Lua 'require' but files are only in memory

Question

Setting: I\'m using Lua from a C/C++ environment.

I have several lua files on disk. Those are read into memory and some more memory-only lua files become available duri

Answer 1

There is no package.loaders in lua 5.2
It called package.searchers now.

#include 
#include 
#include 

std::string    module_script;


int MyLoader(lua_State *L)
{
    const char *name = luaL_checkstring(L, 1);  // Module name

//  std::string    result = SearchScript(name); // Search your database.
    std::string    result = module_script;      // Just for demo.

    if( luaL_loadbuffer(L, result.c_str(), result.size(), name) )
    {
        printf("%s", lua_tostring(L, -1));
        lua_pop(L, 1);
    }

    return 1;
}

void SetLoader(lua_State* L)
{
    lua_register(L, "my_loader", MyLoader);

    std::string     str;

//  str += "table.insert(package.loaders,   2, my_loader) \n";   // Older than lua v5.2
    str += "table.insert(package.searchers, 2, my_loader) \n";

    luaL_dostring(L, str.c_str());
}

void SetModule()
{
    std::string     str;

    str += "print([[It is add.lua]]) \n";
    str += "return { func = function() print([[message from add.lua]]) end } \n";

    module_script=str;
}

void LoadMainScript(lua_State* L)
{
    std::string     str;

    str += "dev = require [[add]] \n";
    str += "print([[It is main.lua]]) \n";
    str += "dev.func() \n";

    if ( luaL_loadbuffer(L, str.c_str(), str.size(), "main") )
    {
        printf("%s", lua_tostring(L, -1));
        lua_pop(L, 1);
        return;
    }
}

int main()
{
    lua_State*  L = luaL_newstate();

    luaL_openlibs(L);

    SetModule(L);       // Write down module in memory. Lua not load it yet.
    SetLoader(L);
    LoadMainScript(L);

    lua_pcall(L,0,0,0);
    lua_close(L);

    return 0;
}