PHP Notes Plus

Here are some basic PHP expressions and statements for ez reference..

Common Statements:

"\n" = new line
"\t" = tab
"\r" = carriage return
"\$" = dollar sign
"\"" = double quote

Example usage:

"\n\t<category>$category->cat_name</category>"
echo '<!-- Category LiveBookmarks Plugin by Monzilla Media ( monzilla.biz ) -->' . "\n";
echo "\n\t<!-- Pink Floyd " . " Meddle -->\n\n";

echo Multiple Lines of Code

echo <<<END
   ... line of code ...
   ... line of code ...
   ... line of code ...
END;

Example usage (this plugin (404 link removed 2013/10/15) code effectively inserts the given CSS rule into the head region of WP Admin documents):

<?php 
   function hide_post_preview() {
      echo <<<END
         <style type="text/css">
            #preview {
               display: none;
            }
         </style>
      END;
   }
   add_action('admin_head', 'hide_post_preview');
?>

Determine System Path:

After preparing a .php file with the following line of code, upload it to the target directory and open with your favorite browser:

<?php echo dirname(__FILE__); ?>

Access PHP System Information:

After preparing a .php file with the following line of code, upload it to the target directory and open with your favorite browser:

<?php phpinfo() ?>

Determine Absolute Path

An absolute path, or full path, refers to the static location of a resource as it exists relative to the root directory within a computer’s file system. A directory’s absolute path is universal and is independent of any relative working directory, dynamic variables, or combined paths. An absolute path includes the root directory and "descending series of subdirectories leading to the end file" (2012/05/04: 404 link removed).

Here is a mighty handy PHP script that provides a simple method of determing the absolute path of a directory. Simply save this script as a file called "absolutepath.php" and upload it to the location for which you wish to determine the absolute (server) path.

The absolute path will appear when you point your browser to the location of the file, absolutepath.php. To determine the absolute path of a different directory, simply move the absolutepath.php file to that directory and go to that location with your browser.

<?php echo $_SERVER['DOCUMENT_ROOT']; ?>