Download file directly from FTP

Question

How do I download a file directly from FTP without temporarily downloading to the PHP server?

Code:

<?php
     //....
     $fcon = ftp_connect($ftp_host);
     $conecta = ftp_login($fcon, $ftp_username, $ftp_senha);
     ftp_pasv($fcon, true);
     ftp_chdir($fcon , $ftp_pasta);

     $arquivo = basename($arquivo_ftp);

     $arquivo_temp = "../anexos/" . $arquivo;

     ftp_get($fcon, $arquivo_temp, $arquivo, FTP_BINARY); 


     ftp_close($fcon);

     //Prepara o arquivo para download no navegador
     $file = $arquivo;

     //Vê a extensão do arquivo
     $type = filetype($arquivo_temp);

     //Vê o tamanho do arquivo
     $size = filesize($arquivo_temp);

    //Seta o header da página para forçar o navegador a fazer download
    header("Content-Description: File Transfer");
    header("Content-Type:{$type}");
    header("Content-Length:{$size}");
    header("Content-Disposition: attachment; filename=\"" . $file . "\"");

    //Faz download
    readfile($arquivo_temp);

    //Apaga o arquivo temporário
    unlink($arquivo_temp);

As it is in the above code, the file needs to be fetched from FTP and temporarily downloaded to a server folder, and then sent to the user. With this very large files and the large amount of users is slowing down the network.

How can I get authentication to FTP through PHP and make a direct download link between user and FTP?

Answer 1

You can use "protocol" php:// for example the php://temp, thus:

 <?php
 $fcon = ftp_connect($ftp_host);
 $conecta = ftp_login($fcon, $ftp_username, $ftp_senha);
 ftp_pasv($fcon, true);
 ftp_chdir($fcon , $ftp_pasta);

 $arquivo = basename($arquivo_ftp);

 $arquivo_temp = "php://temp";

 ftp_get($fcon, $arquivo_temp, $arquivo, FTP_BINARY); 


 ftp_close($fcon);

 //Prepara o arquivo para download no navegador
 $file = $arquivo;

 //Vê a extensão do arquivo
 $type = filetype($arquivo_temp);

 //Vê o tamanho do arquivo
 $size = filesize($arquivo_temp);

//Seta o header da página para forçar o navegador a fazer download
header("Content-Description: File Transfer");
header("Content-Type:{$type}");
header("Content-Length:{$size}");
header("Content-Disposition: attachment; filename=\"" . $file . "\"");

//Faz download
readfile($arquivo_temp);

Note that by default the limit is 2MB, so if it is larger you will have to adjust in the settings, or you can choose to use php://output combined with ob_start, thus:

 <?php
 ob_start();

 $fcon = ftp_connect($ftp_host);
 $conecta = ftp_login($fcon, $ftp_username, $ftp_senha);
 ftp_pasv($fcon, true);
 ftp_chdir($fcon , $ftp_pasta);

 $arquivo = basename($arquivo_ftp);

 $arquivo_temp = "php://output";

 ftp_get($fcon, $arquivo_temp, $arquivo, FTP_BINARY); 

 ftp_close($fcon);

 //Prepara o arquivo para download no navegador
 $file = $arquivo;

 //Vê a extensão do arquivo
 $type = filetype($arquivo_temp);

 //Vê o tamanho do arquivo
 $size = filesize($arquivo_temp);

//Seta o header da página para forçar o navegador a fazer download
header("Content-Description: File Transfer");
header("Content-Type: {$type}");
header("Content-Length: {$size}");
header("Content-Disposition: attachment; filename=\"" . $file . "\"");

Documentation: http://php.net/manual/en/wrappers.php.php

Answer 2

One possible solution is to use the Library Client URL

See how it works:

//Configuração de conexão com o FTP
$ftp_arquivo = "pasta/pasta/meuarquivo.txt";
$ftp_host = "199.99.854.99"; //exemplo
$ftp_port = "21";
$ftp_username = "usuarioAtenticacaoFTP";
$ftp_senha = "MinhaSenhaFTP";


header("Content-type: application/octet-stream");
header("Content-Disposition: attachment; filename=\"" . basename($ftp_arquivo) . "\"");
header("Content-Transfer-Encoding: binary");

//Configura a conexão curl
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL,  "ftp://$ftp_host:$ftp_port/$ftp_arquivo"); //Caminho do arquivo
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_setopt($ch, CURLOPT_HTTPAUTH, CURLAUTH_ANY);
curl_setopt($ch, CURLOPT_USERPWD, "$ftp_username:$ftp_senha"); //Faz a autenticação
curl_exec ($ch); //Executa

curl_close($ch);

This way the file does not need to be temporarily downloaded from the PHP.

The PHP only realizes the authentication with FTP and the file is downloaded directly to the user’s browser.