pub type FileOpenHook = fn(filename: &[u8], mode: &[u8]) -> Result<Box<dyn LuaFileHandle>, LuaError>;Expand description
Function-pointer signature for opening a file handle, installed on
GlobalState::file_open_hook by the embedder.
std::fs is banned outside lua-cli, so lua-stdlib’s io library reaches
the filesystem via this hook. None causes io.open and io.output(name)
to return a “file system not available” error, which is appropriate for
sandboxed embeddings.
mode is a Lua fopen-style mode string (e.g. b"r", b"w", b"a",
b"r+", etc.). The hook must honour at least r, w, and a.