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:
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).
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)
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.
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.
Users of Arch Linux can install the AUR package: https://aur.archlinux.org/packages/callisto
If you use Nix, you can use the flake:
nix profile install github:jtbx/callisto
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.
Docs can be found here: https://jtbx.github.io/callisto/doc