Key combination syntax

Wherever Rune accepts a key combination (bindings in rune.star, the goto template for the exoeditor, key sequences sent into a vte, or error messages from a misconfigured binding) the same grammar is used. Use this page as the single reference for what you can write.

At a glance

• Plain printable characters stand for themselves: a, A, 1, ?.
• Named keys, modifier-decorated keys, and mouse events go inside angle brackets: <enter>, <ctrl-space>, <shift-up>, <mouse-left>.
• Modifier names are lowercase and may be spelled out (ctrl, shift, alt, meta) or written as a single-letter alias (c, s, a, m).
• When combining modifiers, the order is fixed; see Modifier order. <shift-ctrl-x> is rejected; <ctrl-shift-x> is accepted.
• Multiple keystrokes are concatenated: <esc>:wq<enter> is four keys.
• The literal characters <, >, and \ must be escaped with a backslash: \<, \>, \\.
• A literal space is <space>; a bare inside a key sequence is rejected.

Plain characters

Any single printable character (other than <, >, \, and space) is itself a key combination. Case matters:

a       # the letter a
A       # shift-a, as a single key
1       # the digit 1
?       # the question mark

Concatenate characters to describe a sequence:

gg      # press g, then g again
:wq     # colon, w, q

Named keys

Named keys are bracketed, lowercase, and have no modifier prefix:

Name	Key
<enter>	Return / Enter
<esc>	Escape
<tab>	Tab
<space>	Space bar
<backspace>	Backspace
<insert>, <delete>	Insert, Delete
<home>, <end>	Home, End
<pgup>, <pgdn>	Page Up, Page Down
<up>, <down>, <left>, <right>	Arrow keys
<f1> … <f12>	Function keys

Mouse events

Mouse events use the same bracket-and-modifier grammar:

Name	Event
<mouse-left>	Primary button press
<mouse-middle>	Middle button press
<mouse-right>	Secondary button press
<mouse-release>	Button release
<mouse-wheel-up>	Wheel scroll up
<mouse-wheel-down>	Wheel scroll down

Modifiers attach the same way as for keys: <ctrl-mouse-left>, <shift-mouse-wheel-up>, <alt-mouse-right>.

Modifiers

Prefix a bracketed key with one or more modifier names:

<ctrl-...>
<shift-...>
<alt-...>
<meta-...>

Notes on individual modifiers:

• ctrl combines with letters, digits, function keys, arrows, mouse events, and most named keys (e.g. <ctrl-a>, <ctrl-_>, <ctrl-space>, <ctrl-pgdn>).
• shift is meaningful on non-letter keys where Rune can detect it (<shift-tab>, <shift-up>, <shift-f5>). For plain letters, prefer the uppercase character (A) over <shift-a>.
• alt is the Linux/Windows "Alt" key.
• meta is the OS "super" key: Command on macOS, the Windows/Super key on Linux.

Short-form modifiers

Each modifier has a single-letter alias that is interchangeable with the spelled-out form: c for ctrl, s for shift, a for alt, m for meta. The alias rules apply in combinations too, so all of the following describe the same key:

<ctrl-shift-x>
<c-shift-x>
<ctrl-s-x>
<c-s-x>

The spelled-out form is the canonical one and is what Rune emits when it renders a key combination back to a string; pick that form in configuration you write by hand so what you type matches what Rune prints in error messages and log output.

Modifier order

Modifiers must appear in the order Rune expects, not in the order you'd say them out loud. The accepted combinations are exactly:

Modifiers	Canonical form
ctrl + shift	<ctrl-shift-…>
ctrl + alt	<ctrl-alt-…>
ctrl + meta	<ctrl-meta-…>
ctrl + shift + alt	<ctrl-shift-alt-…>
ctrl + shift + meta	<ctrl-shift-meta-…>
ctrl + alt + meta	<ctrl-alt-meta-…>
shift + meta	<shift-meta-…>
alt + shift	<alt-shift-…>
alt + meta	<alt-meta-…>
alt + shift + meta	<alt-shift-meta-…>

Anything else (<shift-ctrl-x>, <meta-alt-up>, <alt-ctrl-f1>) is rejected at parse time, even though the meaning is unambiguous. There is no combination that mixes all four modifiers (ctrl + shift + alt + meta).

Sequences

A binding value is a sequence of key combinations, concatenated with no separator. Each character or <…> block is one keystroke:

<ctrl-x><ctrl-s>           # press Ctrl-X, then Ctrl-S
<esc>:goto<space>42<enter> # esc, colon, g, o, t, o, space, 4, 2, enter
gg                         # press g twice

Escaping

<, >, and \ are the three reserved characters. Escape them with a leading backslash to use them as literal keystrokes:

Escape	Literal key
\<	<
\>	>
\\	\

A bare space inside a sequence is rejected; write <space> instead. This makes whitespace in a binding value purely cosmetic and prevents accidental truncation when a sequence is copied across formats.

Common mistakes

Wrong	Correct	Why
Ctrl-Space	<ctrl-space>	Bracketed, lowercase, no +
Ctrl+S	<ctrl-s>	Hyphen, not +
<C-s>	<c-s> or <ctrl-s>	Modifier names are lowercase (see Short-form modifiers)
<A-x>	<a-x> or <alt-x>	Modifier names are lowercase
<Shift-Tab>	<shift-tab>	All-lowercase inside brackets
<ctrl- >	<ctrl-space>	A literal space is not allowed
<meta-cmd-k>	<meta-k>	meta already covers Command/Super
<shift-ctrl-x>	<ctrl-shift-x>	Modifier order is fixed (see Modifier order)
<meta-alt-up>	<alt-meta-up>	Modifier order is fixed
<ctrl-shift-alt-meta-x>		Four-modifier combinations are not accepted