Try: run a command and inspect its effects before changing your live system
As cool as this is, it shouldn’t be necessary. A proper undo turns every command into the equivalent of a “try”, allowing users to experiment without fear of data loss. Everything in a computer user interface should be undoable.<p>This has been known for over 40 years, but the industry has been very slow to get the memo. The undo implementation on the iPhone is a weird joke. CLIs have barely even tried (with a few exceptions like Jef Raskin’s Canon Cat, a textual UI completely different from anything else I’ve ever seen).<p>Maybe one day…