On Thu, Nov 09, 2023 at 04:54:19PM +0800, heminhong wrote: > In the main() function, the open() function is used to open the file. > When the file is successfully opened, fd is used to interact with the file, > but the fd is not closed, it will cause resource leak. > All open files are automatically closed when a process exits. That includes both those returned by open() and by the GPIO ioctls. So explicitly closing them here before exiting is redundant. Cheers, Kent.