Mount one file to another (with offset and append_only support) 

Examples:

# Simplest mode
echo qqq > source
touch mountpoint
fusefile source mountpoint

# 1KB random file (frandom is a fast urandom)
fusefile /dev/frandom mountpoint -r -S 1024 -M 0100666

# Instead of "losetup -r -o"
fusefile /dev/sda sda1_readonly -r -S 1024 -O $((63*512)) -S $((626535*512)) -M 0100600

# Append-only public log using FUSE
fusefile /var/log/mylog publiclog -a -M 0100777 -o allow_other

# Force a file to be "regular"
fusefile /dev/uba1 mountpoint -w -M 0100600 -S `blockdev --getsize64 /dev/uba1`
# Note: for this purpose there are also special FUSE filesystems:
# * https://github.com/vasi/diskfile
# * https://github.com/vi/simplecowfs#bonus-2-demotetoregularfilefs