This famous story is called The Lady Or The Tiger (1882), by Frank R. Stockton.
The cliffhanger ending is complicated by the fact that the princess knows which door is which, and directs her lover to open the (actually right, not left) door. The man opens it without hesitation.
The story is famous because it asks the reader to decide the ending for ...
I found it:
Apparently this is from the book Build a Better Life by Stealing Office Supplies: Dogbert's Big Book of Business - many thanks to @Carmeister for knowing this!
How I found it: a Google image search for comic strip unix "clothes say" about you (note the quotes) led me to this page. Having found the image, I tried searching for an exact quote but ...
TL;DR: This story is recognisable as a mangled version of Donald Knuth’s solution to the ‘K most common words’ problem and Doug McIlroy’s review of it, in the June 1986 Communications of the ACM.
In the 1980s, Jon Bentley wrote a column called ‘Programming Pearls’ that appeared in the Communications of the ACM. He devoted the columns ...
Found it! It's "Philomel Cottage" by Agatha Christie!!
I just dug it up at my parents' house, it was a story in a Longman simplified edition called "Stories of Detection and Mystery". Had apparently confused it with Poe's Tales of Mystery and Imagination!
"I'm just going to telephone to the butcher," she announced nonchalantly. "Don't you bother to move." ...
Rebel Raider by H. Beam Piper looks like a possibility. It ends with:
Jeb Stuart left John Singleton Mosby behind Northern lines "to look
after loyal Confederate people." But before the war was over, Mosby
did a lot more than that....
A True Book-Length Feature
Laporte must refer to The Grand Mystery: Or, Art of Meditating Over an House of Office, Restor'd and Unveil'd, published in 1726; whether this is to be attributed to Swift or to Edward Ward is apparently unclear. A modern reproduction is for sale online but I couldn't find any more information on this book.
It seems this was resolved on Goodreads' group "What's the name of that book???":
More Five Minute Bunny Tales for Bedtime by Geoffrey Cowan
I'm posting the answer here for the sake of potential future searches. If someone wants to add more detailed answer I'll gladly delete mine (if I'm allowed to).
This sounds like it might be Factoring Humanity (1998) by Robert J. Sawyer. (Admittedly it's more like 20 years old than 30.)
The aliens (from Alpha Centauri) first send a message, then a ship. (The decoded message contains instructions for building a device that allows people to visit and explore what is essentially the collective unconscious of humanity....