The example here is if you had a form on a website that when submitted, needed to use that information to go to a special URL where the login information was all appeneded to the URL. You could have the form post with method GET, but that is limited to the typical ?variable=foo&variable2=bar format.
HTML Form
Typical form with three bits of information that submits to a file called ftp.php
<form action="../processing/ftp.php" method="post">
<p><label for="ftp-company-name">Company</label><input type="text" name="ftp-company-name" id="ftp-company-name" /></p>
<p><label for="ftp-user-name">User Name</label><input type="text" name="ftp-user-name" id="ftp-user-name" /></p>
<p><label for="ftp-password">Password</label><input type="password" name="ftp-password" id="ftp-password" /></p>
<p><input type="submit" id="ftp-submit" class="button" value="submit" /></p>
</form>
PHP file
This file reads in the POST variables (if they are set), builds the URL from them, and redirects to it. You'd probably want to clean up the POST variables for security purposes.
<?php
if (isset($_POST["ftp-company-name"])) {
$company = $_POST["ftp-company-name"];
$username = $_POST["ftp-user-name"];
$password = $_POST["ftp-password"];
$url = "ftp://$username:$password@ftp2.edgeconsult.com/$company";
header( "Location: $url" ) ;
} else {
// do nothing
}
?>