Key-up event in Emacs, or poll keyboard state?

In emacs is there is a way to check for a key-up ev开发者_StackOverflow社区ent, or, alternatively, is it possible to poll the keyboard and check if a key is currently pressed?

Emacs elisp API don't allow you get info how long key pressed and if it still currently pressed.

Emacs work not only in GUI mode but also in terminals, where this info is not available (as hardware don't support it).

So GNU Emacs written in way that it can not pull such info to you.

If you want more complete answer ask on emacs-devel@gnu.org but be careful do not be offtopic. help-gnu-emacs@gnu.org is primary list for Emacs questions.

Also check: EmacsMailingLists EmacsNewsgroups

StackOverflow is not good site for question about Emacs internals...