mle - Man Page
flexible terminal-based text editor
Synopsis
Description
mle is a small, flexible, terminal-based text editor written in C. It runs on Linux, Windows (Cygwin or WSL), FreeBSD, macOS, and more.
Basic usage
$ 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.
Options
- -h
Show help
- -a ⟨1|0⟩
Enable/disable tab to space (default: 1)
- -b ⟨1|0⟩
Enable/disable highlight bracket pairs (default: 1)
- -c column
Color column (default: -1, disabled)
- -e ⟨1|0⟩
Enable/disable mouse support (default: 0)
- -H ⟨1|0⟩
Enable/disable headless mode (default: 1 if no tty, else 0)
- -i ⟨1|0⟩
Enable/disable auto indent (default: 0)
- -K kdef
Make a kmap definition (use with -k).
kdef is formatted as
`<name>,<default_cmd>,<allow_fallthru>`, where name is the name of the kmap, default_cmd is the default command handler (can be empty), and allow_fallthru is a 0 or 1 specifying whether unhandled key input should be forwarded to the previous kmap on the stack or not.- -k kbind
Add key binding to current kmap definition (use after -K).
kbind is formatted as
`<cmd>,<key>,<param>`, where cmd is a command name, key is a key name, and param is a static parameter passed to the command (can be empty).- -l ltype
Set linenum type (default: 0, absolute).
ltype can be 0 (absolute), 1 (relative), or 2 (both)
- -M macro
Add a macro.
macro is formatted as
`<name> <key1> <key2> ... <keyN>`, where name is the name of the macro, and keyN are space-separated key names.- -m key
Set macro toggle key (default: M-r). key is a key name.
- -N
Skip reading of rc file
- -n kmap
Set init kmap (default: mle_normal). kmap is a kmap name.
- -p macro
Set startup macro. macro is a macro name.
- -S syndef
Make a syntax definition (use with -s).
syndef is formatted as
`<name>,<path_pattern>,<tab_width>,<tab_to_space>`, where name is a syntax name, path_pattern is a path matching regex (PCRE), tab_width is the default tab width, tab_to_space is a 0 or 1 specifying whether to convert tabs to spaces or not.- -s synrule
Add syntax rule to current syntax definition (use after -S).
synrule is formatted as
`<start>,<end>,<fg>,<bg>`, where start and end are text matching regexes (PCRE), and fg and bg are attributes to apply to matching text.If both start and end are supplied, the rule applies to all text matched in between the regexes, potentially spanning multiple lines. If only start is specified, the rule applies to text matched by the regex on a single line.
Attributes for fg and bg are as follows:
- 0
default
- 1
black
- 2
red
- 4
yellow
- 5
blue
- 6
magenta
- 7
cyan
- 8
white
- 256
bold
- 512
underline
- 1024
reverse
- 2048
italic
- -t size
Set tab size (default: 4)
- -u ⟨1|0⟩
Enable/disable coarse undo/redo (default: 0)
- -v
Print version and exit
- -w ⟨1|0⟩
Enable/disable soft word wrap (default: 0)
- -x uscript
Run a Lua user script (experimental)
- -y syntax
Set override syntax for files opened at start up. If '-' is specified, use the built-in generic syntax. syntax is any syntax name.
- -z ⟨1|0⟩
Enable/disable trimmed paste (default: 1)
Key Names
Key names for -k, -M, and -m are formatted as `<key>` or `<mod>-<key>`.
key is any character or one of the following: space, tab, enter, backspace, comma, up, down, left, right, insert, delete, home, end, pgup, pgdn, backtab, f1, f2, f3, f4, f5, f6, f7, f8, f9, f10, f11, f12.
mod is one of
- S
Shift
- M
Alt (Meta)
- MS
Alt-Shift
- C
Ctrl
- CS
Ctrl-Shift
- CM
Ctrl-Alt
- CMS
Ctrl-Alt-Shift
Not all key names are valid or supported by all terminals. Run with `-Qk` to display key names for given input.
Advanced Usage
Below are some advanced things you can do with mle.
rc file
To customize the editor, 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 interpreted as comments.
If the rc file 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.
Shell command integration
The following programs will enable or enhance certain features of mle if they exist in PATH.
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.
Headless mode
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.
Scripting (experimental)
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 https://github.com/adsr/mle for more info.
Acknowledgements
mle makes extensive use of the following libraries.
- uthash
for hash maps and linked lists
- termbox2
for TUI
- PCRE2
for syntax highlighting and search