bea-sanitize-filename.php

<?php
/*
Plugin Name: BEA - Sanitize Filename
Version: 2.0.7
Plugin URI: https://github.com/BeAPI/bea-sanitize-filename
Description: Remove all punctuation and accents from the filename of uploaded files.
Author: Be API
Author URI: https://beapi.fr
Domain Path: languages
Text Domain: bea-sanitize-filename
Contributors: Amaury Balmer, Maxime Culea

--------

Copyright 2018-2019 Be API Technical team (human@beapi.fr)

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

/**
 * Add some special chats to espace to WordPress basic list
 *
 * @param array $special_chars
 *
 * @return array
 */
function bea_sanitize_file_name_chars( $special_chars = array() ) {
	// Special caracters
	$special_chars = array_merge( array( '’', '‘', '“', '”', '«', '»', '‹', '›', '—', '€', '©' ), $special_chars );
	/**
	 * Accentued caracters
	 * @see   https://github.com/BeAPI/bea-sanitize-filename/issues/8
	 * @since 2.0.6
	 */
	$special_chars = array_merge( array( 'À', 'Á', 'Â', 'Ã', 'Ä', 'Å', 'Ç', 'È', 'É', 'Ê', 'Ë', 'Ì', 'Í', 'Î', 'Ï', 'Ò', 'Ó', 'Ô', 'Õ', 'Ö', 'Ù', 'Ú', 'Û', 'Ü', 'Ý', 'à', 'á', 'â', 'ã', 'ä', 'å', 'ç', 'è', 'é', 'ê', 'ë', 'ì', 'í', 'î', 'ï', 'ð', 'ò', 'ó', 'ô', 'õ', 'ö', 'ù', 'ú', 'û', 'ü', 'ý', 'ÿ' ), $special_chars );

	return $special_chars;
}

add_filter( 'sanitize_file_name_chars', 'bea_sanitize_file_name_chars', 10, 1 );

/**
 * Filters the filename by adding more rules :
 * - only lowercase
 * - replace _ by -
 *
 * @since 1.0.1
 *
 * @param string $file_name
 *
 * @return string
 */
function bea_sanitize_file_name( $file_name = '' ) {
	// Empty filename
	if ( empty( $file_name ) ) {
		return $file_name;
	}

	// get extension
	preg_match( '/\.[^\.]+$/i', $file_name, $ext );

	// No extension, go out ?
	if ( ! isset( $ext[0] ) ) {
		return $file_name;
	}

	// Get only first part
	$ext = $ext[0];

	// work only on the filename without extension
	$file_name = str_replace( $ext, '', $file_name );

	// only lowercase
	$file_name = mb_strtolower( $file_name );
	// remove accents
	$file_name = remove_accents( $file_name );

	// replace _ by -
	$file_name = str_replace( '_', '-', $file_name );

	// Return sanitized file name
	return $file_name . $ext;
}

add_filter( 'sanitize_file_name', 'bea_sanitize_file_name', 10, 1 );