Php application development-file download details

Php application development-file download details

This article introduces some code for downloading files using php. For more information, see. 1. the php download function uses the header () and readfile () functions to download files. 2. php user-defined functions downloaded by php with a more complete php file download script. 'download/tool1_v30.exe', 'PROG2' => 'download/prog2setup.exe', ); // Get/check download file name if (empty($fileid) || empty($DLFILES[$fileid])) { return ''; } // Set base directory to document root directory // (could also be set to a directory outside document root!) $basedir = getGlobalVar('DOCUMENT_ROOT'); // Build and return download file name return $basedir.'/'.$DLFILES[$fileid]; } function DownloadFile($filename) // Download file // Returns: TRUE if download successfully started, FALSE if download failed // Parameters: // $filename : Download file pathname { // Verify filename if (empty($filename) || !file_exists($filename)) { return FALSE; } // Create download file name to be displayed to user $saveasname = basename($filename); // Send binary filetype HTTP header header('Content-Type: application/octet-stream'); // Send content-length HTTP header header('Content-Length: '.filesize($filename)); // Send content-disposition with save file name HTTP header header('Content-Disposition: attachment; filename="'.$saveasname.'"'); // Output file readfile($filename); // Download successfully started return TRUE; } function getGlobalVar($g, $formflag = 0) // Get global PHP variable value // Returns: global variable value or empty string if not available // Parameters: // $g : Global PHP variable name // $formflag : Flag - global var from GET/POST input { if (empty($g)) { return 0; } // Try superglobal access (PHP 4.1.0+) if ($formflag) { if (isset($_POST[$g])) { return $_POST[$g]; } if (isset($_GET[$g])) { return $_GET[$g]; } if (isset($_REQUEST[$g])) { return $_REQUEST[$g]; } } else { if (isset($_SERVER[$g])) { return $_SERVER[$g]; } if (isset($_ENV[$g])) { return $_ENV[$g]; } } // Try superglobal access (PHP 3.0.0+) if (isset($GLOBALS[$g])) { return $GLOBALS[$g]; } // Try global variable access (PHP 3+) global $$g; if (!empty($$g)) { return $$g; } // Assume global variable empty/not set return ''; } ?> Save the preceding script as dl. php and input the id parameter during the application. For example, Download Program 2 can also be implemented through the php redirection statement Location, for example: The above code can prevent users from directly accessing and downloading files, which provides certain file protection and even anti-Leech functions. The following code can be used to provide more secure file downloads based on http header information. Code: