foot.ini(5)

# NAME

foot.ini - configuration file for *foot*(1)

# DESCRIPTION

*foot* uses the standard _unix configuration format_, with section based
key/value pairs. The default section is usually unnamed, i.e. not prefixed
with a _[section]_. However it can also be explicitly named _[main]_,
say if it needs to be reopened after any of the other sections.

foot will search for a configuration file in the following locations,
in this order:

	- *XDG_CONFIG_HOME/foot/foot.ini* (defaulting to
	  *$HOME/.config/foot/foot.ini* if unset)
	- *XDG_CONFIG_DIRS/foot/foot.ini* (defaulting to
	  */etc/xdg/foot/foot.ini* if unset)

An example configuration file containing all options with their default value
commented out will usually be installed to */etc/xdg/foot/foot.ini*.

Options are set using KEY=VALUE pairs:

	*\[colors\]*++
*background=000000*++
*foreground=ffffff*

Empty values (*KEY=*) are not supported. String options do allow the
empty string to be set, but it must be quoted: *KEY=""*)

# SECTION: main

*shell*
	Executable to launch. Typically a shell. Default: _$SHELL_ if set,
	otherwise the user's default shell (as specified in
	_/etc/passwd_). You can also pass arguments. For example
	*/bin/bash --norc*.

*login-shell*
	Boolean. If enabled, the shell will be launched as a login shell,
	by prepending a '-' to argv[0]. Default: _no_.

*term*
	Value to set the environment variable *TERM* to. Default:
	_@default_terminfo@_

*font*, *font-bold*, *font-italic*, *font-bold-italic*
	Comma separated list of fonts to use, in fontconfig format. That
	is, a font name followed by a list of colon-separated
	options. Most noteworthy is *:size=n* (or *:pixelsize=n*), which
	is used to set the font size. Note that the font size is also
	affected by the *dpi-aware* option.
	
	Examples:
		- Dina:weight=bold:slant=italic
		- Courier New:size=12
		- Fantasque Sans Mono:fontfeatures=ss01
		- Meslo LG S:size=12, Noto Color Emoji:size=12
		- Courier New:pixelsize=8
	
	For each option, the first font is the primary font. The remaining
	fonts are fallback fonts that will be used whenever a glyph cannot
	be found in the primary font.
	
	The fallback fonts are searched in the order they appear. If a
	glyph cannot be found in any of the fallback fonts, the dynamic
	fallback list from fontconfig (for the primary font) is
	searched.
	
	*font-bold*, *font-italic* and *font-bold-italic* allow custom
	fonts to be used for bold/italic/bold+italic fonts. If left
	unconfigured, the bold/italic variants of the regular font(s)
	specified in *font* are used. *Note*: you _may_ have to tweak the
	size(s) of the custom bold/italic fonts to match the regular font.
	
	To disable bold and/or italic fonts, set e.g. *font-bold* to
	_exactly_ the same value as *font*.
	
	**size** is in _points_ (as defined by the FontConfig format). To
	set a _pixel_ size, use **pixelsize** instead. Note that pixel
	sizes are unaffected by DPI aware rendering (see *dpi-aware*), but
	are affected by desktop scaling.
	
	Default: _monospace:size=8_ (*font*), _not set_ (*font-bold*,
	*font-italic*, *font-bold-italic*).

*font-size-adjustment*
	Amount, in _points_, _pixels_ or _percent_, to increment/decrement
	the font size when zooming in our out.
	
	Examples:
	```
	font-size-adjustment=0.5   # Adjust by 0.5 points
	font-size-adjustment=10px  # Adjust by 10 pixels
	font-size-adjustment=7.5%  # Adjust by 7.5 percent
	```
	
	Default: _0.5_

*include*
	Absolute path to configuration file to import.
	
	The import file has its own section scope. I.e. the including
	configuration is still in the default section after the include,
	regardless of which section the included file ends in.
	
		- The path must be an absolute path, or start with *~/*.
		- Multiple include directives are allowed, but only one path per
		  directive.
		- Nested imports are allowed.
	
	Default: _not set_.

*line-height*
	An absolute value, in _points_, that override line height from the
	font metrics.
	
	You can specify a height in _pixels_ by using the *px* suffix:
	e.g. *line-height=12px*.
	
	*Warning*: when changing the font size at runtime (i.e. zooming in
	our out), foot will change the line height by the same
	percentage. However, due to rounding, it is possible the line
	height will be "too small" for some font sizes, causing
	e.g. underscores to "disappear".
	
	See also: *vertical-letter-offset*.
	
	Default: _not set_.

*letter-spacing*
	Spacing between letters, in _points_. A positive value will
	increase the cell size, and a negative value shrinks it.
	
	You can specify a letter spacing in _pixels_ by using the *px*
	suffix: e.g. *letter-spacing=2px*.
	
	See also: *horizontal-letter-offset*.
	
	Default: _0_.

*horizontal-letter-offset*, *vertical-letter-offset*
	Configure the horizontal and vertical offsets used when
	positioning glyphs within cells, in _points_, relative to the top
	left corner.
	
	To specify an offset in _pixels_, append *px*:
	e.g. *horizontal-letter-offset=2px*.
	
	Default: _0_.

*underline-offset*
	Use a custom offset for underlines. The offset is, by default, in
	_points_ and relative the font's baseline. A positive value
	positions the underline under the baseline, while a negative value
	positions it above the baseline.
	
	To specify an offset in _pixels_, append *px*:
	*underline-offset=2px*.
	
	If left unset (the default), the offset specified in the font is
	used, or estimated by foot if the font lacks underline positioning
	information.
	
	Default: _unset_.

*underline-thickness*
	Use a custom thickness (height) for underlines. The thickness is, by
	default, in _points_.

	To specify a thickness in _pixels_, append *px*:
	*underline-thickness=1px*.

	If left unset (the default), the thickness specified in the font is
	used.

	Default: _unset_

*box-drawings-uses-font-glyphs* Boolean. When disabled, foot generates
	box/line drawing characters itself. The are several advantages to
	doing this instead of using font glyphs:
	
		- No antialiasing effects where e.g. line endpoints appear
		  dimmed down, or blurred.
		- Line- and box characters are guaranteed to span the entire cell,
		  resulting in a gap-less appearance.
		- No alignment issues, i.e. lines are centered when they should be.
		- Many fonts lack some, or all, of the line- and box drawing
		  characters, causing fallback fonts to be used, which results
		  in out-of-place looking glyphs (for example, badly sized).
	
	When enabled, box/line drawing characters are rendered using font
	glyphs. This may result in a more uniform look, in some use cases.
	
	Default: _no_.

*dpi-aware*
	Boolean.
	
	When set to *yes*, fonts are sized using the monitor's DPI, making
	a font of a given size have the same physical size, regardless of
	monitor. In other words, if you drag a foot window between
	different monitors, the font size remains the same.
	
	In this mode, the monitor's scaling factor is ignored; doubling
	the scaling factor will *not* double the font size.
	
	When set to *no*, the monitor's DPI is ignored. The font is
	instead sized using the monitor's scaling factor; doubling the
	scaling factor *does* double the font size.
	
	Note that this option typically does not work with bitmap fonts,
	which only contains a pre-defined set of sizes, and cannot be
	dynamically scaled. Whichever size (of the available ones) that
	best matches the DPI or scaling factor, will be used.
	
	Also note that if the font size has been specified in pixels
	(*:pixelsize=*_N_, instead of *:size=*_N_), DPI scaling
	(*dpi-aware=yes*) will have no effect (the specified pixel size
	will be used as is). But, if the monitor's scaling factor is used
	to size the font (*dpi-aware=no*), the font's pixel size will be
	multiplied with the scaling factor.
	
	Default: _no_

*pad*
	Padding between border and glyphs, in pixels (subject to output
	scaling), in the form _XxY_.
	
	This will add _at least_ X pixels on both the left and right
	sides, and Y pixels on the top and bottom sides. The grid content
	will be anchored in the top left corner. I.e. if the window
	manager forces an odd window size on foot, the additional pixels
	will be added to the right and bottom sides.
	
	To instead center the grid content, append *center* (e.g. *pad=5x5
	center*).
	
	Default: _0x0_.

*resize-delay-ms*

	Time, in milliseconds, of "idle time" before foot performs text
	reflow, and sends the new window dimensions to the client
	application while doing an interactive resize of a foot
	window. Idle time in this context is a period of time where the
	window size is not changing.
	
	In other words, while you are fiddling with the window size, foot
	does not send the updated dimensions to the client. It also does a
	fast "truncating" resize of the grid, instead of actually
	reflowing the contents. Only when you pause the fiddling for
	*resize-delay-ms* milliseconds is the client updated, and the
	contents properly reflowed.
	
	Emphasis is on _while_ here; as soon as the interactive resize
	ends (i.e. when you let go of the window border), the final
	dimensions is sent to the client, without any delays.
	
	Setting it to 0 disables the delay completely.
	
	Default: _100_.

*resize-by-cells*
	Boolean.

	When set to *yes*, the window size will be constrained to multiples
	of the cell size (plus any configured padding). When set to *no*,
	the window size will be unconstrained, and padding may be adjusted
	as necessary to accommodate window sizes that are not multiples of
	the cell size.

	This option only applies to floating windows. Sizes of maxmized, tiled
	or fullscreen windows will not be constrained to multiples of the cell
	size.

	Default: _yes_

*initial-window-size-pixels*
	Initial window width and height in _pixels_ (subject to output
	scaling), in the form _WIDTHxHEIGHT_. The height _includes_ the
	titlebar when using CSDs. Mutually exclusive to
	*initial-window-size-chars*.
	
	Note that this option may not work as expected if fractional
	scaling is being used, due to the fact that many compositors do
	not report the correct scaling factor until after a window has
	been mapped.
	
	Default: _700x500_.

*initial-window-size-chars*
	Initial window width and height in _characters_, in the form
	_WIDTHxHEIGHT_. Mutually exclusive to
	*initial-window-size-pixels*.'
	
	Note that if you have a multi-monitor setup, with different
	scaling factors, there is a possibility the window size will not
	be set correctly. If that is the case, use
	*initial-window-size-pixels* instead.
	
	And, just like *initial-window-size-pixels*, this option may not
	work as expected if fractional scaling is being used (see
	*initial-window-size-pixels* for details).
	
	Default: _not set_.

*initial-window-mode*
	Initial window mode for each newly spawned window: *windowed*,
	*maximized* or *fullscreen*. Default: _windowed_.

*title*
	Initial window title. Default: _foot_.

*locked-title*
	Boolean. If enabled, applications are not allowed to change the
	title at run-time. Default: _no_.

*app-id*
	Value to set the *app-id* property on the Wayland window to. The
	compositor can use this value to e.g. group multiple windows, or
	apply window management rules. Default: _foot_ (normal mode), or
	_footclient_ (server mode).

*bold-text-in-bright*
	Semi-boolean. When enabled, bold text is rendered in a brighter
	color (in addition to using a bold font). The color is brightened
	by increasing its luminance.
	
	If set to *palette-based*, rather than a simple *yes|true*, colors
	matching one of the 8 regular palette colors will be brightened
	using the corresponding bright palette color. Other colors will
	not be brightened.
	
	Default: _no_.

*word-delimiters*
	String of characters that act as word delimiters when selecting
	text. Note that whitespace characters are _always_ word
	delimiters, regardless of this setting. Default: _,│`|:"'()[]{}<>_

*selection-target*
	Clipboard target to automatically copy selected text to. One of
	*none*, *primary*, *clipboard* or *both*. Default: _primary_.

*workers*
	Number of threads to use for rendering. Set to 0 to disable
	multithreading. Default: the number of available logical CPUs
	(including SMT). Note that this is not always the best value. In
	some cases, the number of physical _cores_ is better.

*utmp-helper*
	Path to utmp logging helper binary.
	
	When starting foot, an utmp record is created by launching the
	helper binary with the following arguments:
	
	```
	@utmp_add_args@
	```
	
	When foot is closed, the utmp record is removed by launching the
	helper binary with the following arguments:
	
	```
	@utmp_del_args@
	```
	
	Set to *none* to disable utmp records. Default: _@utmp_helper_path@_.

# SECTION: environment

This section is used to define environment variables that will be set
in the client application, in addition to the variables inherited from
the terminal process itself.

The format is simply:

*name*=_value_

Note: do not set *TERM* here; use the *term* option in the main
(default) section instead.

# SECTION: bell

*urgent*
	When set to _yes_, foot will signal urgency to the compositor
	through the XDG activation protocol whenever *BEL* is received,
	and the window does NOT have keyboard focus.
	
	If the compositor does not implement this protocol, the margins
	will be painted in red instead.
	
	Applications can enable/disable this feature programmatically with
	the *CSI ? 1042 h* and *CSI ? 1042 l* escape sequences.
	
	Default: _no_

*notify*
	When set to _yes_, foot will emit a desktop notification using the
	command specified in the *notify* option whenever *BEL* is
	received. By default, bell notifications are shown only when the
	window does *not* have keyboard focus. See
	_desktop-notifications.inhibit-when-focused_.

	Default: _no_

*visual*
	When set to _yes_, foot will flash the terminal window. Default:
	_no_

*command*
	When set, foot will execute this command when *BEL* is received.
	Default: none

*command-focused*
	Whether to run the command on *BEL* even while focused. Default:
	_no_

# SECTION: desktop-notifications

*command*
	Command to execute to display a notification.
	
	Template arguments
		_${title}_ and _${body}_ will be replaced with the
		notification's actual _title_ and _body_ (message content).
		
		_${app-id}_ is replaced with the value of the command line
		option _--app-id_, and defaults to *foot* (normal mode), or
		*footclient* (server mode).
		
		_${window-title}_ is replaced with the current window title.
		
		_${icon}_ is replaced by the icon specified in the
		notification request, or the empty string if no icon was
		specified. Can be used with e.g. notify-send's *--icon*
		option, or preferably, by setting the *image-path* hint (with
		e.g. notify-send's *--hint* option).
		
		_${category}_ is replaced by the notification's catogory. Can
		be used together with e.g. notify-send's *--category* option.
		
		_${urgency}_ is replaced with the notifications urgency;
		*low*, *normal* or *critical*. Can be used together with
		e.g. notify-send's *--urgency* option.
		
		_${expire-time}_ is replaced with the notification specified
		notification timeout. Can be used together with
		e.g. notify-send's *--expire-time* option.
		
		_${replace-id}_ is replaced by the notification daemon
		assigned ID that the notification replaces/updates. For this
		to work, foot needs to know the externally assigned IDs of
		previously emitted notifications, see the 'stdout' section
		below. Can be used together with e.g. notify-send's
		*--replace-id* option.
		
		_${action-argument}_ will be expanded to the
		*command-action-argument* option, for each notification
		action. There will always be at least one action, the
		"default" action. Foot uses this to enable window focusing,
		and reporting notification activation to applications that
		requested such events.
		
		Applications can also define their own custom notification
		actions. See the *command-action-argument* option for details.
	
	Ways to trigger notifications
		Applications can trigger notifications in the following ways:
	
		- OSC 777: *\\e]777;notify;<title>;<body>\\e\\\\*
		- OSC 99: *\\e]99;;<title>\\e\\\\* (this is just a bare bones
		  example; this protocol has lots of features, see
		  https://sw.kovidgoyal.net/kitty/desktop-notifications)
		
		By default, notifications are *inhibited* if the foot window
		has keyboard focus. See
		_desktop-notifications.inhibit-when-focused_.
	
	Window activation (focusing)
		Foot can focus the window when the notification is
		'activated'. It can also send an event back to the client
		application, notifying it that the notification has been
		'activated', This typically happens when the default action is
		invoked, and/or when the notification is clicked, but exact
		behavior depends on the notification daemon in use, and how it
		has been configured.
		
		For this to work, foot needs to know when the notification was
		activated (as opposed to just dismissed), and it needs an XDG
		activation token.
		
		There are two parts to handle this. First, the notification
		must define an action. For this purpose, foot will add a
		"default" action to the notification (see the
		*command-action-argument* option).
		
		Second, foot needs to know when the notification is activated,
		and it needs to get hold of the XDG activation token.
		
		Both are expected to be printed on stdout.
		
		Foot expects the action name (not label) to be printed on a
		single line. No prefix, no postfix.
		
		Foot expects the activation token to be printed on a single
		line, prefixed with *xdgtoken=*.
		
		Example:
			default++
xdgtoken=18179adf579a7a904ce73754964b1ec3
		
		The expected format of stdout may change at any time. Please
		read the changelog when upgrading foot.
		
		*Note*: notify-send does not, out of the box, support
		reporting the XDG activation token in any way. This means
		window activation will not work by default.
	
	Stdout
		Foot recognizes the following things from the notification
		helper's stdout:
		
		- _id_: integer in base 10, daemon assigned notification ID
		- *id=*_id_: same as plain _nnn_.
		- *default*: the 'default' action was triggered
		- *action=*_default_: same as _default_
		- *action=*_n_: application custom action _n_ triggered
		- _n_: integer in base 10, appearing after the ID; application
		  custom action _n_ triggered
		- *xdgtoken=*_xyz_: XDG activation token.
		
		Example #1:
			17++
action=default++
xdgtoken=95ebdfe56e4f47ddb5bba9d7dc3a2c35
		
			Foot recognizes this as:
			- notification has the daemon assigned ID 17
			- the user triggered the default action
			- the notification send an XDG activation token
		
		Example #2:
			17++
1
		
			Foot recognizes this as:
			- notification has the daemon assigned ID 17
			- the user triggered the first custom action, "1"
		
		Example #3:
			id=17++
1
		
			Foot recognizes this as:
			- notification has the daemon assigned ID 17
			- the user triggered the first custom action, "1
	
	Default: _notify-send++
			--wait++
			--app-name    ${app-id}++
			--icon        ${app-id}++
			--category    ${category}++
			--urgency     ${urgency}++
			--expire-time ${expire-time}++
			--hint        STRING:image-path:${icon}++
			--replace-id  ${replace-id}++
			${action-argument}++
			--print-id++
			-- ${title} ${body}_.

*command-action-argument*
	String to use with *command* to enable passing action/button names
	to the notification helper.

	Foot will always configure a "default" action that can be used to
	"activate" the notification, which in turn can cause the foot
	window to be focused, or an escape to be sent to the terminal
	application (depending on how the application generated the
	notification).
	
	Furthermore, the OSC-99 notifications protocol allows applications
	to define their own actions. Foot uses a combination of the
	*command* option, and the *command-action-argument* option to pass
	the names of the actions to the notification helper.
	
	This option has the following template arguments:
	
	- _${action-name}_: the name of the action; *default* for the
	  default action configured by foot, and _n_, where _n_ is an
	  integer >= 1, for application defined actions.
	- _${action-label}_: *Activate* for the default action, and a
	  free-form string for application defined actions.
	
	For each notification action (remember, there will always be at
	least one), *command-action-argument* will be expanded with the
	action's name and label.

	Then, _${action-argument}_ is expanded *command* to the full list
	of actions.
	
	If *command-action-argument* is set to the empty string, no
	actions will be passed to *command*. That is, _${action-argument}_
	will be replaced with the empty string.
	
	Example:
	
	*command-action-argument=--action ${action-name}=${action-label}*++
*command=notify-send ${action-argument} ...*
	
	Assume the application defined two custom actions: *OK* and
	*Cancel*.
	
	Given the above, foot will execute:
	
		notify-send++
			--action default='Click to activate'++
			--action 1=OK++
			--action 2=Cancel++
			...
	
	Default: _--action ${action-name}=${action-label}_

*close*
	Command to execute to close an existing notification.
	
	_${id}_ is expanded to the ID of the notification that should be
	closed. For example:
	
		fyi --close ${id}
	
	Closing a notification is only supported by the Kitty Desktop
	Notification protocol, OSC-99.
	
	If set to the empty string (the default), foot will instead try to
	close the notification by sending SIGINT to the notification
	helper process. For example, *notify-send --wait* (libnotify >=
	0.8.0) responds to SIGINT by closing the notification.
	
	Default: _not set_

*inhibit-when-focused*
	Boolean. If enabled, foot will not display notifications if the
	terminal window has keyboard focus.
	
	Default: _yes_

# SECTION: scrollback

*lines*
	Number of scrollback lines. The maximum number of allocated lines
	will be this value plus the number of visible lines, rounded up to
	the nearest power of 2. Default: _1000_.

*multiplier*
	Amount to multiply mouse scrolling with. It is a decimal number,
	i.e. fractions are allowed. Default: _3.0_.

*indicator-position*
	Configures the style of the scrollback position indicator. One of
	*none*, *fixed* or *relative*. *none* disables the indicator
	completely. *fixed* always renders the indicator near the top of
	the window, and *relative* renders the indicator at the position
	corresponding to the current scrollback position. Default:
	_relative_.

*indicator-format*
	Which format to use when displaying the scrollback position
	indicator. Either _percentage_, _line_, or a custom fixed
	string. This option is ignored if
	*indicator-position=none*. Default: _empty string_.

# SECTION: url

*launch*
	Command to execute when opening URLs. _${url}_ will be replaced
	with the actual URL. Default: _xdg-open ${url}_.

*osc8-underline*
	When to underline OSC-8 URLs. Possible values are *url-mode* and
	*always*.
	
	When set to *url-mode*, OSC-8 URLs are only highlighted in URL
	mode, just like auto-detected URLs.
	
	When set to *always*, OSC-8 URLs are always highlighted,
	regardless of their other attributes (bold, italic etc). Note that
	this does _not_ make them clickable.
	
	Default: _url-mode_

*label-letters*
	String of characters to use when generating key sequences for URL
	jump labels.
	
	If you change this option to include the letter *t*, you should
	also change the default *[url-bindings].toggle-url-visible* key
	binding to avoid a clash.
	
	Default: _sadfjklewcmpgh_.

*protocols*
	Comma separated list of protocols (schemes) that should be
	recognized in URL mode. Note that only auto-detected URLs are
	affected by this option. OSC-8 URLs are always enabled, regardless
	of protocol. Default: _http, https, ftp, ftps, file, gemini,
	gopher, irc, ircs_.

*uri-characters*
	Set of characters allowed in auto-detected URLs. Any character not
	included in this set constitutes a URL delimiter.
	
	Default:
	_abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-\_.,~:;/?#@!$&%\*+="'()[]_

# SECTION: cursor

This section controls the cursor style and color. Note that
applications can change these at runtime.

*style*
	Configures the default cursor style, and is one of: *block*,
	*beam* or *underline*. Note that this can be overridden by
	applications. Default: _block_.

*unfocused-style*
	Configures how the cursor is rendered when the terminal window is
	unfocused. Possible values are:
	
	- unchanged: render cursor in exactly the same way as when the
	  window has focus.
	- hollow: render a block cursor, but hollowed out.
	- none: do not display any cursor at all.

*blink*
	Boolean. Enables blinking cursor. Note that this can be overridden
	by applications. Related option: *blink-rate*. Default: _no_.

*blink-rate*
	The rate at which the cursor blink, when cursor blinking has been
	enabled. Expressed in milliseconds between each blink. Default:
	_500_.

*color*
	Two space separated RRGGBB values (i.e. plain old 6-digit hex
	values, without prefix) specifying the foreground (text) and
	background (cursor) colors for the cursor.
	
	Example: *ff0000 00ff00* (green cursor, red text)
	
	Default: the regular foreground and background colors, reversed.

*beam-thickness*
	Thickness (width) of the beam styled cursor. The value is in
	points, and its exact value thus depends on the monitor's DPI. To
	instead specify a thickness in pixels, use the *px* suffix:
	e.g. *beam-thickness=2px*. Default: _1.5_

*underline-thickness*
	Thickness (height) of the underline styled cursor. The value is in
	points, and its exact value thus depends on the monitor's DPI.
	
	To instead specify a thickness in pixels, use the *px* suffix:
	e.g. *underline-thickness=2px*.
	
	Note that if left unset, the cursor's thickness will scale with
	the font size, while if set, the size is fixed.
	
	Default: _font underline thickness_.

# SECTION: mouse

*hide-when-typing*
	Boolean. When enabled, the mouse cursor is hidden while
	typing. Default: _no_.

*alternate-scroll-mode*
	Boolean. This option controls the initial value for the _alternate
	scroll mode_. When this mode is enabled, mouse scroll events are
	translated to _up_/_down_ key events when displaying the alternate
	screen.
	
	This lets you scroll with the mouse in e.g. pagers (like _less_)
	without enabling native mouse support in them.
	
	Alternate scrolling is *not* used if the application enables
	native mouse support.
	
	This option can be modified by applications at run-time using the
	escape sequences *CSI ? 1007 h* (enable) and *CSI ? 1007 l*
	(disable).
	
	Default: _yes_.

# SECTION: touch

*long-press-delay*
	Number of milliseconds to distinguish between a short press and
	a long press on the touchscreen.

	Default: _400_.

# SECTION: colors

This section controls the 16 ANSI colors, the default foreground and
background colors, and the extended 256 color palette. Note that
applications can change these at runtime.

The colors are in RRGGBB format (i.e. plain old 6-digit hex values,
without prefix). That is, they do *not* have an alpha component. You
can configure the background transparency with the _alpha_ option.

*foreground*
	Default foreground color. This is the color used when no ANSI
	color is being used. Default: _839496_.

*background*
	Default background color. This is the color used when no ANSI
	color is being used. Default: _002b36_.

*regular0*, *regular1* *..* *regular7*
	The eight basic ANSI colors (Black, Red, Green, Yellow, Blue,
	Magenta, Cyan, White). Default: _242424_, _f62b5a_, _47b413_,
	_e3c401_, _24acd4_, _f2affd_, _13c299_, _e6e6e6_ (starlight
	theme, V4).

*bright0*, *bright1* *..* *bright7*
	The eight bright ANSI colors (Black, Red, Green, Yellow, Blue,
	Magenta, Cyan, White). Default: _616161_, _ff4d51_, _35d450_,
	_e9e836_, _5dc5f8_, _feabf2_, _24dfc4_, _ffffff_ (starlight
	theme, V4).

*dim0*, *dim1* *..* *dim7*
	Custom colors to use with dimmed colors. Dimmed colors do not have
	an entry in the color palette. Applications emit them by combining
	a color value, and a "dim" attribute.
	
	By default, foot implements this by reducing the luminance of the
	current color. This is a generic approach that applies to both
	colors from the 256-color palette, as well as 24-bit RGB colors.
	
	You can change this behavior by setting the *dimN* options. When
	set, foot will match the current color against the color palette,
	and if it matches one of the *regularN* colors, the corresponding
	*dimN* color will be used.
	
	If instead the current color matches one of the *brightN* colors,
	the corresponding *regularN* color will be used.
	
	If the current color does not match any known color, it is dimmed
	by reducing the luminance (i.e. the same behavior as if the *dimN*
	options are unconfigured). 24-bit RGB colors will typically fall
	into this category.
	
	Note that applications can change the *regularN* and *brightN*
	colors at runtime. However, they have no way of changing the
	*dimN* colors. If an application has changed the *regularN*
	colors, foot will still use the corresponding *dimN* color, as
	configured in foot.ini.
	
	Default: _not set_.

*0* *..* *255*
	Arbitrary colors in the 256-color palette. Default: for *0* *..*
	*15*, see regular and bright defaults above; see
	https://en.wikipedia.org/wiki/ANSI_escape_code#8-bit for an
	explanation of the remainder.

*alpha*
	Background translucency. A value in the range 0.0-1.0, where 0.0
	means completely transparent, and 1.0 is opaque. Default: _1.0_.

*selection-foreground*, *selection-background*
	Foreground (text) and background color to use in selected
	text. Note that *both* options must be set, or the default will be
	used. Default: _inverse foreground/background_.

*jump-labels*
	Two color values specifying the foreground (text) and background
	colors to use when rendering jump labels in URL mode. Default:
	_regular0 regular3_.

*scrollback-indicator*
	Two color values specifying the foreground (text) and background
	(indicator itself) colors for the scrollback indicator. Default:
	_regular0 bright4_.

*search-box-no-match*
	Two color values specifying the foreground (text) and background
	colors for the scrollback search box, when there are no
	matches. Default: _regular0 regular1_.

*search-box-match*
	Two color values specifying the foreground (text) and background
	colors for the scrollback search box, when the search box is
	either empty, or there are matches. Default: _regular0 regular3_.

*urls*
	Color to use for the underline used to highlight URLs in URL
	mode. Default: _regular3_.

*flash*
	Color to use for the terminal window flash. Default: _7f7f00_.

*flash-alpha*
	Flash translucency. A value in the range 0.0-1.0, where 0.0 means
	completely transparent, and 1.0 is opaque. Default: _0.5_.

# SECTION: csd

This section controls the look of the _CSDs_ (Client Side
Decorations). Note that the default is to *not* use CSDs, but instead
to use _SSDs_ (Server Side Decorations) when the compositor supports
it.

Note that unlike the colors defined in the _colors_ section, the color
values here are in AARRGGBB (i.e. plain old 8-digit hex values)
format. I.e. they contain an alpha component - 00 means completely
transparent, and ff fully opaque.

Examples:

- ffffffff: white, fully opaque
- ff000000: black, fully opaque
- 7fffffff: white, semi-transparent
- ff00ff00: green, fully opaque

*preferred*
	Which type of window decorations to prefer: *client* (CSD),
	*server* (SSD) or *none*.
	
	Note that this is only a hint to the compositor. Depending on
	compositor support, and how it has been configured, it may
	instruct foot to use CSDs even though this option has been set to
	*server*, or render SSDs despite *client* or *none* being set.
	
	Default: _server_.

*size*
	Height, in pixels (subject to output scaling), of the
	titlebar. Setting it to 0 will hide the titlebar, while still
	showing the border (if *border-width* is set to a non-zero
	value). Default: _26_.

*color*
	Titlebar color. Default: use the default _foreground_ color.

*font*
	Font to use for the title bar. This is a list of fonts, similar to
	the main *font* option. Note that the font will be sized using the
	title bar size. That is, all *:size* and *:pixelsize* attributes
	will be ignored. Default: _primary font_.

*hide-when-maximized*
	Boolean. When enabled, the CSD titlebar is hidden when the window
	is maximized. The completely disable the titlebar, set *size* to 0
	instead. Default: _no_.

*double-click-to-maximize*
	Boolean. When enabled, double-clicking the CSD titlebar will
	(un)maximize the window. Default: _yes_.

*border-width*
	Width of the border, in pixels (subject to output scaling). Note
	that the border encompasses the entire window, including the title
	bar. Default: _0_.

*border-color*
	Color of border. By default, the title bar color is used. If the
	title bar color has not been set, the default foreground color
	(from the color scheme) is used. Default: _titlebar color_.

*button-width*
	Width, in pixels (subject to output scaling), of the
	minimize/maximize/close buttons. Default: _26_.

*button-color*
	Foreground color on the minimize/maximize/close buttons. Default:
	use the default _background_ color.

*button-minimize-color*
	Minimize button's background color. Default: use the default
	_regular4_ color (blue).

*button-maximize-color*
	Maximize button's background color. Default: use the default
	_regular2_ color (green).

*button-close-color*
	Close button's background color. Default: use the default
	_regular1_ color (red).

# SECTION: key-bindings

This section lets you override the default key bindings.

The general format is _action=combo1...comboN_. That is, each action
may have one or more key combinations, space separated. Each
combination is in the form _mod1+mod2+key_. The names of the modifiers
and the key *must* be valid XKB key names.

Note that if *Shift* is one of the modifiers, the _key_ *must not* be
in upper case. For example, *Control+Shift+V* will never trigger, but
*Control+Shift+v* will.

Note that *Alt* is usually called *Mod1*.

*xkbcli interactive-wayland* can be useful for finding keysym names.

A key combination can only be mapped to *one* action. Lets say you
want to bind *Control+Shift+R* to *fullscreen*. Since this is the
default shortcut for *search-start*, you first need to unmap the
default binding. This can be done by setting _action=none_;
e.g. *search-start=none*.

*noop*
	All key combinations listed here will not be sent to the
	application. Default: _none_.

*scrollback-up-page*
	Scrolls up/back one page in history. Default: _Shift+Page\_Up_.

*scrollback-up-half-page*
	Scrolls up/back half of a page in history. Default: _none_.

*scrollback-up-line*
	Scrolls up/back a single line in history. Default: _none_.

*scrollback-down-page*
	Scroll down/forward one page in history. Default:
	_Shift+Page\_Down_.

*scrollback-down-half-page*
	Scroll down/forward half of a page in history. Default: _none_.

*scrollback-down-line*
	Scroll down/forward a single line in history. Default: _none_.

*scrollback-home*
	Scroll to the beginning of the scrollback. Default: _none_.

*scrollback-end*
	Scroll to the end (bottom) of the scrollback. Default: _none_.

*clipboard-copy*
	Copies the current selection into the _clipboard_. Default: _Control+Shift+c_
	_XF86Copy_.

*clipboard-paste*
	Pastes from the _clipboard_. Default: _Control+Shift+v_ _XF86Paste_.

*primary-paste*
	Pastes from the _primary selection_. Default: _Shift+Insert_ (also
	defined in *mouse-bindings*).

*search-start*
	Starts a scrollback/history search. Default: _Control+Shift+r_.

*font-increase*
	Increases the font size by 0.5pt. Default: _Control+plus
	Control+equal Control+KP\_Add_ (also defined in *mouse-bindings*).

*font-decrease*
	Decreases the font size by 0.5pt. Default: _Control+minus
	Control+KP\_Subtract_ (also defined in *mouse-bindings*).

*font-reset*
	Resets the font size to the default. Default: _Control+0 Control+KP\_0_.

*spawn-terminal*
	Spawns a new terminal. If the shell has been configured to emit
	the OSC 7 escape sequence, the new terminal will start in the
	current working directory. Default: _Control+Shift+n_.

*minimize*
	Minimizes the window. Default: _none_.

*maximize*
	Toggle the maximized state. Default: _none_.

*fullscreen*
	Toggles the fullscreen state. Default: _none_.

*pipe-visible*, *pipe-scrollback*, *pipe-selected*, *pipe-command-output*
	Pipes the currently visible text, the entire scrollback, the
	currently selected text, or the last command's output to an
	external tool. The syntax for this option is a bit special; the
	first part of the value is the command to execute enclosed in
	"[]", followed by the binding(s).
	
	You can configure multiple pipes as long as the command strings
	are different and the key bindings are unique.
	
	Note that the command is *not* automatically run inside a shell;
	use *sh -c "command line"* if you need that.
	
	Example #1:
		# Extract currently visible URLs, let user choose one (via
		fuzzel), then launch firefox with the selected URL++
*pipe-visible=[sh -c "xurls | uniq | tac | fuzzel | xargs -r firefox"] Control+Print*
	
	Example #2:
		# Open scrollback contents in Emacs running in a new foot instance++
*pipe-scrollback=[sh -c "f=$(mktemp) && cat - > $f && foot emacsclient -t $f; rm $f"] Control+Shift+Print*
	
	Default: _none_

*show-urls-launch*
	Enter URL mode, where all currently visible URLs are tagged with a
	jump label with a key sequence that will open the URL (and exit
	URL mode). Default: _Control+Shift+o_.

*show-urls-persistent*
	Similar to *show-urls-launch*, but does not automatically exit URL
	mode after activating an URL. Default: _none_.

*show-urls-copy*
	Enter URL mode, where all currently visible URLs are tagged with a
	jump label with a key sequence that will place the URL in the
	clipboard. Default: _none_.

*prompt-prev*
	Jump to the previous, currently not visible, prompt (requires
	shell integration, see *foot*(1)). Default: _Control+Shift+z_.

*prompt-next*
	Jump the next prompt (requires shell integration, see
	*foot*(1)). Default: _Control+Shift+x_.

*unicode-input*
	Input a Unicode character by typing its codepoint in hexadecimal,
	followed by *Enter* or *Space*.
	
	For example, to input the character _ö_ (LATIN SMALL LETTER O WITH
	DIAERESIS, Unicode codepoint 0xf6), you would first activate this
	key binding, then type: *f*, *6*, *Enter*.
	
	Another example: to input 😍 (SMILING FACE WITH HEART-SHAPED EYES,
	Unicode codepoint 0x1f60d), activate this key binding, then type:
	*1*, *f*, *6*, *0*, *d*, *Enter*.
	
	Recognized key bindings in Unicode input mode:
	
	- Enter, Space: commit the Unicode character, then exit this mode.
	- Escape, q, Ctrl+c, Ctrl+d, Ctrl+g: abort input, then exit this mode.
	- 0-9, a-f: append next digit to the Unicode's codepoint.
	- Backspace: undo the last digit.
	
	Note that there is no visual feedback while in this mode. This is
	by design; foot's Unicode input mode is considered to be a
	fallback. The preferred way of entering Unicode characters, emojis
	etc is by using an IME.
	
	Default: _Control+Shift+u_.

*quit*
	Quit foot. Default: _none_.

# SECTION: search-bindings

This section lets you override the default key bindings used in
scrollback search mode. The syntax is exactly the same as the regular
**key-bindings**.

*cancel*
	Aborts the search. The viewport is restored and the _primary
	selection_ is **not** updated. Default: _Control+g Control+c
	Escape_.

*commit*
	Exit search mode and copy current selection into the _primary
	selection_. Viewport is **not** restored. To copy the selection to
	the regular _clipboard_, use *Control+Shift+c*. Default: _Return_.

*find-prev*
	Search **backwards** in the scrollback history for the next
	match. Default: _Control+r_.

*find-next*
	Searches **forwards** in the scrollback history for the next
	match. Default: _Control+s_.

*cursor-left*
	Moves the cursor in the search box one **character** to the
	left. Default: _Left Control+b_.

*cursor-left-word*
	Moves the cursor in the search box one **word** to the
	left. Default: _Control+Left Mod1+b_.

*cursor-right*
	Moves the cursor in the search box one **character** to the
	right. Default: _Right Control+f_.

*cursor-right-word*
	Moves the cursor in the search box one **word** to the
	right. Default: _Control+Right Mod1+f_.

*cursor-home*
	Moves the cursor in the search box to the beginning of the
	input. Default: _Home Control+a_.

*cursor-end*
	Moves the cursor in the search box to the end of the
	input. Default: _End Control+e_.

*delete-prev*
	Deletes the **character before** the cursor. Default: _BackSpace_.

*delete-prev-word*
	Deletes the **word before** the cursor. Default: _Mod1+BackSpace
	Control+BackSpace_.

*delete-next*
	Deletes the **character after** the cursor. Default: _Delete_.

*delete-next-word*
	Deletes the **word after** the cursor. Default: _Mod1+d
	Control+Delete_.

*extend-char*
	Extend current selection to the right, by one character. Default:
	_Shift+Right_.

*extend-to-word-boundary*
	Extend current selection to the right, to the next word
	boundary. Default: _Control+w Control+Shift+Right_.

*extend-to-next-whitespace*
	Extend the current selection to the right, to the next
	whitespace. Default: _Control+Shift+w_.

*extend-line-down*
	Extend current selection down one line. Default: _Shift+Down_.

*extend-backward-char*
	Extend current selection to the left, by one character. Default:
	_Shift+Left_.

*extend-backward-to-word-boundary*
	Extend current selection to the left, to the next word
	boundary. Default: _Control+Shift+Left_.

*extend-backward-to-next-whitespace*
	Extend the current selection to the left, to the next
	whitespace. Default: _none_.

*extend-line-up*
	Extend current selection up one line. Default: _Shift+Up_.

*clipboard-paste*
	Paste from the _clipboard_ into the search buffer. Default:
	_Control+v Control+y_.

*primary-paste*
	Paste from the _primary selection_ into the search
	buffer. Default: _Shift+Insert_.

*unicode-input*
	Unicode input mode. See _key-bindings.unicode-input_ for
	details. Default: _none_.

*scrollback-up-page*
	Scrolls up/back one page in history. Default: _Shift+Page\_Up_.

*scrollback-up-half-page*
	Scrolls up/back half of a page in history. Default: _none_.

*scrollback-up-line*
	Scrolls up/back a single line in history. Default: _none_.

*scrollback-down-page*
	Scroll down/forward one page in history. Default:
	_Shift+Page\_Down_.

*scrollback-down-half-page*
	Scroll down/forward half of a page in history. Default: _none_.

*scrollback-down-line*
	Scroll down/forward a single line in history. Default: _none_.

*scrollback-home*
	Scroll to the beginning of the scrollback. Default: _none_.

*scrollback-end*
	Scroll to the end (bottom) of the scrollback. Default: _none_.

# SECTION: url-bindings

This section lets you override the default key bindings used in URL
mode. The syntax is exactly the same as the regular **key-bindings**.

Be careful; do not use single-letter keys that are also used in
*[url].label-letters*, as doing so will make some URLs inaccessible.

*cancel*
	Exits URL mode without opening a URL. Default: _Control+g
	Control+c Control+d Escape_.

*toggle-url-visible*
	By default, the jump label only shows the key sequence required to
	activate it. This is fine as long as the URL is visible in the
	original text.
	
	But with e.g. OSC-8 URLs (the terminal version of HTML anchors,
	i.e. "links"), the text on the screen can be something completely
	different than the URL.
	
	This action toggles between showing and hiding the URL on the jump
	label.
	
	Default: _t_.

# SECTION: text-bindings

This section lets you remap key combinations to custom escape
sequences.

The format is _text=combo1...comboN_. That is, the string to emit may
have one or more key combinations, space separated. Each combination
is in the form _mod1+mod2+key_. The names of the modifiers and the key
*must* be valid XKB key names.

The text string specifies the characters, or bytes, to emit when the
associated key combination(s) are pressed. There are two ways to
specify a character:

- Normal, printable characters are written as-is: *abcdef*.
- Bytes (e.g. ESC) are written as two-digit hexadecimal numbers, with
  a *\\x* prefix: *\\x1b*.

Example: you would like to remap _Super+k_ to the _Up_ key.

The escape sequence for the Up key is _ESC [ A_ (without the
spaces). Thus, we need to specify this in foot.ini (*Mod4* is the XKB
name for the Super/logo key):

*\\x1b[A = Mod4+k*

Another example: to remap _Super+c_ to _Control+c_:

*\\x03 = Mod4+c*

# SECTION: mouse-bindings

This section lets you override the default mouse bindings.

The general format is _action=combo1...comboN_. That is, each action
may have one or more key combinations, space separated. Each
combination is in the form _mod1+mod2+BTN\_<name>[-COUNT]_. The names
of the modifiers *must* be valid XKB key names, and the button name
*must* be a valid libinput name. You can find the button names using
*libinput debug-events*.

The trailing *COUNT* (number of times the button has to be clicked) is
optional and specifies the click count required to trigger the
binding. The default if *COUNT* is omitted is _1_.

To map wheel events (i.e. scrolling), use the button names
*BTN_WHEEL_BACK* (up) and *BTN_WHEEL_FORWARD* (down). Note that these
events never generate a *COUNT* larger than 1. That is,
*BTN_WHEEL_BACK+2*, for example, will never trigger.

Foot also recognizes tiltable wheels; to map these, use
*BTN_WHEEL_LEFT* and *BTN_WHEEL_RIGHT*.

A modifier+button combination can only be mapped to *one* action. Lets
say you want to bind *BTN\_MIDDLE* to *fullscreen*. Since
*BTN\_MIDDLE* is the default binding for *primary-paste*, you first
need to unmap the default binding. This can be done by setting
_action=none_; e.g. *primary-paste=none*.

*selection-override-modifiers*
	The modifiers set in this set (which may be set to any combination
	of modifiers, e.g. _mod1+mod2+mod3_, as well as _none_) are used
	to enable selecting text with the mouse irrespective of whether a
	client application currently has the mouse grabbed.
	These modifiers cannot be used as modifiers in mouse bindings.
	Because the order of bindings is significant, it is best to set
	this prior to any other mouse bindings that might use modifiers in
	the default set.
	Default: _Shift_

The actions to which mouse combos can be bound are listed below. All
actions listed under *key-bindings* can be used here as well.

*scrollback-up-mouse*
	Normal screen: scrolls up the contents.
	
	Alt screen: send fake _KeyUP_ events to the client application, if
	alternate scroll mode is enabled.
	
	Default: _BTN\_WHEEL\_BACK_

*scrollback-down-mouse*
	Normal screen: scrolls down the contents.
	
	Alt screen: send fake _KeyDOWN_ events to the client application, if
	alternate scroll mode is enabled.

	Default: _BTN\_WHEEL\_FORWARD_

*select-begin*
	Begin an interactive selection. The selection is finalized, and
	copied to the _primary selection_, when the button is
	released. Default: _BTN\_LEFT_.

*select-begin-block*
	Begin an interactive block selection. The selection is finalized,
	and copied to the _primary selection_, when the button is
	released. Default: _Control+BTN\_LEFT_.

*select-word*
	Begin an interactive word-wise selection, where words are
	separated by whitespace and all characters defined by the
	*word-delimiters* option. The selection is finalized, and copied
	to the _primary selection_, when the button is released. Default:
	_BTN\_LEFT-2_.

*select-word-whitespace*
	Same as *select-word*, but the characters in the *word-delimiters*
	option are ignored. I.e only whitespace characters act as
	delimiters. The selection is finalized, and copied to the _primary
	selection_, when the button is released. Default:
	_Control+BTN\_LEFT-2_.

*select-quote*
	Begin an interactive "quote" selection. This is similar to
	*select-word*, except an entire quote is selected (that is,
	everything inside the quote, excluding the quote
	characters). Recognized quote characters are: *"* and *'*.
	
	If a complete quote cannot be found on the current logical row
	(only one quote character, or none are found), the entire row is
	selected.
	
	The selection is finalized, and copied to the _primary selection_,
	when the button is released.

	After the initial selection has been made, it behaves like a
	normal word, or row selection, depending on whether a quote was
	found or not. This affects what happens when, for example,
	extending the selection.
	
	Notes:
	- Escaped quote characters are not supported (*"foo \\"bar"* will
	  match *'foo \\'*, not *'foo "bar'*).
	- Foot does not try to handle mismatched quote characters; they
	  will simply not match.
	- Nested quotes (using different quote characters) are supported.
	
	Default: _BTN\_LEFT-3_.

*select-row*
	Begin an interactive row-wise selection. The selection is
	finalized, and copied to the _primary selection_, when the button
	is released. Default: _BTN\_LEFT-4_.

*select-extend*
	Interactively extend an existing selection, using the original
	selection mode (normal, block, word-wise or row-wise). The
	selection is finalized, and copied to the _primary selection_,
	when the button is released. Default: _BTN\_RIGHT_.

*select-extend-character-wise*
	Same as *select-extend*, but forces the selection mode to _normal_
	(i.e. character wise). Note that this causes subsequent
	*select-extend* operations to be character wise. This action is
	ignored for block selections. Default: _Control+BTN\_RIGHT_.

*primary-paste*
	Pastes from the _primary selection_. Default: _BTN\_MIDDLE_.

*font-increase*
	Increases the font size by 0.5pt. Default:
	_Control+BTN\_WHEEL\_BACK_ (also defined in *key-bindings*).

*font-decrease*
	Decreases the font size by 0.5pt. Default:
	_Control+BTN\_WHEEL\_FORWARD_ (also defined in *key-bindings*).


# TWEAK

This section is for advanced users and describes configuration options
that can be used to tweak foot's low-level behavior.

These options are *not* included in the example configuration. You
should not change these unless you understand what they do.

Note that these options may change, or be removed at any time, without
prior notice.

When reporting bugs, please mention if, and to what, you have changed
any of these options.

*scaling-filter*
	Overrides the default scaling filter used when down-scaling bitmap
	fonts (e.g. emoji fonts). Possible values are *none*, *nearest*,
	*bilinear*, *cubic* or *lanczos3*. *cubic* and *lanczos3* produce
	the best results, but are slower (with *lanczos3* being the best
	_and_ slowest).
	
	Default: _lanczos3_.

*overflowing-glyphs*
	Boolean. When enabled, glyphs wider than their cell(s) are allowed
	to render into one additional neighbouring cell.
	
	One use case for this are fonts with wide italic characters that
	"bend" into the next cell. Without this option, such glyphs will
	appear "cut off".
	
	Another use case are fonts with "icon" characters in the Unicode
	private usage area, e.g. Nerd Fonts, or Powerline Fonts and legacy
	emoji characters like *WHITE FROWNING FACE*.
	
	Note: might impact performance depending on the font used.
	Especially small font sizes can cause many overflowing glyphs
	because of subpixel rendering.
	
	Default: _yes_.

*render-timer*
	Enables a frame rendering timer, that prints the time it takes to
	render each frame, in microseconds, either on-screen, to stderr,
	or both. Valid values are *none*, *osd*, *log* and
	*both*. Default: _none_.

*box-drawing-base-thickness*
	Line thickness to use for *LIGHT* box drawing line characters, in
	points. This value is converted to pixels using the monitor's DPI,
	and then multiplied with the cell size. The end result is that a
	larger font (and thus larger cells) result in thicker
	lines. Default: _0.04_.

*box-drawing-solid-shades*
	Boolean. When enabled, box drawing "shades" (e.g. LIGHT SHADE,
	MEDIUM SHADE and DARK SHADE) are rendered as solid blocks using a
	darker variant of the current foreground color.
	
	When disabled, they are instead rendered as checker box pattern,
	using the current foreground color as is.
	
	Default: _yes_.

*delayed-render-lower*, *delayed-render-upper*
	These two values control the timeouts (in nanoseconds) that are
	used to mitigate screen flicker caused by clients writing large,
	non-atomic screen updates.
	
	If a client splits up a screen update over multiple *write*(3)
	calls, we may end up rendering an intermediate frame, quickly
	followed by another frame with the final screen content. For
	example, the client may erase part of the screen (or scroll) in
	one write, and then write new content in one or more subsequent
	writes. Rendering the frame when the screen has been erased, but
	not yet filled with new content will be perceived as screen
	flicker.
	
	The *real* solution to this is _Application Synchronized Updates_
	(https://gitlab.freedesktop.org/terminal-wg/specifications/-/merge_requests/2).
	
	The problem with this is twofold - first, it has not yet been
	standardized, and thus there are not many terminal emulators that
	implement it (foot *does* implement it), and second, applications
	must be patched to use it.
	
	Until this has happened, foot offers an interim workaround; an
	attempt to mitigate the screen flicker *without* affecting neither
	performance nor latency.
	
	It is based on the fact that the screen is updated at a fixed
	interval (typically 60Hz). For us, this means it does not matter
	if we render a new frame at the *beginning* of a frame interval,
	or at the *end*. Thus, the goal is to introduce a delay between
	receiving client data and rendering the resulting state, but
	without causing a frame skip.
	
	While it should be possible to estimate the amount of time left
	until the next frame, foot's algorithm is currently not that
	advanced, but is based on statistics I guess you could say - the
	delay we introduce is so small that the risk of pushing the frame
	over to the next frame interval is also very small.
	
	Now, that was a lot of text. But what is it foot actually does?
	
	When receiving client data, it schedules a timer, the
	*delayed-render-lower*. If we do not receive any more client data
	before the timer has run out, we render the frame. If however, we
	do receive more data, the timer is re-scheduled. That is, each
	time we receive client data, frame rendering is delayed another
	*delayed-render-lower* nanoseconds.
	
	Now, while this works very well with most clients, it would be
	possible to construct a malicious client that keeps writing data
	at a slow pace. To the user, this would look like foot has frozen
	as we never get to render a new frame. To prevent this, an upper
	limit is set - *delayed-render-upper*. If this timer runs out, we
	render the frame regardless of what the client is doing.
	
	If changing these values, note that the lower timeout *must* be
	set lower than the upper timeout, but that this is not verified by
	foot. Furthermore, both values must be less than 16ms (that is,
	16000000 nanoseconds).
	
	You can disable the feature altogether by setting either value to
	0. In this case, frames are rendered "as soon as possible".
	
	Default: lower=_500000_ (0.5ms), upper=_8333333_ (8.3ms - half a
	frame interval).

*damage-whole-window*
	Boolean. When enabled, foot will 'damage' the entire window each
	time a frame has been rendered. This forces the compositor to
	redraw the entire window. If disabled, foot will only 'damage'
	updated rows.
	
	There is normally *no* reason to enable this. However, it has been
	seen to workaround an issue with _fractional scaling_ in _Gnome_.
	
	Note that enabling this option is likely to increase CPU and/or
	GPU usage (by the compositor, not by foot), and may have a
	negative impact on battery life.
	
	Default: _no_.

*grapheme-shaping*
	Boolean. When enabled, foot will use _utf8proc_ to do grapheme
	cluster segmentation while parsing "printed" text. Then, when
	rendering, it will use _fcft_ (if compiled with _HarfBuzz_
	support) to shape the grapheme clusters.
	
	This is required to render e.g. flag (emoji) sequences, keycap
	sequences, modifier sequences, zero-width-joiner (ZWJ) sequences
	and emoji tag sequences. It might also improve rendering of
	composed characters, depending on font.
	
		- foot must have been compiled with utf8proc support
		- fcft must have been compiled with HarfBuzz support
	
	This option can also be set runtime with DECSET/DECRST 2027.
	
	See also: *grapheme-width-method*.
	
	Default: _yes_

*grapheme-width-method*
	Selects which method to use when calculating the width
	(i.e. number of columns) of a grapheme cluster. One of
	*wcswidth*, *double-width* and *max*.
	
	*wcswidth* simply adds together the individual width of all
	codepoints making up the cluster.
	
	*double-width* does the same, but limits the maximum number of
	columns to 2. This is more correct, but may break some
	applications since applications typically use *wcswidth*(3)
	internally to calculate the width. This results in cursor
	de-synchronization issues.
	
	*max* uses the width of the largest codepoint in the cluster.
	
	Default: _double-width_

*font-monospace-warn*
	Boolean. When enabled, foot will use heuristics to try to verify
	the primary font is a monospace font, and warn if it is not.
	
	Disable this if you still want to use the font, even if foot
	thinks it is not monospaced.
	
	You may also want to disable it to get slightly faster startup times.
	
	Default: _yes_

*max-shm-pool-size-mb*
	This option controls the amount of virtual address space used by
	the pixmap memory to which the terminal screen content is
	rendered.
	
	It does not change how much physical memory foot uses.
	
	Foot uses a memory mapping trick to implement fast rendering of
	interactive scrolling (typically, but applies to "slow" scrolling
	in general). Example: holding down the 'up' or 'down' arrow key to
	scroll in a text editor.
	
	For this to work, it needs a large amount of virtual address
	space. Again, note that this is not physical memory.
	
	On a normal x64 based computer, each process has 128TB of virtual
	address space, and newer ones have 64PB. This is an insane amount
	and most applications do not use anywhere near that amount.
	
	Each foot terminal window can allocate up to 2GB of virtual
	address space. With 128TB of address space, that means a maximum
	of 65536 windows in server/daemon mode (for 2GB). That should be
	enough, yes?
	
	However, the Wayland compositor also needs to allocate the same
	amount of virtual address space. Thus, it has a slightly higher
	chance of running out of address space since it needs to host
	all running Wayland clients in the same way, at the same time.
	
	In the off chance that this becomes a problem for you, you can
	reduce the amount used with this option.
	
	Or, for optimal performance, you can increase it to the maximum
	allowed value, 2GB (but note that you most likely will not notice
	any difference compared to the default value).
	
	Setting it to 0 disables the feature.
	
	Limitations:
		- only supported on 64-bit architectures
		- only supported on Linux
	
	Default: _512_. Maximum allowed: _2048_ (2GB).

*sixel*
	Boolean. When enabled, foot will process sixel images. Default:
	_yes_

*bold-text-in-bright-amount*
	Amount by which bold fonts are brightened when
	*bold-text-in-bright* is set to *yes* (the *palette-based* variant
	is not affected by this option). Default: _1.3_.

# SEE ALSO

*foot*(1), *footclient*(1)
