Description
Legacy PHP 8.1 programs can call native C libraries directly through a foreign function interface. This runtime extension is useful for specialized integrations, prototypes, and low-level bindings when no normal PHP extension exists. It is dependency-only and has no separate launcher; PHP code uses FFI only when enabled and configured. Native calls can bypass PHP safety boundaries, crash processes, read memory, or misuse system libraries, so it should be enabled only for trusted code.