<HTML ><HEAD ><TITLE >PHP 3 extension</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="Migrating from PHP 3 to PHP 4" HREF="migration4.html"><LINK REL="PREVIOUS" TITLE="Missing functions" HREF="migration4.missing.html"><LINK REL="NEXT" TITLE="Variable substitution in strings" HREF="migration4.strings.html"><META HTTP-EQUIV="Content-type" CONTENT="text/html; charset=ISO-8859-1"></HEAD ><BODY CLASS="section" 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="migration4.missing.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" >Appendix B. Migrating from PHP 3 to PHP 4</TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="migration4.strings.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="section" ><H1 CLASS="section" ><A NAME="migration4.extensions" ></A >PHP 3 extension</H1 ><P > Extensions written for PHP 3 will not work with PHP 4, neither as binaries nor at the source level. It is not difficult to port extensions to PHP 4 if you have access to the original source. A detailed description of the actual porting process is not part of this text. </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="migration4.missing.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="migration4.strings.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >Missing functions</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="migration4.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >Variable substitution in strings</TD ></TR ></TABLE ></DIV ></BODY ></HTML >