Embed shell integration scripts in fzf binary (`--bash` / `--zsh` / `--fish`) (#3675)

This simplifies the distribution, and the users are less likely to have
problems caused by using incompatible scripts and binaries.

    # Set up fzf key bindings and fuzzy completion
    eval "$(fzf --bash)"

    # Set up fzf key bindings and fuzzy completion
    eval "$(fzf --zsh)"

    # Set up fzf key bindings
    fzf --fish | source

7 files changed, 197 insertions, 54 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 662f0d87..f902833e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,22 @@ CHANGELOG
 
 0.48.0
 ------
+- Shell integration scripts are now embedded in the fzf binary. This simplifies the distribution, and the users are less likely to have problems caused by using incompatible scripts and binaries.
+    - bash
+      ```sh
+      # Set up fzf key bindings and fuzzy completion
+      eval "$(fzf --bash)"
+      ```
+    - zsh
+      ```sh
+      # Set up fzf key bindings and fuzzy completion
+      eval "$(fzf --zsh)"
+      ```
+    - fish
+      ```fish
+      # Set up fzf key bindings
+      fzf --fish | source
+      ```
 - Added options for customizing the behavior of the built-in walker
     | Option               | Description                                       | Default              |
     | ---                  | ---                                               | ---                  |
@@ -28,7 +44,7 @@ CHANGELOG
         export FZF_DEFAULT_COMMAND='seq 100'
         fzf --walker=dir
         ```
-- The shell extensions (key bindings and fuzzy completion) have been updated to use the built-in walker with these new options and they are now much faster out of the box.
+- Shell integration scripts have been updated to use the built-in walker with these new options and they are now much faster out of the box.
 
 0.47.0
 ------
diff --git a/README.md b/README.md
index 3c68962e..e539ea2f 100644
--- a/README.md
+++ b/README.md
@@ -56,6 +56,7 @@ Table of Contents
     * [Using git](#using-git)
     * [Using Linux package managers](#using-linux-package-managers)
     * [Windows](#windows)
+    * [Setting up shell integration](#setting-up-shell-integration)
     * [As Vim plugin](#as-vim-plugin)
 * [Upgrading fzf](#upgrading-fzf)
 * [Building fzf](#building-fzf)
@@ -104,9 +105,9 @@ fzf project consists of the following components:
 
 - `fzf` executable
 - `fzf-tmux` script for launching fzf in a tmux pane
-- Shell extensions
+- Shell integration
     - Key bindings (`CTRL-T`, `CTRL-R`, and `ALT-C`) (bash, zsh, fish)
-    - Fuzzy auto-completion (bash, zsh)
+    - Fuzzy completion (bash, zsh)
 - Vim/Neovim plugin
 
 You can [download fzf executable][bin] alone if you don't need the extra
@@ -121,11 +122,12 @@ to install fzf.
 
 ```sh
 brew install fzf
-
-# To install useful key bindings and fuzzy completion:
-$(brew --prefix)/opt/fzf/install
 ```
 
+> [!IMPORTANT]
+> To set up shell integration (key bindings and fuzzy completion),
+> see [the instructions below](#setting-up-shell-integration).
+
 fzf is also available [via MacPorts][portfile]: `sudo port install fzf`
 
 [portfile]: https://github.com/macports/macports-ports/blob/master/sysutils/fzf/Portfile
@@ -140,6 +142,9 @@ git clone --depth 1 https://github.com/junegunn/fzf.git ~/.fzf
 ~/.fzf/install
 ```
 
+The install script will add lines to your shell configuration file to modify
+`$PATH` and set up shell integration.
+
 ### Using Linux package managers
 
 | Package Manager | Linux Distribution      | Command                            |
@@ -158,10 +163,9 @@ git clone --depth 1 https://github.com/junegunn/fzf.git ~/.fzf
 | XBPS            | Void Linux              | `sudo xbps-install -S fzf`         |
 | Zypper          | openSUSE                | `sudo zypper install fzf`          |
 
-> :warning: **Key bindings (CTRL-T / CTRL-R / ALT-C) and fuzzy auto-completion
-> may not be enabled by default.**
->
-> Refer to the package documentation for more information. (e.g. `apt show fzf`)
+> [!IMPORTANT]
+> To set up shell integration (key bindings and fuzzy completion),
+> see [the instructions below](#setting-up-shell-integration).
 
 [![Packaging status](https://repology.org/badge/vertical-allrepos/fzf.svg)](https://repology.org/project/fzf/versions)
 
@@ -187,6 +191,31 @@ page][windows-wiki].
 
 [windows-wiki]: https://github.com/junegunn/fzf/wiki/Windows
 
+### Setting up shell integration
+
+Add the following line to your shell configuration file.
+
+* bash
+  ```sh
+  # Set up fzf key bindings and fuzzy completion
+  eval "$(fzf --bash)"
+  ```
+* zsh
+  ```sh
+  # Set up fzf key bindings and fuzzy completion
+  eval "$(fzf --zsh)"
+  ```
+* fish
+  ```fish
+  # Set up fzf key bindings
+  fzf --fish | source
+  ```
+
+> [!NOTE]
+> `--bash`, `--zsh`, and `--fish` options are only available in
+> fzf 0.48.0 or above. If you have an older version of fzf, refer to the
+> package documentation for more information. (e.g. `apt show fzf`)
+
 ### As Vim plugin
 
 If you use
@@ -237,18 +266,20 @@ directory to get the list of files.
 vim $(fzf)
 ```
 
+> [!NOTE]
 > You can override the default behavior
 > * Either by setting `$FZF_DEFAULT_COMMAND` to a command that generates the desired list
 > * Or by setting `--walker`, `--walker-root`, and `--walker-skip` options in `$FZF_DEFAULT_OPTS`
 
-> *:bulb: A more robust solution would be to use `xargs` but we've presented
-> the above as it's easier to grasp*
+> [!WARNING]
+> A more robust solution would be to use `xargs` but we've presented
+> the above as it's easier to grasp
 > ```sh
 > fzf --print0 | xargs -0 -o vim
 > ```
 
->
-> *:bulb: fzf also has the ability to turn itself into a different process.*
+> [!TIP]
+> fzf also has the ability to turn itself into a different process.
 >
 > ```sh
 > fzf --bind 'enter:become(vim {})'
@@ -322,13 +353,6 @@ or `py`.
 - `FZF_DEFAULT_COMMAND`
     - Default command to use when input is tty
     - e.g. `export FZF_DEFAULT_COMMAND='fd --type f'`
-    - > :warning: This variable is not used by shell extensions due to the
-      > slight difference in requirements.
-      >
-      > (e.g. `CTRL-T` runs `$FZF_CTRL_T_COMMAND` instead, `vim **<tab>` runs
-      > `_fzf_compgen_path()`, and `cd **<tab>` runs `_fzf_compgen_dir()`)
-      >
-      > The available options are described later in this document.
 - `FZF_DEFAULT_OPTS`
     - Default options
     - e.g. `export FZF_DEFAULT_OPTS="--layout=reverse --inline-info"`
@@ -337,6 +361,17 @@ or `py`.
       point to the location of the file
     - e.g. `export FZF_DEFAULT_OPTS_FILE=~/.fzfrc`
 
+> [!WARNING]
+> `FZF_DEFAULT_COMMAND` is not used by shell integration due to the
+> slight difference in requirements.
+>
+> * `CTRL-T` runs `$FZF_CTRL_T_COMMAND` to get a list of files and directories
+> * `ALT-C` runs `$FZF_ALT_C_COMMAND` to get a list of directories
+> * `vim ~/**<tab>` runs `fzf_compgen_path()` with the prefix (`~/`) as the first argument
+> * `cd foo**<tab>` runs `fzf_compgen_dir()` with the prefix (`foo`) as the first argument
+>
+> The available options are described later in this document.
+
 ### Options
 
 See the man page (`man fzf`) for the full list of options.
@@ -749,22 +784,21 @@ See the man page (`man fzf`) for the full list of options.
 
 More advanced examples can be found [here](https://github.com/junegunn/fzf/blob/master/ADVANCED.md).
 
-----
-
-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 `$FZF_DEFAULT_OPTS`**.
-
-```sh
-# *********************
-# ** DO NOT DO THIS! **
-# *********************
-export FZF_DEFAULT_OPTS='--preview "bat --style=numbers --color=always --line-range :500 {}"'
-
-# bat doesn't work with any input other than the list of files
-ps -ef | fzf
-seq 100 | fzf
-history | fzf
-```
+> [!WARNING]
+> Since fzf is a general-purpose text filter rather than a file finder, **it is
+> not a good idea to add `--preview` option to your `$FZF_DEFAULT_OPTS`**.
+>
+> ```sh
+> # *********************
+> # ** DO NOT DO THIS! **
+> # *********************
+> export FZF_DEFAULT_OPTS='--preview "bat --style=numbers --color=always --line-range :500 {}"'
+>
+> # bat doesn't work with any input other than the list of files
+> ps -ef | fzf
+> seq 100 | fzf
+> history | fzf
+> ```
 
 ### Previewing an image
 
diff --git a/install b/install
index e790b749..22a0c0be 100755
--- a/install
+++ b/install
@@ -262,6 +262,12 @@ if [[ ! "\$PATH" == *$fzf_base_esc/bin* ]]; then
   PATH="\${PATH:+\${PATH}:}$fzf_base/bin"
 fi
 
+EOF
+
+  if [[ $auto_completion -eq 1 ]] && [[ $key_bindings -eq 1 ]]; then
+    echo "eval \"\$(fzf --$shell)\"" >> "$src"
+  else
+    cat >> "$src" << EOF
 # Auto-completion
 # ---------------
 $fzf_completion
@@ -270,6 +276,7 @@ $fzf_completion
 # ------------
 $fzf_key_bindings
 EOF
+  fi
   echo "OK"
 done
 
@@ -281,18 +288,6 @@ if [[ "$shells" =~ fish ]]; then
   or set --universal fish_user_paths \$fish_user_paths "$fzf_base"/bin
 EOF
   [ $? -eq 0 ] && echo "OK" || echo "Failed"
-
-  mkdir -p "${fish_dir}/functions"
-  fish_binding="${fish_dir}/functions/fzf_key_bindings.fish"
-  if [ $key_bindings -ne 0 ]; then
-    echo -n "Symlink $fish_binding ... "
-    ln -sf "$fzf_base/shell/key-bindings.fish" \
-           "$fish_binding" && echo "OK" || echo "Failed"
-  else
-    echo -n "Removing $fish_binding ... "
-    rm -f "$fish_binding"
-    echo "OK"
-  fi
 fi
 
 append_line() {
@@ -355,12 +350,23 @@ done
 if [ $key_bindings -eq 1 ] && [[ "$shells" =~ fish ]]; then
   bind_file="${fish_dir}/functions/fish_user_key_bindings.fish"
   if [ ! -e "$bind_file" ]; then
+    mkdir -p "${fish_dir}/functions"
     create_file "$bind_file" \
       'function fish_user_key_bindings' \
-      '  fzf_key_bindings' \
+      '  fzf --fish | source' \
       'end'
   else
-    append_line $update_config "fzf_key_bindings" "$bind_file"
+    echo "Check $bind_file:"
+    lno=$(\grep -nF "fzf_key_bindings" "$bind_file" | sed 's/:.*//' | tr '\n' ' ')
+    if [[ -n $lno ]]; then
+      echo "  ** Found 'fzf_key_bindings' in line #$lno"
+      echo "  ** You have to replace the line to 'fzf --fish | source'"
+      echo
+    else
+      echo "  - Clear"
+      echo
+      append_line $update_config "fzf --fish | source" "$bind_file"
+    fi
   fi
 fi
 
diff --git a/main.go b/main.go
index d0350601..debd2408 100644
--- a/main.go
+++ b/main.go
@@ -1,6 +1,10 @@
 package main
 
 import (
+	_ "embed"
+	"fmt"
+	"strings"
+
 	fzf "github.com/junegunn/fzf/src"
 	"github.com/junegunn/fzf/src/protector"
 )
@@ -8,7 +12,44 @@ import (
 var version string = "0.47"
 var revision string = "devel"
 
+//go:embed shell/key-bindings.bash
+var bashKeyBindings []byte
+
+//go:embed shell/completion.bash
+var bashCompletion []byte
+
+//go:embed shell/key-bindings.zsh
+var zshKeyBindings []byte
+
+//go:embed shell/completion.zsh
+var zshCompletion []byte
+
+//go:embed shell/key-bindings.fish
+var fishKeyBindings []byte
+
+func printScript(label string, content []byte) {
+	fmt.Println("### " + label + " ###")
+	fmt.Println(strings.TrimSpace(string(content)))
+	fmt.Println("### end: " + label + " ###")
+}
+
 func main() {
 	protector.Protect()
-	fzf.Run(fzf.ParseOptions(), version, revision)
+	options := fzf.ParseOptions()
+	if options.Bash {
+		printScript("key-bindings.bash", bashKeyBindings)
+		printScript("completion.bash", bashCompletion)
+		return
+	}
+	if options.Zsh {
+		printScript("key-bindings.zsh", zshKeyBindings)
+		printScript("completion.zsh", zshCompletion)
+		return
+	}
+	if options.Fish {
+		printScript("key-bindings.fish", fishKeyBindings)
+		fmt.Println("fzf_key_bindings")
+		return
+	}
+	fzf.Run(options, version, revision)
 }
diff --git a/man/man1/fzf.1 b/man/man1/fzf.1
index c29f1e23..56aeeea5 100644
--- a/man/man1/fzf.1
+++ b/man/man1/fzf.1
@@ -33,6 +33,10 @@ fzf [options]
 fzf is a general-purpose command-line fuzzy finder.
 
 .SH OPTIONS
+.SS Note
+.TP
+Most long options have the opposite version with \fB--no-\fR prefix.
+
 .SS Search mode
 .TP
 .B "-x, --extended"
@@ -879,9 +883,24 @@ The default value is the current working directory.
 Comma-separated list of directory names to skip during the directory walk.
 The default value is \fB.git,node_modules\fR.
 
-.SS Note
+.SS Shell integration
 .TP
-Most options have the opposite versions with \fB--no-\fR prefix.
+.B "--bash"
+Print script to set up Bash shell integration
+
+e.g. \fBeval "$(fzf --bash)"\fR
+
+.TP
+.B "--zsh"
+Print script to set up Zsh shell integration
+
+e.g. \fBeval "$(fzf --zsh)"\fR
+
+.TP
+.B "--fish"
+Print script to set up Fish shell integration
+
+e.g. \fBfzf --fish | source\fR
 
 .SH ENVIRONMENT VARIABLES
 .TP
diff --git a/src/options.go b/src/options.go
index fdad058d..692ce6b2 100644
--- a/src/options.go
+++ b/src/options.go
@@ -130,6 +130,11 @@ const usage = `usage: fzf [options]
     --walker-skip=DIRS     Comma-separated list of directory names to skip
                            (default: .git,node_modules)
 
+  Shell integration
+    --bash                 Print script to set up Bash shell integration
+    --zsh                  Print script to set up Zsh shell integration
+    --fish                 Print script to set up Fish shell integration
+
   Environment variables
     FZF_DEFAULT_COMMAND    Default command to use when input is tty
     FZF_DEFAULT_OPTS       Default options (e.g. '--layout=reverse --info=inline')
@@ -289,6 +294,9 @@ type walkerOpts struct {
 
 // Options stores the values of command-line options
 type Options struct {
+	Bash         bool
+	Zsh          bool
+	Fish         bool
 	Fuzzy        bool
 	FuzzyAlgo    algo.Algo
 	Scheme       string
@@ -377,6 +385,9 @@ func defaultPreviewOpts(command string) previewOpts {
 
 func defaultOptions() *Options {
 	return &Options{
+		Bash:         false,
+		Zsh:          false,
+		Fish:         false,
 		Fuzzy:        true,
 		FuzzyAlgo:    algo.FuzzyMatchV2,
 		Scheme:       "default",
@@ -1655,6 +1666,21 @@ func parseOptions(opts *Options, allArgs []string) {
 	for i := 0; i < len(allArgs); i++ {
 		arg := allArgs[i]
 		switch arg {
+		case "--bash":
+			opts.Bash = true
+			if opts.Zsh || opts.Fish {
+				errorExit("cannot specify --bash with --zsh or --fish")
+			}
+		case "--zsh":
+			opts.Zsh = true
+			if opts.Bash || opts.Fish {
+				errorExit("cannot specify --zsh with --bash or --fish")
+			}
+		case "--fish":
+			opts.Fish = true
+			if opts.Bash || opts.Zsh {
+				errorExit("cannot specify --fish with --bash or --zsh")
+			}
 		case "-h", "--help":
 			help(exitOk)
 		case "-x", "--extended":
diff --git a/uninstall b/uninstall
index 4e587211..1d338cb4 100755
--- a/uninstall
+++ b/uninstall
@@ -94,6 +94,7 @@ done
 bind_file="${fish_dir}/functions/fish_user_key_bindings.fish"
 if [ -f "$bind_file" ]; then
   remove_line "$bind_file" "fzf_key_bindings"
+  remove_line "$bind_file" "fzf --fish | source"
 fi
 
 if [ -d "${fish_dir}/functions" ]; then