On Thu, Nov 09, 2023 at 03:53:45PM +0200, Andy Shevchenko wrote: > On Thu, Nov 9, 2023 at 2:36 PM Kent Gibson <warthog618@xxxxxxxxx> wrote: > > > > 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. > > I would argue that this is a good practice for GPIO cases. > More the GPIOs we have, the more line handles we can get, then default > MAX open FD limit may occur. The best is to combine both. > That makes sense if the application is long lived and is continually requesting and releasing resources, but that is not the case here - this is a short lived app that makes a single request. Note the "here" in my initial reply. Cheers, Kent.