A PHP file containing useful utilities for backing up files and databases on a Linux server.

backup_utils.php

<?php 
class MailChunker {
  public function __construct( $addr = "", $sub = "", $msg = "" , $from = "", $file = "", $maxfsize = "9MB") {
    $this->addr = $addr; # Comma-separated string of email addresses.
    $this->sub = $sub;
    $this->msg = $msg;
    $this->from = $from;
    $this->fname = $file;
    $this->maxfsize = $maxfsize;
  };
  public function send() {
    $this->fsize = filesize($this->fname);
    // Check for valid type of maxfsize.  Should be of the form 123B or 98MB, etc.
    if (! is_string($this->maxfsize)) {
      // If the max file size has been specified as a number, assume it is in Bytes.
      $this->maxfsize = $this->maxfsize . "B";
    };
    if ($this->fsize <= filesize2bytes($this->maxfsize) {
      // Send single chunk.
      mail_file($this->addr, $this->sub, $this->msg, $this->from, $this->fname);
    } else {
      // Break up and send chunks.
    }
  }
};

/**
 * Source:
 * http://www.barattalo.it/2010/01/10/sending-emails-with-attachment-and-html-with-php/
 */
function mail_file( $to, $subject, $messagehtml, $from, $fileatt, $replyto="" ) {
  // handles mime type for better receiving
  $ext = strrchr( $fileatt , '.');
  $ftype = "";
  if ($ext == ".doc") $ftype = "application/msword";
  if ($ext == ".jpg") $ftype = "image/jpeg";
  if ($ext == ".gif") $ftype = "image/gif";
  if ($ext == ".zip") $ftype = "application/zip";
  if ($ext == ".pdf") $ftype = "application/pdf";
  if ($ext == ".gz") $ftype = "applicatoin/gzip";
  if ($ftype=="") $ftype = "application/octet-stream";
   
  // read file into $data var
  $file = fopen($fileatt, "rb");
  $data = fread($file,  filesize( $fileatt ) );
  fclose($file);

  // split the file into chunks for attaching
  $content = chunk_split(base64_encode($data));
  $uid = md5(uniqid(time()));

  // build the headers for attachment and html
  $h = "From: $from\r\n";
  if ($replyto) $h .= "Reply-To: ".$replyto."\r\n";
  $h .= "MIME-Version: 1.0\r\n";
  $h .= "Content-Type: multipart/mixed; boundary=\"".$uid."\"\r\n\r\n";
  $h .= "This is a multi-part message in MIME format.\r\n";
  $h .= "--".$uid."\r\n";
  $h .= "Content-type:text/html; charset=iso-8859-1\r\n";
  $h .= "Content-Transfer-Encoding: 7bit\r\n\r\n";
  $h .= $messagehtml."\r\n\r\n";
  $h .= "--".$uid."\r\n";
  $h .= "Content-Type: ".$ftype."; name=\"".basename($fileatt)."\"\r\n";
  $h .= "Content-Transfer-Encoding: base64\r\n";
  $h .= "Content-Disposition: attachment; filename=\"".basename($fileatt)."\"\r\n\r\n";
  $h .= $content."\r\n\r\n";
  $h .= "--".$uid."--";

  // send mail
  return mail( $to, $subject, strip_tags($messagehtml), str_replace("\r\n","\n",$h) ) ;
};

/** 
 * Converts human readable file size (e.g. 10 MB, 200.20 GB) into bytes. 
 * 
 * @param string $str 
 * @return int the result is in bytes 
 * @author Svetoslav Marinov 
 * @author http://slavi.biz 
 */ 
function filesize2bytes($str) { 
  $bytes = 0; 

  $bytes_array = array( 
    'B' => 1, 
    'KB' => 1024, 
    'MB' => 1024 * 1024, 
    'GB' => 1024 * 1024 * 1024, 
    'TB' => 1024 * 1024 * 1024 * 1024, 
    'PB' => 1024 * 1024 * 1024 * 1024 * 1024, 
  ); 

  $bytes = floatval($str); 

  if (preg_match('#([KMGTP]?B)$#si', $str, $matches) && !empty($bytes_array[$matches[1]])) { 
    $bytes *= $bytes_array[$matches[1]]; 
  } 

  $bytes = intval(round($bytes, 2)); 

  return $bytes; 
};
?>