Terminal Escape Characters – Meaning of ^ Character in Sequences Like ^X^I

When you say Function-F1, I assume you mean pressing that funny little Fn key in the corner of a laptop followed by the F1 key at the top left of the keyboard. And that your trying to map one of the extra keys like Sleep that some laptop keyboards have. It looks like that key is literally pressing multiple keys for you. First I see Win+L as one combo. On Windows, this shortcut locks the screen, but does not start the screensaver. Next, I see a mapping for XF86ScreenSaver which might mean that X is seeing some kind of sleep keycode. I'm guessing that that key on your laptop keyboard is physically sending out those three keycodes of Win + L + Sleep as a convenience for Windows users to quickly lock the screen and activate the screensaver. I'm not sure of a good way to filter those out. The Fn key on keyboards normally is not seen by the Linux Kernel. Instead, it changes which codes the keyboard tells the kernel. When I was trying to use a USB RF PowerPoint remote with OOo on Linux, I discovered that the button to start/stop the presentation was just a lame control to send out alternating F5 and ESC key codes. Other buttons were just as lame like sending out b to blank the screen.

The interface between a terminal application and a terminal emulator (or hardware terminal) transmits bytes, not keys. Function keys such as cursor movement keys are translated into escape sequences (beginning with the escape character ESC a.k.a. \e a.k.a. \033 a.k.a. 0x1b a.k.a. ^[). The same goes for combinations of a function key or a character key with modifiers, though not all terminals send different sequences for all the different modifier combinations. A few keys are sent encoded as control characters (e.g. Tab → Ctrl-I = \t = \011).

As you can see, there are many ways to describe control characters. Some have a name, corresponding to their traditional function (e.g. Tab, Line feed); those tend to have a backslash+letter combination that you can use inside $'…' or in an argument to echo or print (as well as in sed regular expressions and in string literals in awk, C and other languages (note that different tools may have a slightly different set of escape sequences)). You can use backslash+octal (e.g. \033) in these contexts as well.

There is some variation as to which escape sequence terminals send for each key. Fortunately, there is almost no overlap: there are very few character sequences that mean different keys on different terminal. The main problem is character 127 = \177 = 0x7f which is most often Backspace nowadays but sometimes Delete.

^[OF and ^[[F (i.e. \eOF and \e[F) are the two common escape sequences sent by End. ^E (i.e. \005) is the Emacs key binding (Ctrl+E) for end-of-line.

To see what your terminal emulator sends for a particular key or key combination, press Ctrl+V and then the key in question. This inserts the first character of the escape sequence literally. Escape sequences normally consist of an escape character followed by printable characters, so the rest of the escape sequence is inserted literally too.

The Terminfo database contains the escape sequences for some keys. You'll find the list of Terminfo capabilities in the terminfo(5) man page on your system. In zsh, you can list the values in the database through the terminfo associative array. Beware when printing out values that they contain escape sequences which are also interpreted by the terminal when displayed, so print them in a quoted form.

% print -lr ${(q)terminfo[kend]}
$'\033'OF

See How do keyboard input and text output work? for a more complete overview of what happens when you press a key. It isn't necessary to understand key bindings in zsh.