First you will want to get the S3 PHP library from Amazon. Then you add the following to the file:

/**
 * putObjectStream -- Streams data to a bucket.
 *
 * Takes ($bucket, $key, $streamFunction, $contentType, $contentLength [,$acl, $metadataArray, $md5])
 *
 *
 * - [str] $bucket: the bucket into which file will be written
 * - [str] $key: key of written file
 * - [str] $streamFunction: function to call for data to stream
 * - [str] $contentType: file content type
 * - [str] $contentLength: file content length
 * - [str] $acl: access control policy of file (OPTIONAL: defaults to 'private')
 * - [str] $metadataArray: associative array containing user-defined metadata (name=>value) (OPTIONAL)
 * - [bool] $md5: the MD5 hash of the object (OPTIONAL)
*/
function putObjectStream($bucket, $key, $streamFunction, $contentType, $contentLength, $acl, $metadataArray, $md5){
        sort($metadataArray);
        $resource = "$bucket/$key";
        $resource = urlencode($resource);
        $httpDate = gmdate("D, d M Y G:i:s T");

        $curl_inst = curl_init();

        curl_setopt ($curl_inst, CURLOPT_CONNECTTIMEOUT, 30);
        curl_setopt ($curl_inst, CURLOPT_LOW_SPEED_LIMIT, 1);
        curl_setopt ($curl_inst, CURLOPT_LOW_SPEED_TIME, 180);
        curl_setopt ($curl_inst, CURLOPT_NOSIGNAL, 1);
        curl_setopt ($curl_inst, CURLOPT_READFUNCTION, $streamFunction);
        curl_setopt ($curl_inst, CURLOPT_URL, $this->serviceUrl . $resource);
        curl_setopt ($curl_inst, CURLOPT_UPLOAD, true);
        curl_setopt ($curl_inst, CURLINFO_CONTENT_LENGTH_UPLOAD, $contentLength);

        $header[] = "Date: $httpDate";
        $header[] = "Content-Type: $contentType";
        $header[] = "Content-Length: $contentLength";
        $header[] = "Expect: ";
        $header[] = "Transfer-Encoding: ";
        $header[] = "x-amz-acl: $acl";

        $MD5 = "";
        if($md5){
                $MD5 = $this->hex2b64(md5_file($filePath));
                $header[] = "Content-MD5: $MD5";
        }

        $stringToSign="PUT\n$MD5\n$contentType\n$httpDate\nx-amz-acl:$acl\n";
        foreach($metadataArray as $current){
                if($current!=""){
                        $stringToSign.="x-amz-meta-$current\n";
                        $header = substr($current,0,strpos($current,':'));
                        $meta = substr($current,strpos($current,':')+1,strlen($current));
                        $header[] = "x-amz-meta-$header: $meta";
                }
        }

        $stringToSign.="/$resource";

        $signature = $this->constructSig($stringToSign);

        $header[] = "Authorization: AWS $this->accessKeyId:$signature";

        curl_setopt($curl_inst, CURLOPT_HTTPHEADER, $header);
        curl_setopt($curl_inst, CURLOPT_RETURNTRANSFER, 1);

        $result = curl_exec ($curl_inst);

        $this->responseString = $result;
        $this->responseCode = curl_getinfo($curl_inst, CURLINFO_HTTP_CODE);

        curl_close($curl_inst);
}

Now you have an updated s3.php you are ready to start streaming. Be aware that the content length value needs to be correct. If it is not the correct size your upload will be either truncated (too short) or it will hang (too long). If it hangs the S3 service will timeout after a small amount of time and give you an error.

Here are two examples of how to use it. First with a file:

<?php

include 's3.php';

class MyClass
{
  var $data;

  function stream_function($handle, $fd, $length)
  {
    return fread($this->data, $length);
  }
}

$my_class_inst = new MyClass();

$fsize = filesize("/tmp/largefile.tar.gz");

$my_class_inst->data = fopen("/tmp/largefile.tar.gz", "r");

$s3_inst = new s3("access key", "private key");
$s3_inst->putObjectStream("abucket", "largefile.tar.gz", array($my_class_inst, "stream_function"), "application/x-gzip", $fsize, "public-read", array(), null);

print "Response String: " . $s3_inst->responseString . "\n";
print "Response Code: " . $s3_inst->responseCode . "\n";
print "Parsed XML: " . $s3_inst->parsed_xml . "\n";

fclose($my_class_inst->data);

?>

Another example of streaming some random text:

<?php

include 's3.php';

class MyClass
{
  var $data;

  function stream_function($handle, $fd, $length)
  {
    return $this->data;
  }
}

$my_class_inst = new MyClass();

$my_class_inst->data = "A test string";
$size = strlen($my_class_inst->data);

$s3_inst = new s3("access key", "private key");
$s3_inst->putObjectStream("bucketname", "test.txt", array($my_class_inst, "stream_function"), "text/html", $size, "public-read", array(), null);

print "Response String: " . $s3_inst->responseString . "\n";
print "Response Code: " . $s3_inst->responseCode . "\n";
print "Parsed XML: " . $s3_inst->parsed_xml . "\n";

?>

To clear up the expiration time issue I think these two steps are needed:

1) Keep in mind that the HTTP header dates must be in GMT.
2) The PHP function time() returns the seconds since the epoch January 1 1970 00:00:00 GMT). Notice here this is in GMT as well.
3) The HTTP Date header you see in a response from an S3 server is the time on that server. The machine you use to sign your request should be synced with that time. I think a good guess is that all the Amazon servers are synced with the atomic clock.

There isn’t much to securing a URL after you have that tucked away. Here is an example that will sign a URL so that it is valid for 60 seconds:

<?php

require_once('Crypt/HMAC.php');

echo getS3Redirect("/test.jpg") . "\\n";

function getS3Redirect($objectName)
{
  $S3_URL = "http://s3.amazonaws.com";
  $keyId = "your key";
  $secretKey = "your secret";
  $expires = time() + 60;
  $bucketName = "/your bucket";

  $stringToSign = "GET\\n\\n\\n$expires\\n$bucketName$objectName";
  $hasher =& new Crypt_HMAC($secretKey, "sha1");
  $sig = urlencode(hex2b64($hasher->hash($stringToSign)));

  return "$S3_URL$bucketName$objectName?AWSAccessKeyId=$keyId&Expires=$expires&Signature=$sig";
}

function hex2b64($str)
{
    $raw = '';
    for ($i=0; $i < strlen($str); $i+=2)
    {
        $raw .= chr(hexdec(substr($str, $i, 2)));
    }
    return base64_encode($raw);
}

?>

The hex2b64 function was pulled from the amazon S3 PHP example library.

Step 1. Get the PHP rrdtool source

Go to the contrib directory on the rrdtool distribution site:
http://people.ee.ethz.ch/~oetiker/webtools/rrdtool/pub/contrib/

There are a number of files in this directory that mention rrd. You want the one named: php_rrdtool.tgz

Step 2. Untar into the correct place

Now that you have the source go into your php source directory and then into the ext directory. So you will be somewhere like this:

/usr/local/src/php-5.1.3/ext/

Now untar the source into this directory.

Step 3. Recreate the php configuration file

There is a warning that you will get if you do not have autoconf 2.13 installed on your system when you try to do this. It is easy enough to get this version if you have fedora so that is what I did.

One tricky part to this is that I had to remove the old configuration file first before the new one could be created.

1. Change directory to your PHP source, if you are still in the ext directory just cd ..
2. Remove the existing configuration file
3. If you are using autoconf 2.13 run the following command:
   PHP_AUTOCONF=autoconf-2.13 ./buildconf –force
   If you are using whatever other autoconf you have installed just run:
   ./buildconf –force
4. You should now have a new configuration file that can be run with the –with-rrdtool option

Step 4. Test

After compiling with rrdtool you should be able to use the phpinfo() function to list the installed extensions. If everything went right you should see rrdtool listed.