Paul Moore writes:
They are on the keyboard. The £ sign is shift-3, the € sign uses the AltGr key (which is woefully underused on the standard UK keyboard driver - accented letters *should* be available using it :-()
Believe me, I've tried. But I should point out that I *don't* count the "official" way (Alt plus typing the numeric code out on the numeric keypad) as a viable option:
I don't either.
A question, though. On Linux, (pick your distribution, but ideally "it doesn't matter")
It does matter, at least last I checked. Different distros default to different keyboard configurations. And it definitely matters what language you configure as your primary -- accented letters and punctuation used in that language will use AltGr, while those that aren't may require a mode switch or a COMPOSE-ACCENT-BASE sequence.
how would I type é, √, ☺ ? Assume any answer that starts with "look up the numeric code" is unacceptable, as is anything that only works in a specific application.
Because this is X11/Unix, the answer is "it depends." (For math symbols and emoji, the common denominator default would surely be selection from a palette.) I suspect if there was a popular programming language that used a half-dozen non-ASCII characters, a slew of applets to configure those characters onto the keymap would arise quickly, and one of those that provided relative sane default mappings would become TOOWTDI. This is definitely possible, but at the moment, aside from language-specific mappings we already have, there's no obvious set of default characters that "everybody" needs.
So a consistent, discoverable system for Unix won't happen until there's a bunch of non-ASCII everybody needs (and that can't be treated algorithmically like smart quotes), and no programming language will impose that until there's a consistent discoverable system of non-ASCII keymaps. :-(