getAttribute

inline fun Path.getAttribute(attribute: String, vararg options: LinkOption): Any?(source)

import java.nio.file.Paths
import java.nio.file.LinkOption
import kotlin.io.path.getAttribute

fun main() {
    val path = Paths.get("sample.txt")
    val size = path.getAttribute("size", LinkOption.NOFOLLOW_LINKS) as? Long
    println("Size: $size bytes")
}