<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <HTML ><HEAD ><TITLE >crc32</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK REL="HOME" TITLE="Manual do PHP" HREF="index.html"><LINK REL="UP" TITLE="String" HREF="ref.strings.html"><LINK REL="PREVIOUS" TITLE="count_chars" HREF="function.count-chars.html"><LINK REL="NEXT" TITLE="crypt" HREF="function.crypt.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" >Manual do PHP</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="function.count-chars.html" ACCESSKEY="P" >Anterior</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="function.crypt.html" ACCESSKEY="N" >Próxima</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="function.crc32" ></A >crc32</H1 ><DIV CLASS="refnamediv" ><A NAME="AEN218827" ></A ><P > (PHP 4 >= 4.0.1, PHP 5)</P >crc32 -- Calcula polinômio crc32 de uma string</DIV ><DIV CLASS="refsect1" ><A NAME="AEN218830" ></A ><H2 >Descrição</H2 >int <B CLASS="methodname" >crc32</B > ( string str )<BR ></BR ><P > Gera o polinômio cyclic redundancy checksum de 32-bit de comprimento do <CODE CLASS="parameter" >str</CODE >. É usado geralmente para validar a integridade de um dado sendo transferido. </P ><P > Devido ao tipo integer do PHP conter sinal e muitos dos checksums crc32 resultarem em integers negativos, você precisa usar o formatador "%u" de <A HREF="function.sprintf.html" ><B CLASS="function" >sprintf()</B ></A > ou <A HREF="function.printf.html" ><B CLASS="function" >printf()</B ></A > para obter uma string representando o checksum crc32 sem sinal. </P ><P > Este segundo exemplo mostra com exibir um checksum convertido com a função <A HREF="function.printf.html" ><B CLASS="function" >printf()</B ></A >: <TABLE WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" CLASS="EXAMPLE" ><TR ><TD ><DIV CLASS="example" ><A NAME="AEN218845" ></A ><P ><B >Exemplo 1. Mostrando um checksum crc32</B ></P ><TABLE BORDER="0" BGCOLOR="#E0E0E0" CELLPADDING="5" ><TR ><TD ><code><font color="#000000"> <font color="#0000BB"><?php<br />$checksum </font><font color="#007700">= </font><font color="#0000BB">crc32</font><font color="#007700">(</font><font color="#DD0000">"The quick brown fox jumped over the lazy dog."</font><font color="#007700">); <br /></font><font color="#0000BB">printf</font><font color="#007700">(</font><font color="#DD0000">"%u\n"</font><font color="#007700">, </font><font color="#0000BB">$checksum</font><font color="#007700">);<br /></font><font color="#0000BB">?></font> </font> </code></TD ></TR ></TABLE ></DIV ></TD ></TR ></TABLE > </P ><P > Veja também <A HREF="function.md5.html" ><B CLASS="function" >md5()</B ></A > e <A HREF="function.sha1.html" ><B CLASS="function" >sha1()</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="function.count-chars.html" ACCESSKEY="P" >Anterior</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Principal</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="function.crypt.html" ACCESSKEY="N" >Próxima</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >count_chars</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="ref.strings.html" ACCESSKEY="U" >Acima</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >crypt</TD ></TR ></TABLE ></DIV ></BODY ></HTML >