Provided by: foot_1.11.0-2_amd64 
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
• ~/.config/foot/foot.ini
• XDG_CONFIG_DIRS/foot/foot.ini
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: foot
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, 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
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.
Default: monospace:size=8 (font), not set (font-bold, font-italic, font-bold-italic).
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.
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.
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
auto, yes, or no.
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.
Finally, if set to auto, fonts will be sized using the monitor's DPI if all monitors have a scaling
factor of 1. If at least one monitor as a scaling factor larger than 1 (regardless of whether the
foot window is mapped on that monitor or not), fonts will be scaled using the scaling factor.
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: auto
pad
Padding between border and glyphs, in pixels (subject to output scaling), on 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: 2x2.
resize-delay-ms
Time, in milliseconds, of "idle time" before foot 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. Only when you pause the fiddling for resize-delay-ms milliseconds is the
client updated.
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.
initial-window-size-pixels
Initial window width and height in pixels (subject to output scaling), on the form WIDTHxHEIGHT. The
height includes the titlebar when using CSDs. Mutually exclusive to initial-window-size-chars.
Default: 700x500.
initial-window-size-chars
Initial window width and height in characters, on 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.
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.
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: ,│`|:"'()[]{}<>
notify
Command to execute to display a notification. ${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.
${window-title} is replaced with the current window title.
Applications can trigger notifications in the following ways:
• OSC 777: \e]777;notify;<title>;<body>\e\\
By default, notifications are inhibited if the foot window has keyboard focus. See notify-focus-
inhibit.
Default: notify-send -a ${app-id} -i ${app-id} ${title} ${body}.
notify-focus-inhibit
Boolean. If enabled, foot will not display notifications if the terminal window has keyboard focus.
Default: yes
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.
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 foccus.
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 notify-focus-inhibit.
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: 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
${url}.
osc8-underline
When to underline OSC-8 URLs. Possible values are url-mode and always.
When set to url-mode, OSC-8 URLs are only highlighted in URL mode, just like auto-detected URLs.
When set to always, OSC-8 URLs are always highlighted, regardless of their other attributes (bold,
italic etc). Note that this does not make them clickable.
Default: url-mode
label-letters
String of characters to use when generating key sequences for URL jump labels.
If you change this option to include the letter t, you should also change the default [url-
bindings].toggle-url-visible key binding to avoid a clash.
Default: sadfjklewcmpgh.
protocols
Comma separated list of protocols (schemes) that should be recognized in URL mode. Note that only
auto-detected URLs are affected by this option. OSC-8 URLs are always enabled, regardless of
protocol. Default: http, https, ftp, ftps, file, gemini, gopher, irc, ircs.
uri-characters
Set of characters allowed in auto-detected URLs. Any character not included in this set constitutes
an URL delimiter.
Default: abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-_.,~:;/?#@!$&%*+="'.
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.
blink
Boolean. Enables blinking cursor. Note that this can be overridden by applications. Default: no.
color
Two RRGGBB values (i.e. plain old 6-digit hex values, without prefix) specifying the foreground
(text) and background (cursor) colors for the cursor.
Default: inversed foreground and background colors.
Note that this value only applies to the block cursor. The other cursor styles are always rendered
with the foreground color.
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: 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: dcdccc.
background
Default background color. This is the color used when no ANSI color is being used. Default: 111111.
regular0, regular1 .. regular7
The eight basic ANSI colors (Black, Red, Green, Yellow, Blue, Magenta, Cyan, White). Default: 222222,
cc9393, 7f9f7f, d0bf8f, 6ca0a3, dc8cc3, 93e0e3 and dcdccc (a variant of the zenburn theme).
bright0, bright1 .. bright7
The eight bright ANSI colors (Black, Red, Green, Yellow, Blue, Magenta, Cyan, White). Default:
666666, dca3a3, bfebbf, f0dfaf, 8cd0d3, fcace3, b3ffff and ffffff (a variant of the zenburn theme).
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 colors, 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 brighN 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: first regular color (black) for foreground, and fifth bright color (light blue) for
background.
urls
Color to use for the underline used to highlight URLs in URL mode. Default: regular3.
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. 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.
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 on 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: not bound.
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: not bound.
scrollback-up-line
Scrolls up/back a single line in history. Default: not bound.
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: not bound.
scrollback-down-line
Scroll down/forward a single line in history. Default: not bound.
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.
font-decrease
Decreases the font size by 0.5pt. Default: Control+minus Control+KP_Subtract.
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: not bound.
maximize
Toggle the maximized state. Default: not bound.
fullscreen
Toggles the fullscreen state. Default: not bound.
pipe-visible, pipe-scrollback, pipe-selected
Pipes the currently visible text, the entire scrollback, or the currently selected text 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:
pipe-visible=[sh -c "xurls | uniq | tac | fuzzel | xargs -r firefox"] Control+Print
Default: not bound
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. Default: Control+Shift+u.
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.
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-to-word-boundary
Extend current selection to the next word boundary. Default: Control+w.
extend-to-next-whitespace
Extend the current selection to the next whitespace. Default: Control+Shift+w.
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.
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 an 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 completey different than the URL.
This action toggles between showing and hiding the URL on the jump label.
Default: t.
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 on 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 is optional and specifies the click count required to trigger the binding. The default
if COUNT is omitted is 1.
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.
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-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-3.
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.
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
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: wcswidth
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).
SEE ALSO
foot(1), footclient(1)
2022-02-21 foot.ini(5)