wp-includes/formatting.php:2035Sanitizes a filename, replacing whitespace with dashes.
$filenamestringstring3 hooks fire while sanitize_file_name() runs, in this order:
Filters the list of characters to remove from a filename.
Filters a sanitized filename string.
Filters a sanitized filename string.
function sanitize_file_name( $filename ) { $filename_raw = $filename; $filename = remove_accents( $filename ); $special_chars = array( '?', '[', ']', '/', '\\', '=', '<', '>', ':', ';', ',', "'", '"', '&', '$', '#', '*', '(', ')', '|', '~', '`', '!', '{', '}', '%', '+', '’', '«', '»', '”', '“', chr( 0 ) ); if ( ! wp_is_valid_utf8( $filename ) ) { $_ext = pathinfo( $filename, PATHINFO_EXTENSION ); $_name = pathinfo( $filename, PATHINFO_FILENAME ); $filename = sanitize_title_with_dashes( $_name ) . '.' . $_ext; } if ( _wp_can_use_pcre_u() ) { /** * Replace all whitespace characters with a basic space (U+0020). * * The “Zs” in the pattern selects characters in the `Space_Separator` * category, which is what Unicode considers space characters. * * @see https://www.unicode.org/reports/tr44/#General_Category_Values * @see https://www.unicode.org/versions/Unicode16.0.0/core-spec/chapter-6/#G17548 * @see https://www.php.net/manual/en/regexp.reference.unicode.php */ $filename = preg_replace( '#\p{Zs}#siu', ' ', $filename ); } /** * Filters the list of characters to remove from a filename. * * @since 2.8.0 * * @param string[] $special_chars Array of characters to remove. * @param string $filename_raw The original filename to be sanitized. */ $special_chars = apply_filters( 'sanitize_file_name_chars', $special_chars, $filename_raw ); $filename = str_replace( $special_chars, '', $filename ); $filename = str_replace( array( '%20', '+' ), '-', $filename ); $filename = preg_replace( '/\.{2,}/', '.', $filename ); $filename = preg_replace( '/[\r\n\t -]+/', '-', $filename ); $filename = trim( $filename, '.-_' ); if ( ! str_contains( $filename, '.' ) ) { $mime_types = wp_get_mime_types(); $filetype = wp_check_filetype( 'test.' . $filename, $mime_types ); if ( $filetype['ext'] === $filename ) { $filename = 'unnamed-file.' . $filetype['ext']; } } // Split the filename into a base and extension[s]. $parts = explode( '.', $filename ); // Return if only one extension. if ( count( $parts ) <= 2 ) { /** This filter is documented in wp-includes/formatting.php */ return apply_filters( 'sanitize_file_name', $filename, $filename_raw ); } // Process multiple extensions. $filename = array_shift( $parts ); $extension = array_pop( $parts ); $mimes = get_allowed_mime_types(); /* * Loop over any intermediate extensions. Postfix them with a trailing underscore * if they are a 2 - 5 character long alpha string not in the allowed extension list. */ foreach ( (array) $parts as $part ) { $filename .= '.' . $part; if ( preg_match( '/^[a-zA-Z]{2,5}\d?$/', $part ) ) { $allowed = false; foreach ( $mimes as $ext_preg => $mime_match ) { $ext_preg = '!^(' . $ext_preg . ')$!i'; if ( preg_match( $ext_preg, $part ) ) { $allowed = true; break; } }Introduced in 2.1.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/formatting.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.