wp_check_filetype_and_ext

Source code

function wp_check_filetype_and_ext( $file, $filename, $mimes = null ) {



	$proper_filename = false;



	// Do basic extension validation and MIME mapping

	$wp_filetype = wp_check_filetype( $filename, $mimes );

	extract( $wp_filetype );



	// We can't do any further validation without a file to work with

	if ( ! file_exists( $file ) )

		return compact( 'ext', 'type', 'proper_filename' );



	// We're able to validate images using GD

	if ( $type && 0 === strpos( $type, 'image/' ) && function_exists('getimagesize') ) {



		// Attempt to figure out what type of image it actually is

		$imgstats = @getimagesize( $file );



		// If getimagesize() knows what kind of image it really is and if the real MIME doesn't match the claimed MIME

		if ( !empty($imgstats['mime']) && $imgstats['mime'] != $type ) {

			// This is a simplified array of MIMEs that getimagesize() can detect and their extensions

			// You shouldn't need to use this filter, but it's here just in case

			$mime_to_ext = apply_filters( 'getimagesize_mimes_to_exts', array(

				'image/jpeg' => 'jpg',

				'image/png'  => 'png',

				'image/gif'  => 'gif',

				'image/bmp'  => 'bmp',

				'image/tiff' => 'tif',

			) );



			// Replace whatever is after the last period in the filename with the correct extension

			if ( ! empty( $mime_to_ext[ $imgstats['mime'] ] ) ) {

				$filename_parts = explode( '.', $filename );

				array_pop( $filename_parts );

				$filename_parts[] = $mime_to_ext[ $imgstats['mime'] ];

				$new_filename = implode( '.', $filename_parts );



				if ( $new_filename != $filename )

					$proper_filename = $new_filename; // Mark that it changed



				// Redefine the extension / MIME

				$wp_filetype = wp_check_filetype( $new_filename, $mimes );

				extract( $wp_filetype );

			}

		}

	}



	// Let plugins try and validate other types of files

	// Should return an array in the style of array( 'ext' => $ext, 'type' => $type, 'proper_filename' => $proper_filename )

	return apply_filters( 'wp_check_filetype_and_ext', compact( 'ext', 'type', 'proper_filename' ), $file, $filename, $mimes );

}