Follow this lesson in Ullman Chapter 8. The scripts are located in the 08 directory.
if (isset ($_POST[‘submit’])) {
//Handle the form
….
}
See Ullman page 198.
<?php
include (‘../../../dbcon.php’);
….
?>Included files are “brought in” to the current file. If include() fails, PHP simply generates a warning (which is visible to visitors on the web).
<?php
require (‘../../../dbcon.php’);
….
?>Required files are also “brought in” to the current file. But if require() fails, PHP stops execution of the script.
See also include_once() and require_once().
You can’t change it after you set it!
define (‘CONSTANT’, ‘value);
for instance:
define (‘PI’, 3.1416);
Constants DO NOT USE THE $:
print PI;
Constants WON’T PRINT WITHIN ANY QUOTATION MARKS. Use concatenation to print them:
print ‘Pi equals ‘ . PI;
defined(‘PI’) //returns TRUE
defined(‘foo’) //returns FALSESee Ullman page 207 for this usage.
PHP_VERSION
PHP_OS
date(‘format’)
See Ullman page 209 for format options
time()
mktime()
if(isset($_POST[‘submit’])) {
//Then handle the form
} else {
//Display the form here
}
See Ullman’s register.php script for the full text.
// Display the form.
print ‘<form action=”register.php” method=”post”><p>’;print ‘Username: <input type=”text” name=”username” size=”20″ value=”‘ . $_POST[‘username’] . ‘” /><br />’;
mail ( ’email_address’, ‘subject’, ‘message’);
Life will be much easier if you populate a variable with the message, and use that variable as the third parameter.
This function simply sends the output of your page/script to a buffer, so that time-sensitive functions like session_start() won’t run until ready.
Place this at the very top of your code, before everything, including <html> and <head> elements:
<?php
ob_start();
?>Place this at the very end of your code, after everything, including the </body> and </html> elements:
<?php
ob_end_flush();
?><?php
ob_end_clean();
?>Either of these last two turn off buffering.
See Ullman page 231 for other buffer functions.
Header functions must be called before anything else is sent to the browser!
The most frequent use is for redirecting the user to a new page:
header(‘Location: some_page.php);
exit();
Review Chapter 8 of Ullman.