Syntax highlighting variables

The colors used by fish for syntax highlighting can be configured by changing the values of various variables. The value of these variables can be one of the colors accepted by the set_color command. The modifier switches accepted by set_color like --bold, --dim, --italics, --reverse and --underline are also accepted.

Example: to make errors highlighted and red, use:

set fish_color_error red --bold

The following variables are available to change the highlighting colors in fish:

If a variable isn't set or is empty, fish usually tries $fish_color_normal, except for:

Pager color variables

fish will sometimes present a list of choices in a table, called the pager.

Example: to set the background of each pager row, use:

set fish_pager_color_background --background=white

To have black text on alternating white and gray backgrounds:

set fish_pager_color_prefix black
set fish_pager_color_completion black
set fish_pager_color_description black
set fish_pager_color_background --background=white
set fish_pager_color_secondary_background --background=brwhite

Variables affecting the pager colors:

When the secondary or selected variables aren't set or are empty, the normal variables are used, except for $fish_pager_color_selected_background, where the background of $fish_color_search_match is tried first.

Shared bindings

Some bindings are common across Emacs and vi mode, because they aren't text editing bindings, or because what vi/Vim does for a particular key doesn't make sense for a shell.

Emacs mode commands

To enable emacs mode, use fish_default_key_bindings. This is also the default.

You can change these key bindings using the bind builtin.

Vi mode commands

Vi mode allows for the use of vi-like commands at the prompt. Initially, insert mode is active. escape enters command mode. The commands available in command, insert and visual mode are described below. Vi mode shares some bindings with Emacs mode.

To enable vi mode, use fish_vi_key_bindings. It is also possible to add all Emacs mode bindings to vi mode by using something like:

function fish_user_key_bindings


    # Execute this once per mode that emacs bindings should be used in


    fish_default_key_bindings -M insert


    # Then execute the vi-bindings so they take precedence when there's a conflict.


    # Without --no-erase fish_vi_key_bindings will default to


    # resetting all bindings.


    # The argument specifies the initial mode (insert, "default" or visual).


    fish_vi_key_bindings --no-erase insert
end

When in vi mode, the fish_mode_prompt function will display a mode indicator to the left of the prompt. To disable this feature, override it with an empty function. To display the mode elsewhere (like in your right prompt), use the output of the fish_default_mode_prompt function.

When a binding switches the mode, it will repaint the mode-prompt if it exists, and the rest of the prompt only if it doesn't. So if you want a mode-indicator in your fish_prompt, you need to erase fish_mode_prompt e.g. by adding an empty file at ~/.config/fish/functions/fish_mode_prompt.fish. (Bindings that change the mode are supposed to call the repaint-mode bind function, see bind)

The fish_vi_cursor function will be used to change the cursor's shape depending on the mode in supported terminals. The following snippet can be used to manually configure cursors after enabling vi mode:

# Emulates vim's cursor shape behavior
# Set the normal and visual mode cursors to a block
set fish_cursor_default block
# Set the insert mode cursor to a line
set fish_cursor_insert line
# Set the replace mode cursors to an underscore
set fish_cursor_replace_one underscore
set fish_cursor_replace underscore
# Set the external cursor to a line. The external cursor appears when a command is started.
# The cursor shape takes the value of fish_cursor_default when fish_cursor_external is not specified.
set fish_cursor_external line
# The following variable can be used to configure cursor shape in
# visual mode, but due to fish_cursor_default, is redundant here
set fish_cursor_visual block

Additionally, blink can be added after each of the cursor shape parameters to set a blinking cursor in the specified shape.

Fish knows the shapes "block", "line" and "underscore", other values will be ignored.

If the cursor shape does not appear to be changing after setting the above variables, it's likely your terminal emulator does not support the capabilities necessary to do this.

Command mode

Command mode is also known as normal mode.

Insert mode

Visual mode

Custom bindings

In addition to the standard bindings listed here, you can also define your own with bind:

# Just clear the commandline on control-c
bind ctrl-c 'commandline -r ""'

Put bind statements into config.fish or a function called fish_user_key_bindings.

If you change your mind on a binding and want to go back to fish's default, you can simply erase it again:

bind --erase ctrl-c

Fish remembers its preset bindings and so it will take effect again. This saves you from having to remember what it was before and add it again yourself.

If you use vi bindings, note that bind will by default bind keys in command mode. To bind something in insert mode:

bind --mode insert ctrl-c 'commandline -r ""'

Key sequences

To find out the name of a key, you can use fish_key_reader.

> fish_key_reader # Press Alt + right-arrow
Press a key:
bind alt-right 'do something'

Note that the historical way the terminal encodes keys and sends them to the application (fish, in this case) makes a lot of combinations indistinguishable or unbindable. In the usual encoding, ctrl-i is the same as the tab key, and shift cannot be detected when ctrl is also pressed.

There are more powerful encoding schemes, and fish tries to tell the terminal to turn them on, but there are still many terminals that do not support them. When fish_key_reader prints the same sequence for two different keys, then that is because your terminal sends the same sequence for them, and there isn't anything fish can do about it. It is our hope that these schemes will become more widespread, making input more flexible.

In the historical scheme, escape is the same thing as alt in a terminal. To distinguish between pressing escape and then another key, and pressing alt and that key (or an escape sequence the key sends), fish waits for a certain time after seeing an escape character. This is configurable via the fish_escape_delay_ms variable.

If you want to be able to press escape and then a character and have it count as alt+that character, set it to a higher value, e.g.:

set -g fish_escape_delay_ms 100

Similarly, to disambiguate other keypresses where you've bound a subsequence and a longer sequence, fish has fish_sequence_key_delay_ms:

# This binds the sequence j,k to switch to normal mode in vi mode.
# If you kept it like that, every time you press "j",
# fish would wait for a "k" or other key to disambiguate
bind -M insert -m default j,k cancel repaint-mode
# After setting this, fish only waits 200ms for the "k",
# or decides to treat the "j" as a separate sequence, inserting it.
set -g fish_sequence_key_delay_ms 200

Copy and paste (Kill Ring)

Fish uses an Emacs-style kill ring for copy and paste functionality. For example, use ctrl-k (kill-line) to cut from the current cursor position to the end of the line. The string that is cut (a.k.a. killed in emacs-ese) is inserted into a list of kills, called the kill ring. To paste the latest value from the kill ring (emacs calls this "yanking") use ctrl-y (the yank input function). After pasting, use alt-y (yank-pop) to rotate to the previous kill.

Copy and paste from outside are also supported, both via the ctrl-x / ctrl-v bindings (the fish_clipboard_copy and fish_clipboard_paste functions [3]) and via the terminal's paste function, for which fish enables "Bracketed Paste Mode", so it can tell a paste from manually entered text. In addition, when pasting inside single quotes, pasted single quotes and backslashes are automatically escaped so that the result can be used as a single token simply by closing the quote after. Kill ring entries are stored in fish_killring variable.

The commands begin-selection and end-selection (unbound by default; used for selection in vi visual mode) control text selection together with cursor movement commands that extend the current selection. The variable fish_cursor_selection_mode can be used to configure if that selection should include the character under the cursor (inclusive) or not (exclusive). The default is exclusive, which works well with any cursor shape. For vi mode, and particularly for the block or underscore cursor shapes you may prefer inclusive.

[3]

These rely on external tools. Currently xsel, xclip, wl-copy/wl-paste and pbcopy/pbpaste are supported.

Multiline editing

The fish commandline editor can be used to work on commands that are several lines long. There are three ways to make a command span more than a single line:

The fish commandline editor works exactly the same in single line mode and in multiline mode. To move between lines use the left and right arrow keys and other such keyboard shortcuts.

Searchable command history

After a command has been executed, it is remembered in the history list. Any duplicate history items are automatically removed. By pressing the up and down keys, you can search forwards and backwards in the history. If the current command line is not empty when starting a history search, only the commands containing the string entered into the command line are shown.

By pressing alt-up (↑) and alt-down (↓), a history search is also performed, but instead of searching for a complete commandline, each commandline is broken into separate elements just like it would be before execution, and the history is searched for an element matching that under the cursor.

For more complicated searches, you can press ctrl-r to open a pager that allows you to search the history. It shows a limited number of entries in one page, press ctrl-r [4] again to move to the next page and ctrl-s [5] to move to the previous page. You can change the text to refine your search.

History searches are case-insensitive unless the search string contains an uppercase character. You can stop a search to edit your search string by pressing escape or pagedown.

Prefixing the commandline with a space will prevent the entire line from being stored in the history. It will still be available for recall until the next command is executed, but will not be stored on disk. This is to allow you to fix misspellings and such.

The command history is stored in the file ~/.local/share/fish/fish_history (or $XDG_DATA_HOME/fish/fish_history if that variable is set) by default. However, you can set the fish_history environment variable to change the name of the history session (resulting in a <session>_history file); both before starting the shell and while the shell is running.

See the history command for other manipulations.

Examples:

To search for previous entries containing the word 'make', type make in the console and press the up key.

If the commandline reads cd m, place the cursor over the m character and press alt-up (↑) to search for previously typed words containing 'm'.

[4]

Or another binding that triggers the history-pager input function. See bind for a list.

[5]

Or another binding that triggers the pager-toggle-search input function.

Directory history

Fish automatically keeps a trail of the recent visited directories with cd by storing this history in the dirprev and dirnext variables.

Several commands are provided to interact with this directory history:

Directory stack

Another set of commands, usually also available in other shells like bash, deal with the directory stack. Stack handling is not automatic and needs explicit calls of the following commands: