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[ Languages: English | 日本語 (Japanese) ] (/blɛʃ/) ―Bash Line Editor―

[ README | Manual | Q&A | contrib | Recipes ]

Bash Line Editor ( is a command line editor written in pure Bash which replaces the default GNU Readline.

Current devel version is 0.4. This script supports Bash 3.0 or higher although we recommend to use with release versions of Bash 4.0 or higher. Currently, only UTF-8 encoding is supported for non-ASCII characters. This script is provided under the BSD License (3-clause BSD license).

Disclaimer: The core part of the line editor is written in pure Bash, but relies on POSIX stty to set up TTY states before and after the execution of user commands. It also uses other POSIX utilities for acceleration in some part of initialization and cleanup code, processing of large data in completions, paste of large data, etc.

Pronunciation: The easiest pronunciation of that users use is /blɛʃ/, but you can actually pronounce it as you like. I do not specify the canonical way of pronoucing In fact, I personally read it verbosely as /biːɛliː dɑt ɛseɪtʃ/ in my head.

Quick instructions

To use, Bash 3.0+ and POSIX standard utilities are required. There are two ways to get to download and build using git, or to download the nightly build using curl or wget. For the detailed descriptions, see Sec 1.1 and Sec 1.2 for trial/installation, and Sec 1.3 for the setup of your ~/.bashrc.

Download and generate using git

This requires the commands git, make (GNU make), and gawk (GNU awk). In the following, please replace make with gmake if your system provides GNU make as gmake (such as in BSD).

# TRIAL without installation

git clone --recursive
make -C

# Quick INSTALL to BASHRC (If this doesn't work, please follow Sec 1.3)

git clone --recursive
make -C install PREFIX=~/.local
echo 'source ~/.local/share/blesh/' >> ~/.bashrc
Download the nightly build with curl

This requires the commands curl, tar (with the support for the J flag), and xz (XZ Utils).

# TRIAL without installation

curl -L | tar xJf -
source ble-nightly*/

# Quick INSTALL to BASHRC (If this doesn't work, please follow Sec 1.3)

curl -L | tar xJf -
mkdir -p ~/.local/share/blesh
mv ble-nightly* ~/.local/share/blesh
echo 'source ~/.local/share/blesh/' >> ~/.bashrc
Download the nightly build with wget

This requires the commands wget, tar (with the support for the J flag), and xz (XZ Utils).

# TRIAL without installation

wget -O - | tar xJf -
source ble-nightly*/

# Quick INSTALL to BASHRC (If this doesn't work, please follow Sec 1.3)

wget -O - | tar xJf -
mkdir -p ~/.local/share/blesh
mv ble-nightly* ~/.local/share/blesh
echo 'source ~/.local/share/blesh/' >> ~/.bashrc
Install a package using a package manager (currently only AUR packages)

This only requires the corresponding package manager.

Update an existing copy of
# UPDATE (in a session)


# UPDATE (outside sessions)

bash /path/to/ --update
Create a package of
# PACKAGE (for package maintainers)

git clone --recursive
make -C install DESTDIR=/tmp/blesh-package PREFIX=/usr/local


  • Syntax highlighting: Highlight command lines input by users as in fish and zsh-syntax-highlighting. Unlike the simple highlighting in zsh-syntax-highlighting, performs syntactic analysis to enable the correct highlighting of complex structures such as nested command substitutions, multiple here documents, etc. Highlighting colors and styles are fully configurable.
  • Enhanced completion: Extend completion by syntax-aware completion, completion with quotes and parameter expansions in prefix texts, ambiguous candidate generation, etc. Also, menu-complete supports selection of candidates in menu (candidate list) by cursor keys, TAB and S-TAB. The feature auto-complete supports the automatic suggestion of completed texts as in fish and zsh-autosuggestions (with Bash 4.0+). The feature menu-filter integrates automatic filtering of candidates into menu completion (with Bash 4.0+). There are other functionalities such as dabbrev and sabbrev like zsh abbreviations or zsh-abbr.
  • Vim editing mode: Enhance readline's vi editing mode available with set -o vi. Vim editing mode supports various vim modes such as char/line/block visual/select mode, replace mode, command mode, operator pending mode as well as insert mode and normal mode. Vim editing mode supports various operators, text objects, registers, keyboard macros, marks, etc. It also provides vim-surround as an option.
  • Other interesting features include status line, history share, right prompt, transient prompt, xterm title, etc.

Note: does not provide specific settings of the prompt, aliases, functions, etc. provides a more fundamental infrastructure so that users can set up their own prompt, aliases, functions, etc. Of course can be used in combination with other Bash configurations such as bash-it and oh-my-bash.

Demo (version 0.2) demo gif

History and roadmap

My little experiment has took place in one corner of my bashrc in the end of May, 2013 after I enjoyed some article on zsh-syntax-highlighting. I initially thought something can be achieved by writing a few hundred of lines of codes but soon realized that everything needs to be re-implemented for the authentic support of syntax highlighting in Bash. I decided to make it as an independent script The name stemmed from that of Zsh's line editor, ZLE (Zsh Line Editor), but suffixed with .sh for the implication of being written in shell script. I'm occasinally asked about the pronunciation of, but you can actually pronounce it as you like. After the two-week experiment, I was satisfied with my conclusion that it is possible to implement a full-featured line editor in Bash that satisfies the actual daily uses. The real efforts of improving the prototype implementation for the real uses was started in Feburuary, 2015. I released the initial version in the next December. Until then, the basic part of the line editor was completed. The implementation of vim mode has been started in September, 2017 and completed in the next March. I started working on the enhancement of the completion in August, 2018 and released it in the next February.

  • 2013-06 v0.0 -- prototype
  • 2015-12 v0.1 -- Syntax highlighting [v0.1.14]
  • 2018-03 v0.2 -- Vim mode [v0.2.6]
  • 2019-02 v0.3 -- Enhanced completion [v0.3.3]
  • 20xx-xx v0.4 (plan) -- programmable highlighting [nightly build]
  • 20xx-xx v0.5 (plan) -- TUI configuration
  • 20xx-xx v0.6 (plan) -- error diagnostics?


Some user configurations or other Bash frameworks may conflict with For example,

  • assumes that common variable names and environment variables (such as LC_*) are not used for the global readonly variables. In Bash, global readonly variables take effect in any scope including the local scope of the function, which means that we cannot even define a local variable that have the same name as a global readonly variable. This is not the problem specific to, but any Bash framework may suffer from the global readonly variables. It is generally not recommended to define global readonly variables in Bash except for the security reasoning (Refs. [1], [2], [3]).

1 Usage

1.1 Try generated from source (version ble-0.4 devel)


To generate, gawk (GNU awk) and gmake (GNU make) (in addition to Bash and POSIX standard utilities) is required. The file can be generated using the following commands. If you have GNU make installed on gmake, please use gmake instead of make.

git clone --recursive

A script file will be generated in the directory


Then, you can load in the Bash session using the source command:

source out/


To install in a specified directory, use make install.

# INSTALL to ~/.local/share/blesh
make install

# INSTALL to a specified directory
make install INSDIR=/path/to/blesh

# PACKAGE (for package maintainers)
make install DESTDIR=/tmp/blesh-package PREFIX=/usr/local

If either the make variables DESTDIR or PREFIX is supplied, will be copied to $DESTDIR/$PREFIX/share/blesh. Otherwise, if the make variables INSDIR is specified, it will be installed directly on $INSDIR. Otherwise, if the environment variable $XDG_DATA_HOME is defined, the install location will be $XDG_DATA_HOME/blesh. If none of these variables are specified, the default install location is ~/.local/share/blesh.

To set up .bashrc see Sec. 1.3.

1.2 Or, use a tar ball of obtained from GitHub releases

For download, trial and install, see the description at each release page. The stable versions are significantly old compared to the devel version, so many features are unavailable.

1.3 Set up .bashrc

If you want to load by default in interactive sessions of bash, usually one can just source in ~/.bashrc, but more reliable way is to add the following codes to your .bashrc file:

# bashrc

# Add this lines at the top of .bashrc:
[[ $- == *i* ]] && source /path/to/blesh/ --noattach

# your bashrc settings come here...

# Add this line at the end of .bashrc:
[[ ${BLE_VERSION-} ]] && ble-attach

1.4 User settings ~/.blerc

User settings can be placed in the init script ~/.blerc (or ${XDG_CONFIG_HOME:-$HOME/.config}/blesh/ if ~/.blerc is not available) whose template is available as the file blerc in the repository. The init script is a Bash script which will be sourced during the load of, so any shell commands can be used in ~/.blerc. If you want to change the default path of the init script, you can add the option --rcfile INITFILE to source as the following example:

# in bashrc

# Example 1: ~/.blerc will be used by default
[[ $- == *i* ]] && source /path/to/blesh/ --noattach

# Example 2: /path/to/your/blerc will be used
[[ $- == *i* ]] && source /path/to/blesh/ --noattach --rcfile /path/to/your/blerc

1.5 Update

You need Git (git), GNU awk (gawk) and GNU make (make). For ble-0.3+, you can run ble-update in the session with loaded:

$ ble-update

For ble.0.4+, you can also update it outside the session using

$ bash /path/to/ --update

You can instead download the latest version by git pull and install it:

cd   # <-- enter the git repository you already have
git pull
git submodule update --recursive --remote
make INSDIR="$HOME/.local/share/blesh" install

1.6 Uninstall

Basically you can simply delete the installed directory and the settings that the user added.

  • Close all the sessions (the Bash interactive sessions with
  • Remove the added lines in .bashrc.
  • Remove blerc files (~/.blerc or ~/.config/blesh/ if any.
  • Remove the installed directory.
  • Remove the cache directory ~/.cache/blesh if any.
  • Remove the temporary directory /tmp/blesh if any [ Only needed when your system does not automatically clears /tmp ].

2 Basic settings

Here, some of the settings for ~/.blerc are picked up. You can find useful settings also in Q&A, Recipes and contrib repository. The complete list of setting items can be found in the template blerc. For detailed explanations please refer to Manual.

2.1 Vim mode

For the vi/vim mode, check the wiki page.

2.2 Disable features

One of frequently asked questions is the way to disable a specific feature that adds. Here the settings for disabling features are summarized.

# Disable syntax highlighting
bleopt highlight_syntax=

# Disable highlighting based on filenames
bleopt highlight_filename=

# Disable highlighting based on variable types
bleopt highlight_variable=

# Disable auto-complete (Note: auto-complete is enabled by default in bash-4.0+)
bleopt complete_auto_complete=
# Tip: you may instead specify the delay of auto-complete in millisecond
bleopt complete_auto_delay=300

# Disable auto-complete based on the command history
bleopt complete_auto_history=

# Disable ambiguous completion
bleopt complete_ambiguous=

# Disable menu-complete by TAB
bleopt complete_menu_complete=

# Disable menu filtering (Note: auto-complete is enabled by default in bash-4.0+)
bleopt complete_menu_filter=

# Disable EOF marker like "[ble: EOF]"
bleopt prompt_eol_mark=''
# Tip: you may instead specify another string:
bleopt prompt_eol_mark=''

# Disable error exit marker like "[ble: exit %d]"
bleopt exec_errexit_mark=
# Tip: you may instead specify another string:
bleopt exec_errexit_mark=$'\e[91m[error %d]\e[m'

# Disable elapsed-time marker like "[ble: elapsed 1.203s (CPU 0.4%)]"
bleopt exec_elapsed_mark=
# Tip: you may instead specify another string
bleopt exec_elapsed_mark=$'\e[94m[%ss (%s %%)]\e[m'
# Tip: you may instead change the threshold of showing the mark
bleopt exec_elapsed_enabled='sys+usr>=10*60*1000' # e.g. ten minutes for total CPU usage

2.3 CJK Width

The option char_width_mode controls the width of the Unicode characters with East_Asian_Width=A (Ambiguous characters). Currently four values emacs, west, east, and auto are supported. With the value emacs, the default width in emacs is used. With west all the ambiguous characters have width 1 (Hankaku). With east all the ambiguous characters have width 2 (Zenkaku). With auto the width mode west or east is automatically chosen based on the terminal behavior. The default value is auto. Appropriate value should be chosen in accordance with your terminal behavior. For example, the value can be changed to west as:

bleopt char_width_mode='west'

2.4 Input Encoding

The option input_encoding controls the encoding scheme used in the decode of input. Currently UTF-8 and C are available. With the value C, byte values are directly interpreted as character codes. The default value is UTF-8. For example, the value can be changed to C as:

bleopt input_encoding='C'

2.5 Bell

The options edit_abell and edit_vbell control the behavior of the edit function bell. If edit_abell is a non-empty string, audible bell is enabled, i.e. ASCII Control Character BEL (0x07) will be written to stderr. If edit_vbell is a non-empty string, visual bell is enabled. By default, the audible bell is enabled while the visual bell is disabled.

The option vbell_default_message specifies the message shown as the visual bell. The default value is ' Wuff, -- Wuff!! '. The option vbell_duration specifies the display duration of the visual-bell message. The unit is millisecond. The default value is 2000.

For example, the visual bell can be enabled as:

bleopt edit_vbell=1 vbell_default_message=' BEL ' vbell_duration=3000

For another instance, the audible bell is disabled as:

bleopt edit_abell=

2.6 Highlight Colors

The colors and attributes used in the syntax highlighting are controlled by ble-face function. The following code reproduces the default configuration:

# highlighting related to editing
ble-face -s region                    bg=60,fg=white
ble-face -s region_target             bg=153,fg=black
ble-face -s region_match              bg=55,fg=white
ble-face -s region_insert             fg=12,bg=252
ble-face -s disabled                  fg=242
ble-face -s overwrite_mode            fg=black,bg=51
ble-face -s auto_complete             fg=238,bg=254
ble-face -s menu_filter_fixed         bold
ble-face -s menu_filter_input         fg=16,bg=229
ble-face -s vbell                     reverse
ble-face -s vbell_erase               bg=252
ble-face -s vbell_flash               fg=green,reverse
ble-face -s prompt_status_line        fg=231,bg=240

# syntax highlighting
ble-face -s syntax_default            none
ble-face -s syntax_command            fg=brown
ble-face -s syntax_quoted             fg=green
ble-face -s syntax_quotation          fg=green,bold
ble-face -s syntax_escape             fg=magenta
ble-face -s syntax_expr               fg=26
ble-face -s syntax_error              bg=203,fg=231
ble-face -s syntax_varname            fg=202
ble-face -s syntax_delimiter          bold
ble-face -s syntax_param_expansion    fg=purple
ble-face -s syntax_history_expansion  bg=94,fg=231
ble-face -s syntax_function_name      fg=92,bold
ble-face -s syntax_comment            fg=242
ble-face -s syntax_glob               fg=198,bold
ble-face -s syntax_brace              fg=37,bold
ble-face -s syntax_tilde              fg=navy,bold
ble-face -s syntax_document           fg=94
ble-face -s syntax_document_begin     fg=94,bold
ble-face -s command_builtin_dot       fg=red,bold
ble-face -s command_builtin           fg=red
ble-face -s command_alias             fg=teal
ble-face -s command_function          fg=92
ble-face -s command_file              fg=green
ble-face -s command_keyword           fg=blue
ble-face -s command_jobs              fg=red
ble-face -s command_directory         fg=26,underline
ble-face -s filename_directory        underline,fg=26
ble-face -s filename_directory_sticky underline,fg=white,bg=26
ble-face -s filename_link             underline,fg=teal
ble-face -s filename_orphan           underline,fg=teal,bg=224
ble-face -s filename_executable       underline,fg=green
ble-face -s filename_setuid           underline,fg=black,bg=220
ble-face -s filename_setgid           underline,fg=black,bg=191
ble-face -s filename_other            underline
ble-face -s filename_socket           underline,fg=cyan,bg=black
ble-face -s filename_pipe             underline,fg=lime,bg=black
ble-face -s filename_character        underline,fg=white,bg=black
ble-face -s filename_block            underline,fg=yellow,bg=black
ble-face -s filename_warning          underline,fg=red
ble-face -s filename_url              underline,fg=blue
ble-face -s filename_ls_colors        underline
ble-face -s varname_array             fg=orange,bold
ble-face -s varname_empty             fg=31
ble-face -s varname_export            fg=200,bold
ble-face -s varname_expr              fg=92,bold
ble-face -s varname_hash              fg=70,bold
ble-face -s varname_number            fg=64
ble-face -s varname_readonly          fg=200
ble-face -s varname_transform         fg=29,bold
ble-face -s varname_unset             fg=124
ble-face -s argument_option           fg=teal
ble-face -s argument_error            fg=black,bg=225

The current list of faces can be obtained by the following command (ble-face without arguments):

$ ble-face

The color codes can be checked in output of the function ble-color-show (defined in

$ ble-color-show

2.7 Key Bindings

Key bindings can be controlled with the shell function, ble-bind. For example, with the following setting, "Hello, world!" will be inserted on typing C-x h

ble-bind -f 'C-x h' 'insert-string "Hello, world!"'

For another example, if you want to invoke a command on typing M-c, you can write as follows:

ble-bind -c 'M-c' 'my-command'

Or, if you want to invoke a edit function (designed for Bash bind -x) on typing C-r, you can write as follows:

ble-bind -x 'C-r' 'my-edit-function'

The existing key bindings are shown by the following command:

$ ble-bind -P

The list of widgets is shown by the following command:

$ ble-bind -L

If you want to run multiple widgets with a key, you can define your own widget by creating a function of the name ble/widget/YOUR_WIDGET_NAME as illustrated in the following example. It is highly recommended to prefix the widget name with YOUR_NAME/, my/, blerc/, dotfiles/, etc. in order not to conflict with the names of the existing standard widgets.

# Example of calling multiple widgets with the key C-t
function ble/widget/my/example1 {
  ble/widget/insert-string 'echo $('
  ble/widget/insert-string ')'
ble-bind -f C-t my/example1

3 Tips

3.1 Use multiline mode

When the command line string contains a newline character, enters the MULTILINE mode.

By typing C-v C-j or C-q C-j, you can insert a newline character in the command line string. In the MULTILINE mode, RET (C-m) causes insertion of a new newline character. In the MULTILINE mode, the command can be executed by typing C-j.

When the shell option shopt -s cmdhist is set (which is the default), RET (C-m) inserts a newline if the current command line string is syntactically incomplete.

3.2 Use vim editing mode

If set -o vi is specified in .bashrc or set editing-mode vi is specified in .inputrc, the vim mode is enabled. For details, please check the wiki page.

3.3 Use auto-complete

The feature auto-complete is available in Bash 4.0 or later. auto-complete automatically suggests a possible completion on user input. The suggested contents can be inserted by typing S-RET (when the cursor is at the end of the command line, you can also use right, C-f or end to insert the suggestion). If you want to insert only first word of the suggested contents, you can use M-right or M-f. If you want to accept the suggestion and immediately run the command, you can use C-RET (if your terminal supports this special key combination).

3.4 Use sabbrev (static abbrev expansions)

By registering words to sabbrev, the words can be expanded to predefined strings. When the cursor is just after a registered word, typing SP causes the sabbrev expansion. For example, with the following settings, when you type SP after the string command L, the command line will be expanded to command | less.

# blerc
ble-sabbrev L='| less'

The sabbrev names that starts with \ plus alphabetical letters are also recommended since it is unlikely to conflict with real words that are a part of the executed command.

# blerc
ble-sabbrev '\L'='| less'

4 Contributors

I received many feedbacks from many people in GitHub Issues/PRs. I thank all such people for supporting the project. Among them, the following people have made particularly significant contributions.

  • @cmplstofB helped me implementing vim-mode by testing it and giving me a lot of suggestions.
  • @dylankb reported many issues for fzf-integration, initialization, etc.
  • @rux616 reported several issues and created a PR for fixing the default path of .blerc
  • @timjrd suggested and contributed to performance improvements in completion.
  • @3ximus reported many issues for a wide variety of problems.


Bash Line Editor―a full-featured line editor written in pure Bash! Syntax highlighting, auto suggestions, vim modes, etc. are available in Bash interactive sessions!








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