Calling Julia from LuaJIT via a shared library

hello_julia.lua

ffi = require("ffi")
julia = ffi.load("/Users/inorton/git/julia/usr/lib/libjulia.dylib", true)
ffi.cdef[[
  void jl_eval_string(const char*);
  void jl_init(const char*);
]]
julia.jl_init("/Users/inorton/git/julia/usr/lib/")
julia.jl_eval_string(" println(\"hello, world\") ")
-- should print "hello, world"

test.c

#include "julia.h"

int
loadjl(char* path)
{
  jl_init(path);
  JL_SET_STACK_BASE;

  jl_eval_string("println(sqrt(2.0))");

  return 0;
}

test.lua

local ffi = require("ffi")
local test = ffi.load("./test.so", true) -- note the optional second argument means to load symbols globally
ffi.cdef[[
    void loadjl(char*);
    ]]

local path = ffi.new("char[19]", "/cmn/jldev/usr/bin")

test.loadjl(path)

test_compile

gcc -o test.so -I$JULIA_DIR/src -I$JULIA_DIR/src/support -I$JULIA_DIR/usr/include -L$JULIA_DIR/usr/lib -fPIC -shared test.c -ljulia-debug