How to avoid file names with spaces and/or special characters - php

Question

I have a web form to upload pictures from the users.
Then I am creating an iOS app to show the pictures loaded from the users. But the app is not loading the pictures if the file name contains spaces or special characters (like á, é, í, ó, ú, ñ, etc.), most of the users are from Spain...
This is the code I am using:
<?php if ((isset($_POST["enviado"])) && ($_POST["enviado"] == "form1")) {
$randomString = substr(str_shuffle("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"), 0, 1) . substr(str_shuffle("0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"), 0, 10);
echo $randomString;
$nombre_archivo = $_FILES['userfile']['name'];
move_uploaded_file($_FILES['userfile']['tmp_name'], "logos/".$randomString.$nombre_archivo);
?>
I am using the random function to avoid repeated file names.
How could I change the file name given by the user and that may contain spaces and/or special characters, in a way that can be perfectly loaded in the iOS app?

Answer 1

rename the file after upload. this is an answer to OP's question in comments
// get the uploaded file's temp filename
$tmp_filename = $_FILES['userfile']['tmp_name'];
// get the file's extension
$path = $_FILES['userfile']['name'];
$ext = pathinfo($path, PATHINFO_EXTENSION);
// rename the uploaded file with a timestamp, insert the destination directory and add the extension
$new_filename = 'logos/'.date('Ymdhms').'.'.$ext;
// put the renamed file in the destination directory
move_uploaded_file($tmp_filename, $new_filename);
Edit: new answer per OP's question
<?php
if((isset($_POST["enviado"])) && ($_POST["enviado"] == "form1")) {
// get the uploaded file's temp filename
$tmp_filename = $_FILES['userfile']['tmp_name'];
// get the file's extension
$path = $_FILES['userfile']['name'];
$ext = pathinfo($path, PATHINFO_EXTENSION);
// rename the uploaded with a timestamp file, add the extension and assign the directory
$new_filename = 'logos/'.date('Ymdhms').'.'.$ext;
// put the renamed file in the destination directory
move_uploaded_file($tmp_filename, $new_filename);
}

Answer 2

Here is what you need to do.
1) generate a unique id based filename string.
2) Rename the file with newly generated filename.
<?php
rename("/tmp/tmp_file.txt", "/home/user/login/docs/my_file.txt");
?>

Answer 3

If you actually wanted to keep the user-entered string as part of the file name, you could do something like this which transliterates UTF-8 characters to their ASCII equivalent (if possible) and then removes any non ASCII and invalid characters:
function get_file_name($string) {
// Transliterate non-ascii characters to ascii
$str = trim(strtolower($string));
$str = iconv('UTF-8', 'ASCII//TRANSLIT', $str);
// Do other search and replace
$searches = array(' ', '&', '/');
$replaces = array('-', 'and', '-');
$str = str_replace($searches, $replaces, $str);
// Make sure we don't have more than one dash together because that's ugly
$str = preg_replace("/(-{2,})/", "-", $str );
// Remove all invalid characters
$str = preg_replace("/[^A-Za-z0-9-]/", "", $str );
// Done!
return $str;
}
You could try combining this together with the unique ID for the file so if two users upload a file with the same file name they don't clash.