<HTML ><HEAD ><TITLE >Execution Operators</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.7"><LINK REL="HOME" TITLE="PHP Manual" HREF="index.html"><LINK REL="UP" TITLE="Operators" HREF="language.operators.html"><LINK REL="PREVIOUS" TITLE="Error Control Operators" HREF="language.operators.errorcontrol.html"><LINK REL="NEXT" TITLE="Incrementing/Decrementing Operators" HREF="language.operators.increment.html"><META HTTP-EQUIV="Content-type" CONTENT="text/html; charset=ISO-8859-1"></HEAD ><BODY CLASS="sect1" 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 Manual</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="language.operators.errorcontrol.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" >Chapter 11. Operators</TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="language.operators.increment.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="sect1" ><H1 CLASS="sect1" ><A NAME="language.operators.execution" ></A >Execution Operators</H1 ><P > PHP supports one execution operator: backticks (``). Note that these are not single-quotes! PHP will attempt to execute the contents of the backticks as a shell command; the output will be returned (i.e., it won't simply be dumped to output; it can be assigned to a variable). <DIV CLASS="informalexample" ><A NAME="AEN4645" ></A ><P ></P ><TABLE BORDER="0" BGCOLOR="#E0E0E0" CELLPADDING="5" ><TR ><TD ><PRE CLASS="php" >$output = `ls -al`; echo "<pre>$output</pre>";</PRE ></TD ></TR ></TABLE ><P ></P ></DIV > </P ><DIV CLASS="note" ><BLOCKQUOTE CLASS="note" ><P ><B >Note: </B > The backtick operator is disabled when <A HREF="features.safe-mode.html#ini.safe-mode" >safe mode</A > is enabled or <A HREF="function.shell-exec.html" ><B CLASS="function" >shell_exec()</B ></A > is disabled. </P ></BLOCKQUOTE ></DIV ><P > See also <A HREF="function.escapeshellcmd.html" ><B CLASS="function" >escapeshellcmd()</B ></A >, <A HREF="function.exec.html" ><B CLASS="function" >exec()</B ></A >, <A HREF="function.passthru.html" ><B CLASS="function" >passthru()</B ></A >, <A HREF="function.popen.html" ><B CLASS="function" >popen()</B ></A >, <A HREF="function.shell-exec.html" ><B CLASS="function" >shell_exec()</B ></A >, and <A HREF="function.system.html" ><B CLASS="function" >system()</B ></A >. </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="language.operators.errorcontrol.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="language.operators.increment.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >Error Control Operators</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="language.operators.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >Incrementing/Decrementing Operators</TD ></TR ></TABLE ></DIV ></BODY ></HTML >