appendBytes

inline fun Path.appendBytes(array: ByteArray)(source)

import java.nio.file.Paths
import kotlin.io.path.appendBytes
import kotlin.io.path.readText

fun main() {
    val path = Paths.get("demo.txt")

    // Append first chunk of bytes
    val firstChunk = "Hello, ".toByteArray(Charsets.UTF_8)
    path.appendBytes(firstChunk)

    // Append second chunk of bytes
    val secondChunk = "world!".toByteArray(Charsets.UTF_8)
    path.appendBytes(secondChunk)

    // Verify the result
    println(path.readText())   // Prints: Hello, world!
}