Lambda-Term

Lambda-Term is a cross-platform library for manipulating the terminal. It provides an abstraction for keys, mouse events, colors, as well as a set of widgets to write curses-like applications.

The main objective of Lambda-Term is to provide a higher level functional interface to terminal manipulation than, for example, ncurses, by providing a native OCaml interface instead of bindings to a C library.

Lambda-Term integrates with zed to provide text edition facilities in console applications.

Dependencies

• OCaml (>= 3.12)
• findlib
• react
• lwt (>= 2.4.0) built with react support
• Camomile (>= 0.8)
• zed (>= 1.2)

For building the development version, you also need to install oasis (>= 0.3.0).

Installation

To build and install Lambda-Term:

$ ./configure
$ make
$ make install

Documentation and manual pages (optional)

To build the documentation:

$ make doc

It will then be installed by make install.

Tests (optional)

To build and execute tests:

$ ./configure --enable-tests
$ make test

Terminal emulators compatibility

All terminal emulators behave differently, especially regarding how keystrokes are reported to the application on its standard input. Lambda-Term tries to handle all of them, but it may happen that a particular key of combination of keys is not recognized by Lambda-Term, and thus does not produce the expected effect (for example: arrow keys or backspace not working).

To check what is reported by your terminal you can run the script print_sequences.ml which at the root of the repository:

$ ocaml print_sequences.ml
press 'q' to quit
\027[A
\027[D
\027[C
\027[A
\027[D
a
z
e
q

You can then send the result to [email protected], including:

• the application you are using as terminal emulator,
• the contents of the TERM environment variable inside the terminal (echo $TERM),
• the output of print_sequences.ml with, for each line, the keystroke.

Main modules

• LTerm: basic interface to the terminal, it allows to put the terminal in raw mode, hide the cursor, render an offscreen array of points, ...
• LTerm_draw: drawing functions, for rendering in an offscreen array.
• LTerm_read_line: line edition.
• LTerm_inputrc: parsing of configurations files for key bindings.
• LTerm_history: history and history file management.
• LTerm_ui: helpers for writing full-screen applications.
• LTerm_widget: widget system (not stable).
• LTerm_resources: resources loading for widgets.