CloneZFS - clonezfs.sh to recursively clone a snapshot or dataset

clonezfs.sh

#!/bin/sh

#-----------------------------------------
#
# CloneZFS - sh shell script to recursively create a zfs clone of a dataset
#
# Copyright 2013 Evan Susarret evansus@gmail.com
#
#-----------------------------------------

#-----------------------------------------
#
# Constants
#
#-----------------------------------------

CLONEZFS_ERROR_SRC_MISSING=11
CLONEZFS_ERROR_SRC_SNAPSHOT=10
CLONEZFS_ERROR_DEST_EXISTS=11
CLONEZFS_ERROR_DEST_DELETE=12
CLONEZFS_ERROR_DEST_RENAME=13
CLONEZFS_ERROR_SRC_LISTING=20

#-----------------------------------------
#
# Functions
#
#-----------------------------------------

#-----------------------------------------
# clonezfs_usage
#   Print command usage and exit 1
#-----------------------------------------
clonezfs_usage() {
  cat << EOF
 usage: clonezfs [-bfnq] <dataset@snapshot> <destination>
        clonezfs [-bfnq] [-s <snapshotname>] <source> <destination>

  [ COMMAND ]

  In its first form, clonezfs will recursively clone an existing snapshot
    from <source@snapshot> to the <destination> dataset, prompting to
    rename, overwrite, or cancel if the destination exists.
  The second form of clonezfs creates a snapshot on the <source> dataset
    then clones the new snapshot to the <destination> dataset, as if the
    first form was called on an existing snapshot.
    The new snapshot will be named 'clone-YY-MM-DD-HH-MM', using 'date'
    to format the timestamp, unless <snapshotname> is specified by using
    the -s flag.

  [ ARGUMENTS ]

   <source@snapshot> : zpool/mydataset@newsnapshot
     If the source dataset or snapshot cannot be located, an error will
       be output, unless the -q flag is set.

   <source> : zpool/mydataset
     This form of the command will create a recursive snapshot:
       source@clone-YY-MM-DD-HH-MM
     Then will proceed to clone dataset@snapshot to destination.

   <destination> : zpool/myclone
     If the destination dataset cannot be located, an error will be
       output, unless the -q flag is set.
     If destination already exists, you will be prompted to overwrite
       the destination dataset, rename, or cancel. This behavior can be
       overridden by using the -f, -b, or -n flags; -f to overwrite,
       -b to backup / rename the dataset, and -n to cancel the operation.

  [ OPTIONS ]

    -b    If <destination> already exists, make a backup by renaming it
            to <destination>.backup-YY-MM-DD-HH-MM before proceeding.
            If the dataset cannot be renamed, an error will be output
            unless -q is set, and clonezfs will exit with status
            CLONEZFS_ERROR_BACKUP

    -f    Force the operation to continue, overwriting <destination> if
            it exists. If the destination cannot be overwritten, an
            error will be output unless -q is set, and clonezfs will
            exit with status CLONEZFS_ERROR_DELETE

    -n    If <destination> already exists, do not proceed with any action,
            and exit with status CLONEZFS_ERROR_EXISTS

EOF

  # Error out with generic error 1
  exit 1

} # End clonezfs_usage

#-----------------------------------------
# clonezfs_get_children
#   Get recursive listing from source
#-----------------------------------------
clonezfs_get_children() {

  # Not yet implemented

  exit $CLONEZFS_ERROR_SRC_LISTING

} # End clonezfs_get_children

#-----------------------------------------
# clonezfs_make_snapshot
#   Make snapshot on source
#-----------------------------------------
clonezfs_make_snapshot() {

  # Not yet implemented

  exit $CLONEZFS_ERROR_SRC_SNAPSHOT

} # End clonezfs_make_snapshot

#-----------------------------------------
#
# Main
#
#-----------------------------------------

#-----------------------------------------
# Arguments
#   Get and validate arguments
#-----------------------------------------

# Show usage and exit
clonezfs_usage



# Should not reach this point
exit 2