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Sunday, 3 May 2020

fzf

A command-line fuzzy finder。
fzf is a general-purpose command-line fuzzy finder.
It's an interactive Unix filter for command-line that can be used with any list; files, command history, processes, hostnames, bookmarks, git commits, etc.

Pros

  • Portable, no dependencies
  • Blazingly fast
  • The most comprehensive feature set
  • Flexible layout
  • Batteries included
    • Vim/Neovim plugin, key bindings and fuzzy auto-completion

Table of Contents

Installation

fzf project consists of the following components:
  • fzf executable
  • fzf-tmux script for launching fzf in a tmux pane
  • Shell extensions
    • Key bindings (CTRL-T, CTRL-R, and ALT-C) (bash, zsh, fish)
    • Fuzzy auto-completion (bash, zsh)
  • Vim/Neovim plugin
You can download fzf executable alone if you don't need the extra stuff.

Using Homebrew or Linuxbrew

You can use Homebrew or Linuxbrew to install fzf.
brew install fzf

# To install useful key bindings and fuzzy completion:
$(brew --prefix)/opt/fzf/install
fzf is also available via MacPorts: sudo port install fzf

Using git

Alternatively, you can "git clone" this repository to any directory and run install script.
git clone --depth 1 https://github.com/junegunn/fzf.git ~/.fzf
~/.fzf/install

Using Linux package managers

Package ManagerLinux DistributionCommand
APKAlpine Linuxsudo apk add fzf
APTDebian 9+/Ubuntu 19.10+sudo apt-get install fzf
Condaconda install -c conda-forge fzf
DNFFedorasudo dnf install fzf
NixNixOSnix-env -iA nixpkgs.fzf
PacmanArch Linuxsudo pacman -S fzf
pkgFreeBSDpkg install fzf
pkg_addOpenBSDpkg_add fzf
ZypperopenSUSEsudo zypper install fzf
Shell extensions (key bindings and fuzzy auto-completion) and Vim/Neovim plugin may or may not be enabled by default depending on the package manager. Refer to the package documentation for more information.

Windows

Pre-built binaries for Windows can be downloaded here. fzf is also available via Chocolatey and Scoop:
Package managerCommand
Chocolateychoco install fzf
Scoopscoop install fzf
Known issues and limitations on Windows can be found on the wiki page.

As Vim plugin

If you use vim-plug, add this line to your Vim configuration file:
Plug 'junegunn/fzf', { 'do': { -> fzf#install() } }
fzf#install() makes sure that you have the latest binary, but it's optional, so you can omit it if you use a plugin manager that doesn't support hooks.
For more installation options, see README-VIM.md.

Upgrading fzf

fzf is being actively developed and you might want to upgrade it once in a while. Please follow the instruction below depending on the installation method used.
  • git: cd ~/.fzf && git pull && ./install
  • brew: brew update; brew reinstall fzf
  • macports: sudo port upgrade fzf
  • chocolatey: choco upgrade fzf
  • vim-plug: :PlugUpdate fzf

Building fzf

See BUILD.md.

Usage

fzf will launch interactive finder, read the list from STDIN, and write the selected item to STDOUT.
find * -type f | fzf > selected
Without STDIN pipe, fzf will use find command to fetch the list of files excluding hidden ones. (You can override the default command with FZF_DEFAULT_COMMAND)
vim $(fzf)

Using the finder

  • CTRL-J / CTRL-K (or CTRL-N / CTRL-P) to move cursor up and down
  • Enter key to select the item, CTRL-C / CTRL-G / ESC to exit
  • On multi-select mode (-m), TAB and Shift-TAB to mark multiple items
  • Emacs style key bindings
  • Mouse: scroll, click, double-click; shift-click and shift-scroll on multi-select mode

Layout

fzf by default starts in fullscreen mode, but you can make it start below the cursor with --height option.
vim $(fzf --height 40%)
Also check out --reverse and --layout options if you prefer "top-down" layout instead of the default "bottom-up" layout.
vim $(fzf --height 40% --reverse)
You can add these options to $FZF_DEFAULT_OPTS so that they're applied by default. For example,
export FZF_DEFAULT_OPTS='--height 40% --layout=reverse --border'

Search syntax

Unless otherwise specified, fzf starts in "extended-search mode" where you can type in multiple search terms delimited by spaces. e.g. ^music .mp3$ sbtrkt !fire
TokenMatch typeDescription
sbtrktfuzzy-matchItems that match sbtrkt
'wildexact-match (quoted)Items that include wild
^musicprefix-exact-matchItems that start with music
.mp3$suffix-exact-matchItems that end with .mp3
!fireinverse-exact-matchItems that do not include fire
!^musicinverse-prefix-exact-matchItems that do not start with music
!.mp3$inverse-suffix-exact-matchItems that do not end with .mp3
If you don't prefer fuzzy matching and do not wish to "quote" every word, start fzf with -e or --exact option. Note that when --exact is set, '-prefix "unquotes" the term.
A single bar character term acts as an OR operator. For example, the following query matches entries that start with core and end with either go, rb, or py.
^core go$ | rb$ | py$

Environment variables

  • FZF_DEFAULT_COMMAND
    • Default command to use when input is tty
    • e.g. export FZF_DEFAULT_COMMAND='fd --type f'
  • FZF_DEFAULT_OPTS
    • Default options
    • e.g. export FZF_DEFAULT_OPTS="--layout=reverse --inline-info"

Options

See the man page (man fzf) for the full list of options.

Demo

If you learn by watching videos, check out this screencast by @samoshkin to explore fzf features.

Examples

Many useful examples can be found on the wiki page. Feel free to add your own as well.

fzf-tmux script

fzf-tmux is a bash script that opens fzf in a tmux pane.
# usage: fzf-tmux [LAYOUT OPTIONS] [--] [FZF OPTIONS]

# See available options
fzf-tmux --help

# select git branches in horizontal split below (15 lines)
git branch | fzf-tmux -d 15

# select multiple words in vertical split on the left (20% of screen width)
cat /usr/share/dict/words | fzf-tmux -l 20% --multi --reverse
It will still work even when you're not on tmux, silently ignoring -[pudlr] options, so you can invariably use fzf-tmux in your scripts.
Alternatively, you can use --height HEIGHT[%] option not to start fzf in fullscreen mode.
fzf --height 40%

Key bindings for command-line

The install script will setup the following key bindings for bash, zsh, and fish.
  • CTRL-T - Paste the selected files and directories onto the command-line
    • Set FZF_CTRL_T_COMMAND to override the default command
    • Set FZF_CTRL_T_OPTS to pass additional options
  • CTRL-R - Paste the selected command from history onto the command-line
    • If you want to see the commands in chronological order, press CTRL-R again which toggles sorting by relevance
    • Set FZF_CTRL_R_OPTS to pass additional options
  • ALT-C - cd into the selected directory
    • Set FZF_ALT_C_COMMAND to override the default command
    • Set FZF_ALT_C_OPTS to pass additional options
If you're on a tmux session, you can start fzf in a tmux split pane or in a tmux popup window by setting FZF_TMUX_OPTS (e.g. -d 40%). See fzf-tmux --help for available options.
More tips can be found on the wiki page.

Fuzzy completion for bash and zsh

Files and directories

Fuzzy completion for files and directories can be triggered if the word before the cursor ends with the trigger sequence which is by default **.
  • COMMAND [DIRECTORY/][FUZZY_PATTERN]**
# Files under current directory
# - You can select multiple items with TAB key
vim **<TAB>

# Files under parent directory
vim ../**<TAB>

# Files under parent directory that match `fzf`
vim ../fzf**<TAB>

# Files under your home directory
vim ~/**<TAB>


# Directories under current directory (single-selection)
cd **<TAB>

# Directories under ~/github that match `fzf`
cd ~/github/fzf**<TAB>

Process IDs

Fuzzy completion for PIDs is provided for kill command. In this case, there is no trigger sequence, just press tab key after kill command.
# Can select multiple processes with  or  keys
kill -9 <TAB>

Host names

For ssh and telnet commands, fuzzy completion for host names is provided. The names are extracted from /etc/hosts and ~/.ssh/config.
ssh **<TAB>
telnet **<TAB>

Environment variables / Aliases

unset **<TAB>
export **<TAB>
unalias **<TAB>

Settings

# Use ~~ as the trigger sequence instead of the default **
export FZF_COMPLETION_TRIGGER='~~'

# Options to fzf command
export FZF_COMPLETION_OPTS='+c -x'

# Use fd (https://github.com/sharkdp/fd) instead of the default find
# command for listing path candidates.
# - The first argument to the function ($1) is the base path to start traversal
# - See the source code (completion.{bash,zsh}) for the details.
_fzf_compgen_path() {
  fd --hidden --follow --exclude ".git" . "$1"
}

# Use fd to generate the list for directory completion
_fzf_compgen_dir() {
  fd --type d --hidden --follow --exclude ".git" . "$1"
}

# (EXPERIMENTAL) Advanced customization of fzf options via _fzf_comprun function
# - The first argument to the function is the name of the command.
# - You should make sure to pass the rest of the arguments to fzf.
_fzf_comprun() {
  local command=$1
  shift

  case "$command" in
    cd)           fzf "$@" --preview 'tree -C {} | head -200' ;;
    export|unset) fzf "$@" --preview "eval 'echo \$'{}" ;;
    ssh)          fzf "$@" --preview 'dig {}' ;;
    *)            fzf "$@" ;;
  esac
}

Supported commands

On bash, fuzzy completion is enabled only for a predefined set of commands (complete | grep _fzf to see the list). But you can enable it for other commands as well by using _fzf_setup_completion helper function.
# usage: _fzf_setup_completion path|dir|var|alias|host COMMANDS...
_fzf_setup_completion path ag git kubectl
_fzf_setup_completion dir tree

Custom fuzzy completion

(Custom completion API is experimental and subject to change)
For a command named "COMMAND", define _fzf_complete_COMMAND function using _fzf_complete helper.
# Custom fuzzy completion for "doge" command
#   e.g. doge **
_fzf_complete_doge() {
  _fzf_complete --multi --reverse --prompt="doge> " -- "$@" < <(
    echo very
    echo wow
    echo such
    echo doge
  )
}
  • The arguments before -- are the options to fzf.
  • After --, simply pass the original completion arguments unchanged ("$@").
  • Then write a set of commands that generates the completion candidates and feed its output to the function using process substitution (< <(...)).
zsh will automatically pick up the function using the naming convention but in bash you have to manually associate the function with the command using complete command.
[ -n "$BASH" ] && complete -F _fzf_complete_doge -o default -o bashdefault doge
If you need to post-process the output from fzf, define _fzf_complete_COMMAND_post as follows.
_fzf_complete_foo() {
  _fzf_complete --multi --reverse --header-lines=3 -- "$@" < <(
    ls -al
  )
}

_fzf_complete_foo_post() {
  awk '{print $NF}'
}

[ -n "$BASH" ] && complete -F _fzf_complete_foo -o default -o bashdefault foo

Vim plugin

Advanced topics

Performance

fzf is fast and is getting even faster. Performance should not be a problem in most use cases. However, you might want to be aware of the options that affect the performance.
  • --ansi tells fzf to extract and parse ANSI color codes in the input and it makes the initial scanning slower. So it's not recommended that you add it to your $FZF_DEFAULT_OPTS.
  • --nth makes fzf slower as fzf has to tokenize each line.
  • --with-nth makes fzf slower as fzf has to tokenize and reassemble each line.
  • If you absolutely need better performance, you can consider using --algo=v1 (the default being v2) to make fzf use a faster greedy algorithm. However, this algorithm is not guaranteed to find the optimal ordering of the matches and is not recommended.

Executing external programs

You can set up key bindings for starting external processes without leaving fzf (execute, execute-silent).
# Press F1 to open the file with less without leaving fzf
# Press CTRL-Y to copy the line to clipboard and aborts fzf (requires pbcopy)
fzf --bind 'f1:execute(less -f {}),ctrl-y:execute-silent(echo {} | pbcopy)+abort'
See KEY BINDINGS section of the man page for details.

Preview window

When --preview option is set, fzf automatically starts an external process with the current line as the argument and shows the result in the split window. Your $SHELL is used to execute the command with $SHELL -c COMMAND.
# {} is replaced to the single-quoted string of the focused line
fzf --preview 'cat {}'
Since the preview window is updated only after the process is complete, it's important that the command finishes quickly.
# Use head instead of cat so that the command doesn't take too long to finish
fzf --preview 'head -100 {}'
Preview window supports ANSI colors, so you can use any program that syntax-highlights the content of a file.
fzf --preview 'bat --style=numbers --color=always {} | head -500'
You can customize the size, position, and border of the preview window using --preview-window option, and the foreground and background color of it with --color option. For example,
fzf --height 40% --layout reverse --info inline --border \
    --preview 'file {}' --preview-window down:1:noborder \
    --color 'fg:#bbccdd,fg+:#ddeeff,bg:#334455,preview-bg:#223344,border:#778899'
See the man page (man fzf) for the full list of options.
For more advanced examples, see Key bindings for git with fzf (code).
Since fzf is a general-purpose text filter rather than a file finder, it is not a good idea to add --preview option to your $FZF_DEFAULT_OPTS.
# *********************
# ** DO NOT DO THIS! **
# *********************
export FZF_DEFAULT_OPTS='--preview "bat --style=numbers --color=always {} | head -500"'

# bat doesn't work with any input other than the list of files
ps -ef | fzf
seq 100 | fzf
history | fzf

Tips

Respecting .gitignore

You can use fd, ripgrep, or the silver searcher instead of the default find command to traverse the file system while respecting .gitignore.
# Feed the output of fd into fzf
fd --type f | fzf

# Setting fd as the default source for fzf
export FZF_DEFAULT_COMMAND='fd --type f'

# Now fzf (w/o pipe) will use fd instead of find
fzf

# To apply the command to CTRL-T as well
export FZF_CTRL_T_COMMAND="$FZF_DEFAULT_COMMAND"
If you want the command to follow symbolic links, and don't want it to exclude hidden files, use the following command:
export FZF_DEFAULT_COMMAND='fd --type f --hidden --follow --exclude .git'

Fish shell

CTRL-T key binding of fish, unlike those of bash and zsh, will use the last token on the command-line as the root directory for the recursive search. For instance, hitting CTRL-T at the end of the following command-line
ls /var/
will list all files and directories under /var/.
When using a custom FZF_CTRL_T_COMMAND, use the unexpanded $dir variable to make use of this feature. $dir defaults to . when the last token is not a valid directory. Example:
set -g FZF_CTRL_T_COMMAND "command find -L \$dir -type f 2> /dev/null | sed '1d; s#^\./##'"

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