Warnings preventing file_get_content from reading properly - php

Question

In appending an attachment I am receiving a warning message preventing me attaching an existing pdf file to my e-mail. I know it isn't my headers since the script is successfully attaching a vcard generated by a string earlier within it.
Since I am not editing the file, TDPDF & FPDF shouldn't be required. (not 100% on that though) Here is the code I've been working with. I've included my output testing lines & comments.
//File Definition
$filepath = "docs/";
//$filepath = "./docs/"; //tried: same result
$fullpath = $filepath . $filename; //$filename defined earlier
//File Manipulation
$file = fopen($fullpath,'rb');
$pdfdata = fread($file, filesize($fullpath));
fclose($file);
//Testing
echo $fullpath . "<br />\n";
echo "Filename: " .$filename . "<br />\n";
echo "Filesize: " .filesize($fullpath). "<br />\n";
echo "String Length: " .strlen($pdfdata). "<br />\n";
//The Following line proved the variable is dumping properly,
//but its content cannot be used for file_get_contents...huh?
//var_dump($pdfdata); //Only used for proofing
echo "Probable Errors for file_get_contents<br />\n";
$data = file_get_contents($pdfdata);
// The following line: Sends File, but is 0 bytes
//$attachment = chunk_split(base64_encode($pdfdata));
//default
$attachment = chunk_split(base64_encode(file_get_contents($pdfdata)));
This outputs:
docs/pdf-to-send.pdf
Filename: pdf-to-send.pdf
Filesize: 37907
String Length: 37907
Probable Errors for file_get_contents
Warning: file_get_contents(%PDF-1.5 % ... (truncated by me)
... ) [function.file-get-contents]: failed to open stream: No such file or directory in /my/hosting/directory/mailer.php on line 337
Warning: file_get_contents(%PDF-1.5 % ... (truncated by me )
... ) [function.file-get-contents]: failed to open stream: No such file or directory in /my/hosting/directory/mailer.php on line 339
Its telling me the file size, that can be found in 2 different variables: $pdfdata & $filesize. They match up. I will mention that the response that I truncated (due to the charset) is already truncated by the server. Its why I started checking the length.
Finally, just in case it could possibly be my headers since I was able to successfully send a 0 byte file, here are those lines...
$body .= "--". $mime_boundary. "\r\n" ;
$body .= "Content-Type: application/octet-stream; name=\"".$filename."\"". "\r\n";
$body .= "Content-Transfer-Encoding: base64" . "\r\n";
$body .= "Content-Disposition: attachment;" . "\r\n";
$body .= "filename=\"".$filename."\"" . "\r\n\n";
$body .= $attachment . "\n\n";
I am aware that I can change (and have tried) the "Content-Type" to "application/pdf".
My charset is UTF-8. I may be misunderstanding "binary-safe" descriptions for fopen() & fread(), but that shouldn't cause the script to fail. Should it?
Any help resolving this would be greatly appreciated.

Answer 1

Ok. I fixed it. Oddly enough it WAS in my headers.
The header command I posted was actually correct. Sadly I posted my vcard attachment body ammendment. So the question already had my answer in it. ::bonk::
This line is correct.
$body .= "filename=\"".$filename."\"" . "\r\n\n";
$body .= $attachment . "\n\n";
This is what I actually had.
$body .= "filename=\"".$filename."\"" . "\r\n";
This explains why I had a 0 byte attachment.
And, just to show the snippet that actually worked:
//File Manipulation
$file = fopen($fullpath,'rb');
$pdfdata = fread($file, filesize($fullpath));
fclose($file);
//Testing
// echo $fullpath . "<br />\n";
//echo "Filename: " .$filename . "<br />\n";
//echo "Filesize: " .filesize($fullpath). "<br />\n";
// echo "String Length: " .strlen($pdfdata). "<br />\n";
//var_dump($pdfdata); // Don't remove this (as a comment) again. LOL
// echo "Probable Errors for file_get_contents<br />\n";
//$data = file_get_contents($pdfdata, true);
$attachment = chunk_split(base64_encode($pdfdata));
//$attachment = chunk_split(base64_encode(file_get_contents($pdfdata)));
Sorry if I wasted anyone's time.