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temp_local_download_remote_file()

Description

Download remote file to the temp filestore location.

Parameters

ColumnTypeDefaultDescription
$url string Source URL
$key string "" Optional key to use - to prevent conflicts when simultaneous calls use same file name

Return

string|bool Returns the new temp filestore location or false otherwise.

Location

include/file_functions.php lines 125 to 223

Definition

 
function temp_local_download_remote_file(string $url, string $key = "")
    {
    $userref = $GLOBALS['userref'] ?? 0;
    if($userref === 0)
        {
        return false;
        }

    if ($key != "" && preg_match('/\W+/', $key) !== 0)
        {
        // Block potential path traversal - allow only word characters.
        return false;
        }

    $url = trim($url);
    $url_original = $url;
    // Remove query string from URL
    $url = explode('?', $url);
    $url = reset($url);
    
    $path_parts = pathinfo(basename($url));
    $filename = safe_file_name($path_parts['filename'] ?? '');
    $extension = $path_parts['extension'] ?? '';
    $filename .= ($extension !== '' ? ".{$extension}" : '');

    if(strpos($filename,".") === false && filter_var($url_original, FILTER_VALIDATE_URL))
        {
        // $filename not valid, try and get from HTTP header
        $urlinfo = parse_url($url);
        if (!isset($urlinfo["scheme"]) || !in_array($urlinfo["scheme"],["http","https"]))
            {
            return false;
            }

        $headers = get_headers($url_original,true);
        foreach($headers as $header=>$headervalue)
            {
            if (
                strtolower($header) == "content-disposition"
                // Check for double quotes first (e.g. attachment; filename="O'Malley's Bar.pdf")
                // OR Check for single quotes (e.g. attachment; filename='Space Travel.jpg')
                // OR Get file name up to first space
                && 
                ( 
                    preg_match('/.*filename=[\"]([^\"]+)/', $headervalue, $matches)
                    || preg_match('/.*filename=[\']([^\']+)/', $headervalue, $matches)
                    || preg_match("/.*filename=([^ ]+)/", $headervalue, $matches) 
                )
                ) {
                    $filename = $matches[1];
                }
            }
        
        $extension = pathinfo(basename($filename), PATHINFO_EXTENSION);
        $filename = safe_file_name(pathinfo(basename($filename), PATHINFO_FILENAME)) . ".{$extension}";
        }

    if (is_banned_extension($extension))
        {
        debug('[temp_local_download_remote_file] WARN: Banned extension for ' . $filename);
        return false;
        }

    // Get temp location
    $tmp_uniq_path_id = $userref . "_" . $key . generateUserFilenameUID($userref);
    $tmp_dir = get_temp_dir(false) . "/remote_files/" . $tmp_uniq_path_id;
    if(!is_dir($tmp_dir))
        {
        mkdir($tmp_dir,0777,true);
        }
    $tmp_file_path = $tmp_dir. "/" . $filename;
    if($tmp_file_path == $url)
        {
        // Already downloaded earlier by API call 
        return $tmp_file_path;
        }

    // Download the file
    $GLOBALS['use_error_exception'] = true;
    try
        {
        if(copy($url_original, $tmp_file_path))
            {
            return $tmp_file_path;
            }
        }
    catch(Throwable $t)
        {
        debug(sprintf(
            'Failed to download remote file from "%s" to temp location "%s". Reason: %s',
            $url_original,
            $tmp_file_path,
            $t->getMessage()
        ));
        }
    unset($GLOBALS['use_error_exception']);

    return false;
    }

This article was last updated 17th November 2024 15:35 Europe/London time based on the source file dated 22nd August 2024 16:45 Europe/London time.