Cleaning strings by removing anything that is not a letter or number can be very useful, like building clean URLs based on customer data.

This will replace anything that isn’t a letter, number or space. Then, you can further clean the spaces by replacing with dashes (“-“) for better URL readability.

$stringToClean = preg_replace("/[^a-zA-Z 0-9]+/", "", $stringToClean);

Note that “preg_replace” uses the REGEX patterns and matching rules which is also used in .htaccess files. If sometimes you struggle with getting REGEX right, visit this excellent REGEX Cheatsheet: http://www.cheatography.com/davechild/cheat-sheets/regular-expressions/

Here is a typical way to send PHP data to another script and have that data returned via CURL POST. Keep in mind there are a lot of server security restrictions that may impede CURL from working properly. Visit the PHP cURL book to learn more.

function curlPost ($url,$valsArr)
{
   //create name / value pairs
   foreach($valsArr as $key => $val)
   {
      $postDataArr[]= $key . ‘=’.$val;
   }

$postData=implode("&",$postDataArr);

$ch = curl_init();

curl_setopt($ch,CURLOPT_URL,$url);
curl_setopt($ch,CURLOPT_RETURNTRANSFER,true);
curl_setopt($ch,CURLOPT_HEADER, false);
curl_setopt($ch, CURLOPT_POST, count($postData));
curl_setopt($ch, CURLOPT_POSTFIELDS, $postData);

$output=curl_exec($ch);

curl_close($ch);
return $output;

}

// Call function like so:

$valsArr = array(
   “sampleField1” => “value1”,
   “sampleField2” => “value2″,
   “sampleField3” => “value3”
);

echo curlPost(“http://www.prolificfutility.com/path-to-curlPost.php”,$valsArr);

This is always something that seems to be overcomplicated, if you generate PDFs or other files and use some form of AJAX to call that file, how do you force the user’s browser to treat the link as an attachment for them to save on their computer? You have to make sure the script hasn’t sent any output and send the headers along with the file data in the following sequence:

// "pdf" can be any other type of valid file
header('Content-type: application/pdf');

// File will be called "document.pdf"
header('Content-Disposition: attachment; filename="document.pdf"');

// The actual PDF file on the server can be called anything.  This is a clever way to obfuscate the real file name from the public, by using a different naming convention.

readfile('/path/to/source/file.pdf');