// There is no api to retrieve the fd count of the process for ios.
// following links contains a available way, but it's complicated and
// inefficient. <https://stackoverflow.com/questions/4083608/on-ios-iphone-too-many-open-files-need-to-list-open-files-like-lsof>
pubfnfd_count_cur()->std::io::Result<usize>{unimplemented!()}pubfnfd_count_pid(pid:u32)->std::io::Result<usize>{unimplemented!()}