<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <HTML ><HEAD ><TITLE >passthru</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="Program Execution Functions" HREF="ref.exec.html"><LINK REL="PREVIOUS" TITLE="exec" HREF="function.exec.html"><LINK REL="NEXT" TITLE="proc_close" HREF="function.proc-close.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.exec.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.proc-close.html" ACCESSKEY="N" >下一页</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="function.passthru" ></A >passthru</H1 ><DIV CLASS="refnamediv" ><A NAME="AEN188958" ></A ><P > (PHP 3, PHP 4, PHP 5)</P >passthru -- Execute an external program and display raw output</DIV ><DIV CLASS="refsect1" ><A NAME="AEN188961" ></A ><H2 >说明</H2 >void <B CLASS="methodname" >passthru</B > ( string command [, int &return_var] )<BR ></BR ><P > The <B CLASS="function" >passthru()</B > function is similar to the <A HREF="function.exec.html" ><B CLASS="function" >exec()</B ></A > function in that it executes a <CODE CLASS="parameter" >command</CODE >. This function should be used in place of <A HREF="function.exec.html" ><B CLASS="function" >exec()</B ></A > or <A HREF="function.system.html" ><B CLASS="function" >system()</B ></A > when the output from the Unix command is binary data which needs to be passed directly back to the browser. A common use for this is to execute something like the pbmplus utilities that can output an image stream directly. By setting the Content-type to <SPAN CLASS="emphasis" ><I CLASS="emphasis" >image/gif</I ></SPAN > and then calling a pbmplus program to output a gif, you can create PHP scripts that output images directly. </P ></DIV ><DIV CLASS="refsect1" ><A NAME="AEN188979" ></A ><H2 >参数</H2 ><P > <P ></P ><DIV CLASS="variablelist" ><DL ><DT ><CODE CLASS="parameter" >command</CODE ></DT ><DD ><P > The command that will be executed. </P ></DD ><DT ><CODE CLASS="parameter" >return_var</CODE ></DT ><DD ><P > If the <CODE CLASS="parameter" >return_var</CODE > argument is present, the return status of the Unix command will be placed here. </P ></DD ></DL ></DIV > </P ></DIV ><DIV CLASS="refsect1" ><A NAME="AEN188994" ></A ><H2 >返回值</H2 ><P > 无返回值。 </P ></DIV ><DIV CLASS="refsect1" ><A NAME="AEN188997" ></A ><H2 >注释</H2 ><DIV CLASS="warning" ><P ></P ><TABLE CLASS="warning" BORDER="1" WIDTH="100%" ><TR ><TD ALIGN="CENTER" ><B >警告</B ></TD ></TR ><TR ><TD ALIGN="LEFT" ><P >如果想允许用户输入的数据被传入本函数,则应使用 <A HREF="function.escapeshellarg.html" ><B CLASS="function" >escapeshellarg()</B ></A > 或 <A HREF="function.escapeshellcmd.html" ><B CLASS="function" >escapeshellcmd()</B ></A > 函数来确保用户不能欺骗系统从而执行任意命令。</P ></TD ></TR ></TABLE ></DIV ><DIV CLASS="note" ><BLOCKQUOTE CLASS="note" ><P ><B >注意: </B >如果用本函数启动一个程序并希望保持在后台运行,必须确保该程序的输出被重定向到一个文件或者其它输出流去,否则 PHP 会在程序执行结束前挂起。</P ></BLOCKQUOTE ></DIV ><DIV CLASS="note" ><BLOCKQUOTE CLASS="note" ><P ><B >注意: </B >在打开了<A HREF="features.safe-mode.html" >安全模式</A >时,只能执行在 <A HREF="features.safe-mode.html#ini.safe-mode-exec-dir" >safe_mode_exec_dir</A > 之内的程序。为实用起见目前不能在指向程序的路径中包含 <TT CLASS="literal" >..</TT > 成分。</P ></BLOCKQUOTE ></DIV ><DIV CLASS="warning" ><P ></P ><TABLE CLASS="warning" BORDER="1" WIDTH="100%" ><TR ><TD ALIGN="CENTER" ><B >警告</B ></TD ></TR ><TR ><TD ALIGN="LEFT" ><P >在打开了<A HREF="features.safe-mode.html" >安全模式</A >时,命令字符串会被 <A HREF="function.escapeshellcmd.html" ><B CLASS="function" >escapeshellcmd()</B ></A > 转义。从而 <TT CLASS="literal" >echo y | echo x</TT > 就成了 <TT CLASS="literal" >echo "y | echo x"</TT >。</P ></TD ></TR ></TABLE ></DIV ></DIV ><DIV CLASS="refsect1" ><A NAME="AEN189016" ></A ><H2 >参见</H2 ><P > <P ></P ><TABLE BORDER="0" ><TBODY ><TR ><TD ><A HREF="function.exec.html" ><B CLASS="function" >exec()</B ></A ></TD ></TR ><TR ><TD ><A HREF="function.system.html" ><B CLASS="function" >system()</B ></A ></TD ></TR ><TR ><TD ><A HREF="function.popen.html" ><B CLASS="function" >popen()</B ></A ></TD ></TR ><TR ><TD ><A HREF="function.escapeshellcmd.html" ><B CLASS="function" >escapeshellcmd()</B ></A ></TD ></TR ><TR ><TD ><A HREF="language.operators.execution.html" >backtick operator</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.exec.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.proc-close.html" ACCESSKEY="N" >下一页</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >exec</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="ref.exec.html" ACCESSKEY="U" >上一级</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >proc_close</TD ></TR ></TABLE ></DIV ></BODY ></HTML >