require 'fstab'

# Use default /etc/fstab
# With safe_mode only valid devices/filesystems will be added to fstab
# Trying to add non existant device or filesystem will raise an exception
#
# :backup => true will create a timestamped fstab backup before saving
# the changes
fstab = Fstab.new '/etc/fstab', :safe_mode => true, 
                                :backup => true, :backup_dir = '/etc/'

# Asuming /dev/sda1 has a valid FS
# The library will use the FS UUID automatically by default even if the block device path
# was used as an argument. This is usually safer.
fstab.add_fs '/dev/sda1', '/mnt', 'ext4', 'discard,errors=remount-ro', 0, 1

# You can use filesystem UUID also
fstab.add_fs '15baeabd-b419-4a69-a306-bc550dc8355f', '/mnt', 'ext4', 'discard,errors=remount-ro', 0, 1

# List fstab entries
fstab.entries.each do |key, val|
  puts val[:label] # FS label, may be nil
  puts val[:uuid]  # FS UUID, nil if entry marked as invalid
  puts val[:mount_point] 
  puts val[:type]
  puts val[:opts]
  puts val[:dump]
  puts val[:pass]
  puts val[:special] # special FS, i.e. not a block device
  puts val[:line_number] # line number for the FS in fstab
  puts val[:invalid] # the parser marked the entry as invalid 
end

fstab.has_device? '/dev/sda1' # => true
# Assuming /dev/sda1 UUID is 15baeabd-b419-4a69-a306-bc550dc8355f
fstab.has_device? '15baeabd-b419-4a69-a306-bc550dc8355f' # => true

# Return a hash of 'invalid' entries, i.e. device does not exist or the
# entry is malformed
fstab.invalid_entries
# Automatically remove invalid entries creating a backup file
fstab.remove_invalid_entries

# Get FS UUID
Fstab.get_uuid '/dev/sda1'

# Get FS label, assuming it has one
# return nil otherwise
Fstab.get_label '/dev/sda1'

rake spec