<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <HTML ><HEAD ><TITLE >Using PHP</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="FAQ: Perguntas Mais Freqüentes" HREF="faq.html"><LINK REL="PREVIOUS" TITLE="Build Problems" HREF="faq.build.html"><LINK REL="NEXT" TITLE="PHP and HTML" HREF="faq.html.html"><META HTTP-EQUIV="Content-type" CONTENT="text/html; charset=UTF-8"></HEAD ><BODY CLASS="chapter" 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="faq.build.html" ACCESSKEY="P" >Anterior</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="faq.html.html" ACCESSKEY="N" >Próxima</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="chapter" ><H1 ><A NAME="faq.using" >Capítulo 55. Using PHP</A ></H1 ><P > This section gathers many common errors that you may face while writing PHP scripts. </P ><DIV CLASS="qandaset" ><DL ><DT >1. <A HREF="faq.using.html#faq.using.anyform" > I would like to write a generic PHP script that can handle data coming from any form. How do I know which POST method variables are available? </A ></DT ><DT >2. <A HREF="faq.using.html#faq.using.addslashes" > I need to convert all single-quotes (') to a backslash followed by a single-quote (\'). How can I do this with a regular expression? I'd also like to convert " to \" and \ to \\. </A ></DT ><DT >3. <A HREF="faq.using.html#faq.using.stripslashes" > All my " turn into \" and my ' turn into \', how do I get rid of all these unwanted backslashes? How and why did they get there? </A ></DT ><DT >4. <A HREF="faq.using.html#faq.using.wrong-order" > When I do the following, the output is printed in the wrong order: <TABLE BORDER="0" BGCOLOR="#E0E0E0" CELLPADDING="5" ><TR ><TD ><code><font color="#000000"> <font color="#0000BB"><?php<br /></font><font color="#007700">function </font><font color="#0000BB">myfunc</font><font color="#007700">(</font><font color="#0000BB">$argument</font><font color="#007700">)<br />{<br /> echo </font><font color="#0000BB">$argument </font><font color="#007700">+ </font><font color="#0000BB">10</font><font color="#007700">;<br />}<br /></font><font color="#0000BB">$variable </font><font color="#007700">= </font><font color="#0000BB">10</font><font color="#007700">;<br />echo </font><font color="#DD0000">"myfunc($variable) = " </font><font color="#007700">. </font><font color="#0000BB">myfunc</font><font color="#007700">(</font><font color="#0000BB">$variable</font><font color="#007700">);<br /></font><font color="#0000BB">?></font> </font> </code></TD ></TR ></TABLE > what's going on? </A ></DT ><DT >5. <A HREF="faq.using.html#faq.using.newlines" > Hey, what happened to my newlines? <TABLE BORDER="0" BGCOLOR="#E0E0E0" CELLPADDING="5" ><TR ><TD ><code><font color="#000000"> <pre><br /><font color="#0000BB"><?php </font><font color="#007700">echo </font><font color="#DD0000">"This should be the first line."</font><font color="#007700">; </font><font color="#0000BB">?><br /><?php </font><font color="#007700">echo </font><font color="#DD0000">"This should show up after the new line above."</font><font color="#007700">; </font><font color="#0000BB">?><br /></font></pre></font> </code></TD ></TR ></TABLE > </A ></DT ><DT >6. <A HREF="faq.using.html#faq.using.headers-sent" > I get the message 'Warning: Cannot send session cookie - headers already sent...' or 'Cannot add header information - headers already sent...'. </A ></DT ><DT >7. <A HREF="faq.using.html#faq.using.header" > I need to access information in the request header directly. How can I do this? </A ></DT ><DT >8. <A HREF="faq.using.html#faq.using.authentication" > When I try to use authentication with IIS I get 'No Input file specified'. </A ></DT ><DT >9. <A HREF="faq.using.html#faq.using.iis.sharing" > Windows: I can't access files shared on another computer using IIS </A ></DT ><DT >10. <A HREF="faq.using.html#faq.using.netscape" > My PHP script works on IE and Lynx, but on Netscape some of my output is missing. When I do a "View Source" I see the content in IE but not in Netscape. </A ></DT ><DT >11. <A HREF="faq.using.html#faq.using.mixml" > How am I supposed to mix XML and PHP? It complains about my <?xml tags! </A ></DT ><DT >12. <A HREF="faq.using.html#faq.using.editor" > How can I use PHP with FrontPage or some other HTML editor that insists on moving my code around? </A ></DT ><DT >13. <A HREF="faq.using.html#faq.using.variables" > Where can I find a complete list of variables are available to me in PHP? </A ></DT ><DT >14. <A HREF="faq.using.html#faq.using.freepdf" > How can I generate PDF files without using the non-free and commercial libraries <A HREF="ref.cpdf.html" >ClibPDF</A > and <A HREF="ref.pdf.html" >PDFLib</A >? I'd like something that's free and doesn't require external PDF libraries. </A ></DT ><DT >15. <A HREF="faq.using.html#faq.using.cgi-vars" > I'm trying to access one of the standard CGI variables (such as $DOCUMENT_ROOT or $HTTP_REFERER) in a user-defined function, and it can't seem to find it. What's wrong? </A ></DT ><DT >16. <A HREF="faq.using.html#faq.using.shorthandbytes" > A few PHP directives may also take on shorthand byte values, as opposed to only <A HREF="language.types.integer.html" ><B CLASS="type" >integer</B ></A > byte values. What are all the available shorthand byte options? And can I use these outside of <TT CLASS="filename" >php.ini</TT >? </A ></DT ></DL ><DIV CLASS="qandaentry" ><B ><DIV CLASS="question" ><P ><A NAME="faq.using.anyform" ></A ><B >1. </B > I would like to write a generic PHP script that can handle data coming from any form. How do I know which POST method variables are available? </P ></DIV ></B ><DIV CLASS="answer" ><P ><B > </B > PHP offers many <A HREF="language.variables.predefined.html" > predefined variables</A >, like the superglobal <CODE CLASS="varname" > $_POST</CODE >. You may loop through <CODE CLASS="varname" >$_POST</CODE > as it's an associate array of all POSTed values. For example, let's simply loop through it with <A HREF="control-structures.foreach.html" > foreach</A >, check for <A HREF="function.empty.html" ><B CLASS="function" >empty()</B ></A > values, and print them out. <TABLE BORDER="0" BGCOLOR="#E0E0E0" CELLPADDING="5" ><TR ><TD ><code><font color="#000000"> <font color="#0000BB"><?php<br />$empty </font><font color="#007700">= </font><font color="#0000BB">$post </font><font color="#007700">= array();<br />foreach (</font><font color="#0000BB">$_POST </font><font color="#007700">as </font><font color="#0000BB">$varname </font><font color="#007700">=> </font><font color="#0000BB">$varvalue</font><font color="#007700">) {<br /> if (empty(</font><font color="#0000BB">$varvalue</font><font color="#007700">)) {<br /> </font><font color="#0000BB">$empty</font><font color="#007700">[</font><font color="#0000BB">$varname</font><font color="#007700">] = </font><font color="#0000BB">$varvalue</font><font color="#007700">;<br /> } else {<br /> </font><font color="#0000BB">$post</font><font color="#007700">[</font><font color="#0000BB">$varname</font><font color="#007700">] = </font><font color="#0000BB">$varvalue</font><font color="#007700">;<br /> }<br />}<br /><br />print </font><font color="#DD0000">"<pre>"</font><font color="#007700">;<br />if (empty(</font><font color="#0000BB">$empty</font><font color="#007700">)) {<br /> print </font><font color="#DD0000">"None of the POSTed values are empty, posted:\n"</font><font color="#007700">;<br /> </font><font color="#0000BB">var_dump</font><font color="#007700">(</font><font color="#0000BB">$post</font><font color="#007700">);<br />} else {<br /> print </font><font color="#DD0000">"We have " </font><font color="#007700">. </font><font color="#0000BB">count</font><font color="#007700">(</font><font color="#0000BB">$empty</font><font color="#007700">) . </font><font color="#DD0000">" empty values\n"</font><font color="#007700">;<br /> print </font><font color="#DD0000">"Posted:\n"</font><font color="#007700">; </font><font color="#0000BB">var_dump</font><font color="#007700">(</font><font color="#0000BB">$post</font><font color="#007700">);<br /> print </font><font color="#DD0000">"Empty:\n"</font><font color="#007700">; </font><font color="#0000BB">var_dump</font><font color="#007700">(</font><font color="#0000BB">$empty</font><font color="#007700">);<br /> exit;<br />}<br /></font><font color="#0000BB">?></font> </font> </code></TD ></TR ></TABLE > </P ><DIV CLASS="note" ><BLOCKQUOTE CLASS="note" ><P ><B >Disponibilidade das superglobais:: </B >Desde o PHP 4.1.0, os arrays superglobais como <CODE CLASS="varname" >$_GET </CODE >, <CODE CLASS="varname" >$_POST</CODE >, <CODE CLASS="varname" >$_SERVER</CODE >, etc. sempre estão carregados. Para mais informações, leia a seção do manual sobre <A HREF="language.variables.predefined.html" >superglobals</A ></P ></BLOCKQUOTE ></DIV ></DIV ></DIV ><DIV CLASS="qandaentry" ><B ><DIV CLASS="question" ><P ><A NAME="faq.using.addslashes" ></A ><B >2. </B > I need to convert all single-quotes (') to a backslash followed by a single-quote (\'). How can I do this with a regular expression? I'd also like to convert " to \" and \ to \\. </P ></DIV ></B ><DIV CLASS="answer" ><P ><B > </B > The function <A HREF="function.addslashes.html" ><B CLASS="function" >addslashes()</B ></A > will do this. See also <A HREF="function.mysql-escape-string.html" ><B CLASS="function" >mysql_escape_string()</B ></A >. You may also strip backslashes with <A HREF="function.stripslashes.html" ><B CLASS="function" >stripslashes()</B ></A >. </P ><DIV CLASS="note" ><BLOCKQUOTE CLASS="note" ><P ><B >Nota sobre a diretiva magic_quotes_gpc:: </B >A diretiva do PHP <A HREF="ref.info.html#ini.magic-quotes-gpc" > magic_quotes_gpc</A > tem default <TT CLASS="literal" >on</TT >. Ela essencialmente roda <A HREF="function.addslashes.html" ><B CLASS="function" >addslashes()</B ></A > em todos os dados postados por GET, POST e COOKIEs. Você pode utilizar <A HREF="function.stripslashes.html" ><B CLASS="function" >stripslashes()</B ></A > para reverter isso.</P ></BLOCKQUOTE ></DIV ></DIV ></DIV ><DIV CLASS="qandaentry" ><B ><DIV CLASS="question" ><P ><A NAME="faq.using.stripslashes" ></A ><B >3. </B > All my " turn into \" and my ' turn into \', how do I get rid of all these unwanted backslashes? How and why did they get there? </P ></DIV ></B ><DIV CLASS="answer" ><P ><B > </B > The PHP function <A HREF="function.stripslashes.html" ><B CLASS="function" >stripslashes()</B ></A > will strip those backslashes from your <A HREF="language.types.string.html" ><B CLASS="type" >string</B ></A >. Most likely the backslashes magically exist because the PHP directive <A HREF="ref.info.html#ini.magic-quotes-gpc" >magic_quotes_gpc</A > is on. </P ><DIV CLASS="note" ><BLOCKQUOTE CLASS="note" ><P ><B >Nota sobre a diretiva magic_quotes_gpc:: </B >A diretiva do PHP <A HREF="ref.info.html#ini.magic-quotes-gpc" > magic_quotes_gpc</A > tem default <TT CLASS="literal" >on</TT >. Ela essencialmente roda <A HREF="function.addslashes.html" ><B CLASS="function" >addslashes()</B ></A > em todos os dados postados por GET, POST e COOKIEs. Você pode utilizar <A HREF="function.stripslashes.html" ><B CLASS="function" >stripslashes()</B ></A > para reverter isso.</P ></BLOCKQUOTE ></DIV ></DIV ></DIV ><DIV CLASS="qandaentry" ><B ><DIV CLASS="question" ><P ><A NAME="faq.using.wrong-order" ></A ><B >4. </B > When I do the following, the output is printed in the wrong order: <TABLE BORDER="0" BGCOLOR="#E0E0E0" CELLPADDING="5" ><TR ><TD ><code><font color="#000000"> <font color="#0000BB"><?php<br /></font><font color="#007700">function </font><font color="#0000BB">myfunc</font><font color="#007700">(</font><font color="#0000BB">$argument</font><font color="#007700">)<br />{<br /> echo </font><font color="#0000BB">$argument </font><font color="#007700">+ </font><font color="#0000BB">10</font><font color="#007700">;<br />}<br /></font><font color="#0000BB">$variable </font><font color="#007700">= </font><font color="#0000BB">10</font><font color="#007700">;<br />echo </font><font color="#DD0000">"myfunc($variable) = " </font><font color="#007700">. </font><font color="#0000BB">myfunc</font><font color="#007700">(</font><font color="#0000BB">$variable</font><font color="#007700">);<br /></font><font color="#0000BB">?></font> </font> </code></TD ></TR ></TABLE > what's going on? </P ></DIV ></B ><DIV CLASS="answer" ><P ><B > </B > To be able to use the results of your function in an expression (such as concatenating it with other strings in the example above), you need to <A HREF="function.return.html" ><B CLASS="function" >return()</B ></A > the value, not <A HREF="function.echo.html" ><B CLASS="function" >echo()</B ></A > it. </P ></DIV ></DIV ><DIV CLASS="qandaentry" ><B ><DIV CLASS="question" ><P ><A NAME="faq.using.newlines" ></A ><B >5. </B > Hey, what happened to my newlines? <TABLE BORDER="0" BGCOLOR="#E0E0E0" CELLPADDING="5" ><TR ><TD ><code><font color="#000000"> <pre><br /><font color="#0000BB"><?php </font><font color="#007700">echo </font><font color="#DD0000">"This should be the first line."</font><font color="#007700">; </font><font color="#0000BB">?><br /><?php </font><font color="#007700">echo </font><font color="#DD0000">"This should show up after the new line above."</font><font color="#007700">; </font><font color="#0000BB">?><br /></font></pre></font> </code></TD ></TR ></TABLE > </P ></DIV ></B ><DIV CLASS="answer" ><P ><B > </B > In PHP, the ending for a block of code is either "?>" or "?>\n" (where \n means a newline). So in the example above, the echoed sentences will be on one line, because PHP omits the newlines after the block ending. This means that you need to insert an extra newline after each block of PHP code to make it print out one newline. </P ><P > Why does PHP do this? Because when formatting normal HTML, this usually makes your life easier because you don't want that newline, but you'd have to create extremely long lines or otherwise make the raw page source unreadable to achieve that effect. </P ></DIV ></DIV ><DIV CLASS="qandaentry" ><B ><DIV CLASS="question" ><P ><A NAME="faq.using.headers-sent" ></A ><B >6. </B > I get the message 'Warning: Cannot send session cookie - headers already sent...' or 'Cannot add header information - headers already sent...'. </P ></DIV ></B ><DIV CLASS="answer" ><P ><B > </B > The functions <A HREF="function.header.html" ><B CLASS="function" >header()</B ></A >, <A HREF="function.setcookie.html" ><B CLASS="function" >setcookie()</B ></A >, and the <A HREF="ref.session.html" >session functions</A > need to add headers to the output stream but headers can only be sent before all other content. There can be no output before using these functions, output such as HTML. The function <B CLASS="function" > headers_sent()</B > will check if your script has already sent headers and see also the <A HREF="ref.outcontrol.html" >Output Control functions</A >. </P ></DIV ></DIV ><DIV CLASS="qandaentry" ><B ><DIV CLASS="question" ><P ><A NAME="faq.using.header" ></A ><B >7. </B > I need to access information in the request header directly. How can I do this? </P ></DIV ></B ><DIV CLASS="answer" ><P ><B > </B > The <A HREF="function.getallheaders.html" ><B CLASS="function" >getallheaders()</B ></A > function will do this if you are running PHP as an Apache module. So, the following bit of code will show you all the request headers: <TABLE BORDER="0" BGCOLOR="#E0E0E0" CELLPADDING="5" ><TR ><TD ><code><font color="#000000"> <font color="#0000BB"><?php<br />$headers </font><font color="#007700">= </font><font color="#0000BB">getallheaders</font><font color="#007700">();<br />foreach (</font><font color="#0000BB">$headers </font><font color="#007700">as </font><font color="#0000BB">$name </font><font color="#007700">=> </font><font color="#0000BB">$content</font><font color="#007700">) {<br /> echo </font><font color="#DD0000">"headers</font><font color="#007700">[</font><font color="#DD0000">$name</font><font color="#007700">]</font><font color="#DD0000"> = $content<br /></font><font color="#007700">\n</font><font color="#DD0000">"</font><font color="#007700">;<br />}<br /></font><font color="#0000BB">?></font> </font> </code></TD ></TR ></TABLE > </P ><P > See also <A HREF="function.apache-lookup-uri.html" ><B CLASS="function" >apache_lookup_uri()</B ></A >, <A HREF="function.apache-response-headers.html" ><B CLASS="function" >apache_response_headers()</B ></A >, and <A HREF="function.fsockopen.html" ><B CLASS="function" >fsockopen()</B ></A > </P ></DIV ></DIV ><DIV CLASS="qandaentry" ><B ><DIV CLASS="question" ><P ><A NAME="faq.using.authentication" ></A ><B >8. </B > When I try to use authentication with IIS I get 'No Input file specified'. </P ></DIV ></B ><DIV CLASS="answer" ><P ><B > </B > The security model of IIS is at fault here. This is a problem common to all CGI programs running under IIS. A workaround is to create a plain HTML file (not parsed by PHP) as the entry page into an authenticated directory. Then use a META tag to redirect to the PHP page, or have a link to the PHP page. PHP will then recognize the authentication correctly. With the ISAPI module, this is not a problem. This should not effect other NT web servers. For more information, see: <A HREF="http://support.microsoft.com/kb/q160422/" TARGET="_top" >http://support.microsoft.com/kb/q160422/</A > and the manual section on <A HREF="features.http-auth.html" >HTTP Authentication </A >. </P ></DIV ></DIV ><DIV CLASS="qandaentry" ><B ><DIV CLASS="question" ><P ><A NAME="faq.using.iis.sharing" ></A ><B >9. </B > Windows: I can't access files shared on another computer using IIS </P ></DIV ></B ><DIV CLASS="answer" ><P ><B > </B > You have to change the <TT CLASS="literal" >Go to Internet Information Services</TT >. Locate your PHP file and go to its properties. Go to the <TT CLASS="literal" >File Security</TT > tab, <TT CLASS="literal" >Edit -< Anonymous access and authentication control</TT >. </P ><P > You can fix the problem either by unticking <TT CLASS="literal" >Anonymous Access</TT > and leaving <TT CLASS="literal" >Integrated Window Authentication</TT > ticked, or, by ticking <TT CLASS="literal" >Anonymous Access</TT > and editing the user as he may not have the access right. </P ></DIV ></DIV ><DIV CLASS="qandaentry" ><B ><DIV CLASS="question" ><P ><A NAME="faq.using.netscape" ></A ><B >10. </B > My PHP script works on IE and Lynx, but on Netscape some of my output is missing. When I do a "View Source" I see the content in IE but not in Netscape. </P ></DIV ></B ><DIV CLASS="answer" ><P ><B > </B > Netscape is more strict regarding HTML tags (such as tables) then IE. Running your HTML output through a HTML validator, such as <A HREF="http://validator.w3.org/" TARGET="_top" >validator.w3.org</A >, might be helpful. For example, a missing </table> might cause this. </P ><P > Also, both IE and Lynx ignore any NULs (<TT CLASS="literal" >\0</TT >) in the HTML stream, Netscape does not. The best way to check for this is to compile the <A HREF="features.commandline.html" >command line</A > version of PHP (also known as the CGI version) and run your script from the command line. In *nix, pipe it through <TT CLASS="literal" >od -c</TT > and look for any <TT CLASS="literal" >\0</TT > characters. If you are on Windows you need to find an editor or some other program that lets you look at binary files. When Netscape sees a NUL in a file it will typically not output anything else on that line whereas both IE and Lynx will. </P ></DIV ></DIV ><DIV CLASS="qandaentry" ><B ><DIV CLASS="question" ><P ><A NAME="faq.using.mixml" ></A ><B >11. </B > How am I supposed to mix XML and PHP? It complains about my <?xml tags! </P ></DIV ></B ><DIV CLASS="answer" ><P ><B > </B > In order to embed <?xml straight into your PHP code, you'll have to turn off short tags by having the PHP directive <A HREF="ini.core.html#ini.short-open-tag" >short_open_tags</A > set to <TT CLASS="literal" >0</TT >. You cannot set this directive with <B CLASS="function" > ini_set()</B >. Regardless of <A HREF="ini.core.html#ini.short-open-tag" > short_open_tags</A > being on or off, you can do something like: <TT CLASS="literal" ><?php echo '<?xml'; ?></TT >. The default for this directive is on. </P ></DIV ></DIV ><DIV CLASS="qandaentry" ><B ><DIV CLASS="question" ><P ><A NAME="faq.using.editor" ></A ><B >12. </B > How can I use PHP with FrontPage or some other HTML editor that insists on moving my code around? </P ></DIV ></B ><DIV CLASS="answer" ><P ><B > </B > One of the easiest things to do is to enable using ASP tags in your PHP code. This allows you to use the ASP-style <% and %> code delimiters. Some of the popular HTML editors handle those more intelligently (for now). To enable the ASP-style tags, you need to set the <A HREF="ini.core.html#ini.asp-tags" >asp_tags</A > <TT CLASS="filename" >php.ini</TT > variable, or use the appropriate Apache directive. </P ></DIV ></DIV ><DIV CLASS="qandaentry" ><B ><DIV CLASS="question" ><P ><A NAME="faq.using.variables" ></A ><B >13. </B > Where can I find a complete list of variables are available to me in PHP? </P ></DIV ></B ><DIV CLASS="answer" ><P ><B > </B > Read the manual page on <A HREF="language.variables.predefined.html" > predefined variables</A > as it includes a partial list of predefined variables available to your script. A complete list of available variables (and much more information) can be seen by calling the <A HREF="function.phpinfo.html" ><B CLASS="function" >phpinfo()</B ></A > function. Be sure to read the manual section on <A HREF="language.variables.external.html" >variables from outside of PHP</A > as it describes common scenarios for external variables, like from a HTML form, a Cookie, and the URL. </P ><DIV CLASS="note" ><BLOCKQUOTE CLASS="note" ><P ><B >Nota importante sobre register_globals:: </B >Desde o PHP 4.2.0, o valor padrão para a diretiva <A HREF="ini.core.html#ini.register-globals" >register_globals</A > é <SPAN CLASS="emphasis" ><I CLASS="emphasis" > off</I ></SPAN > e foi completamente removida a partir do PHP 6.0.0. A comunidade do PHP encoraja a todos a não depender desta configuração mas ao invés usar outros meios, como, por exemplo, <A HREF="language.variables.predefined.html" >superglobals</A >. </P ></BLOCKQUOTE ></DIV ></DIV ></DIV ><DIV CLASS="qandaentry" ><B ><DIV CLASS="question" ><P ><A NAME="faq.using.freepdf" ></A ><B >14. </B > How can I generate PDF files without using the non-free and commercial libraries <A HREF="ref.cpdf.html" >ClibPDF</A > and <A HREF="ref.pdf.html" >PDFLib</A >? I'd like something that's free and doesn't require external PDF libraries. </P ></DIV ></B ><DIV CLASS="answer" ><P ><B > </B > There are a few alternatives written in PHP such as <A HREF="http://www.ros.co.nz/pdf/" TARGET="_top" >http://www.ros.co.nz/pdf/</A >, <A HREF="http://www.fpdf.org/" TARGET="_top" >http://www.fpdf.org/</A >, <A HREF="http://www.gnuvox.com/pdf4php/" TARGET="_top" >http://www.gnuvox.com/pdf4php/</A >, and <A HREF="http://www.potentialtech.com/ppl.php" TARGET="_top" >http://www.potentialtech.com/ppl.php</A >. There is also the <A HREF="http://www.stillhq.com/cgi-bin/getpage?area=panda" TARGET="_top" >Panda</A > module. </P ></DIV ></DIV ><DIV CLASS="qandaentry" ><B ><DIV CLASS="question" ><P ><A NAME="faq.using.cgi-vars" ></A ><B >15. </B > I'm trying to access one of the standard CGI variables (such as $DOCUMENT_ROOT or $HTTP_REFERER) in a user-defined function, and it can't seem to find it. What's wrong? </P ></DIV ></B ><DIV CLASS="answer" ><P ><B > </B > It's important to realize that the PHP directive <A HREF="ini.core.html#ini.register-globals" >register_globals</A > also affects server and environment variables. When register_globals = off (the default is off since PHP 4.2.0), <CODE CLASS="varname" >$DOCUMENT_ROOT</CODE > will not exist. Instead, use <CODE CLASS="varname" >$_SERVER['DOCUMENT_ROOT'] </CODE >. If register_globals = on then the variables <CODE CLASS="varname" >$DOCUMENT_ROOT</CODE > and <CODE CLASS="varname" >$GLOBALS['DOCUMENT_ROOT']</CODE > will also exist. </P ><P > If you're sure register_globals = on and wonder why <CODE CLASS="varname" >$DOCUMENT_ROOT</CODE > isn't available inside functions, it's because these are like any other variables and would require <TT CLASS="literal" >global $DOCUMENT_ROOT</TT > inside the function. See also the manual page on <A HREF="language.variables.scope.html" >variable scope</A >. It's preferred to code with register_globals = off. </P ><DIV CLASS="note" ><BLOCKQUOTE CLASS="note" ><P ><B >Disponibilidade das superglobais:: </B >Desde o PHP 4.1.0, os arrays superglobais como <CODE CLASS="varname" >$_GET </CODE >, <CODE CLASS="varname" >$_POST</CODE >, <CODE CLASS="varname" >$_SERVER</CODE >, etc. sempre estão carregados. Para mais informações, leia a seção do manual sobre <A HREF="language.variables.predefined.html" >superglobals</A ></P ></BLOCKQUOTE ></DIV ></DIV ></DIV ><DIV CLASS="qandaentry" ><B ><DIV CLASS="question" ><P ><A NAME="faq.using.shorthandbytes" ></A ><B >16. </B > A few PHP directives may also take on shorthand byte values, as opposed to only <A HREF="language.types.integer.html" ><B CLASS="type" >integer</B ></A > byte values. What are all the available shorthand byte options? And can I use these outside of <TT CLASS="filename" >php.ini</TT >? </P ></DIV ></B ><DIV CLASS="answer" ><P ><B > </B > The available options are K (for Kilobytes), M (for Megabytes) and G (for Gigabytes; available since PHP 5.1.0), these are case insensitive. Anything else assumes bytes. <TT CLASS="literal" >1M</TT > equals one Megabyte or <TT CLASS="literal" >1048576</TT > bytes. <TT CLASS="literal" >1K</TT > equals one Kilobyte or <TT CLASS="literal" >1024</TT > bytes. You may not use these shorthand notations outside of <TT CLASS="filename" >php.ini</TT >, instead use an <A HREF="language.types.integer.html" ><B CLASS="type" >integer</B ></A > value of bytes. See the <A HREF="function.ini-get.html" ><B CLASS="function" >ini_get()</B ></A > documentation for an example on how to convert these values. </P ></DIV ></DIV ></DIV ></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="faq.build.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="faq.html.html" ACCESSKEY="N" >Próxima</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >Build Problems</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="faq.html" ACCESSKEY="U" >Acima</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >PHP and HTML</TD ></TR ></TABLE ></DIV ></BODY ></HTML >