<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>Common Functions : CodeIgniter User Guide</title> <style type='text/css' media='all'>@import url('../userguide.css');</style> <link rel='stylesheet' type='text/css' media='all' href='../userguide.css' /> <script type="text/javascript" src="../nav/nav.js"></script> <script type="text/javascript" src="../nav/prototype.lite.js"></script> <script type="text/javascript" src="../nav/moo.fx.js"></script> <script type="text/javascript" src="../nav/user_guide_menu.js"></script> <meta http-equiv='expires' content='-1' /> <meta http-equiv= 'pragma' content='no-cache' /> <meta name='robots' content='all' /> <meta name='author' content='ExpressionEngine Dev Team' /> <meta name='description' content='CodeIgniter User Guide' /> </head> <body> <!-- START NAVIGATION --> <div id="nav"><div id="nav_inner"><script type="text/javascript">create_menu('../');</script></div></div> <div id="nav2"><a name="top"></a><a href="javascript:void(0);" onclick="myHeight.toggle();"><img src="../images/nav_toggle_darker.jpg" width="154" height="43" border="0" title="Toggle Table of Contents" alt="Toggle Table of Contents" /></a></div> <div id="masthead"> <table cellpadding="0" cellspacing="0" border="0" style="width:100%"> <tr> <td><h1>CodeIgniter User Guide Version 2.0.0</h1></td> <td id="breadcrumb_right"><a href="../toc.html">Table of Contents Page</a></td> </tr> </table> </div> <!-- END NAVIGATION --> <!-- START BREADCRUMB --> <table cellpadding="0" cellspacing="0" border="0" style="width:100%"> <tr> <td id="breadcrumb"> <a href="http://codeigniter.com/">CodeIgniter Home</a> › <a href="../index.html">User Guide Home</a> › Auto-loading Resources </td> <td id="searchbox"><form method="get" action="http://www.google.com/search"><input type="hidden" name="as_sitesearch" id="as_sitesearch" value="codeigniter.com/user_guide/" />Search User Guide <input type="text" class="input" style="width:200px;" name="q" id="q" size="31" maxlength="255" value="" /> <input type="submit" class="submit" name="sa" value="Go" /></form></td> </tr> </table> <!-- END BREADCRUMB --> <br clear="all" /> <!-- START CONTENT --> <div id="content"> <h1>Common Functions</h1> <p>CodeIgniter uses a few functions for its operation that are globally defined, and are available to you at any point. These do not require loading any libraries or helpers.</p> <h2>is_php('<var>version_number</var>')</h2> <p>is_php() determines of the PHP version being used is greater than the supplied <var>version_number</var>.</p> <code>if (is_php('5.3.0'))<br /> {<br /> $str = quoted_printable_encode($str);<br /> }</code> <p>Returns boolean <kbd>TRUE</kbd> if the installed version of PHP is equal to or greater than the supplied version number. Returns <kbd>FALSE</kbd> if the installed version of PHP is lower than the supplied version number.</p> <h2>is_really_writable('<var>path/to/file</var>')</h2> <p>is_writable() returns TRUE on Windows servers when you really can't write to the file as the OS reports to PHP as FALSE only if the read-only attribute is marked. This function determines if a file is actually writable by attempting to write to it first. Generally only recommended on platforms where this information may be unreliable.</p> <code>if (is_really_writable('file.txt'))<br /> {<br /> echo "I could write to this if I wanted to";<br /> }<br /> else<br /> {<br /> echo "File is not writable";<br /> }</code> <h2>config_item('<var>item_key</var>')</h2> <p>The <a href="../libraries/config.html">Config library</a> is the preferred way of accessing configuration information, however config_item() can be used to retrieve single keys. See Config library documentation for more information.</p> <h2>show_error('<var>message</var>'), show_404('<var>page</var>'), log_message('<var>level</var>', '<samp>message</samp>')</h2> <p>These are each outlined on the <a href="errors.html">Error Handling</a> page.</p> <h2>set_status_header(<var>code</var>, '<var>text</var>');</h2> <p>Permits you to manually set a server status header. Example:</p> <code>set_status_header(401);<br /> // Sets the header as: Unauthorized</code> <p><a href="http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html">See here</a> for a full list of headers.</p> <h2>remove_invisible_characters(<var>$str</var>)</h2> <p>This function prevents inserting null characters between ascii characters, like Java\0script.</p> </div> <!-- END CONTENT --> <div id="footer"> <p> Previous Topic: <a href="autoloader.html">Auto-loading Resources</a><a href="hooks.html"></a> · <a href="#top">Top of Page</a> · <a href="../index.html">User Guide Home</a> · Next Topic: <a href="routing.html">URI Routing</a></p> <p><a href="http://codeigniter.com">CodeIgniter</a> · Copyright © 2006-2010 · <a href="http://ellislab.com/">EllisLab, Inc.</a></p> </div> </body> </html>