| 1 | <HTML
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| 2 | ><HEAD
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| 3 | ><TITLE
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| 4 | >Overview</TITLE
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| 5 | ><META
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| 6 | NAME="GENERATOR"
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| 7 | CONTENT="Modular DocBook HTML Stylesheet Version 1.7"><LINK
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| 8 | REL="HOME"
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| 9 | TITLE="Manuál PHP"
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| 10 | HREF="index.html"><LINK
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| 11 | REL="UP"
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| 12 | TITLE="Extending PHP 4.0"
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| 13 | HREF="zend.html"><LINK
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| 14 | REL="PREVIOUS"
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| 15 | TITLE="Extending PHP 4.0"
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| 16 | HREF="zend.html"><LINK
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| 17 | REL="NEXT"
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| 18 | TITLE="Extension Possibilities"
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| 19 | HREF="zend.possibilities.html"><META
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| 20 | HTTP-EQUIV="Content-type"
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| 21 | CONTENT="text/html; charset=ISO-8859-2"></HEAD
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| 22 | ><BODY
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| 23 | CLASS="chapter"
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| 24 | BGCOLOR="#FFFFFF"
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| 25 | TEXT="#000000"
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| 26 | LINK="#0000FF"
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| 27 | VLINK="#840084"
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| 28 | ALINK="#0000FF"
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| 29 | ><DIV
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| 30 | CLASS="NAVHEADER"
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| 31 | ><TABLE
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| 32 | SUMMARY="Header navigation table"
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| 33 | WIDTH="100%"
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| 34 | BORDER="0"
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| 35 | CELLPADDING="0"
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| 36 | CELLSPACING="0"
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| 37 | ><TR
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| 38 | ><TH
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| 39 | COLSPAN="3"
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| 40 | ALIGN="center"
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| 41 | >Manuál PHP</TH
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| 42 | ></TR
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| 43 | ><TR
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| 44 | ><TD
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| 45 | WIDTH="10%"
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| 46 | ALIGN="left"
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| 47 | VALIGN="bottom"
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| 48 | ><A
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| 49 | HREF="zend.html"
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| 50 | ACCESSKEY="P"
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| 51 | >Pøedcházející</A
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| 52 | ></TD
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| 53 | ><TD
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| 54 | WIDTH="80%"
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| 55 | ALIGN="center"
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| 56 | VALIGN="bottom"
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| 57 | ></TD
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| 58 | ><TD
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| 59 | WIDTH="10%"
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| 60 | ALIGN="right"
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| 61 | VALIGN="bottom"
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| 62 | ><A
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| 63 | HREF="zend.possibilities.html"
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| 64 | ACCESSKEY="N"
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| 65 | >Dal¹í</A
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| 66 | ></TD
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| 67 | ></TR
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| 68 | ></TABLE
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| 69 | ><HR
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| 70 | ALIGN="LEFT"
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| 71 | WIDTH="100%"></DIV
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| 72 | ><DIV
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| 73 | CLASS="chapter"
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| 74 | ><H1
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| 75 | ><A
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| 76 | NAME="zend.overview"
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| 77 | >Kapitola 24. Overview</A
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| 78 | ></H1
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| 79 | ><DIV
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| 80 | CLASS="TOC"
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| 81 | ><DL
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| 82 | ><DT
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| 83 | ><B
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| 84 | >Obsah</B
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| 85 | ></DT
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| 86 | ><DT
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| 87 | ><A
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| 88 | HREF="zend.overview.html#zend.overview.whatisit"
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| 89 | >What Is Zend? and What Is PHP?</A
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| 90 | ></DT
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| 91 | ></DL
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| 92 | ></DIV
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| 93 | ><P
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| 94 | > "Extending PHP" is easier said than done. PHP has evolved to a
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| 95 | full-fledged tool consisting of a few megabytes of source code,
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| 96 | and to hack a system like this quite a few things have to be
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| 97 | learned and considered. When structuring this chapter, we finally
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| 98 | decided on the "learn by doing" approach. This is not the most
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| 99 | scientific and professional approach, but the method that's the
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| 100 | most fun and gives the best end results. In the following
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| 101 | sections, you'll learn quickly how to get the most basic
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| 102 | extensions to work almost instantly. After that, you'll learn
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| 103 | about Zend's advanced API functionality. The alternative would
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| 104 | have been to try to impart the functionality, design, tips,
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| 105 | tricks, etc. as a whole, all at once, thus giving a complete look
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| 106 | at the big picture before doing anything practical. Although this
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| 107 | is the "better" method, as no dirty hacks have to be made, it can
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| 108 | be very frustrating as well as energy- and time-consuming, which
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| 109 | is why we've decided on the direct approach.
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| 110 | </P
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| 111 | ><P
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| 112 | > Note that even though this chapter tries to impart as much
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| 113 | knowledge as possible about the inner workings of PHP, it's
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| 114 | impossible to really give a complete guide to extending PHP that
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| 115 | works 100% of the time in all cases. PHP is such a huge and
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| 116 | complex package that its inner workings can only be understood if
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| 117 | you make yourself familiar with it by practicing, so we encourage
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| 118 | you to work with the source.
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| 119 | </P
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| 120 | ><DIV
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| 121 | CLASS="section"
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| 122 | ><H1
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| 123 | CLASS="section"
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| 124 | ><A
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| 125 | NAME="zend.overview.whatisit"
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| 126 | ></A
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| 127 | >What Is Zend? and What Is PHP?</H1
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| 128 | ><P
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| 129 | > The name <SPAN
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| 130 | CLASS="emphasis"
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| 131 | ><I
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| 132 | CLASS="emphasis"
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| 133 | >Zend</I
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| 134 | ></SPAN
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| 135 | > refers to the language engine,
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| 136 | PHP's core. The term <SPAN
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| 137 | CLASS="emphasis"
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| 138 | ><I
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| 139 | CLASS="emphasis"
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| 140 | >PHP</I
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| 141 | ></SPAN
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| 142 | > refers to the
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| 143 | complete system as it appears from the outside. This might sound
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| 144 | a bit confusing at first, but it's not that complicated (see
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| 145 | <A
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| 146 | HREF="zend.overview.html#fig.internal-struct"
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| 147 | >24-1</A
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| 148 | >). To implement a Web script interpreter, you need
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| 149 | three parts:
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| 150 | <P
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| 151 | ></P
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| 152 | ><OL
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| 153 | TYPE="1"
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| 154 | ><LI
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| 155 | ><P
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| 156 | > The <SPAN
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| 157 | CLASS="emphasis"
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| 158 | ><I
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| 159 | CLASS="emphasis"
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| 160 | >interpreter</I
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| 161 | ></SPAN
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| 162 | > part analyzes the input
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| 163 | code, translates it, and executes it.
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| 164 | </P
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| 165 | ></LI
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| 166 | ><LI
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| 167 | ><P
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| 168 | > The <SPAN
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| 169 | CLASS="emphasis"
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| 170 | ><I
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| 171 | CLASS="emphasis"
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| 172 | >functionality</I
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| 173 | ></SPAN
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| 174 | > part implements the
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| 175 | functionality of the language (its functions, etc.).
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| 176 | </P
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| 177 | ></LI
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| 178 | ><LI
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| 179 | ><P
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| 180 | > The <SPAN
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| 181 | CLASS="emphasis"
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| 182 | ><I
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| 183 | CLASS="emphasis"
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| 184 | >interface</I
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| 185 | ></SPAN
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| 186 | > part talks to the Web
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| 187 | server, etc.
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| 188 | </P
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| 189 | ></LI
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| 190 | ></OL
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| 191 | >
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| 192 | Zend takes part 1 completely and a bit of part 2; PHP takes parts
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| 193 | 2 and 3. Together they form the complete PHP package. Zend itself
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| 194 | really forms only the language core, implementing PHP at its very
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| 195 | basics with some predefined functions. PHP contains all the
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| 196 | modules that actually create the language's outstanding
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| 197 | capabilities.
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| 198 | <DIV
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| 199 | CLASS="figure"
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| 200 | ><A
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| 201 | NAME="fig.internal-struct"
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| 202 | ></A
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| 203 | ><P
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| 204 | ><B
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| 205 | >Obrázek 24-1. The internal structure of PHP.</B
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| 206 | ></P
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| 207 | ><P
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| 208 | ><IMG
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| 209 | SRC="figures/Extending_Zend_1_PHPs_internal_structure.png"></P
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| 210 | ></DIV
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| 211 | >
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| 212 | </P
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| 213 | ><P
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| 214 | > The following sections discuss where PHP can be extended and how
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| 215 | it's done.
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| 216 | </P
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| 217 | ></DIV
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| 218 | ></DIV
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| 219 | ><DIV
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| 220 | CLASS="NAVFOOTER"
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| 221 | ><HR
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| 222 | ALIGN="LEFT"
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| 223 | WIDTH="100%"><TABLE
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| 224 | SUMMARY="Footer navigation table"
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| 225 | WIDTH="100%"
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| 226 | BORDER="0"
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| 227 | CELLPADDING="0"
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| 228 | CELLSPACING="0"
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| 229 | ><TR
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| 230 | ><TD
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| 231 | WIDTH="33%"
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| 232 | ALIGN="left"
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| 233 | VALIGN="top"
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| 234 | ><A
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| 235 | HREF="zend.html"
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| 236 | ACCESSKEY="P"
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| 237 | >Pøedcházející</A
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| 238 | ></TD
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| 239 | ><TD
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| 240 | WIDTH="34%"
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| 241 | ALIGN="center"
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| 242 | VALIGN="top"
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| 243 | ><A
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| 244 | HREF="index.html"
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| 245 | ACCESSKEY="H"
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| 246 | >Domù</A
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| 247 | ></TD
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| 248 | ><TD
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| 249 | WIDTH="33%"
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| 250 | ALIGN="right"
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| 251 | VALIGN="top"
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| 252 | ><A
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| 253 | HREF="zend.possibilities.html"
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| 254 | ACCESSKEY="N"
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| 255 | >Dal¹í</A
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| 256 | ></TD
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| 257 | ></TR
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| 258 | ><TR
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| 259 | ><TD
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| 260 | WIDTH="33%"
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| 261 | ALIGN="left"
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| 262 | VALIGN="top"
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| 263 | >Extending PHP 4.0</TD
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| 264 | ><TD
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| 265 | WIDTH="34%"
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| 266 | ALIGN="center"
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| 267 | VALIGN="top"
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| 268 | ><A
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| 269 | HREF="zend.html"
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| 270 | ACCESSKEY="U"
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| 271 | >Nahoru</A
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| 272 | ></TD
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| 273 | ><TD
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| 274 | WIDTH="33%"
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| 275 | ALIGN="right"
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| 276 | VALIGN="top"
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| 277 | >Extension Possibilities</TD
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| 278 | ></TR
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| 279 | ></TABLE
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| 280 | ></DIV
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| 281 | ></BODY
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| 282 | ></HTML
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| 283 | >
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