lincheney / fzf-tab-completion

Tab completion using fzf

fzf-tab-completion

Tab completion using fzf in zsh, bash, GNU readline apps (e.g. python, php -a etc.)

This is distinct from fzf's own implementation for completion, in that it works with the existing completion mechanisms rather than creating a new mechanism.

Example

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Installation

1. You need to install fzf first.

2. If you are using OSX you may need to install some additional things:

   • e.g. brew install gawk grep gnu-sed coreutils

3. Clone this repository: git clone https://github.com/lincheney/fzf-tab-completion ...

   • you can also choose to download only the scripts you need, up to you.

4. Follow instructions on how to set up for:

   • zsh
   • bash
   • readline
   • nodejs

5. The following environment variables are supported, just as in fzf's "vanilla" completion.

   • $FZF_TMUX_HEIGHT
   • $FZF_COMPLETION_OPTS
   • $FZF_DEFAULT_OPTS

   See also https://github.com/junegunn/fzf#settings

   Avoid changing these fzf flags: -n, --nth, --with-nth, -d

zsh

Add to your ~/.zshrc:

source /path/to/fzf-tab-completion/zsh/fzf-zsh-completion.sh
bindkey '^I' fzf_completion

If you have also enabled fzf's zsh completion, then the bindkey line is optional.

Note that this does not provide **-style triggers, you will need to enable fzf's zsh completion as well.

--tiebreak=chunk

The default fzf tiebreak setting is line: Prefers line with shorter length. The length of the zsh display strings may skew the ordering of the results even though they are not part of the match. You may find that adding the fzf flag --tiebreak=chunk to the environment variable $FZF_COMPLETION_OPTS provides better behaviour.

tmux

$FZF_TMUX_OPTS is respected same as in fzf however you must have fzf's keybindings enabled as well.

Searching display strings

By default, display strings are shown but cannot be searched in fzf. This is configurable via zstyle:

# only for git
zstyle ':completion:*:*:git:*' fzf-search-display true
# or for everything
zstyle ':completion:*' fzf-search-display true

Specifying keybindings

You can specify fzf keybindings to execute shell commands after fzf has closed. This is configurable via the fzf-completion-keybindings zstyle.

Keybinds look like: KEY:SCRIPT When KEY is pressed, fzf will exit and the zsh SCRIPT will run. If the keybind is given in the form KEY:accept:SCRIPT then the selected matches will also be completed before SCRIPT is run. KEY is any valid fzf key.

There is an additional function repeat-fzf-completion that can be called in the SCRIPT to retrigger fzf completion.

No keybinds are configured by default.

# press ctrl-r to repeat completion *without* accepting i.e. reload the completion
# press right to accept the completion and retrigger it
# press alt-enter to accept the completion and run it
keys=(
    ctrl-r:'repeat-fzf-completion'
    right:accept:'repeat-fzf-completion'
    alt-enter:accept:'zle accept-line'
)

zstyle ':completion:*' fzf-completion-keybindings "${keys[@]}"
# also accept and retrigger completion when pressing / when completing cd
zstyle ':completion::*:cd:*' fzf-completion-keybindings "${keys[@]}" /:accept:'repeat-fzf-completion'

Note that you can still specify the normal --bind ... options in e.g. $FZF_COMPLETION_OPTS if you need to perform fzf specific actions or don't need to run zsh commands.

Specifying custom fzf options

You can specify custom fzf options with the fzf-completion-opts style. This allows you to have different options based on the command being completed (as opposed to the $FZF_DEFAULT_OPTS etc environment variables which are global).

This is most useful for changing the --preview option. Use {1} for the selected text (or {+1} if using multi-select). Note {1} or {+1} will come through "shell-escaped", so you will need to unescape it, e.g. using eval or printf %b

# basic file preview for ls (you can replace with something more sophisticated than head)
zstyle ':completion::*:ls::*' fzf-completion-opts --preview='eval head {1}'

# preview when completing env vars (note: only works for exported variables)
# eval twice, first to unescape the string, second to expand the $variable
zstyle ':completion::*:(-command-|-parameter-|-brace-parameter-|export|unset|expand):*' fzf-completion-opts --preview='eval eval echo {1}'

# preview a `git status` when completing git add
zstyle ':completion::*:git::git,add,*' fzf-completion-opts --preview='git -c color.status=always status --short'

# if other subcommand to git is given, show a git diff or git log
zstyle ':completion::*:git::*,[a-z]*' fzf-completion-opts --preview='
eval set -- {+1}
for arg in "$@"; do
    { git diff --color=always -- "$arg" | git log --color=always "$arg" } 2>/dev/null
done'

bash

Add to your ~/.bashrc:

source /path/to/fzf-tab-completion/bash/fzf-bash-completion.sh
bind -x '"\t": fzf_bash_completion'

Note that this does not provide **-style triggers, you will need to enable fzf's bash completion as well.

If you are using a bash that is dynamically linked against readline (LD_PRELOAD= ldd $(which bash)) you may prefer (or not!) to use the readline method instead.

Autocomplete common prefix

By default, fzf is always shown whenever there are at least 2 matches. You can change this to a more "vanilla" tab completion experience where it attempts to complete the longest common prefix before showing matches in fzf.

This is controlled by the variables

• FZF_COMPLETION_AUTO_COMMON_PREFIX=true - completes the common prefix if it is also a match
• FZF_COMPLETION_AUTO_COMMON_PREFIX_PART=true - with the above variable, completes the common prefix even if it is not a match

For example, if we have following files in a directory:

abcdef-1234
abcdef-5678
abc
other

With FZF_COMPLETION_AUTO_COMMON_PREFIX=true:

• when completing ls <tab>, it will display fzf with all 4 files (as normal)
• when completing ls a<tab>, it will automatically complete to ls abc. Pressing tab again will show fzf with the first 3 files.
• when completing ls abcd<tab> it will show fzf with the first 2 files (as normal)
• With FZF_COMPLETION_AUTO_COMMON_PREFIX_PART=true set as well:
  • when completing ls abcd<tab>, it will automatically complete to ls abcdef-. Pressing tab again will show fzf with the first 2 files.

tmux

$FZF_TMUX_OPTS is respected same as in fzf however you must have fzf's keybindings enabled as well.

Custom loading message

bash clears the prompt and input line before running the completion, so a loading message is printed instead.

You can customise the message by overriding the _fzf_bash_completion_loading_msg() function.

For example the following "re-prints" the prompt and input line to make this less jarring (note this may or may not work, there's no detection of $PS2 and there is always some unavoidable flicker):

_fzf_bash_completion_loading_msg() { echo "${PS1@P}${READLINE_LINE}" | tail -n1; }

readline

NOTE: This uses a LD_PRELOAD hack, is only supported on Linux and only for GNU readline (not e.g. libedit or other readline alternatives).

1. Run: cd /path/to/fzf-tab-completion/readline/ && cargo build --release
2. Copy/symlink /path/to/fzf-tab-completion/readline/bin/rl_custom_complete into your $PATH
3. Add to your ~/.inputrc:

   $include function rl_custom_complete /path/to/fzf-tab-completion/readline/target/release/librl_custom_complete.so
   "\t": rl_custom_complete
   

4. Build https://github.com/lincheney/rl_custom_function/
   • this should produce a file librl_custom_function.so which you will use with LD_PRELOAD in the next step.
5. Run something interactive that uses readline, e.g. python:

   LD_PRELOAD=/path/to/librl_custom_function.so python

6. To apply this all applications more permanently, you will need to set LD_PRELOAD somewhere like /etc/environment or ~/.pam_environment.
   • NOTE: if you set LD_PRELOAD in your .bashrc, or similar, it will affect applications run from bash but not the parent bash process itself.
   • See also: link

These are the applications that I have seen working:

• python2, python3
• php -a
• R
• lftp
• irb --legacy (the new irb in ruby 2.7 uses ruby-reline instead of readline)
• gdb
• sqlite3
• bash (only when not statically but dynamically linked to libreadline)

nodejs repl

1. Copy/symlink /path/to/fzf-tab-completion/readline/bin/rl_custom_complete into your $PATH
2. Then run node -r /path/to/fzf-tab-completion.git/node/fzf-node-completion.js
   • You may wish to add a shell alias to your zshrc/bashrc to avoid typing out the full command each time, e.g.: alias node='node -r /path/to/fzf-tab-completion.git/node/fzf-node-completion.js

Related projects

• https://github.com/rockandska/fzf-obc (fzf tab completion in bash)
• https://github.com/Aloxaf/fzf-tab (fzf tab completion in zsh)
• https://github.com/lincheney/rl_custom_isearch (fzf for history search in all readline applications)