os/which

    cfunction
    src/core/os.c on line 145, column 1

    (os/which &opt test)

    Check the current operating system. If `test` is nil or unset, 
    Returns one of:

    * :windows

    * :mingw

    * :cygwin

    * :macos

    * :web - Web assembly (emscripten)

    * :linux

    * :freebsd

    * :openbsd

    * :netbsd

    * :dragonfly

    * :bsd

    * :posix - A POSIX compatible system (default)

    May also return a custom keyword specified at build time. Is `test` 
    is truthy, will check if the current operating system equals `test` 
    and return true if they are the same, false otherwise.