Hello, it seems on Linux, GNU tail -f uses inotify to check if data is available even for those types of files where inotify doesn't work.
For instance, when running: tail -fn+1 /dev/tty Then press 1<Return><Ctrl-D>2<Return><Ctrl-D>3<Return>4<Return> $ tail -fn+1 /dev/tty 1 1 ^D2 2 ^D3 4 upon the first <Ctrl-D> tail installs an inotify watcher on /dev/tty and tries another read loop. But upon the second <Ctrl-D>, it waits on the inotify watch which will never return because inotify doesn't work on device files. So while 1 and 2 are being displayed, 3 and 4 and anything afterwards are not. That shouldn't be too big of a problem because it's unlikely one would use tail -f on a device and not many devices may return multiple eofs like tty devices do. AFAIK, pipes and sockets can't return more than one eof. But I suppose if one ever wants to use tail -f on non-regular files, that would be for some that do exhibit a multiple-eof behaviour. Work around for now is the undocumented ---disable-inotify option. -- Stephane
