Save Screen (program) output to a file
There is a command line option for logging. The output is saved to screenlog.n file, where n is a number of the screen. From man pages of screen:
‘-L’ Tell screen to turn on automatic output logging for the windows.
You can also use Control-a + H to save loggings into screenlog.n file. One more Control-a + H to turn off.
C-a H: Begins/ends logging of the current window to the file "screenlog.n".