Fish Cheatsheet

A comprehensive reference for the Friendly Interactive SHell (fish).

Basics

Variables

Fish uses set instead of =.

set name "Fish"              # Set variable
echo $name                   # Use variable
set -x PATH $PATH /new/path  # Export variable (Global)
set -U name "Fish"           # Universal variable (Persistent)
set -e name                  # Erase variable

Substitution

echo (date)                  # Command substitution (no backticks or $())
echo $status                 # Exit status of last command

Control Flow

If Statements

if test -f foo.txt
    echo "File exists"
else if test -d foo
    echo "Directory exists"
else
    echo "Nothing"
end

Loops

# For loop
for i in (seq 1 5)
    echo $i
end

# While loop
while test $count -lt 5
    echo $count
    set count (math $count + 1)
end

Functions

Definition

function say_hello
    echo "Hello $argv[1]"
end
say_hello "World"

# Save function for autoloading
funcsave say_hello

Abbreviations

Better than aliases because they expand in place.

abbr -a gco git checkout
abbr -a ga git add

Keybindings

Modes

Fish has Emacs keybindings by default.

fish_vi_key_bindings         # Enable Vi mode
fish_default_key_bindings    # Enable Emacs mode

Prompt Customization

fish_prompt

Modify the fish_prompt function.

function fish_prompt
    set_color purple
    echo -n (whoami)
    set_color normal
    echo -n "@"
    set_color yellow
    echo -n (hostname)
    set_color normal
    echo -n " "
    echo -n (prompt_pwd)
    echo -n "> "
end

History

prevd                        # Go back
nextd                        # Go forward
dirh                         # Print directory history
cd -                         # Go to previous directory

Configuration

config.fish

Located at ~/.config/fish/config.fish.

if status is-interactive
    # Commands to run in interactive sessions can go here
end

Useful Built-ins

math "1 + 2"                 # Arithmetic
string match "foo*" "foobar" # String matching
string sub -s 1 -l 2 "foo"   # Substring