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sanitize_file_name ›

Since2.1.0
Deprecatedn/a
sanitize_file_name ( $filename )
Parameters:
  • (string) $filename The filename to be sanitized.
    Required: Yes
Returns:
  • (string) The sanitized filename.
Defined at:
Codex:

Sanitizes a filename, replacing whitespace with dashes.

Removes special characters that are illegal in filenames on certain operating systems and special characters requiring special escaping to manipulate at the command line. Replaces spaces and consecutive dashes with a single dash. Trims period, dash and underscore from beginning and end of filename. It is not guaranteed that this function will return a filename that is allowed to be uploaded.


Source

function sanitize_file_name( $filename ) {
	$filename_raw  = $filename;
	$special_chars = array( '?', '[', ']', '/', '\\', '=', '<', '>', ':', ';', ',', "'", '"', '&', '$', '#', '*', '(', ')', '|', '~', '`', '!', '{', '}', '%', '+', chr( 0 ) );

	// Check for support for utf8 in the installed PCRE library once and store the result in a static.
	static $utf8_pcre = null;
	if ( ! isset( $utf8_pcre ) ) {
		// phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged
		$utf8_pcre = @preg_match( '/^./u', 'a' );
	}

	if ( ! seems_utf8( $filename ) ) {
		$_ext     = pathinfo( $filename, PATHINFO_EXTENSION );
		$_name    = pathinfo( $filename, PATHINFO_FILENAME );
		$filename = sanitize_title_with_dashes( $_name ) . '.' . $_ext;
	}

	if ( $utf8_pcre ) {
		$filename = preg_replace( "#\x{00a0}#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( '/[\r\n\t -]+/', '-', $filename );
	$filename      = trim( $filename, '.-_' );

	if ( false === strpos( $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 ) {
		/**
		 * Filters a sanitized filename string.
		 *
		 * @since 2.8.0
		 *
		 * @param string $filename     Sanitized filename.
		 * @param string $filename_raw The filename prior to sanitization.
		 */
		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;
				}
			}
			if ( ! $allowed ) {
				$filename .= '_';
			}
		}
	}
	$filename .= '.' . $extension;
	/** This filter is documented in wp-includes/formatting.php */
	return apply_filters( 'sanitize_file_name', $filename, $filename_raw );
}