The implementation of `os.File.Close()` in Go clears the file descriptor. https://pkg.go.dev/os#File.Close https://pkg.go.dev/os#File.Close “Close will return

The implementation of `os.File.Close()` in Go clears the file descriptor. https://pkg.go.dev/os#File.Close https://pkg.go.dev/os#File.Close “Close will return an error if it has already been called.” An os.File is a data structure containing a file descriptor and some other fields. It is safe to call Close() multiple times, because it will only call the underlying syscall close() once.