kotlin_log2file.kt

import android.content.Context
import java.io.File
import java.io.FileOutputStream
import java.io.PrintWriter
import java.io.StringWriter

fun Context.logToFile(str: String, filename: String = "LOG.txt") {
    val file = File("$filesDir${File.separator}$filename")
    if (!file.exists()) file.createNewFile()
    FileOutputStream(file, true).bufferedWriter().use { out -> out.appendLine(str) }
}

fun Context.logToFile(exception: Exception) {
    logToFile(getStackTraceString(exception))
}

fun getStackTraceString(tr: Throwable?): String {
    var t = tr
    while (t != null) {
        t = t.cause
    }
    val sw = StringWriter()
    val pw = PrintWriter(sw)
    tr?.printStackTrace(pw)
    pw.flush()
    return sw.toString()
}