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)