callisto - standalone scripting platform for Lua 5.4

Callisto extends Lua 5.4's standard library by adding new libraries and facilities to the language. It includes a file system library to manage and manipulate files, a process library to find active processes and manipulate signals, and a JSON manipulation library (lua-cjson) among many more.

It is a standalone interpreter designed for people using Lua as a general scripting language, instead of using it embedded into another application (what Lua was designed for).

Before I made Callisto, I had to rely on luaposix for basic file system manipulation and occasionally luasocket for HTTP plus lua-cjson for JSON parsing.

luaposix provides most of the necessary functions, but is generally aimed towards people who already know how to use the POSIX APIs in C.

First and foremost, Callisto tries to be:

• an all-in-one zero-dependencies library for Lua that includes most features people would need, out of the box
• a library that works and integrates well with Lua and its standard library, and is easy to use for those who have no experience with C

Callisto relies on APIs specified in the POSIX specification; therefore it does not support operating systems that do not implement these APIs (like Microsoft Windows), only ones that do (like Linux, macOS, and the BSDs).

Dependencies

To build Callisto, you'll need nothing but a C compiler. The default C compiler is cc which is usually a symbolic link to your system's default C compiler. This should be gcc on Linux, and clang on most of the BSDs. If cc doesn't exist on your system, override it by adding CC=ccompiler to make's command like (replace ccompiler with the nameor the path to your C compiler)

Portability

Callisto has zero runtime dependencies, unless you built it with support for GNU libreadline. Lua 5.4 is statically linked in. This means that the same binary will likely work across differnt Linux distributions/versions. The only strictly required library is libc which is available on all systems.

Installation

Callisto is distributed as source-only, but it's not hard to compile.

First, get the source code using one of the tarballs found in the Releases page. Untar it then enter the directory with Callisto's source code.

After that, run

make

to compile Callisto and all its dependencies.

To install it, run make install as the root user in the source code directory to install Callisto and its shared library.

Arch Linux

Users of Arch Linux can install the AUR package: https://aur.archlinux.org/packages/callisto

Nix

If you use Nix, you can use the flake:

nix profile install github:jtbx/callisto

Usage

The standalone Callisto interpreter is called csto. Running it will start a REPL so you can execute chunks of code interactively.

csto works just like the standalone Lua 5.4 interpreter. To execute a file, run csto file where file is the name of the file containing code that you want to run. Alternatively, you can put #!/usr/bin/env csto at the top of your script, run chmod +x on it, and then you can run the script as if it was a standalone executable, for example ./yourscript.lua.

Documentation

Docs can be found here: https://jtbx.github.io/callisto/doc