Jeremy Baxter
ef3da25fb5
We don't know what the system cc supports in terms of command line flags, it could be tcc for all we know. Aiming for gcc over cc allows the build to succeed when cc is not gcc or clang, but the user can always override it themselves with the -c configure switch.
102 lines
3.6 KiB
Markdown
102 lines
3.6 KiB
Markdown
## callisto - standalone scripting platform for Lua 5.4
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Callisto extends Lua 5.4's standard library by adding new modules and
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facilities to the interpreter. It includes a file system library to
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manage and manipulate files and directories, a process library to find
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active processes and manipulate signals, and a JSON manipulation
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library (lua-cjson) *among many more*.
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It is a standalone interpreter designed for people using Lua as a
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general scripting language, rather than using it embedded into another
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program, which is what Lua was designed for. Perhaps you could think
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of it as a replacement for Python.
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First and foremost, Callisto tries to be:
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- a runtime environment for Lua that includes most features people
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would need out of the box, all in one executable with zero
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dependencies
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- a library that works well and integrates well with the Lua language
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and its standard library, and is easy to use for those who have no
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prior experience with C
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Callisto relies on APIs specified in the POSIX specification;
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therefore it cannot be used on operating systems that are not
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POSIX-compliant (like Microsoft Windows).
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## portability
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To build Callisto, all you need is a C99 compiler. The configure
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script will check for the presence of various compilers before
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building, to decide which one to use.
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The compilers checked are clang, followed by gcc, followed by cc. If
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you have a compiler at a custom path that you would like to use over
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the system C compiler, just pass `-c /path/to/compiler` to the
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configure script before you build. The compiler must support gcc-like
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command line arguments.
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Callisto has zero runtime dependencies, unless you built it with
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support for GNU libreadline*. Lua 5.4 is statically linked in. This
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means that the same binary will work across different Linux
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distributions.
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*libreadline support can be enabled at build time, but is disabled by
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default. To force building with libreadline support, pass the
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`-wreadline` flag to the configure script.
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## installation
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Callisto is distributed as source-only, but it's very easy to build it
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yourself. Just make sure you have a compiler such as gcc installed, as
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well as git for downloading the source code and make for compiling.
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First, obtain a copy of the source code using the following command:
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git clone https://github.com/jtbx/callisto
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After that, run
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./configure
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make
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to compile Callisto and all its dependencies.
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To install it, run `make install` as the root user in the source code
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directory. If you choose not to install it, you can still invoke it in
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the current directory.
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### Arch Linux
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Users of Arch Linux can install the AUR package:
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https://aur.archlinux.org/packages/callisto-git
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### Nix
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If you use Nix, you can use the flake:
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nix profile install github:jtbx/callisto
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## usage
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The standalone Callisto interpreter is called `csto`. This is the main
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way to run Lua programs using the Callisto libraries. Running it
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without arguments will start a read-eval-print loop so you can execute
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chunks of code interactively.
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csto works just like the standalone Lua 5.4 interpreter. To execute
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code in a file, run `csto file` where *file* is the name of the file
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containing code you want to run.
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Alternatively, put `#!/usr/bin/env csto` at the top of your script,
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make it executable with `chmod +x`, and then you can run the script as
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if it was a standalone executable, for example `./script.lua`.
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## documentation
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Library documentation can be found here:
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https://jtbx.github.io/callisto/doc
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## contributing
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Drop me an email with your patch at jtbx@disroot.org or open a Github
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pull request. You can optionally read the style.md document :)
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