ne allows you to associate any keystroke with any command. These
associations are referred to as key bindings. You define your key
bindings in a (possibly UTF-8) file named .keys in your
~/.ne directory. You could additionally create a .keys file in
your current directory, any your system administrator might also place a
.keys file in your system’s global directory. These will always be
loaded each time you start ne, but you can also create key binding
files with the same base name (.keys) followed by a dash and some
string. Such a file will only be loaded when the string matches the value of
your TERM environment variable. For example, you might have files
named ~/.ne/.keys, ~/.ne/.keys-xterm, and
~/.ne/.keys-vt102. The first file’s key bindings will always be
loaded, while at most one of the latter two files will be loaded, depending
on your TERM environment variable.
You can change your key binding files’ default base name from .keys by
passing an argument to the --keys option when you start ne, and
you can prevent any configuration from being loaded with the
--no-config option (see Arguments).
The format of key binding files is simple: each line starting with the ‘KEY’ sequence of capital characters is considered the description of a key binding. Each line starting with ‘SEQ’ binds a character sequence to a key. All other lines are considered comments. The format of a key binding description is
KEY hexcode command
The hexcode value is the ASCII code of the keystroke. (For
special keys such as Insert or function keys, you should take a
look at the file default.keys that comes with ne’s
distribution: it contains a complete, commented definition of
ne’s standard bindings that you can modify with a trial-and-error
approach.) The easiest way to see the code ne uses for a given
key is by using the KeyCode command. It prompts you to press a
key, then reports the code for that key on the status bar. It also
displays the command bound to that key if there is one.
You can write just the hexadecimal digits, nothing else is necessary (but a prefixing ‘0x’ is tolerated). For instance,
KEY 1 MoveSOL
binds to Control-A the action of moving to the start of a line, while
KEY 101 LineUp
binds to the “cursor-up” key the action of moving the cursor one line up.
command can be any ne command, including Escape
(which allows reconfiguring the menu activator) and Macro, which
allows binding complex sequences of actions to a single keystroke. The binding
of a macro is very fast because on the first call the macro is cached in memory.
See Macro.
Note that you cannot ever redefine Return or Escape. This is a basic issue—however brain damaged is the current configuration, you will always be able to exploit fully the menus and the command line.
Besides the “standard” combinations (e.g.,
Control-letter), it possible to program combinations
based on the Meta key (a.k.a. Alt). The situation in this
case is a bit more involved, because depending on the terminal emulator you are
using, the effect of the Meta key can be widely different. For
instance, xterm raises the eighth bit of a character, so, for
instance,
KEY 81 MoveSOF
binds Control-Meta-a to the action of moving to the
start of the document. However, gnome-terminal will emit the
character of ASCII code 1 prefixed with ESC instead (“\x1b\x01”). To handle this case,
ne provides codes from 180 on for simulated Meta
sequences: for instance,
KEY 181 MoveSOF
binds the abovementioned sequence to the same action as before. In general, the code 180+x corresponds to the sequence ESC followed by the ASCII character of code x. Note that some of these sequences may be disabled, if they conflict with existing sequences of your terminal (for instance, ESC followed by ‘O’ is always disabled because it prefixes several built-in keyboard sequences).
As a final note, we remark that typing Meta-a on
gnome-terminal will produce an ESC followed by ‘a’ (“\x1ba”). Since it
is obviously easier to press just Meta rather than Meta and
Control at the same time, it is a good idea to associate the same
sequence also to this combination, using
KEY 1E1 MoveSOF
Moreover, this setting provides the user with a second choice: one can press Escape followed by a letter instead of using modifiers.
This is the approach used by default in ne: this way,
Control with Meta plus a letter should always work, and
Meta should work sometimes (of course, if you’re sure to use
always the same kind of emulator you can bind more features). Again, the
best place to look is the default.keys file.
As stated above, each line starting with ‘SEQ’ binds a character sequence to a key code. The format for a ‘SEQ’ binding is
SEQ "sequence" hexcode
where "sequence" is a double-quoted string of characters (which can include escaped hexadecimals) followed by a hexadecimal key code as described above for ‘KEY’ definitions.
You should rarely need this, as properly configured systems already do
this for most keys. However, some key combinations (Control in
conjunction with cursor keys for example) are usually not defined. If you
know the character sequence your system generates for such a combination, you may use
‘SEQ’ to bind that sequence to a particular key code if that sequence
isn’t already defined on your system. For example,
Control-“cursor-left” may generate the sequence
\x1b[1;5D. The following lines bind that sequence to the f10
key code ‘14A’, then bind that key code to the ‘HELP’ command.
SEQ "\x1b[1;5D" 14A KEY 14A HELP
Sequences are inherently terminal- or terminal emulator-specific, so
their utility will vary depending on how many emulators you use. At least
they give you the possibility to use keys or key combinations that aren’t
covered by curses.
The key binding file is parsed at startup. If something does not work,
ne exits displaying an error message. If you want ne to skip
parsing the key binding file (for instance, to correct the broken
file), just give ne the --no-config argument. See Arguments.