<?php
define('DB_HOST', 'localhost');
define('DB_USER', 'root');
define('DB_PASS', '');
define('DB_NAME', 'database');
define('DB_TABLE', 'table');

$db = mysql_connect(DB_HOST, DB_USER, DB_PASS) or die('Could not connect to MySQL server.');
mysql_select_db(DB_NAME, $db) or die('Could not connect to MySQL database.');

if ($result = mysql_query('EXPLAIN `'.DB_TABLE.'`', $db))
{
    echo '<pre>';
    $widths = array // Column names and widths (number of spaces)
    (    'Field'   => 20
    ,    'Type'    => 12
    ,    'Null'    => 4
    ,    'Key'     => 3
    ,    'Default' => 7
    ,    'Extra'   => 14
    );
    $margin = 2; // Number of spaces between columns
    // Displays column headings
    foreach ($widths as $field => $width)
    {
        /*
         * Limits the width of the column. If the contents are wider than the
         * column, the full contents can be displayed by hovering the mouse
         * over the cell
         */
        echo '<span title="'.$field.'">';
        if (strlen($field) > $width)
            $field = substr($field, 0, $width - 1).'…';
        echo '<b>'.str_pad($field, $width + $margin, ' ', STR_PAD_RIGHT).'</b></span>';
    }
    echo "\n";
    // Displays a row for each explained field containing name, type, etc.
    while ($row = mysql_fetch_assoc($result))
    {
        // Displays each column for the current row
        foreach ($widths as $field => $width)
        {
            // Similar to the previous foreach loop
            echo '<span title="'.$row[$field].'">';
            if (strlen($row[$field]) > $width)
                $row[$field] = substr($row[$field], 0, $width - 1).'…';
            echo str_pad($row[$field], $width + $margin, ' ', STR_PAD_RIGHT).'</span>';
        }
        echo "\n";
    }
    echo '</pre>';
}
else
    echo 'Explain query failed.';
?>