Gio.DataInputStream.prototype.read_line_finish_utf8

function read_line_finish_utf8(result: Gio.AsyncResult): [return_value: String, length: Number(gsize)] {
    // Gjs wrapper for g_data_input_stream_read_line_finish_utf8()
}

Finish an asynchronous call started by Gio.DataInputStream.prototype.read_line_async.

Since 2.30

result: the Gio.AsyncResult that was provided to the callback.
return_value: a string with the line that was read in (without the newlines). Set length to a #gsize to get the length of the read line. On an error, it will return null and @error will be set. For UTF-8 conversion errors, the set error domain is %G_CONVERT_ERROR. If there's no content to read, it will still return null, but @error won't be set.
length: a #gsize to get the length of the data read in.