evilytwisted@evilytwisted-desktop / $ umount dh -h /dev/sda1
Usage: umount -h | -V
       umount -a [-d] [-f] [-r] [-n] [-v] [-t vfstypes] [-O opts]
       umount [-d] [-f] [-r] [-n] [-v] special | node...
evilytwisted@evilytwisted-desktop / $ umount dh /dev/sda1
umount: dh is not mounted (according to mtab)
evilytwisted@evilytwisted-desktop / $ umount -h /dev/sda1
Usage: umount -h | -V
       umount -a [-d] [-f] [-r] [-n] [-v] [-t vfstypes] [-O opts]
       umount [-d] [-f] [-r] [-n] [-v] special | node...
evilytwisted@evilytwisted-desktop / $ umount -h /dev/sda1
Usage: umount -h | -V
       umount -a [-d] [-f] [-r] [-n] [-v] [-t vfstypes] [-O opts]
       umount [-d] [-f] [-r] [-n] [-v] special | node...
evilytwisted@evilytwisted-desktop / $ umount -h
Usage: umount -h | -V
       umount -a [-d] [-f] [-r] [-n] [-v] [-t vfstypes] [-O opts]
       umount [-d] [-f] [-r] [-n] [-v] special | node...
evilytwisted@evilytwisted-desktop / $ umount -h
Usage: umount -h | -V
       umount -a [-d] [-f] [-r] [-n] [-v] [-t vfstypes] [-O opts]
       umount [-d] [-f] [-r] [-n] [-v] special | node...
evilytwisted@evilytwisted-desktop / $ umount -h | -V
-V: command not found
evilytwisted@evilytwisted-desktop / $ umount -h |
> /dev/sda1
bash: /dev/sda1: Permission denied
evilytwisted@evilytwisted-desktop / $ sudo umount -h | /dev/sda1
bash: /dev/sda1: Permission denied
evilytwisted@evilytwisted-desktop / $ sudo umount -h |
> /dev/sda1
bash: /dev/sda1: Permission denied
evilytwisted@evilytwisted-desktop / $