drupal/includes/file.inc

529 lines
16 KiB
PHP

<?php
/* $Id$ */
/**
* @file
* API for handling file uploads and server file management.
*/
/**
* @defgroup file File interface
* @{
* Common file handling functions.
*/
define('IS_WINDOWS', substr(PHP_OS, 0, 3) == 'WIN');
define('FILE_DOWNLOADS_PUBLIC', 1);
define('FILE_DOWNLOADS_PRIVATE', 2);
define('FILE_CREATE_DIRECTORY', 1);
define('FILE_MODIFY_PERMISSIONS', 2);
define('FILE_DIRECTORY_TEMP', IS_WINDOWS ? 'c:\\windows\\temp' : '/tmp');
define('FILE_EXISTS_RENAME', 0);
define('FILE_EXISTS_REPLACE', 1);
define('FILE_EXISTS_ERROR', 2);
/**
* Create the download path to a file.
*
* @param $path Path to the file to generate URL for
* @return URL pointing to the file
*/
function file_create_url($path) {
if (strpos($path, variable_get('file_directory_path', 'files')) !== false) {
$path = trim(substr($path, strlen(variable_get('file_directory_path', 'files'))), '\\/');
}
switch (variable_get('file_downloads', FILE_DOWNLOADS_PUBLIC)) {
case FILE_DOWNLOADS_PUBLIC:
return $GLOBALS['base_url'] .'/'. variable_get('file_directory_path', 'files') .'/'. str_replace('\\', '/', $path);
case FILE_DOWNLOADS_PRIVATE:
return url('system/files', 'file='. $path);
}
}
/**
* Make sure the destination is a complete path and resides in the
* file system directory, if it is not prepend the
* file system directory.
*
* @param $dest Path to verify
* @return Path to file with file system directory appended if necessary.
*/
function file_create_path($dest = 0) {
if (!$dest) {
return variable_get('file_directory_path', 'files');
}
$regex = (IS_WINDOWS ? '.?:\\\\' : '/');
if (!file_check_location($dest, variable_get('file_directory_path', 'files')) && !preg_match("|^$regex|", $dest)) {
return variable_get('file_directory_path', 'files') .'/'. trim($dest, '\\/');
}
else {
return $dest;
}
}
/**
* Check that directory exists and is writable.
*
* @param $directory Path to extract and verify directory for.
* @param $mode Try to create the directory if it does not exist.
* @param $form_item Optional name for a field item to attach potential errors to.
* @return False when directory not found, or true when directory exists.
*/
function file_check_directory(&$directory, $mode = 0, $form_item = NULL) {
$directory = rtrim($directory, '/\\');
// Check if directory exists.
if (!is_dir($directory)) {
if (($mode & FILE_CREATE_DIRECTORY) && @mkdir($directory, 0760)) {
drupal_set_message(t('Created directory %directory.', array('%directory' => "<em>$directory</em>")));
}
else {
if ($form_item) {
form_set_error($form_item, t('The directory %directory does not exist.', array('%directory' => "<em>$directory</em>")));
}
return false;
}
}
// Check to see if the directory is writable.
if (!is_writable($directory)) {
if (($mode & FILE_MODIFY_PERMISSIONS) && @chmod($directory, 0760)) {
drupal_set_message(t('Modified permissions on directory %directory.', array('%directory' => "<em>$directory</em>")));
}
else {
form_set_error($form_item, t('The directory %directory is not writable.', array('%directory' => "<em>$directory</em>")));
return false;
}
}
return true;
}
/**
* Checks path to see if it is a directory, or a dir/file.
*
* @param $path
*/
function file_check_path(&$path) {
// Check if path is a directory.
if (file_check_directory($path)) {
return '';
}
// Check if path is a possible dir/file.
$filename = basename($path);
$path = dirname($path);
if (file_check_directory($path)) {
return $filename;
}
return false;
}
/**
* Check if $source is a valid file upload.
*
* @param $source
*/
function file_check_upload($source) {
if (is_object($source)) {
if (is_file($source->filepath)) {
return $source;
}
}
elseif ($_FILES["edit"]["name"][$source] && is_uploaded_file($_FILES["edit"]["tmp_name"][$source])) {
$file = new StdClass();
$file->filename = trim(basename($_FILES["edit"]["name"][$source]), '.');
$file->filemime = $_FILES["edit"]["type"][$source];
$file->filepath = $_FILES["edit"]["tmp_name"][$source];
$file->error = $_FILES["edit"]["error"][$source];
$file->filesize = $_FILES["edit"]["size"][$source];
$file->source = $source;
return $file;
}
else {
// In case of previews return previous file object.
if (file_exists($_SESSION['file_uploads'][$source]->filepath)) {
return $_SESSION['file_uploads'][$source];
}
}
}
/**
* Check if a file is really located inside $directory. Should be used to make
* sure a file specified is really located within the directory to prevent
* exploits.
*
* @code
* // Returns false:
* file_check_location('/www/example.com/files/../../../etc/passwd', '/www/example.com/files');
* @endcode
*
* @param $source A string set to the file to check.
* @param $directory A string where the file should be located.
* @return 0 for invalid path or the real path of the source.
*/
function file_check_location($source, $directory = 0) {
$source = realpath($source);
$directory = realpath($directory);
if ($directory && strpos($source, $directory) !== 0) {
return 0;
}
return $source;
}
/**
* Copies a file to a new location. This is a powerful function that in many ways
* performs like an advanced version of copy().
* - Checks if $source and $dest are valid and readable/writable.
* - Performs a file copy if $source is not equal to $dest.
* - If file already exists in $dest either the call will error out, replace the
* file or rename the file based on the $replace parameter.
*
* @param $source A string specifying the file location of the original file.
* This parameter will contain the resulting destination filename in case of
* success.
* @param $dest A string containing the directory $source should be copied to.
* @param $replace Replace behavior when the destination file already exists.
* - FILE_EXISTS_REPLACE - Replace the existing file
* - FILE_EXISTS_RENAME - Append _{incrementing number} until the filename is unique
* - FILE_EXISTS_ERROR - Do nothing and return false.
* @return True for success, false for failure.
*/
function file_copy(&$source, $dest = 0, $replace = FILE_EXISTS_RENAME) {
$dest = file_create_path($dest);
$directory = $dest;
$basename = file_check_path($directory);
// Make sure we at least have a valid directory.
if ($basename === false) {
drupal_set_message(t('File copy failed: no directory configured, or it could not be accessed.'), 'error');
return 0;
}
// Process a file upload object.
if (is_object($source)) {
$file = $source;
$source = $file->filepath;
if (!$basename) {
$basename = $file->filename;
}
}
$source = realpath($source);
if (!file_exists($source)) {
drupal_set_message(t('File copy failed: source file does not exist.'), 'error');
return 0;
}
// If destination file is not specified then use filename of source file.
$basename = $basename ? $basename : basename($source);
$dest = $directory .'/'. $basename;
// Make sure source and destination filenames are not the same, makes no sense
// to copy it if they are. In fact copying the file will most likely result in
// a 0 byte file. Which is bad. Real bad.
if ($source != realpath($dest)) {
if (file_exists($dest)) {
switch ($replace) {
case FILE_EXISTS_RENAME:
// Destination file already exists and we can't replace is so we try and
// and find a new filename.
if ($pos = strrpos($basename, '.')) {
$name = substr($basename, 0, $pos);
$ext = substr($basename, $pos);
}
else {
$name = $basename;
}
$counter = 0;
do {
$dest = $directory .'/'. $name .'_'. $counter++ . $ext;
} while (file_exists($dest));
break;
case FILE_EXISTS_ERROR:
drupal_set_message(t('File copy failed. File already exists.'), 'error');
return 0;
case FILE_EXISTS_REPLACE:
// Leave $dest where it is for replace.
}
}
if (!@copy($source, $dest)) {
drupal_set_message(t('File copy failed.'), 'error');
return 0;
}
}
if (is_object($file)) {
$file->filename = $basename;
$file->filepath = $dest;
$source = $file;
}
else {
$source = $dest;
}
return 1; // Everything went ok.
}
/**
* Moves a file to a new location.
* - Checks if $source and $dest are valid and readable/writable.
* - Performs a file move if $source is not equal to $dest.
* - If file already exists in $dest either the call will error out, replace the
* file or rename the file based on the $replace parameter.
*
* @param $source A string specifying the file location of the original file.
* This parameter will contain the resulting destination filename in case of
* success.
* @param $dest A string containing the directory $source should be copied to.
* @param $replace Replace behavior when the destination file already exists.
* - FILE_EXISTS_REPLACE - Replace the existing file
* - FILE_EXISTS_RENAME - Append _{incrementing number} until the filename is unique
* - FILE_EXISTS_ERROR - Do nothing and return false.
* @return True for success, false for failure.
*/
function file_move(&$source, $dest = 0, $replace = FILE_EXISTS_RENAME) {
$path_original = is_object($source) ? $source->filepath : $source;
if (file_copy($source, $dest, $replace)) {
$path_current = is_object($source) ? $source->filepath : $source;
if ($path_original == $path_current || file_delete($path_original)) {
return 1;
}
drupal_set_message(t('Removing original file failed.'), 'error');
}
return 0;
}
function file_create_filename($basename, $directory) {
$dest = $directory .'/'. $basename;
if (file_exists($dest)) {
// Destination file already exists, generate an alternative.
if ($pos = strrpos($basename, '.')) {
$name = substr($basename, 0, $pos);
$ext = substr($basename, $pos);
}
else {
$name = $basename;
}
$counter = 0;
do {
$dest = $directory .'/'. $name .'_'. $counter++ . $ext;
} while (file_exists($dest));
}
return $dest;
}
function file_delete($path) {
if (is_file($path)) {
return unlink($path);
}
}
/**
* Saves a file upload to a new location. The source file is validated as a
* proper upload and handled as such.
*
* @param $source A string specifying the name of the upload field to save.
* This parameter will contain the resulting destination filename in case of
* success.
* @param $dest A string containing the directory $source should be copied to,
* will use the temporary directory in case no other value is set.
* @param $replace A boolean, set to true if the destination should be replaced
* when in use, but when false append a _X to the filename.
* @return An object containing file info or 0 in case of error.
*/
function file_save_upload($source, $dest = 0, $replace = FILE_EXISTS_RENAME) {
// Make sure $source exists in $_FILES.
if ($file = file_check_upload($source)) {
if (!$dest) {
$dest = variable_get('file_directory_temp', FILE_DIRECTORY_TEMP);
$temporary = 1;
if (is_file($file->filepath)) {
// If this file was uploaded by this user before replace the temporary copy.
$replace = 1;
}
}
if (!user_access('bypass input data check') && !valid_input_data($file)) {
watchdog('security', t('Possible exploit abuse: invalid data.'), WATCHDOG_WARNING);
drupal_set_message(t('File upload failed: invalid data.'), 'error');
return 0;
}
// Check for file upload errors.
switch ($file->error) {
case 0: // UPLOAD_ERR_OK
break;
case 1: // UPLOAD_ERR_INI_SIZE
case 2: // UPLOAD_ERR_FORM_SIZE
drupal_set_message(t('File upload failed: file size too big.'), 'error');
return 0;
case 3: // UPLOAD_ERR_PARTIAL
case 4: // UPLOAD_ERR_NO_FILE
drupal_set_message(t('File upload failed: incomplete upload.'), 'error');
return 0;
default: // Unknown error
drupal_set_message(t('File upload failed: unknown error.'), 'error');
return 0;
}
unset($_SESSION['file_uploads'][is_object($source) ? $source->source : $source]);
if (file_move($file, $dest, $replace)) {
if ($temporary) {
$_SESSION['file_uploads'][is_object($source) ? $source->source : $source] = $file;
}
return $file;
}
return 0;
}
return 0;
}
/**
* Save a string to the specified destination
*
* @param $data A string containing the contents of the file
* @param $dest A string containing the destination location
*
* @return A string containing the resulting filename or 0 on error
*/
function file_save_data($data, $dest, $replace = FILE_EXISTS_RENAME) {
if (!user_access('bypass input data check') && !valid_input_data($data)) {
watchdog('security', t('Possible exploit abuse: invalid data.'), WATCHDOG_WARNING);
drupal_set_message(t('File upload failed: invalid data.'), 'error');
return 0;
}
$temp = variable_get('file_directory_temp', FILE_DIRECTORY_TEMP);
$file = tempnam($temp, 'file');
if (!$fp = fopen($file, 'wb')) {
drupal_set_message(t('Unable to create file.'), 'error');
return 0;
}
fwrite($fp, $data);
fclose($fp);
if (!file_move($file, $dest, $replace)) {
return 0;
}
return $file;
}
/**
* Transfer file using http to client. Pipes a file through Drupal to the
* client.
*
* @param $source File to transfer.
* @param $headers An array of http headers to send along with file.
*/
function file_transfer($source, $headers) {
ob_end_clean();
foreach ($headers as $header) {
header($header);
}
$source = file_create_path($source);
// Transfer file in 1024 byte chunks to save memory usage.
$fd = fopen($source, 'rb');
while (!feof($fd)) {
print fread($fd, 1024);
}
fclose($fd);
exit();
}
/**
* Call modules to find out if a file is accessible for a given user.
*/
function file_download() {
$file = $_GET['file'];
if (file_exists(file_create_path($file))) {
$list = module_list();
foreach ($list as $module) {
$headers = module_invoke($module, 'file_download', $file);
if ($headers === -1) {
drupal_access_denied();
}
elseif (is_array($headers)) {
file_transfer($file, $headers);
}
}
}
drupal_not_found();
}
/**
* Finds all files that match a given mask in a given
* directory.
*
* @param $dir
* The base directory for the scan.
* @param $mask
* The regular expression of the files to find.
* @param $nomask
* An array of files/directories to ignore.
* @param $callback
* The callback function to call for each match.
* @param $recurse
* When TRUE, the directory scan will recurse the entire tree
* starting at the provided directory.
* @param $key
* The key to be used for the returned array of files. Possible
* values are "filename", for the path starting with $dir,
* "basename", for the basename of the file, and "name" for the name
* of the file without an extension.
*
* @return
* An associative array (keyed on the provided key) of objects with
* "path", "basename", and "name" members corresponding to the
* matching files.
*/
function file_scan_directory($dir, $mask, $nomask = array('.', '..', 'CVS'), $callback = 0, $recurse = TRUE, $key = 'filename') {
$key = (in_array($key, array('filename', 'basename', 'name')) ? $key : 'filename');
$files = array();
if (is_dir($dir) && $handle = opendir($dir)) {
while ($file = readdir($handle)) {
if (!in_array($file, $nomask)) {
if (is_dir("$dir/$file") && $recurse) {
$files = array_merge($files, file_scan_directory("$dir/$file", $mask, $nomask, $callback, $recurse, $key));
}
elseif (ereg($mask, $file)) {
$filename = "$dir/$file";
$basename = basename($file);
$name = substr($basename, 0, strrpos($basename, '.'));
$files[$$key] = new stdClass();
$files[$$key]->filename = $filename;
$files[$$key]->basename = $basename;
$files[$$key]->name = $name;
if ($callback) {
$callback($filename);
}
}
}
}
closedir($handle);
}
return $files;
}
?>