<?xml version="1.0" encoding="iso-8859-1"?>
<!-- $Revision: 1.5 $ -->
<!-- splitted from ./en/functions/exec.xml, last change in rev 1.2 -->
  <refentry id="function.passthru">
   <refnamediv>
    <refname>passthru</refname>
    <refpurpose>
     Execute an external program and display raw output
    </refpurpose>
   </refnamediv>
   <refsect1>
    <title>Description</title>
     <methodsynopsis>
      <type>void</type><methodname>passthru</methodname>
      <methodparam><type>string</type><parameter>command</parameter></methodparam>
      <methodparam choice="opt"><type>int</type><parameter>&amp;return_var</parameter></methodparam>
     </methodsynopsis>
    <para>
     The <function>passthru</function> function is similar to the
     <function>exec</function> function in that it executes a
     <parameter>command</parameter>.  If the
     <parameter>return_var</parameter> argument is present, the return
     status of the Unix command will be placed here.  This function
     should be used in place of <function>exec</function> or
     <function>system</function> 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 <emphasis>image/gif</emphasis> and
     then calling a pbmplus program to output a gif, you can create
     PHP scripts that output images directly.
    </para>
    &warn.escapeshell;
    &note.exec-bg;
    &note.exec-path;
    &warn.sm.exec;
    <para>
     See also <function>exec</function>, <function>system</function>,
     <function>popen</function>, <function>escapeshellcmd</function>,
     and the <link linkend="language.operators.execution">backtick
     operator</link>.
    </para>
   </refsect1>
  </refentry>

<!-- Keep this comment at the end of the file
Local variables:
mode: sgml
sgml-omittag:t
sgml-shorttag:t
sgml-minimize-attributes:nil
sgml-always-quote-attributes:t
sgml-indent-step:1
sgml-indent-data:t
indent-tabs-mode:nil
sgml-parent-document:nil
sgml-default-dtd-file:"../../../../manual.ced"
sgml-exposed-tags:nil
sgml-local-catalogs:nil
sgml-local-ecat-files:nil
End:
vim600: syn=xml fen fdm=syntax fdl=2 si
vim: et tw=78 syn=sgml
vi: ts=1 sw=1
-->