FFIFunction.returns

readonly returns?: FFITypeOrString

Return type to a FFI function (C ABI)

Defaults to FFIType.void

To pass a pointer, use "ptr" or "pointer" as the type name. To get a pointer, see ptr.

From JavaScript:

import { dlopen, CString } from "bun:ffi"

const lib = dlopen('z', {
   version: {
     returns: "ptr",
  }
});
console.log(new CString(lib.symbols.version()));

In C:

char* version()
{
 return "1.0.0";
}