mattduck / 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

Click here to show screencast

Installation

1. You need to install fzf first.

2. 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.

3. Follow instructions on how to set up for:

   • zsh
   • bash
   • readline

4. 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.

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 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'

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.

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)

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)