Thank you ikegame and shmem for your replies. You both seemed to be asking what do I want this for. Indeed from your responses I see I forgot to state clearly what criteria I'm looking for in a solution.
in reply to Wanted: humanly readable `script` output
I want a file which (1) is a snapshot (ignoring color and font type) of the terminal at a given moment in time (rather than a movie, which is what script captures.) and (2) as if the terminal had no buffer size limitation, (3) is editable and searchable with a text editor, (4) is the output of a command-line program, not the result of copy/pasting with a mouse.
Up to now, my usual practice has been to copy/paste stuff from a terminal into an emacs buffer using a mouse. I lose coloring and bold face text, but I obtain a snapshot that respects erased characters and cursor positioning up to a certain point in time. That satisfies criteria (1) and (3), but not (2) and (4).
Thank you all very much for your thoughtful suggestions, but due to my inaccurate description of what I'm looking for, none of the suggestions so far meet my criteria.