/**
 * Upload has a limit of 10 mb
 * @param string $dir $_SERVER['DOCUMENT_ROOT']
 * @param string $path Path do you want to upload the file
 * @param string $filetype jpg|jpeg|gif|png|doc|docx|txt|rtf|pdf|xls|xlsx|ppt|pptx
 * @param array $_FILES An associative array of items uploaded to the current script via the HTTP POST method.
 * @return string ?$fileName:False
 */
function uploadFiles($dir, $path, $filetype) {
 $dir_base = "{$dir}{$path}";
 $dateadded = date('ynj_Gis-');
 $rEFileTypes = "/^\.($filetype){1}$/i";
 $MAXIMUM_FILESIZE = 10 * 1024 * 1024;
// UPLOAD IMAGES
 $isFile = is_uploaded_file($_FILES['file']['tmp_name']);
 if ($isFile) {
 $safe_filename = $dateadded . preg_replace(array('/\s+/', '/[^-\.\w]+/'), array('_', ''), trim($_FILES['file']['name']));
 if ($_FILES['file']['size'] <= $MAXIMUM_FILESIZE && preg_match($rEFileTypes, strrchr($safe_filename, '.'))) {
 $isMove = move_uploaded_file($_FILES['file']['tmp_name'], $dir_base . $safe_filename);
 }
 }
 if ($isMove) {
 return $safe_filename;
 } else {
 return false;
 }
}

/**
 * Upload has a limit of 10 mb
 * @param string $dir $_SERVER['DOCUMENT_ROOT']
 * @param string $path Path do you want to upload the file
 * @param string $filetype jpg|jpeg|gif|png|doc|docx|txt|rtf|pdf|xls|xlsx|ppt|pptx
 * @param array $_FILES An associative array of items uploaded to the current script via the HTTP POST method.
 * @return string ?$fileName:False
 */
function uploadFiles($dir, $path, $filetype) {
 $dir_base = "{$dir}{$path}";
 $dateadded = date('ynj_Gis-');
 $rEFileTypes = "/^\.($filetype){1}$/i";
 $MAXIMUM_FILESIZE = 10 * 1024 * 1024;
// UPLOAD IMAGES
 $isFile = is_uploaded_file($_FILES['file']['tmp_name']);
 if ($isFile) {
 $safe_filename = $dateadded . preg_replace(array('/\s+/', '/[^-\.\w]+/'), array('_', ''), trim($_FILES['file']['name']));
 if ($_FILES['file']['size'] <= $MAXIMUM_FILESIZE && preg_match($rEFileTypes, strrchr($safe_filename, '.'))) {
 $isMove = move_uploaded_file($_FILES['file']['tmp_name'], $dir_base . $safe_filename);
 }
 }
 if ($isMove) {
 return $safe_filename;
 } else {
 return false;
 }
}

How can I improve the name check part or another things?

I have this function working on php 5.3

/**
 * Upload has a limit of 10 mb
 * @param string $dir $_SERVER['DOCUMENT_ROOT']
 * @param string $path Path do you want to upload the file
 * @param string $filetype jpg|jpeg|gif|png|doc|docx|txt|rtf|pdf|xls|xlsx|ppt|pptx
 * @param array $_FILES An associative array of items uploaded to the current script via the HTTP POST method.
 * @return string ?$fileName:False
 */
function uploadFiles($dir, $path, $filetype, $_FILES) {
 $dir_base = "{$dir}{$path}";
 $dateadded = date('ynj_Gis-');
 $rEFileTypes = "/^\.($filetype){1}$/i";
 $MAXIMUM_FILESIZE = 10 * 1024 * 1024;
// UPLOAD IMAGES
 $isFile = is_uploaded_file($_FILES['file']['tmp_name']);
 if ($isFile) {
 $safe_filename = $dateadded . preg_replace(array('/\s+/', '/[^-\.\w]+/'), array('_', ''), trim($_FILES['file']['name']));
 if ($_FILES['file']['size'] <= $MAXIMUM_FILESIZE && preg_match($rEFileTypes, strrchr($safe_filename, '.'))) {
 $isMove = move_uploaded_file($_FILES['file']['tmp_name'], $dir_base . $safe_filename);
 }
 }
 if ($isMove) {
 return $safe_filename;
 } else {
 return false;
 }
}

But when I include this function in another project that run over php 5.4 I get

500 Internal Server Error

Just including this function without call it, I get the error.

What is the issue here?

/**
 * Upload has a limit of 10 mb
 * @param string $dir $_SERVER['DOCUMENT_ROOT']
 * @param string $path Path do you want to upload the file
 * @param string $filetype jpg|jpeg|gif|png|doc|docx|txt|rtf|pdf|xls|xlsx|ppt|pptx
 * @param array $_FILES An associative array of items uploaded to the current script via the HTTP POST method.
 * @return string ?$fileName:False
 */
function uploadFiles($dir, $path, $filetype) {
 $dir_base = "{$dir}{$path}";
 $dateadded = date('ynj_Gis-');
 $rEFileTypes = "/^\.($filetype){1}$/i";
 $MAXIMUM_FILESIZE = 10 * 1024 * 1024;
// UPLOAD IMAGES
 $isFile = is_uploaded_file($_FILES['file']['tmp_name']);
 if ($isFile) {
 $safe_filename = $dateadded . preg_replace(array('/\s+/', '/[^-\.\w]+/'), array('_', ''), trim($_FILES['file']['name']));
 if ($_FILES['file']['size'] <= $MAXIMUM_FILESIZE && preg_match($rEFileTypes, strrchr($safe_filename, '.'))) {
 $isMove = move_uploaded_file($_FILES['file']['tmp_name'], $dir_base . $safe_filename);
 }
 }
 if ($isMove) {
 return $safe_filename;
 } else {
 return false;
 }
}