Today we are going to learn how to upload and download files using php, mysql. While uploading a file to server we need to create a html form with enctype attributes in the form specifies which content-type to use when submitting the form. "multipart/form-data" is used when a form requires binary data, like the contents of a file, to be uploaded. The type="file" attribute of the input tag specifies that the input should be processed as a file. For example, when viewed in a browser, there will be a browse-button next to the input field. The important note for the user is allow only trusted users to upload a file because they may cause severe risk. With the help of global php $_FILES array you can able to upload any files from your computer to remote server. The first index is the form inputs and the second index may be name,type,size,tmp_name,error and so on.

• $_FILES["file"]["name"] : indicates name of the uploaded file
• $_FILES["file"]["type"] : indicates type of the uploaded file
• $_FILES["file"]["size"] : indicates size of the uploaded file in bytes
• $_FILES["file"]["tmp_name"] : indicates the file to be stored on temporary server
• $_FILES["file"]["error"] : indicates the error in the file

Generally the default maximum upload file size less than 8mb.Increase file size upload limit using php.ini or htaccess

Any php web application or server configured with default values set in php.ini and .htacess. Generally almost web hosting providers configures the web application to optimum settings, which effects server bandwidth, server memory limit, server disk space, and peak security measures. For file uploading and PHP script execution there is default configuration in PHP.ini. However almost hosting providers give chance to developer to customize this default configuration by override php.ini or .htaccess . some settings can be configured by ini_set() method at run time of script.

Increasing file upload size by php.ini:

upload_max_filesize = 10M ;
post_max_size = 20M ;

memory_limit = 128M

Increasing file upload size by php.ini:

php_value upload_max_filesize 10M
php_value post_max_size 20M
php_value memory_limit 128M

Copy the above settings into your .htaccess file and put it in your web root directory. Almost all web host providers give to override the .htacces ,so you can use above method.

HTML form input:

  

  

    
    

      
      
      
         Browse
      
    
  
   

    

   
   
   
 
 

Database Connection:

mysql_select_db('filemgr',mysql_connect('localhost','root',''))or die(mysql_error());

File upload with restrictions:

if(isset($_POST['submit'])!=""){
   $name=$_FILES['photo']['name'];

  $size=$_FILES['photo']['size'];
  $type=$_FILES['photo']['type'];
  $temp=$_FILES['photo']['tmp_name'];
  $error = $_FILES['photo']['error'];
  $date = date('Y-m-d H:i:s');
if ($error > 0) //Check file upload has error
    {
    $_SESSION['alert'] = "danger";
    $_SESSION['result'] = "Error: " . $error . "
"; //Sesssio to carry error 
    }
  else{
      
      if ($size > 500000) { //Check File Size
      $_SESSION['alert'] = "danger";
    $_SESSION['result'] = "Error: Maximum file size 5MB!!!
";
      }else{
          $targetPath = "files/".$name;
          
          if(file_exists($targetPath)){  // Check whether the file name already exist in the server.
                    $rename_file= rand(01,1000).$name; //Rename the current file
                    $targetPath = "files/".$rename_file;
                }else{
                $rename_file =     $name;
                }
  move_uploaded_file($temp,$targetPath); 

$query=$conn->query("INSERT INTO upload (name,rename_file,date) VALUES ('$name','$rename_file','$date')");
if($query){
    $_SESSION['alert'] = "success";
    $_SESSION['result'] = "Well done! File successfully uploaded!!!"; //Session to carry success message

}
else{
die(mysql_error());
}
      }
  }
}

Download File in PHP:

  "application/pdf",
        "txt" => "text/plain",
        "html" => "text/html",
        "htm" => "text/html",
        "exe" => "application/octet-stream",
        "zip" => "application/zip",
        "doc" => "application/msword",
        "xls" => "application/vnd.ms-excel",
        "ppt" => "application/vnd.ms-powerpoint",
        "gif" => "image/gif",
        "png" => "image/png",
        "jpeg" => "image/jpg",
        "jpg" => "image/jpg",
        "php" => "text/plain"
    );
    
    if ($mime_type == '') {
        echo $file_extension = pathinfo($file, PATHINFO_EXTENSION);
        
        if (array_key_exists($file_extension, $known_mime_types)) {
            $mime_type = $known_mime_types[$file_extension];
        } else {
            $mime_type = "application/force-download";
        }
        ;
    }
    ;
    
    @ob_end_clean();
    
    
    if (ini_get('zlib.output_compression'))
        ini_set('zlib.output_compression', 'Off');
    header('Content-Type: ' . $mime_type);
    header('Content-Disposition: attachment; filename="' . $name . '"');
    header("Content-Transfer-Encoding: binary");
    header('Accept-Ranges: bytes');
    header("Cache-control: private");
    header('Pragma: private');
    header("Expires: Mon, 26 Jul 2017 05:00:00 GMT");
    if (isset($_SERVER['HTTP_RANGE'])) {
        list($a, $range) = explode("=", $_SERVER['HTTP_RANGE'], 2);
        list($range) = explode(",", $range, 2);
        list($range, $range_end) = explode("-", $range);
        $range = intval($range);
        if (!$range_end) {
            $range_end = $size - 1;
        } else {
            $range_end = intval($range_end);
        }
        $new_length = $range_end - $range + 1;
        header("HTTP/1.1 206 Partial Content");
        header("Content-Length: $new_length");
        header("Content-Range: bytes $range-$range_end/$size");
    } else {
        $new_length = $size;
        header("Content-Length: " . $size);
    }
    $chunksize  = 1 * (1024 * 1024);
    $bytes_send = 0;
    if ($file = fopen($file, 'r')) {
        if (isset($_SERVER['HTTP_RANGE']))
            fseek($file, $range);
        
        while (!feof($file) && (!connection_aborted()) && ($bytes_send < $new_length)) {
            $buffer = fread($file, $chunksize);
            print($buffer);
            flush();
            $bytes_send += strlen($buffer);
        }
        fclose($file);
    } else
        die('Error - cannot open file.');
    die();
}
set_time_limit(0);
$file_path = 'files/' . $_REQUEST['filename'];
output_file($file_path, '' . $_REQUEST['filename'] . '', '');
?> 

By Thirumani Raj posted on - 16th Mar 2017

Live Demo Download Script