mle is a small, flexible, terminal-based text editor written in C.

Runs on Linux, Windows (Cygwin or WSL), FreeBSD, macOS, and more.

• AceJump-like movement
• Large file benchmark
• Older demos

• Keep codebase small and hackable
• Minimize build-time and run-time dependencies
• Favor simplicity over correctness
• Make extensible and configurable
• Use shell commands to enhance functionality (e.g., grep, tree)

• Small codebase (~11k SLOC)
• Full UTF-8 support
• Syntax highlighting
• Stackable key maps (modes)
• Extensible via Lua
• Scriptable rc file
• Key macros
• Window splitting
• Regex search and replace
• Large file support
• Incremental search
• Linear undo and redo
• Multiple cursors
• Auto indent
• Headless mode
• Navigation via ctags
• Movement via less
• Fuzzy file search via fzf
• File browsing via tree
• File grep via grep
• String manip via perl

$ sudo apt install git build-essential # install git, make, gcc, libc-dev
$
$ git clone --recursive https://github.com/adsr/mle.git
$ cd mle
$ make mle_vendor=1

To build a completely static binary, try make mle_vendor=1 mle_static=1.

You can also run plain make to link against system libraries instead of vendor/. Note this requires the following packages to be installed:

uthash-dev
liblua5.4-dev
libpcre2-dev

To install to /usr/local/bin:

$ make install

To install to a custom directory, supply prefix, e.g.:

$ make install prefix=/usr # /usr/bin/mle

mle may be available to install via your system's package manager.

# apt install mle   # Ubuntu and Debian-based distros
# dnf install mle   # CentOS, RHEL, Fedora-based distros
# pkg install mle   # FreeBSD
# yay -S mle        # Arch (via AUR)
# snap install mle  # all major Linux distros
# nix-env -i mle    # NixOS (via nixpkgs)
# apk add mle       # Alpine
# xbps-install mle  # Void
# brew install mle  # macOS (Homebrew)
# port install mle  # macOS (MacPorts)
# setup-x86.exe -q -P mle # Cygwin

$ mle               # Open blank buffer
$ mle one.c         # Edit one.c
$ mle one.c:100     # Edit one.c at line 100
$ mle one.c two.c   # Edit one.c and two.c
$ mle -h            # Show command line help

The default key bindings are intuitive. Input text as normal, use directional keys to move around, use Ctrl-S to save, Ctrl-O to open, Ctrl-X to exit.

Press F2 for full help.

mle is customized via command line options. Run mle -h to view all cli options.

To set default options, make an rc file named ~/.mlerc (or /etc/mlerc). The contents of the rc file are any number of cli options separated by newlines. Lines that begin with a semi-colon are interpretted as comments.

If ~/.mlerc is executable, mle executes it and interprets the resulting stdout as described above. For example, consider the following snippet from an executable ~/.mlerc bash(1) script:

# Define 'test' kmap
echo '-Ktest,,1'

# M-q: replace grep with git grep if `.git` exists
if [ -d ".git" ]; then
  echo '-kcmd_grep,M-q,git grep --color=never -P -i -I -n %s 2>/dev/null'
fi

# Set default kmap
echo '-n test'

This overrides the built-in grep command with git grep if .git exists in the current working directory.

The following programs will enable or enhance certain features of mle if they exist in PATH.

• bash (tab completion)
• fzf (fuzzy file search)
• grep (file grep)
• less (less integration)
• perl (perl 1-liners)
• readtags (ctags integration)
• tree (file browsing)

Arbitrary shell commands can also be run via cmd_shell (M-e by default). If any text is selected, it is sent to stdin of the command. Any resulting stdout is inserted into the text buffer.

mle provides support for non-interactive editing which may be useful for using the editor as a regular command line tool. In headless mode, mle reads stdin into a buffer, applies a startup macro if specified, and then writes the buffer contents to stdout. For example:

$ echo -n hello | mle -M 'test C-e space w o r l d enter' -p test
hello world

If stdin is a pipe, mle goes into headless mode automatically. Headless mode can be explicitly enabled or disabled with the -H option.

If stdin is a pipe and headless mode is disabled via -H0, mle reads stdin into a new buffer and then runs as normal in interactive mode.

mle is extensible via the Lua programming language. Scripts are loaded via the -x cli option. Commands registered by scripts can be mapped to keys as normal via -k. See uscript.lua for a simple example.

There is also a wren branch with Wren scripting support. That work is on pause.

• eon - mouse support and Notepad-like selections
• turbo-mle - Turbo Vision port

mle makes extensive use of the following libraries.

• uthash for hash maps and linked lists
• termbox2 for TUI
• PCRE2 for syntax highlighting and search