DIV
></DIV
><DIV
CLASS="refsect1"
><A
NAME="AEN180716"
></A
><H2
>参见</H2
><P
> <P
></P
><TABLE
BORDER="0"
><TBODY
><TR
><TD
><A
HREF="ini.core.html#ini.extension"
>Extension Loading Directives</A
></TD
></TR
><TR
><TD
><A
HREF="function.extension-loaded.html"
><B
CLASS="function"
>extension_loaded()</B
></A
></TD
></TR
></TBODY
></TABLE
><P
></P
>
</P
></DIV
><DIV
CLASS="NAVFOOTER"
><HR
ALIGN="LEFT"
WIDTH="100%"><TABLE
SUMMARY="Footer navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
><A
HREF="function.assert.html"
ACCESSKEY="P"
>上一页</A
></TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="index.html"
ACCESSKEY="H"
>起始页</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
><A
HREF="function.extension-loaded.html"
ACCESSKEY="N"
>下一页</A
></TD
></TR
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
>assert</TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="ref.info.html"
ACCESSKEY="U"
>上一级</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
>extension_loaded</TD
></TR
></TABLE
></DIV
></BODY
></HTML
>
