fileToHex.kts

val result = StringBuffer()
val HEX_CHARS = "0123456789ABCDEF".toCharArray()
java.io.File("YOUR PATH HERE").forEachBlock { buffer,read->
    
    buffer.forEach {
        val octet = it.toInt()
        val firstIndex = (octet and 0xF0).ushr(4)
        val secondIndex = octet and 0x0F
        result.append(HEX_CHARS[firstIndex])
        result.append(HEX_CHARS[secondIndex])
    }
}
System.out.println(result.toString())