gtk_text_buffer_get_iter_at_line (buffer, &start, 0);
gtk_text_buffer_get_iter_at_offset (buffer, &stop, -1);
text = gtk_text_buffer_get_text (buffer, &start, &stop, FALSE);
gtk_text_buffer_get_iter_at_line (buffer, &start, 0);
gtk_text_buffer_get_iter_at_offset (buffer, &stop, -1);
text = gtk_text_buffer_get_text (buffer, &start, &stop, FALSE);