$cd - путь к файлу, 
$fn - имя файла 

<?php 
$filename = $cd."/".$fn; 
if (!file_exists($filename)) 
   { 
    header ("HTTP/1.0 404 Not Found"); 
    exit; 
   } 
$fsize = filesize($filename); 
$ftime = date("D, d M Y H:i:s T", filemtime($filename)); 
$fd = @fopen($filename, "rb"); 
if (!$fd){ 
  header ("HTTP/1.0 403 Forbidden"); 
  exit; 
} 
// Если запрашивающий агент поддерживает докачку 
if ($HTTP_SERVER_VARS["HTTP_RANGE"]) { 
  $range = $HTTP_SERVER_VARS["HTTP_RANGE"]; 
  $range = str_replace("bytes=", "", $range); 
  $range = str_replace("-", "", $range); 
  if ($range) {fseek($fd, $range);} 
} 
$content = fread($fd, filesize($filename)); 
fclose($fd); 
if ($range) { 
  header("HTTP/1.1 206 Partial Content"); 
} 
else { 
  header("HTTP/1.1 200 OK"); 
} 
header("Content-Disposition: attachment; filename=$fn"); 
header("Last-Modified: $ftime"); 
header("Accept-Ranges: bytes"); 
header("Content-Length: ".($fsize-$range)); 
header("Content-Range: bytes $range-".($fsize - 1 )."/".$fsize); 
header("Content-type: application/octet-stream"); 
print $content; 
exit; 

?> 

> Serge V. Tarasov

>> 5 . 5  Как сделать аттачмент к е-мейлy пpи отпpавке его с помощью фyнкции 
mail? 
<? 
function XMail( $from, $to, $subj, $text, $filename) 
{ 
$f         = fopen($filename,"rb"); 
$un        = strtoupper(uniqid(time())); 
$head      = "From: $from\n"; 
$head     .= "To: $to\n"; 
$head     .= "Subject: $subj\n"; 
$head     .= "X-Mailer: PHPMail Tool\n"; 
$head     .= "Reply-To: $from\n"; 
$head     .= "Mime-Version: 1.0\n"; 
$head     .= "Content-Type:multipart/mixed;"; 
$head     .= "boundary=\"----------".$un."\"\n\n"; 
$zag       = "------------".$un."\nContent-Type:text/html;\n"; 
$zag      .= "Content-Transfer-Encoding: 8bit\n\n$text\n\n"; 
$zag      .= "------------".$un."\n"; 
$zag      .= "Content-Type: application/octet-stream;"; 
$zag      .= "name=\"".basename($filename)."\"\n"; 
$zag      .= "Content-Transfer-Encoding:base64\n"; 
$zag      .= "Content-Disposition:attachment;"; 
$zag      .= "filename=\"".basename($filename)."\"\n\n"; 
$zag      .= chunk_split(base64_encode(fread($f,filesize($filename))))."\n"; 

if (!@mail("$to", "$subj", $zag, $head)) 
 return  0 ; 
else 
 return  1 ; 
} 
?>