DUPLICITY(1)                     User Manuals                     DUPLICITY(1)



NAME
       duplicity - Encrypted incremental backup to local or remote storage.


SYNOPSIS
       For detailed descriptions for each action see chapter ACTIONS.

       duplicity [backup|full|incremental] [options] source_directory
       target_url

       duplicity verify [options] [--compare-data] [--path-to-restore
       <relpath>] [--time time] source_url target_directory

       duplicity collection-status [options] [--file-changed <relpath>]
       [--show-changes-in-set <index>] [--jsonstat]] target_url

       duplicity list-current-files [options] [--time time] target_url

       duplicity [restore] [options] [--path-to-restore <relpath>] [--time
       time] source_url target_directory

       duplicity remove-older-than <time> [options] [--force] target_url

       duplicity remove-all-but-n-full <count> [options] [--force] target_url

       duplicity remove-all-inc-of-but-n-full <count> [options] [--force]
       target_url

       duplicity cleanup [options] [--force] target_url


DESCRIPTION
       Duplicity incrementally backs up files and folders into tar-format
       volumes encrypted with GnuPG and places them to a remote (or local)
       storage backend.  See chapter URL FORMAT for a list of all supported
       backends and how to address them.  Because duplicity uses librsync,
       incremental backups are space efficient and only record the parts of
       files that have changed since the last backup.  Currently duplicity
       supports deleted files, full Unix permissions, uid/gid, directories,
       symbolic links, fifos, etc., but not hard links.

       If you are backing up the root directory /, remember to --exclude
       /proc, or else duplicity will probably crash on the weird stuff in
       there.


EXAMPLES
       Here is an example of a backup, using sftp to back up /home/me to
       some_dir on the other.host machine:

              duplicity /home/me sftp://uid@other.host/some_dir

       If the above is run repeatedly, the first will be a full backup, and
       subsequent ones will be incremental. To force a full backup, use the
       full action:

              duplicity full /home/me sftp://uid@other.host/some_dir

       or enforcing a full every other time via --full-if-older-than <time> ,
       e.g. a full every month:

              duplicity --full-if-older-than 1M /home/me
              sftp://uid@other.host/some_dir

       Now suppose we accidentally delete /home/me and want to restore it the
       way it was at the time of last backup:

              duplicity sftp://uid@other.host/some_dir /home/me

       Duplicity enters restore mode because the URL comes before the local
       directory.  If we wanted to restore just the file "Mail/article" in
       /home/me as it was three days ago into /home/me/restored_file:

              duplicity -t 3D --path-to-restore Mail/article
              sftp://uid@other.host/some_dir /home/me/restored_file

       The following action compares the latest backup with the current files:

              duplicity verify sftp://uid@other.host/some_dir /home/me

       Finally, duplicity recognizes several include/exclude options.  For
       instance, the following will backup the root directory, but exclude
       /mnt, /tmp, and /proc:

              duplicity --exclude /mnt --exclude /tmp --exclude /proc /
              file:///usr/local/backup

       Note that in this case the destination is the local directory
       /usr/local/backup.  The following will backup only the /home and /etc
       directories under root:

              duplicity --include /home --include /etc --exclude '**' /
              file:///usr/local/backup

       Duplicity can also access a repository via ftp.  If a user name is
       given, the environment variable FTP_PASSWORD is read to determine the
       password:

              FTP_PASSWORD=mypassword duplicity /local/dir
              ftp://user@other.host/some_dir


ACTIONS
       Duplicity uses actions, which can be given in long or in short form and
       finetuned with options.
       The actions 'backup' or 'restore' can be implied from the order local
       path and remote url are given. Other actions need to be given
       explicitly.  For the rare case that the local path may be a valid
       duplicity action name you may append a '/' to the local path name so it
       can no longer be mistaken for an action.


       NOTE: The following explanations explain some but not all options that
       can be used in connection with that action.  Consult the OPTIONS
       section for more detailed descriptions.


       backup, bu <folder> <url>
              Perform a backup. Duplicity automatically performs an
              incremental backup if old signatures can be found. Else a new
              backup chain is started.


       full, fb <folder> <url>
              Perform a full backup. A new backup chain is started even if
              signatures are available for an incremental backup.


       incremental, ib <folder> <url>
              If this is requested an incremental backup will be performed.
              Duplicity will abort if no old signatures can be found.


       verify, vb [--compare-data] [--time <time>] [--path-to-restore
       <rel_path>] <url> <local_path>
              Verify tests the integrity of the backup archives at the remote
              location by downloading each file and checking both that it can
              restore the archive and that the restored file matches the
              signature of that file stored in the backup, i.e. compares the
              archived file with its hash value from archival time. Verify
              does not actually restore and will not overwrite any local
              files. Duplicity will exit with a non-zero error level if any
              files do not match the signature stored in the archive for that
              file. On verbosity level 4 or higher, it will log a message for
              each file that differs from the stored signature. Files must be
              downloaded to the local machine in order to compare them.
              Verify does not compare the backed-up version of the file to the
              current local copy of the files unless the --compare-data option
              is used (see below).
              The --path-to-restore option restricts verify to that file or
              folder.  The --time option allows one to select a backup to
              verify.  The --compare-data option enables data comparison (see
              below).


       collection-status, st [--file-changed <relpath>] [--show-changes-in-set
       <index>] <url>
              Summarize the status of the backup repository by printing the
              chains and sets found, and the number of volumes in each.
              The --file-changed option summarizes the changes to the file (in
              the most recent backup chain).  The --show-changes-in-set option
              summarizes all the file changes in the index:th backup set
              (where index 0 means the latest set, 1 means the next to latest,
              etc.).  --jsonstat prints the changes in json format and
              statistics from the jsonstat files if the backups were created
              with --jsonstat. If <index> is set to -1 statistics for the
              whole backup chain printed


       list-current-files, ls [--time <time>] <url>
              Lists the files contained in the most current backup or backup
              at time.  The information will be extracted from the signature
              files, not the archive data itself. Thus the whole archive does
              not have to be downloaded, but on the other hand if the archive
              has been deleted or corrupted, this action will not detect it.


       restore, rb [--path-to-restore <relpath>] [--time <time>] <url>
       <target_folder>
              You can restore the full monty or selected folders/files from a
              specific time.  Use the relative path as it is printed by
              list-current-files.  Usually not needed as duplicity enters
              restore mode when it detects that the URL comes before the local
              folder.


       remove-older-than, ro <time> [--force] <url>
              Delete all backup sets older than the given time.  Old backup
              sets will not be deleted if backup sets newer than time depend
              on them.  See the TIME FORMATS section for more information.
              Note, this action cannot be combined with backup or other
              actions, such as cleanup.  Note also that --force will be needed
              to delete the files instead of just listing them.


       remove-all-but-n-full, ra <count> [--force] <url>
              Delete all backups sets that are older than the count:th last
              full backup (in other words, keep the last count full backups
              and associated incremental sets).  count must be larger than
              zero. A value of 1 means that only the single most recent backup
              chain will be kept.  Note that --force will be needed to delete
              the files instead of just listing them.


       remove-all-inc-of-but-n-full, ri <count> [--force] <url>
              Delete incremental sets of all backups sets that are older than
              the count:th last full backup (in other words, keep only old
              full backups and not their increments).  count must be larger
              than zero. A value of 1 means that only the single most recent
              backup chain will be kept intact.  Note that --force will be
              needed to delete the files instead of just listing them.


       cleanup, cl [--force] <url>
              Delete the extraneous duplicity files on the given backend.
              Non-duplicity files, or files in complete data sets will not be
              deleted.  This should only be necessary after a duplicity
              session fails or is aborted prematurely.  Note that --force will
              be needed to delete the files instead of just listing them.


OPTIONS
       --allow-source-mismatch
              Do not abort on attempts to use the same archive dir or remote
              backend to back up different directories. duplicity will tell
              you if you need this switch.


       --archive-dir path
              The archive directory.

              NOTE: This option changed in 0.6.0.  The archive directory is
              now necessary in order to manage persistence for current and
              future enhancements.  As such, this option is now used only to
              change the location of the archive directory.  The archive
              directory should not be deleted, or duplicity will have to
              recreate it from the remote repository (which may require
              decrypting the backup contents).

              When backing up or restoring, this option specifies that the
              local archive directory is to be created in path.  If the
              archive directory is not specified, the default will be to
              create the archive directory in ~/.cache/duplicity/.

              The archive directory can be shared between backups to multiple
              targets, because a subdirectory of the archive dir is used for
              individual backups (see --name ).

              The combination of archive directory and backup name must be
              unique in order to separate the data of different backups.

              The interaction between the --archive-dir and the --name options
              allows for four possible combinations for the location of the
              archive dir:


              1.     neither specified (default)
                      ~/.cache/duplicity/hash-of-url

              2.     --archive-dir=/arch, no --name
                      /arch/hash-of-url

              3.     no --archive-dir, --name=foo
                      ~/.cache/duplicity/foo

              4.     --archive-dir=/arch, --name=foo
                      /arch/foo


       --asynchronous-upload
              (EXPERIMENTAL) Perform file uploads asynchronously in the
              background, with respect to volume creation. This means that
              duplicity can upload a volume while, at the same time, preparing
              the next volume for upload. The intended end-result is a faster
              backup, because the local CPU and your bandwidth can be more
              consistently utilized. Use of this option implies additional
              need for disk space in the temporary storage location; rather
              than needing to store only one volume at a time, enough storage
              space is required to store two volumes.


       --azure-blob-tier
              Standard storage tier used for backup files (Hot|Cool|Archive).


       --azure-max-single-put-size
              Specify the number of the largest supported upload size where
              the Azure library makes only one put call. If the content size
              is known and below this value the Azure library will only
              perform one put request to upload one block.  The number is
              expected to be in bytes.


       --azure-max-block-size
              Specify the number for the block size used by the Azure library
              to upload blobs if it is split into multiple blocks.  The
              maximum block size the service supports is 104857600 (100MiB)
              and the default is 4194304 (4MiB)


       --azure-max-connections
              Specify the number of maximum connections to transfer one blob
              to Azure blob size exceeds 64MB. The default values is 2.


       --b2-hide-files
              Causes Duplicity to hide files in B2 instead of deleting them.
              Useful in combination with B2's lifecycle rules.


       --backend-retry-delay number
              Specifies the number of seconds that duplicity waits after an
              error has occurred before attempting to repeat the operation.


       --cf-backend backend
              Allows the explicit selection of a cloudfiles backend. Defaults
              to pyrax.  Alternatively you might choose cloudfiles.


       --config-dir path
              Allows selection of duplicity's configuratin dir.  Defaults to
              ~/.config/duplicity.


       --copy-blocksize kilos
              Allows selection of blocksize in kilobytes to use in copying.
              Increasing this may speed copying of large files.  Defaults to
              128.

       --no-check-remote
              Turn off validation of the remote manifest.  Checking is the
              default.  No checking will allow you to backup without the
              private key, but will mean that the remote manifest may exist
              and be corrupted, leading to the possibility that the backup
              might not be recoverable.


       --compare-data
              Enable data comparison of regular files on action verify. This
              conducts a verify as described above to verify the integrity of
              the backup archives, but additionally compares restored files to
              those in target_directory.  Duplicity will not replace any files
              in target_directory. Duplicity will exit with a non-zero error
              level if the files do not correctly verify or if any files from
              the archive differ from those in target_directory. On verbosity
              level 4 or higher, it will log a message for each file that
              differs from its equivalent in target_directory.


       --copy-links
              Resolve symlinks during backup.  Enabling this will resolve &
              back up the symlink's file/folder data instead of the symlink
              itself, potentially increasing the size of the backup.


       --dry-run
              Calculate what would be done, but do not perform any backend
              actions


       --encrypt-key key-id
              When backing up, encrypt to the given public key, instead of
              using symmetric (traditional) encryption.  Can be specified
              multiple times.  The key-id can be given in any of the formats
              supported by GnuPG; see gpg(1), section "HOW TO SPECIFY A USER
              ID" for details.


       --encrypt-secret-keyring filename
              This option can only be used with --encrypt-key, and changes the
              path to the secret keyring for the encrypt key to filename This
              keyring is not used when creating a backup. If not specified,
              the default secret keyring is used which is usually located at
              .gnupg/secring.gpg


       --encrypt-sign-key key-id
              Convenience parameter. Same as --encrypt-key key-id --sign-key
              key-id.


       --exclude shell_pattern
              Exclude the file or files matched by shell_pattern.  If a
              directory is matched, then files under that directory will also
              be matched.  See the FILE SELECTION section for more
              information.


       --exclude-device-files
              Exclude all device files.  This can be useful for
              security/permissions reasons or if duplicity is not handling
              device files correctly.


       --exclude-filelist filename
              Excludes the files listed in filename, with each line of the
              filelist interpreted according to the same rules as --include
              and --exclude.  See the FILE SELECTION section for more
              information.


       --exclude-if-present filename
              Exclude directories if filename is present. Allows the user to
              specify folders that they do not wish to backup by adding a
              specified file (e.g. ".nobackup") instead of maintaining a
              comprehensive exclude/include list.


       --exclude-older-than time
              Exclude any files whose modification date is earlier than the
              specified time.  This can be used to produce a partial backup
              that contains only recently changed files. See the TIME FORMATS
              section for more information.


       --exclude-other-filesystems
              Exclude files on file systems (identified by device number)
              other than the file system the root of the source directory is
              on.


       --exclude-regexp regexp
              Exclude files matching the given regexp.  Unlike the --exclude
              option, this option does not match files in a directory it
              matches.  See the FILE SELECTION section for more information.


       --files-from filename
              Read a list of files to backup from filename rather than
              searching the entire backup source directory. Operation is
              otherwise normal, just on the specified subset of the backup
              source directory.

              Files must be specified one per line and relative to the backup
              source directory. Any absolute paths will raise an error. All
              characters per line are significant and treated as part of the
              path, including leading and trailing whitespace. Lines are
              separated by newlines or nulls, depending on whether the
              --null-separator switch was given.

              It is not necessary to include the parent directory of listed
              files, their inclusion is implied. However, the content of any
              explicitly listed directories is not implied. All required files
              must be listed when this option is used.


       --file-prefix prefix
       --file-prefix-manifest prefix
       --file-prefix-archive prefix
       --file-prefix-signature prefix
              Adds a prefix to either all files or only manifest, archive,
              signature files.  The same set of prefixes must be passed in on
              backup and restore.
              If both global and type-specific prefixes are set, global prefix
              will go before type-specific prefixes.

              See also A NOTE ON FILENAME PREFIXES

       --path-to-restore path
              This option may be given in restore mode, causing only path to
              be restored instead of the entire contents of the backup
              archive.  path should be given relative to the root of the
              directory backed up.

       --filter-globbing
       --filter-ignorecase
       --filter-literal
       --filter-regexp
       --filter-strictcase
              Change the interpretation of patterns passed to the file
              selection condition option arguments --exclude and --include
              (and variations thereof, including file lists). These options
              can appear multiple times to switch between shell globbing
              (default), literal strings, and regular expressions, case
              sensitive (default) or not. The specified interpretation applies
              for all subsequent selection conditions up until the next
              --filter option.

              See the FILE SELECTION section for more information.

       --full-if-older-than time
              Perform a full backup if an incremental backup is requested, but
              the latest full backup in the collection is older than the given
              time.  See the TIME FORMATS section for more information.

       --force
              Proceed even if data loss might result.  Duplicity will let the
              user know when this option is required.

       --ftp-passive
              Use passive (PASV) data connections.  The default is to use
              passive, but to fallback to regular if the passive connection
              fails or times out.

       --ftp-regular
              Use regular (PORT) data connections.

       --gio  Use the GIO backend and interpret any URLs as GIO would.

       --gpg-binary file_path
              Allows you to force duplicity to use file_path as gpg command
              line binary. Can be an absolute or relative file path or a file
              name.  Default value is 'gpg'. The binary will be localized via
              the PATH environment variable.

       --gpg-options options
              Allows you to pass options to gpg encryption.  The options list
              should be of the form "--opt1 --opt2=parm" where the string is
              quoted and the only spaces allowed are between options.

       --hidden-encrypt-key key-id
              Same as --encrypt-key, but it hides user's key id from encrypted
              file. It uses the gpg's --hidden-recipient command to obfuscate
              the owner of the backup. On restore, gpg will automatically try
              all available secret keys in order to decrypt the backup. See
              gpg(1) for more details.

       --ignore-errors
              Try to ignore certain errors if they happen. This option is only
              intended to allow the restoration of a backup in the face of
              certain problems that would otherwise cause the backup to fail.
              It is not ever recommended to use this option unless you have a
              situation where you are trying to restore from backup and it is
              failing because of an issue which you want duplicity to ignore.
              Even then, depending on the issue, this option may not have an
              effect.

              Please note that while ignored errors will be logged, there will
              be no summary at the end of the operation to tell you what was
              ignored, if anything. If this is used for emergency restoration
              of data, it is recommended that you run the backup in such a way
              that you can revisit the backup log (look for lines containing
              the string IGNORED_ERROR).

              If you ever have to use this option for reasons that are not
              understood or understood but not your own responsibility, please
              contact duplicity maintainers. The need to use this option under
              production circumstances would normally be considered a bug.

       --imap-full-address email_address
              The full email address of the user name when logging into an
              imap server.  If not supplied just the user name part of the
              email address is used.

       --imap-mailbox option
              Allows you to specify a different mailbox.  The default is
              "INBOX".  Other languages may require a different mailbox than
              the default.

       --idr-fakeroot
              idrived uses the concept of a "fakeroot" directory, defined via
              the --idr-fakeroot=... switch. This can be an existing
              directory, or the directory is created at runtime on the root of
              the (host) files system. (caveat: you have to have write access
              to the root!). Directories created at runtime are auto-removed
              on exit!
              So, in the above scheme, we could do:
                  duplicity --idr-fakeroot=nicepath idrived://DUPLICITY
              our files end-up at
                  <MYBUCKET>/DUPLICITY/nicepath

       --idr-fakeroot
              idrived uses the concept of a "fakeroot" directory, defined via
              the --idr-fakeroot=... switch. This can be an existing
              directory, or the directory is created at runtime on the root of
              the (host) files system. (caveat: you have to have write access
              to the root!). Directories created at runtime are auto-removed
              on exit!
              So, in the above scheme, we could do:
                  duplicity --idr-fakeroot=nicepath idrived://DUPLICITY
              our files end-up at
                  <MYBUCKET>/DUPLICITY/nicepath

       --include shell_pattern
              Similar to --exclude but include matched files instead.  Unlike
              --exclude, this option will also match parent directories of
              matched files (although not necessarily their contents).  See
              the FILE SELECTION section for more information.

       --include-filelist filename
              Like --exclude-filelist, but include the listed files instead.
              See the FILE SELECTION section for more information.

       --include-regexp regexp
              Include files matching the regular expression regexp.  Only
              files explicitly matched by regexp will be included by this
              option.  See the FILE SELECTION section for more information.

       --jsonstat
              Record statistic data similar to the default stats printed at
              the end of a backup job, addtional it includes some meta data
              about the backup chain e.g. when the full backup was created and
              how many incremental backups were made before.  Output format is
              json. It written to stdout at notice level (as classic stats)
              and the statistics are kept as a separte file next to the
              manifest but with "jsonstat" as extension.  collection-status
              --show-changes-in-set <index> --jsonstat adds data collected in
              the backup job and switch the output format to json.  If <index>
              is set to -1 statistics for the whole backup chain are printed.


       --log-fd number
              Write specially-formatted versions of output messages to the
              specified file descriptor.  The format used is designed to be
              easily consumable by other programs.

       --log-file filename
              Write specially-formatted versions of output messages to the
              specified file.  The format used is designed to be easily
              consumable by other programs.

       --log-timestamp
              Write the log with timestamp and log level before the message,
              similar to syslog.

       --max-blocksize number
              determines the number of the blocks examined for changes during
              the diff process.  For files < 1MB the blocksize is a constant
              of 512.  For files over 1MB the size is given by:
                  file_blocksize = int((file_len / (2000 * 512)) * 512)
                  return min(file_blocksize, config.max_blocksize) where
              config.max_blocksize defaults to 2048.

              If you specify a larger max_blocksize, your difftar files will
              be larger, but your sigtar files will be smaller.  If you
              specify a smaller max_blocksize, the reverse occurs.  The --max-
              blocksize option should be in multiples of 512.

       --mf-purge
              Option for mediafire to purge files on delete instead of sending
              to trash.

       --mp-segment-size megs
              Swift backend segment size in megabytes

       --name symbolicname
              Set the symbolic name of the backup being operated on. The
              intent is to use a separate name for each logically distinct
              backup. For example, someone may use "home_daily_s3" for the
              daily backup of a home directory to Amazon S3. The structure of
              the name is up to the user, it is only important that the names
              be distinct. The symbolic name is currently only used to affect
              the expansion of --archive-dir , but may be used for additional
              features in the future. Users running more than one distinct
              backup are encouraged to use this option.

              If not specified, the default value is a hash of the backend
              URL.

       --no-check-remote
              Turn off validation of the remote manifest.  Checking is the
              default.  No checking will allow you to backup without the
              private key, but will mean that the remote manifest may exist
              and be corrupted, leading to the possibility that the backup
              might not be recoverable.

       --no-compression
              Do not use GZip to compress files on remote system.

       --no-encryption
              Do not use GnuPG to encrypt files on remote system.

       --no-print-statistics
              By default duplicity will print statistics about the current
              session after a successful backup.  This switch disables that
              behavior.

       --no-files-changed
              By default duplicity will collect file names and change action
              in memory (add, del, chg) during backup.  This can be quite
              expensive in memory use, especially with millions of small
              files.  This flag turns off that collection.  This means that
              the --file-changed option for collection-status will return
              nothing.

       --null-separator
              Use nulls (\0) instead of newlines (\n) as line separators,
              which may help when dealing with filenames containing newlines.
              This affects the expected format of the files specified by the
              --{include|exclude}-filelist switches and the --{files-from}
              option, as well as the format of the directory statistics file.

       --numeric-owner
              On restore always use the numeric uid/gid from the archive and
              not the archived user/group names, which is the default
              behaviour.  Recommended for restoring from live cds which might
              have the users with identical names but different uids/gids.

       --no-restore-ownership
              Ignores the uid/gid from the archive and keeps the current
              user's one.  Recommended for restoring data to mounted
              filesystem which do not support Unix ownership or when root
              privileges are not available.

       --num-retries number
              Number of retries to make on errors before giving up.

       --par2-options options
              Verbatim options to pass to par2.

       --par2-redundancy percent
              Adjust the level of redundancy in percent for Par2 recovery
              files (default 10%).

       --par2-volumes number
              Number of Par2 volumes to create (default 1).

       --progress
              When selected, duplicity will output the current upload progress
              and estimated upload time. To annotate changes, it will perform
              a first dry-run before a full or incremental, and then runs the
              real operation estimating the real upload progress.

       --progress-rate number
              Sets the update rate at which duplicity will output the upload
              progress messages (requires --progress option). Default is to
              print the status each 3 seconds.

       --rename <original path> <new path>
              Treats the path orig in the backup as if it were the path new.
              Can be passed multiple times. An example:

              duplicity restore --rename Documents/metal Music/metal
              sftp://uid@other.host/some_dir /home/me

       --rsync-options options
              Allows you to pass options to the rsync backend.  The options
              list should be of the form "opt1=parm1 opt2=parm2" where the
              option string is quoted and the only spaces allowed are between
              options. The option string will be passed verbatim to rsync,
              after any internally generated option designating the remote
              port to use. Here is a possibly useful example:

              duplicity --rsync-options="--partial-dir=.rsync-partial"
              /home/me rsync://uid@other.host/some_dir

       --s3-endpoint-url url
              Specifies the endpoint URL of the S3 storage.

       --s3-multipart-chunk-size
              Chunk size (in MB, default is 20MB) used for S3 multipart
              uploads. Adjust this to maximize bandwidth usage. For example, a
              chunk size of 10MB and a volsize of 100MB would result in 10
              chunks per volume upload.

              NOTE: This value should optimally be an even multiple of your
              --volsize for optimal performance.

              See also A NOTE ON AMAZON S3 below.

       --s3-multipart-max-procs
              Maximum number of concurrent uploads when performing a multipart
              upload.  The default is 4. You can adjust this number to
              maximizing bandwidth and CPU utilization.

              NOTE: Too many concurrent uploads may have diminishing returns.

              See also A NOTE ON AMAZON S3 below.

       --s3-region-name
              Specifies the region of the S3 storage. Usually mandatory if the
              bucket is created in a specific region.

       --s3-unencrypted-connection
              Disable SSL for connections to S3. This may be much faster, at
              some cost to confidentiality.

              With this option set, anyone between your computer and S3 can
              observe the traffic and will be able to tell: that you are using
              Duplicity, the name of the bucket, your AWS Access Key ID, the
              increment dates and the amount of data in each increment.

              This option affects only the connection, not the GPG encryption
              of the backup increment files. Unless that is disabled, an
              observer will not be able to see the file names or contents.

              See also A NOTE ON AMAZON S3 below.

       --s3-use-deep-archive
              Store volumes using Glacier Deep Archive S3 when uploading to
              Amazon S3. This storage class has a lower cost of storage but a
              higher per-request cost along with delays of up to 48 hours from
              the time of retrieval request. This storage cost is calculated
              against a 180-day storage minimum. According to Amazon this
              storage is ideal for data archiving and long-term backup
              offering 99.999999999% durability.  To restore a backup you will
              have to manually migrate all data stored on AWS Glacier Deep
              Archive back to Standard S3 and wait for AWS to complete the
              migration.

              NOTE: Duplicity will store the manifest.gpg and sigtar.gpg files
              from full and incremental backups on AWS S3 standard storage to
              allow quick retrieval for later incremental backups, all other
              data is stored in S3 Glacier Deep Archive.

       --s3-use-glacier
              Store volumes using Glacier Flexible Storage when uploading to
              Amazon S3. This storage class has a lower cost of storage but a
              higher per-request cost along with delays of up to 12 hours from
              the time of retrieval request. This storage cost is calculated
              against a 90-day storage minimum. According to Amazon this
              storage is ideal for data archiving and long-term backup
              offering 99.999999999% durability.  To restore a backup you will
              have to manually migrate all data stored on AWS Glacier back to
              Standard S3 and wait for AWS to complete the migration.

              NOTE: Duplicity will store the manifest.gpg and sigtar.gpg files
              from full and incremental backups on AWS S3 standard storage to
              allow quick retrieval for later incremental backups, all other
              data is stored in S3 Glacier.

       --s3-use-glacier-ir
              Store volumes using Glacier Instant Retrieval when uploading to
              Amazon S3. This storage class is similar to Glacier Flexible
              Storage but offers instant retrieval at standard speeds.

              NOTE: Duplicity will store the manifest.gpg and sigtar.gpg files
              from full and incremental backups on AWS S3 standard storage to
              allow quick retrieval for later incremental backups, all other
              data is stored in S3 Glacier.

       --s3-use-ia
              Store volumes using Standard - Infrequent Access when uploading
              to Amazon S3.  This storage class has a lower storage cost but a
              higher per-request cost, and the storage cost is calculated
              against a 30-day storage minimum. According to Amazon, this
              storage is ideal for long-term file storage, backups, and
              disaster recovery.

       --s3-use-onezone-ia
              Store volumes using One Zone - Infrequent Access when uploading
              to Amazon S3.  This storage is similar to Standard - Infrequent
              Access, but only stores object data in one Availability Zone.

       --s3-use-rrs
              Store volumes using Reduced Redundancy Storage when uploading to
              Amazon S3.  This will lower the cost of storage but also lower
              the durability of stored volumes to 99.99% instead the
              99.999999999% durability offered by Standard Storage on S3.

       --s3-use-server-side-kms-encryption
       --s3-kms-key-id key_id
       --s3-kms-grant grant
              Enable server-side encryption using key management service.

       --skip-if-no-change command
              By default an empty incremental backup is created if no files
              have changed.  Setting this option will skip creating a backup
              if no data has changed.  Nothing will be sent to the target nor
              information be cached.

       --scp-command command
              (only ssh pexpect backend with --use-scp enabled)
              The command will be used instead of "scp" to send or receive
              files.  To list and delete existing files, the sftp command is
              used.
              See also A NOTE ON SSH BACKENDS section SSH pexpect backend.

       --sftp-command command
              (only ssh pexpect backend)
              The command will be used instead of "sftp".
              See also A NOTE ON SSH BACKENDS section SSH pexpect backend.

       --sign-key key-id
              This option can be used when backing up, restoring or verifying.
              When backing up, all backup files will be signed with keyid key.
              When restoring, duplicity will signal an error if any remote
              file is not signed with the given key-id. The key-id can be
              given in any of the formats supported by GnuPG; see gpg(1),
              section "HOW TO SPECIFY A USER ID" for details.  Should be
              specified only once because currently only one signing key is
              supported. Last entry overrides all other entries.
              See also A NOTE ON SYMMETRIC ENCRYPTION AND SIGNING

       --ssh-askpass
              Tells the ssh backend to prompt the user for the remote system
              password, if it was not defined in target url and no
              FTP_PASSWORD env var is set.  This password is also used for
              passphrase-protected ssh keys.

       --ssh-options options
              Allows you to pass options to the ssh backend.  Can be specified
              multiple times or as a space separated options list.  The
              options list should be of the form "-oOpt1='parm1'
              -oOpt2='parm2'" where the option string is quoted and the only
              spaces allowed are between options. The option string will be
              passed verbatim to both scp and sftp, whose command line syntax
              differs slightly hence the options should therefore be given in
              the long option format described in ssh_config(5).
              example of a list:
                     duplicity --ssh-options="-oProtocol=2
                     -oIdentityFile='/my/backup/id'" /home/me
                     scp://user@host/some_dir
              example with multiple parameters:
                     duplicity --ssh-options="-oProtocol=2" --ssh-
                     options="-oIdentityFile='/my/backup/id'" /home/me
                     scp://user@host/some_dir

              NOTE: The ssh paramiko backend currently supports only the -i or
              -oIdentityFile or -oUserKnownHostsFile or -oGlobalKnownHostsFile
              settings. If needed provide more host specific options via
              ssh_config file.

       --ssl-cacert-file file
              (only webdav & lftp backend) Provide a cacert file for ssl
              certificate verification.

              See also A NOTE ON SSL CERTIFICATE VERIFICATION.

       --ssl-cacert-path path/to/certs/
              (only webdav backend and python 2.7.9+ OR lftp+webdavs and a
              recent lftp) Provide a path to a folder containing cacert files
              for ssl certificate verification.

              See also A NOTE ON SSL CERTIFICATE VERIFICATION.

       --ssl-no-check-certificate
              (only webdav & lftp backend) Disable ssl certificate
              verification.

              See also A NOTE ON SSL CERTIFICATE VERIFICATION.

       --swift-storage-policy
              Use this storage policy when operating on Swift containers.

              See also A NOTE ON SWIFT (OPENSTACK OBJECT STORAGE) ACCESS.

       --metadata-sync-mode mode
              This option defaults to 'partial', but you can set it to 'full'

              Use 'partial' to avoid syncing metadata for backup chains that
              you are not going to use.  This saves time when restoring for
              the first time, and lets you restore an old backup that was
              encrypted with a different passphrase by supplying only the
              target passphrase.

              Use 'full' to sync metadata for all backup chains on the remote.

       --tempdir directory
              Use this existing directory for duplicity temporary files
              instead of the system default, which is usually the /tmp
              directory. This option supersedes any environment variable.

              See also ENVIRONMENT VARIABLES.

       -t time, --time time, --restore-time time
              Specify the time from which to restore or list files.

              See section TIME FORMATS for details.

       --time-separator char
              Use char as the time separator in filenames instead of colon
              (":").

              NOTE: This option only applies to recovery and status style
              actions.  We no longer create or write filenames with time
              separators, but will read older backups that may need this
              option.

       --timeout seconds
              Use seconds as the socket timeout value if duplicity begins to
              timeout during network operations.  The default is 30 seconds.

       --use-agent
              If this option is specified, then --use-agent is passed to the
              GnuPG encryption process and it will try to connect to gpg-agent
              before it asks for a passphrase for --encrypt-key or --sign-key
              if needed.

              NOTE: Contrary to previous versions of duplicity, this option
              will also be honored by GnuPG 2 and newer versions. If GnuPG 2
              is in use, duplicity passes the option --pinentry-mode=loopback
              to the the gpg process unless --use-agent is specified on the
              duplicity command line. This has the effect that GnuPG 2 uses
              the agent only if --use-agent is given, just like GnuPG 1.

       --verbosity level, -vlevel
              Specify output verbosity level (log level).  Named levels and
              corresponding values are 0 Error, 2 Warning, 4 Notice (default),
              8 Info, 9 Debug (noisiest).
              level may also be
                     a character: e, w, n, i, d
                     a word: error, warning, notice, info, debug

       The options -v4, -vn and -vnotice are functionally equivalent, as are
       the mixed/upper-case versions -vN, -vNotice and -vNOTICE.

       --version
              Print duplicity's version and quit.

       --volsize number
              Change the volume size to number MB. Default is 200MB.

       --webdav-headers csv formatted key,value pairs
              The input format is comma separated list of key,value pairs.
              Standard CSV encoding may be used.

              For example to set a Cookie use 'Cookie,name=value', or
              '"Cookie","name=value"'.

              You can set multiple headers, e.g.
              '"Cookie","name=value","Authorization","xxx"'.

ENVIRONMENT VARIABLES
       TMPDIR, TEMP, TMP
              In decreasing order of importance, specifies the directory to
              use for temporary files (inherited from Python's tempfile
              module).  Eventually the option --tempdir supersedes any of
              these.

       FTP_PASSWORD
              Supported by most backends which are password capable. More
              secure than setting it in the backend url (which might be
              readable in the operating systems process listing to other users
              on the same machine).

       PASSPHRASE
              This passphrase is passed to GnuPG. If this is not set, the user
              will be prompted for the passphrase.  GPG uses the AES
              encryption method for passphrase encryption.

       SIGN_PASSPHRASE
              The passphrase to be used for --sign-key.  If omitted and sign
              key is also one of the keys to encrypt against PASSPHRASE will
              be reused instead.  Otherwise, if passphrase is needed but not
              set the user will be prompted for it.  GPG uses the AES
              encryption method for passphrase encryption.

              Other environment variables may be used to configure specific
              backends.  See the notes for the particular backend.

URL FORMAT
       Duplicity uses the URL format (as standard as possible) to define data
       locations.  Major difference is that the whole host section is optional
       for some backends.
       NOTE: If path starts with an extra '/' it usually denotes an absolute
       path on the backend.

       The generic format for a URL is:

              scheme://[[user[:password]@]host[:port]/][/]path

       or

              scheme://[/]path

       It is not recommended to expose the password on the command line since
       it could be revealed to anyone with permissions to do process listings,
       it is permitted however.  Consider setting the environment variable
       FTP_PASSWORD instead, which is used by most, if not all backends,
       regardless of it's name.

       In protocols that support it, the path may be preceded by a single
       slash, '/path', to represent a relative path to the target home
       directory, or preceded by a double slash, '//path', to represent an
       absolute filesystem path.

       NOTE: Scheme (protocol) access may be provided by more than one
       backend.  In case the default backend is buggy or simply not working in
       a specific case it might be worth trying an alternative implementation.
       Alternative backends can be selected by prefixing the scheme with the
       name of the alternative backend e.g. ncftp+ftp:// and are mentioned
       below the scheme's syntax summary.

       Formats of each of the URL schemes follow:

       Amazon Drive Backend
              ad://some_dir

              See also A NOTE ON AMAZON DRIVE

       Azure  azure://container-name

              See also A NOTE ON AZURE ACCESS

       B2     b2://account_id[:application_key]@bucket_name/[folder/]

       Box    box:///some_dir[?config=path_to_config]

              See also A NOTE ON BOX ACCESS

       Cloud Files (Rackspace)
              cf+http://container_name

              See also A NOTE ON CLOUD FILES ACCESS

       Dropbox
              dpbx:///some_dir

              Make sure to read A NOTE ON DROPBOX ACCESS first!

       File (local file system)
              file://[relative|/absolute]/local/path

       FISH (Files transferred over Shell protocol) over ssh
              fish://user[:password]@other.host[:port]/[relative|/absolute]_path

       FTP    ftp[s]://user[:password]@other.host[:port]/some_dir

              NOTE: use lftp+, ncftp+ prefixes to enforce a specific backend,
              default is lftp+ftp://...

       Google Cloud Storage (GCS via Interoperable Access)
              s3://bucket[/path]

              See A NOTE ON GOOGLE CLOUD STORAGE about needed endpoint option
              and env vars for authentication.

       Google Docs
              gdocs://user[:password]@other.host/some_dir

              NOTE: use pydrive+, gdata+ prefixes to enforce a specific
              backend, default is pydrive+gdocs://...

       Google Drive
              gdrive://<service account' email
              address>@developer.gserviceaccount.com/some_dir

              See also A NOTE ON GDRIVE BACKEND below.

       HSI    hsi://user[:password]@other.host/some_dir

       hubiC  cf+hubic://container_name

              See also A NOTE ON HUBIC

       IMAP email storage
              imap[s]://user[:password]@host.com[/from_address_prefix]

              See also A NOTE ON IMAP

       MediaFire
              mf://user[:password]@mediafire.com/some_dir

              See also A NOTE ON MEDIAFIRE BACKEND below.

       MEGA.nz cloud storage (only works for accounts created prior to
       November 2018, uses "megatools")
              mega://user[:password]@mega.nz/some_dir

              NOTE: if not given in the URL, relies on password being stored
              within $HOME/.megarc (as used by the "megatools" utilities)

       MEGA.nz cloud storage (works for all MEGA accounts, uses "MEGAcmd"
       tools) megav2://user[:password]@mega.nz/some_dir
              megav3://user[:password]@mega.nz/some_dir[?no_logout=1] (For
              latest MEGAcmd)

              NOTE: despite "MEGAcmd" no longer uses a configuration file, for
              convenience storing the user password this backend searches it
              in the $HOME/.megav2rc file (same syntax as the old
              $HOME/.megarc)
              [Login]
              Username = MEGA_USERNAME
              Password = MEGA_PASSWORD

       multi  multi:///path/to/config.json

              See also A NOTE ON MULTI BACKEND below.

       OneDrive Backend
              onedrive://some_dir See also A NOTE ON ONEDRIVE BACKEND

       Par2 Wrapper Backend
              par2+scheme://[user[:password]@]host[:port]/[/]path

              See also A NOTE ON PAR2 WRAPPER BACKEND

       Public Cloud Archive (OVH)
              pca://container_name[/prefix]

              See also A NOTE ON PCA ACCESS

       pydrive
              pydrive://<service account' email
              address>@developer.gserviceaccount.com/some_dir

              See also A NOTE ON PYDRIVE BACKEND below.

       Rclone Backend
              rclone://remote:/some_dir

              See also A NOTE ON RCLONE BACKEND

       Rsync via daemon
              rsync://user[:password]@host.com[:port]::[/]module/some_dir

       Rsync over ssh (only key auth)
              rsync://user@host.com[:port]/[relative|/absolute]_path

       S3 storage (Amazon)
              s3:///bucket_name[/path]

              See also A NOTE ON AMAZON S3 below.

       SCP/SFTP Secure Copy Protocol/SSH File Transfer Protocol
              scp://.. or
              sftp://user[:password]@other.host[:port]/[relative|/absolute]_path

              defaults are paramiko+scp:// and paramiko+sftp://
              alternatively try pexpect+scp://, pexpect+sftp://, lftp+sftp://
              See also --ssh-askpass, --ssh-options and A NOTE ON SSH
              BACKENDS.

       slate  slate://[slate-id]

              See also A NOTE ON SLATE BACKEND

       Swift (Openstack)
              swift://container_name[/prefix]

              See also A NOTE ON SWIFT (OPENSTACK OBJECT STORAGE) ACCESS

       Tahoe-LAFS
              tahoe://alias/directory

       WebDAV webdav[s]://user[:password]@other.host[:port]/some_dir

              alternatively try lftp+webdav[s]://

       Optical media (ISO9660 CD/DVD/Bluray using xorriso)
              xorriso:///dev/byOpticalDrive[:/path/to/directory/on/iso]
              xorriso:///path/to/image.iso[:/path/to/directory/on/iso]

              See also A NOTE ON THE XORRISO BACKEND

TIME FORMATS
       duplicity uses time strings in two places.  Firstly, many of the files
       duplicity creates will have the time in their filenames in the w3
       datetime format as described in a w3 note at http://www.w3.org/TR/NOTE-
       datetime.  Basically they look like "2001-07-15T04:09:38-07:00", which
       means what it looks like.  The "-07:00" section means the time zone is
       7 hours behind UTC.
       Secondly, the -t, --time, and --restore-time options take a time
       string, which can be given in any of several formats:
       1.     the string "now" (refers to the current time)
       2.     a sequences of digits, like "123456890" (indicating the time in
              seconds after the epoch)
       3.     A string like "2002-01-25T07:00:00+02:00" in datetime format
       4.     An interval, which is a number followed by one of the characters
              s, m, h, D, W, M, or Y (indicating seconds, minutes, hours,
              days, weeks, months, or years respectively), or a series of such
              pairs.  In this case the string refers to the time that preceded
              the current time by the length of the interval.  For instance,
              "1h78m" indicates the time that was one hour and 78 minutes ago.
              The calendar here is unsophisticated: a month is always 30 days,
              a year is always 365 days, and a day is always 86400 seconds.
       5.     A date format of the form YYYY/MM/DD, YYYY-MM-DD, MM/DD/YYYY, or
              MM-DD-YYYY, which indicates midnight on the day in question,
              relative to the current time zone settings.  For instance,
              "2002/3/5", "03-05-2002", and "2002-3-05" all mean March 5th,
              2002.

FILE SELECTION
       When duplicity is run, it searches through the given source directory
       and backs up all the files specified by the file selection system,
       unless --files-from has been specified in which case the passed list of
       individual files is used instead.

       The file selection system comprises a number of file selection
       conditions, which are set using one of the following command line
       options:

              --exclude
              --exclude-device-files
              --exclude-if-present
              --exclude-filelist
              --exclude-regexp
              --include
              --include-filelist
              --include-regexp

       For each individual file found in the source directory, the file
       selection conditions are checked in the order they are specified on the
       command line.  Should a selection condition match, the file will be
       included or excluded accordingly and the file selection system will
       proceed to the next file without checking the remaining conditions.

       Earlier arguments therefore take precedence where multiple conditions
       match any given file, and are thus usually given in order of decreasing
       specificity.  If no selection conditions match a given file, then the
       file is implicitly included.

       For example,

              duplicity --include /usr --exclude /usr /usr
              scp://user@host/backup

       is exactly the same as

              duplicity /usr scp://user@host/backup

       because the --include directive matches all files in the backup source
       directory, and takes precedence over the contradicting --exclude option
       as it comes first.

       As a more meaningful example,

              duplicity --include /usr/local/bin --exclude /usr/local /usr
              scp://user@host/backup

       would backup the /usr/local/bin directory (and its contents), but not
       /usr/local/doc. Note that this is not the same as simply specifying
       /usr/local/bin as the backup source, as other files and folders under
       /usr will also be (implicitly) included.

       The order of the --include and --exclude arguments is important. In the
       previous example, if the less specific --exclude directive had
       precedence it would prevent the more specific --include from matching
       any files.

       The patterns passed to the --include, --exclude, --include-filelist,
       and --exclude-filelist options are interpretted as extended shell
       globbing patterns by default. This behaviour can be changed with the
       following filter mode arguments:
              --filter-globbing
              --filter-literal
              --filter-regexp

       These arguments change the interpretation of the patterns used in
       selection conditions, affecting all subsequent file selection options
       passed on the command line. They may be specified multiple times in
       order to switch pattern interpretations as needed.

       Literal strings differ from globs in that the pattern must match the
       filename exactly. This can be useful where filenames contain characters
       which have special meaning in shell globs or regular expressions. If
       passing dynamically generated file lists to duplicity using the
       --include-filelist or --exclude-filelist options, then the use of
       --filter-literal is recommended unless regular expression or globbing
       is specifically required.

       The regular expression language used for selection conditions specified
       with --include-regexp , --exclude-regexp , or when --filter-regexp is
       in effect is as implemented by the Python standard library.

       Extended shell globbing pattenrs may contain: *, **, ?, and [...]
       (character ranges). As in a normal shell, * can be expanded to any
       string of characters not containing "/", ?  expands to any single
       character except "/", and [...] expands to a single character of those
       characters specified (ranges are acceptable).  The pattern ** expands
       to any string of characters whether or not it contains "/".

       In addition to the above filter mode arguments, the following can be
       used in the same fashion to enable (default) or disable case
       sensitivity in the evaluation of file selection conditions:
              --filter-ignorecase
              --filter-strictcase

       An example of filter mode switching including case insensitivity is

              --filter-ignorecase --include /usr/bin/*.PY --filter-literal
              --filter-include /usr/bin/special?file*name --filter-strictcase
              --exclude /usr/bin

       which would backup *.py, *.pY, *.Py, and *.PY files under /usr/bin and
       also the single literally specified file with globbing characters in
       the name. The use of --filter-strictcase is not technically necessary
       here, but is included as an example which may (depending on the backup
       source path) cause unexpected interactions between --include and
       --exclude options, should the directory portion of the path (/usr/bin)
       contain any uppercase characters.

       If the pattern starts with "ignorecase:" (case insensitive), then this
       prefix will be removed and any character in the string can be replaced
       with an upper- or lowercase version of itself. This prefix is a legacy
       feature supported for shell globbing selection conditions only, but for
       backward compatability reasons is otherwise considered part of the
       pattern itself (use --filter-ignorecase instead).

       Remember that you may need to quote patterns when typing them into a
       shell, so the shell does not interpret the globbing patterns or
       whitespace characters before duplicity sees them.

       Selection patterns should generally be thought of as filesystem paths
       rather than arbitrary strings. For selection conditions using extended
       shell globbing patterns, the --exclude pattern option matches a file
       if:

       1.     pattern can be expanded into the file's filename, or
       2.     the file is inside a directory matched by the option.

              Conversely, the --include  pattern option matches a file if:

       1.     pattern can be expanded into the file's filename, or
       2.     the file is inside a directory matched by the option, or
       3.     the file is a directory which contains a file matched by the
              option.

              For example,

              --exclude /usr/local

       matches e.g. /usr/local, /usr/local/lib, and /usr/local/lib/netscape.
       It is the same as --exclude /usr/local --exclude '/usr/local/**'.
       On the other hand

              --include /usr/local

       specifies that /usr, /usr/local, /usr/local/lib, and
       /usr/local/lib/netscape (but not /usr/doc) all be backed up. Thus you
       don't have to worry about including parent directories to make sure
       that included subdirectories have somewhere to go.

       Finally,

              --include ignorecase:'/usr/[a-z0-9]foo/*/**.py'

       would match a file like /usR/5fOO/hello/there/world.py.  If it did
       match anything, it would also match /usr.  If there is no existing file
       that the given pattern can be expanded into, the option will not match
       /usr alone.

       This treatment of patterns in globbing and literal selection conditions
       as filesystem paths reduces the number of explicit conditions required.
       However, it does require that the paths described by all variants of
       the --include  or --include  option are fully specified relative to the
       backup source directory.

       For selection conditions using literal strings, the same logic applies
       except that scenario 1 is for an exact match of the pattern.

       For selection conditions using regular expressions the pattern is
       evaluated as a regular expression rather than a filesystem path.
       Scenario 3 in the above therefore does not apply, the implications of
       which are discussed at the end of this section.

       The --include-filelist, and --exclude-filelist, options also introduce
       file selection conditions.  They direct duplicity to read in a text
       file (either ASCII or UTF-8), each line of which is a file
       specification, and to include or exclude the matching files.  Lines are
       separated by newlines or nulls, depending on whether the --null-
       separator switch was given.

       Each line in the filelist will be interpreted as a selection pattern in
       the same way --include and --exclude options are interpreted, except
       that lines starting with "+ " are interpreted as include directives,
       even if found in a filelist referenced by --exclude-filelist.
       Similarly, lines starting with "- " exclude files even if they are
       found within an include filelist.

       For example, if file "list.txt" contains the lines:

              /usr/local
              - /usr/local/doc
              /usr/local/bin
              + /var
              - /var

       then --include-filelist list.txt would include /usr, /usr/local, and
       /usr/local/bin.  It would exclude /usr/local/doc,
       /usr/local/doc/python, etc.  It would also include /usr/local/man, as
       this is included within /usr/local.  Finally, it is undefined what
       happens with /var.  A single file list should not contain conflicting
       file specifications.

       Each line in the filelist will be interpreted as per the current filter
       mode in the same way --include and --exclude options are interpreted.
       For instance, if the file "list.txt" contains the lines:

              dir/foo
              + dir/bar
              - **

       Then --include-filelist list.txt would be exactly the same as
       specifying --include dir/foo --include dir/bar --exclude ** on the
       command line.

       Note that specifying very large numbers numbers of selection rules as
       filelists can incur a substantial performance penalty as these rules
       will (potentially) be checked for every file in the backup source
       directory. If you need to backup arbitrary lists of specific files
       (i.e. not described by regexp patterns or shell globs) then
       --files-from is likely to be more performant.

       Finally, the --include-regexp and --exclude-regexp options allow files
       to be included and excluded if their filenames match a regular
       expression.  Regular expression syntax is too complicated to explain
       here, but is covered in Python's library reference.  Unlike the
       --include and --exclude options, the regular expression options don't
       match files containing or contained in matched files.  So for instance

              --include-regexp '[0-9]{7}(?!foo)'

       matches any files whose full pathnames contain 7 consecutive digits
       which aren't followed by 'foo'.  However, it wouldn't match /home even
       if /home/ben/1234567 existed.

A NOTE ON AMAZON DRIVE
       1.     The API Keys used for Amazon Drive have not been granted
              production limits.  Amazon do not say what the development
              limits are and are not replying to to requests to whitelist
              duplicity. A related tool, acd_cli, was demoted to development
              limits, but continues to work fine except for cases of excessive
              usage. If you experience throttling and similar issues with
              Amazon Drive using this backend, please report them to the
              mailing list.
       2.     If you previously used the acd+acdcli backend, it is strongly
              recommended to update to the ad backend instead, since it
              interfaces directly with Amazon Drive. You will need to setup
              the OAuth once again, but can otherwise keep your backups and
              config.

A NOTE ON AMAZON S3
       Backing up to Amazon S3 utilizes the boto3 library.

       The boto3 backend does not support bucket creation.  This deliberate
       choice simplifies the code, and side steps problems related to region
       selection.  Additionally, it is probably not a good practice to give
       your backup role bucket creation rights.  In most cases the role used
       for backups should probably be limited to specific buckets.

       The boto3 backend only supports newer domain style buckets. Amazon is
       moving to deprecate the older bucket style, so migration is
       recommended.

       The boto3 backend does not currently support initiating restores from
       the glacier storage class.  When restoring a backup from glacier or
       glacier deep archive, the backup files must first be restored out of
       band.  There are multiple options when restoring backups from cold
       storage, which vary in both cost and speed.  See Amazon's documentation
       for details.

       The following environment variables are required for authentication:
              AWS_ACCESS_KEY_ID (required),
              AWS_SECRET_ACCESS_KEY (required)
              or
              BOTO_CONFIG (required) pointing to a boto config file.
       For simplicity's sake we will document the use of the AWS_* vars only.
       Research boto3 documentation available in the web if you want to use
       the config file.

       boto3 backend example backup command line:

              AWS_ACCESS_KEY_ID=<key_id> AWS_SECRET_ACCESS_KEY=<access_key>
              duplicity /some/path s3:///bucket/subfolder

       you may add --s3-endpoint-url (to access non Amazon S3 services or
       regional endpoints) and may need --s3-region-name (for buckets created
       in specific regions) and other --s3-...  options documented above.

A NOTE ON AZURE ACCESS
       The Azure backend requires the Microsoft Azure Storage Blobs client
       library for Python to be installed on the system.  See REQUIREMENTS.

       It uses the environment variable AZURE_CONNECTION_STRING (required).
       This string contains all necessary information such as Storage Account
       name and the key for authentication.  You can find it under Access Keys
       for the storage account.

       Duplicity will take care to create the container when performing the
       backup.  Do not create it manually before.

       A container name (as given as the backup url) must be a valid DNS name,
       conforming to the following naming rules:

              1.     Container names must start with a letter or number, and
                     can contain only letters, numbers, and the dash (-)
                     character.
              2.     Every dash (-) character must be immediately preceded and
                     followed by a letter or number; consecutive dashes are
                     not permitted in container names.
              3.     All letters in a container name must be lowercase.
              4.     Container names must be from 3 through 63 characters
                     long.

       These rules come from Azure; see https://docs.microsoft.com/en-
       us/rest/api/storageservices/naming-and-referencing-
       containers--blobs--and-metadata

A NOTE ON BOX ACCESS
       The box backend requires boxsdk with jwt support to be installed on the
       system.  See REQUIREMENTS.

       It uses the environment variable BOX_CONFIG_PATH (optional).  This
       string contains the path to box custom app's config.json. Either this
       environment variable or the config query parameter in the url need to
       be specified, if both are specified, query parameter takes precedence.

   Create a Box custom app
       In order to use box backend, user need to create a box custom app in
       the box developer console (https://app.box.com/developers/console).

       After create a new custom app, please make sure it is configured as
       follow:

              1.     Choose "App Access Only" for "App Access Level"
              2.     Check "Write all files and folders stored in Box"
              3.     Generate a Public/Private Keypair

       The user also need to grant the created custom app permission in the
       admin console (https://app.box.com/master/custom-apps) by clicking the
       "+" button and enter the client_id which can be found on the custom
       app's configuration page.

A NOTE ON CLOUD FILES ACCESS
       Pyrax is Rackspace's next-generation Cloud management API, including
       Cloud Files access.  The cfpyrax backend requires the pyrax library to
       be installed on the system.  See REQUIREMENTS.

       Cloudfiles is Rackspace's now deprecated implementation of OpenStack
       Object Storage protocol.  Users wishing to use Duplicity with Rackspace
       Cloud Files should migrate to the new Pyrax plugin to ensure support.

       The backend requires python-cloudfiles to be installed on the system.
       See REQUIREMENTS.

       It uses three environment variables for authentication:
       CLOUDFILES_USERNAME (required), CLOUDFILES_APIKEY (required),
       CLOUDFILES_AUTHURL (optional)

       If CLOUDFILES_AUTHURL is unspecified it will default to the value
       provided by python-cloudfiles, which points to rackspace, hence this
       value must be set in order to use other cloud files providers.

A NOTE ON DROPBOX ACCESS
       1.     First of all Dropbox backend requires valid authentication
              token. It should be passed via DPBX_ACCESS_TOKEN environment
              variable.
              To obtain it please create 'Dropbox API' application at:
              https://www.dropbox.com/developers/apps/create
              Then visit app settings and just use 'Generated access token'
              under OAuth2 section.
              Alternatively you can let duplicity generate access token
              itself. In such case temporary export DPBX_APP_KEY ,
              DPBX_APP_SECRET using values from app settings page and run
              duplicity interactively.
              It will print the URL that you need to open in the browser to
              obtain OAuth2 token for the application. Just follow on-screen
              instructions and then put generated token to DPBX_ACCESS_TOKEN
              variable. Once done, feel free to unset DPBX_APP_KEY and
              DPBX_APP_SECRET

       2.     "some_dir" must already exist in the Dropbox folder. Depending
              on access token kind it may be:
                     Full Dropbox: path is absolute and starts from 'Dropbox'
                     root folder.
                     App Folder: path is related to application folder.
                     Dropbox client will show it in ~/Dropbox/Apps/<app-name>

       3.     When using Dropbox for storage, be aware that all files,
              including the ones in the Apps folder, will be synced to all
              connected computers.  You may prefer to use a separate Dropbox
              account specially for the backups, and not connect any computers
              to that account. Alternatively you can configure selective sync
              on all computers to avoid syncing of backup files

A NOTE ON FILENAME PREFIXES
       Filename prefixes can be used in multi backend  with mirror  mode to
       define affinity rules. They can also be used in conjunction with S3
       lifecycle rules to transition archive files to Glacier, while keeping
       metadata (signature and manifest files) on S3.

       Duplicity does not require access to archive files except when
       restoring from backup.

A NOTE ON GOOGLE CLOUD STORAGE (GCS via Interoperable Access)
   Overview
       Duplicity access to GCS currently relies on it's Interoperability API
       (basically S3 for GCS).  This needs to actively be enabled before
       access is possible. For details read the next section Preparations
       below.

   Preparations
       1.     login on https://console.cloud.google.com/
       2.     go to Cloud Storage->Settings->Interoperability
       3.     create a Service account (if needed)
       4.     create Service account HMAC access key and secret (!!instantly
              copy!!  the secret, it can NOT be recovered later)
       5.     go to Cloud Storage->Browser
       6.     create a bucket
       7.     add permissions for Service account that was used to set up
              Interoperability access above

       Once set up you can use the generated Interoperable Storage Access key
       and secret and pass them to duplicity as described in the next section.

   Usage
       The following examples show accessing GCS via S3 for a collection-
       status action.  The shown env vars, options and url format can be
       applied for all other actions as well of course.

       using boto3 supplying the --s3-endpoint-url manually.

              AWS_ACCESS_KEY_ID=<keyid> AWS_SECRET_ACCESS_KEY=<secret>
              duplicity collection-status s3:///<bucket>/<folder>
              --s3-endpoint-url=https://storage.googleapis.com

A NOTE ON GDRIVE BACKEND
       GDrive: is a rewritten PyDrive: backend with less dependencies, and a
       simpler setup - it uses the JSON keys downloaded directly from Google
       Cloud Console.

       Note Google has 2 drive methods, `Shared(previously Team) Drives` and
       `My Drive`, both can be shared but require different addressing

       For a Google Shared Drives folder

       Share Drive ID specified as a query parameter, driveID,  in the backend
       URL.  Example:
             gdrive://developer.gserviceaccount.com/target-
       folder/?driveID=<SHARED DRIVE ID>

       For a Google My Drive based shared folder

       MyDrive folder ID specified as a query parameter, myDriveFolderID, in
       the backend URL Example
             export GOOGLE_SERVICE_ACCOUNT_URL=<serviceaccount-
       name>@<serviceaccount-name>.iam.gserviceaccount.com
             gdrive://${GOOGLE_SERVICE_ACCOUNT_URL}/<target-folder-name-in-
       myDriveFolder>?myDriveFolderID=root


       There are also two ways to authenticate to use GDrive: with a regular
       account or with a "service account". With a service account, a separate
       account is created, that is only accessible with Google APIs and not a
       web login.  With a regular account, you can store backups in your
       normal Google Drive.

       To use a service account, go to the Google developers console at
       https://console.developers.google.com. Create a project, and make sure
       Drive API is enabled for the project. In the "Credentials" section,
       click "Create credentials", then select Service Account with JSON key.

       The GOOGLE_SERVICE_JSON_FILE environment variable needs to contain the
       path to the JSON file on duplicity invocation.

       export GOOGLE_SERVICE_JSON_FILE=<path-to-serviceaccount-
       credentials.json>


       The alternative is to use a regular account. To do this, start as
       above, but when creating a new Client ID, select "Create OAuth client
       ID", with application type of "Desktop app". Download the
       client_secret.json file for the new client, and set the
       GOOGLE_CLIENT_SECRET_JSON_FILE environment variable to the path to this
       file, and GOOGLE_CREDENTIALS_FILE to a path to a file where duplicity
       will keep the authentication token - this location must be writable.

       NOTE: As a sanity check, GDrive checks the host and username from the
       URL against the JSON key, and refuses to proceed if the addresses do
       not match. Either the email (for the service accounts) or Client ID
       (for regular OAuth accounts) must be present in the URL. See URL FORMAT
       above.

   First run / OAuth 2.0 authorization
       During the first run, you will be prompted to visit an URL in your
       browser to grant access to your Google Drive. A temporary HTTP-service
       will be started on a local network interface for this purpose (by
       default on http://localhost:8080/).  Ip-address/host and port can be
       adjusted if need be by providing the environment variables
       GOOGLE_OAUTH_LOCAL_SERVER_HOST, GOOGLE_OAUTH_LOCAL_SERVER_PORT
       respectively.

       If you are running duplicity in a remote location, you will need to
       make sure that you will be able to access the above HTTP-service with a
       browser utilizing e.g. port forwarding or temporary firewall
       permission.

       The access credentials will be saved in the JSON file mentioned above
       for future use after a successful authorization.

A NOTE ON HUBIC
       The hubic backend requires the pyrax library to be installed on the
       system. See REQUIREMENTS.  You will need to set your credentials for
       hubiC in a file called ~/.hubic_credentials, following this pattern:
              [hubic]
              email = your_email
              password = your_password
              client_id = api_client_id
              client_secret = api_secret_key
              redirect_uri = http://localhost/

A NOTE ON IMAP
       An IMAP account can be used as a target for the upload.  The userid may
       be specified and the password will be requested.
       The from_address_prefix may be specified (and probably should be). The
       text will be used as the "From" address in the IMAP server.  Then on a
       restore (or list) action the from_address_prefix will distinguish
       between different backups.

A NOTE ON MEDIAFIRE BACKEND
       This backend requires mediafire python library to be installed on the
       system. See REQUIREMENTS.

       Use URL escaping for username (and password, if provided via command
       line):

              mf://duplicity%40example.com@mediafire.com/some_folder
       The destination folder will be created for you if it does not exist.

A NOTE ON MULTI BACKEND
   The multi backend allows duplicity to combine the storage available in more
       than one backend store (e.g., you can store across a google drive
       account and a onedrive account to get effectively the combined storage
       available in both).  The URL path specifies a JSON formatted config
       file containing a list of the backends it will use. The URL may also
       specify "query" parameters to configure overall behavior.  Each element
       of the list must have a "url" element, and may also contain an optional
       "description" and an optional "env" list of environment variables used
       to configure that backend.  Query Parameters
       Query parameters come after the file URL in standard HTTP format for
       example:
              multi:///path/to/config.json?mode=mirror&onfail=abort
              multi:///path/to/config.json?mode=stripe&onfail=continue
              multi:///path/to/config.json?onfail=abort&mode=stripe
              multi:///path/to/config.json?onfail=abort
       Order does not matter, however unrecognized parameters are considered
       an error.

       mode=stripe
              This mode (the default) performs round-robin access to the list
              of backends. In this mode, all backends must be reliable as a
              loss of one means a loss of one of the archive files.

       mode=mirror
              This mode accesses backends as a RAID1-store, storing every file
              in every backend and reading files from the first-successful
              backend.  A loss of any backend should result in no failure.
              Note that backends added later will only get new files and may
              require a manual sync with one of the other operating ones.

       onfail=continue
              This setting (the default) continues all write operations in as
              best-effort. Any failure results in the next backend tried.
              Failure is reported only when all backends fail a given
              operation with the error result from the last failure.

       onfail=abort
              This setting considers any backend write failure as a
              terminating condition and reports the error.  Data reading and
              listing operations are independent of this and will try with the
              next backend on failure.
   JSON File Example
              [
               {
                "description": "a comment about the backend"
                "url": "abackend://myuser@domain.com/backup",
                "env": [
                  {
                   "name" : "MYENV",
                   "value" : "xyz"
                  },
                  {
                   "name" : "FOO",
                   "value" : "bar"
                  }
                 ],
                 "prefixes": ["prefix1_", "prefix2_"]
               },
               {
                "url": "file:///path/to/dir"
               }
              ]

A NOTE ON ONEDRIVE BACKEND
       onedrive:// works with both personal and business onedrive as well as
       sharepoint drives.  On first use you be provided with an URL to with a
       microsoft account. Open it in your web browser.

       After authenticating, copy the redirected URL back to duplicity.
       Duplicity will fetch a token and store it in
       ~/.duplicity_onedrive_oauthtoken.json. This location can be overridden
       by setting the DUPLICITY_ONEDRIVE_TOKEN environment variable.

       Duplicity uses a default App ID registered with Microsoft Azure AD.  It
       will need to be approved by an administrator of your Office365 Tenant
       on a business account.

   Register and set your own microsoft app id
       1.     visit https://portal.azure.com

       2.     Choose "Enterprise Applications", then "Create your own
              Application"

       3.     Input your application name and select "Register an application
              to integrate with Azure AD".

       4.     Continue to the next page and set the redirect uri to
              "https://login.microsoftonline.com/common/oauth2/nativeclient",
              choosing "Public client/native" from the dropdown. Click create.

       5.     Find the application id in "Enterprise Applications" and set the
              environment variable DUPLICITY_ONEDRIVE_CLIENT_ID to it.

              More information on Microsoft Apps at:
              https://learn.microsoft.com/en-us/azure/active-
              directory/develop/quickstart-register-app

   Backup to a sharepoint site instead of onedrive
       to use a sharepoint site you need to find and provide the site's tenant
       and site id.

       1.     Login with your Microsoft Account at
              https://<o365_tenant>.sharepoint.com/

       2.     Navigate to
              https://<o365_tenant>.sharepoint.com/sites/<path_to_site>/_api/site/id

       3.     Copy the disyplayed UUID (site_id) and set the
              DUPLICITY_ONEDRIVE_ROOT environment variable to
              "sites/<o365_tenant>.sharepoint.com,<site_id>/drive"

A NOTE ON PAR2 WRAPPER BACKEND
       Par2 Wrapper Backend can be used in combination with all other backends
       to create recovery files. Just add par2+ before a regular scheme (e.g.
       par2+ftp://user@host/dir or par2+s3+http://bucket_name ). This will
       create par2 recovery files for each archive and upload them all to the
       wrapped backend.
       Before restoring, archives will be verified. Corrupt archives will be
       repaired on the fly if there are enough recovery blocks available.
       Use --par2-redundancy percent to adjust the size (and redundancy) of
       recovery files in percent.

A NOTE ON PCA ACCESS
       PCA is a long-term data archival solution by OVH. It runs a slightly
       modified version of Openstack Swift introducing latency in the data
       retrieval process.  It is a good pick for a multi backend
       configuration where receiving volumes while another backend is used to
       store manifests and signatures.

       The backend requires python-switclient to be installed on the system.
       python-keystoneclient is also needed to interact with OpenStack's
       Keystone Identity service.  See REQUIREMENTS.

       It uses following environment variables for authentication:
       PCA_USERNAME (required), PCA_PASSWORD (required), PCA_AUTHURL
       (required), PCA_USERID (optional), PCA_TENANTID (optional, but either
       the tenant name or tenant id must be supplied) PCA_REGIONNAME
       (optional), PCA_TENANTNAME (optional, but either the tenant name or
       tenant id must be supplied)

       If the user was previously authenticated, the following environment
       variables can be used instead: PCA_PREAUTHURL (required),
       PCA_PREAUTHTOKEN (required)

       If PCA_AUTHVERSION is unspecified, it will default to version 2.

A NOTE ON PYDRIVE BACKEND
       The pydrive backend requires Python PyDrive package to be installed on
       the system. See REQUIREMENTS.

       There are two ways to use PyDrive: with a regular account or with a
       "service account". With a service account, a separate account is
       created, that is only accessible with Google APIs and not a web login.
       With a regular account, you can store backups in your normal Google
       Drive.

       To use a service account, go to the Google developers console at
       https://console.developers.google.com. Create a project, and make sure
       Drive API is enabled for the project. Under "APIs and auth", click
       Create New Client ID, then select Service Account with P12 key.

       Download the .p12 key file of the account and convert it to the .pem
       format:
       openssl pkcs12 -in XXX.p12  -nodes -nocerts > pydriveprivatekey.pem

       The content of .pem file should be passed to GOOGLE_DRIVE_ACCOUNT_KEY
       environment variable for authentication.

       The email address of the account will be used as part of URL. See URL
       FORMAT above.

       The alternative is to use a regular account. To do this, start as
       above, but when creating a new Client ID, select "Installed
       application" of type "Other". Create a file with the following content,
       and pass its filename in the GOOGLE_DRIVE_SETTINGS environment
       variable:
              client_config_backend: settings
              client_config:
                  client_id: <Client ID from developers' console>
                  client_secret: <Client secret from developers' console>
              save_credentials: True
              save_credentials_backend: file
              save_credentials_file: <filename to cache credentials>
              get_refresh_token: True

       In this scenario, the username and host parts of the URL play no role;
       only the path matters. During the first run, you will be prompted to
       visit an URL in your browser to grant access to your drive. Once
       granted, you will receive a verification code to paste back into
       Duplicity. The credentials are then cached in the file references above
       for future use.

A NOTE ON RCLONE BACKEND
       Rclone is a powerful command line program to sync files and directories
       to and from various cloud storage providers.

   Usage
       Once you have configured an rclone remote via

              rclone config

       and successfully set up a remote (e.g. gdrive for Google Drive),
       assuming you can list your remote files with

              rclone ls gdrive:mydocuments

       you can start your backup with

              duplicity /mydocuments rclone://gdrive:/mydocuments

       Please note the slash after the second colon. Some storage provider
       will work with or without slash after colon, but some other will not.
       Since duplicity will complain about malformed URL if a slash is not
       present, always put it after the colon, and the backend will handle it
       for you.

   Options
       Note that all rclone options can be set by env vars as well. This is
       properly documented here

              https://rclone.org/docs/

       but in a nutshell you need to take the long option name, strip the
       leading --, change - to _, make upper case and prepend RCLONE_. for
       example

              the equivalent of '--stats 5s' would be the env var
              RCLONE_STATS=5s

A NOTE ON SLATE BACKEND
       Three environment variables are used with the slate backend:
         1.  `SLATE_API_KEY` - Your slate API key
         2.  `SLATE_SSL_VERIFY` - either '1'(True) or '0'(False) for ssl
       verification (optional - True by default)
         3.  `PASSPHRASE` - your gpg passhprase for encryption (optional -
       will be prompted if not set or not used at all if using the `--no-
       encryption` parameter)

       To use the slate backend, use the following scheme:
              slate://[slate-id]

       e.g. Full backup of current directory to slate:
              duplicity full . "slate://6920df43-5c3w-2x7i-69aw-2390567uav75"

       Here's a demo:
       https://gitlab.com/Shr1ftyy/duplicity/uploads/675664ef0eb431d14c8e20045e3fafb6/slate_demo.mp4

A NOTE ON SSH BACKENDS
       The ssh backends support sftp and scp/ssh transport protocols.  This is
       a known user-confusing issue as these are fundamentally different.  If
       you plan to access your backend via one of those please inform yourself
       about the requirements for a server to support sftp or scp/ssh access.
       To make it even more confusing the user can choose between several ssh
       backends via a scheme prefix: paramiko+ (default), pexpect+, lftp+... .
       paramiko & pexpect support --use-scp, --ssh-askpass and --ssh-options.
       Only the pexpect backend allows one to define --scp-command and
       --sftp-command.
       SSH paramiko backend (default) is a complete reimplementation of ssh
       protocols natively in python. Advantages are speed and maintainability.
       Minor disadvantage is that extra packages are needed as listed in
       REQUIREMENTS.  In sftp (default) mode all operations are done via the
       according sftp commands. In scp mode ( --use-scp ) though scp access is
       used for put/get operations but listing is done via ssh remote shell.
       SSH pexpect backend is the legacy ssh backend using the command line
       ssh binaries via pexpect.  Older versions used scp for get and put
       operations and sftp for list and delete operations.  The current
       version uses sftp for all four supported operations, unless the
       --use-scp option is used to revert to old behavior.
       SSH lftp backend is simply there because lftp can interact with the ssh
       cmd line binaries.  It is meant as a last resort in case the above
       options fail for some reason.

   Why use sftp instead of scp?
       The change to sftp was made in order to allow the remote system to
       chroot the backup, thus providing better security and because it does
       not suffer from shell quoting issues like scp.  Scp also does not
       support any kind of file listing, so sftp or ssh access will always be
       needed in addition for this backend mode to work properly. Sftp does
       not have these limitations but needs an sftp service running on the
       backend server, which is sometimes not an option.

A NOTE ON SSL CERTIFICATE VERIFICATION
       Certificate verification as implemented right now [02.2016] only in the
       webdav and lftp backends. older pythons 2.7.8- and older lftp binaries
       need a file based database of certification authority certificates
       (cacert file).
       Newer python 2.7.9+ and recent lftp versions however support the system
       default certificates (usually in /etc/ssl/certs) and also giving an
       alternative ca cert folder via --ssl-cacert-path.
       The cacert file has to be a PEM formatted text file as currently
       provided by the CURL project. See
              http://curl.haxx.se/docs/caextract.html
       After creating/retrieving a valid cacert file you should copy it to
       either
              ~/.duplicity/cacert.pem
              ~/duplicity_cacert.pem
              /etc/duplicity/cacert.pem
       Duplicity searches it there in the same order and will fail if it can't
       find it.  You can however specify the option --ssl-cacert-file <file>
       to point duplicity to a copy in a different location.
       Finally there is the --ssl-no-check-certificate option to disable
       certificate verification altogether, in case some ssl library is
       missing or verification is not wanted. Use it with care, as even with
       self signed servers manually providing the private ca certificate is
       definitely the safer option.

A NOTE ON SWIFT (OPENSTACK OBJECT STORAGE) ACCESS
       Swift is the OpenStack Object Storage service.
       The backend requires python-switclient to be installed on the system.
       python-keystoneclient is also needed to use OpenStack's Keystone
       Identity service.  See REQUIREMENTS.

       It uses following environment variables for authentication:

              SWIFT_USERNAME (required),
              SWIFT_PASSWORD (required),
              SWIFT_AUTHURL (required),
              SWIFT_TENANTID or SWIFT_TENANTNAME (required with
              SWIFT_AUTHVERSION=2, can alternatively be defined in
              SWIFT_USERNAME like e.g. SWIFT_USERNAME="tenantname:user"),
              SWIFT_PROJECT_ID or SWIFT_PROJECT_NAME (required with
              SWIFT_AUTHVERSION=3),
              SWIFT_USERID (optional, required only for IBM Bluemix
              ObjectStorage),
              SWIFT_REGIONNAME (optional).

       If the user was previously authenticated, the following environment
       variables can be used instead: SWIFT_PREAUTHURL (required),
       SWIFT_PREAUTHTOKEN (required)

       If SWIFT_AUTHVERSION is unspecified, it will default to version 1.

A NOTE ON SYMMETRIC ENCRYPTION AND SIGNING
       Signing and symmetrically encrypt at the same time with the gpg binary
       on the command line, as used within duplicity, is a specifically
       challenging issue.  Tests showed that the following combinations proved
       working.
       1. Setup gpg-agent properly. Use the option --use-agent and enter both
       passphrases (symmetric and sign key) in the gpg-agent's dialog.
       2. Use a PASSPHRASE for symmetric encryption of your choice but the
       signing key has an empty passphrase.
       3. The used PASSPHRASE for symmetric encryption and the passphrase of
       the signing key are identical.

A NOTE ON THE XORRISO BACKEND
       This backend uses the xorriso tool to append backups to optical media
       or ISO9660 images.

       Use the following environment variables for more settings:
              XORRISO_PATH, set an alternative path to the xorriso executable
              XORRISO_WRITE_SPEED, specify the speed for writing to the
              optical disc. One of [min, max]
              XORRISO_ASSERT_VOLID, specify the required volume ID of the ISO.
              Aborts when the actual volume ID is different.
              XORRISO_ARGS, for expert use only. Pass arbitrary arguments to
              xorriso. Example: XORRISO_ARGS='-md5 all'

KNOWN ISSUES / BUGS
       Hard links currently unsupported (they will be treated as non-linked
       regular files).

       Bad signatures will be treated as empty instead of logging appropriate
       error message.

OPERATION AND DATA FORMATS
       This section describes duplicity's basic operation and the format of
       its data files.  It should not necessary to read this section to use
       duplicity.

       The files used by duplicity to store backup data are tarfiles in GNU
       tar format.  For incremental backups, new files are saved normally in
       the tarfile.  But when a file changes, instead of storing a complete
       copy of the file, only a diff is stored, as generated by rdiff(1).  If
       a file is deleted, a 0 length file is stored in the tar.  It is
       possible to restore a duplicity archive "manually" by using tar and
       then cp, rdiff, and rm as necessary.  These duplicity archives have the
       extension difftar.

       Both full and incremental backup sets have the same format.  In effect,
       a full backup set is an incremental one generated from an empty
       signature (see below).  The files in full backup sets will start with
       duplicity-full while the incremental sets start with duplicity-inc.
       When restoring, duplicity applies patches in order, so deleting, for
       instance, a full backup set may make related incremental backup sets
       unusable.

       In order to determine which files have been deleted, and to calculate
       diffs for changed files, duplicity needs to process information about
       previous sessions.  It stores this information in the form of tarfiles
       where each entry's data contains the signature (as produced by rdiff)
       of the file instead of the file's contents.  These signature sets have
       the extension sigtar.

       Signature files are not required to restore a backup set, but without
       an up-to-date signature, duplicity cannot append an incremental backup
       to an existing archive.

       To save bandwidth, duplicity generates full signature sets and
       incremental signature sets.  A full signature set is generated for each
       full backup, and an incremental one for each incremental backup.  These
       start with duplicity-full-signatures and duplicity-new-signatures
       respectively. These signatures will be stored both locally and
       remotely.  The remote signatures will be encrypted if encryption is
       enabled.  The local signatures will not be encrypted and stored in the
       archive dir (see --archive-dir).

REQUIREMENTS
       Duplicity requires a POSIX-like operating system with a python
       interpreter version 3.8+ installed.  It is best used under GNU/Linux.

       Some backends also require additional components (probably available as
       packages for your specific platform):

       Amazon Drive backend
              python-requests - http://python-requests.org
              python-requests-oauthlib - https://github.com/requests/requests-
              oauthlib

       azure backend (Azure Storage Blob Service)
              Microsoft Azure Storage Blobs client library for Python -
              https://pypi.org/project/azure-storage-blob/

       boto3 backend (S3 Amazon Web Services, Google Cloud Storage) (default)
              boto3 version 1.x - https://github.com/boto/boto3

       box backend (box.com)
              boxsdk - https://github.com/box/box-python-sdk

       cfpyrax backend (Rackspace Cloud) and hubic backend (hubic.com)
              Rackspace CloudFiles Pyrax API -
              http://docs.rackspace.com/sdks/guide/content/python.html

       dpbx backend (Dropbox)
              Dropbox Python SDK -
              https://www.dropbox.com/developers/reference/sdk

       gdocs gdata backend (legacy)
              Google Data APIs Python Client Library -
              http://code.google.com/p/gdata-python-client/

       gdocs pydrive backend(default)
              see pydrive backend

       gio backend (Gnome VFS API)
              PyGObject - http://live.gnome.org/PyGObject
              D-Bus (dbus)- http://www.freedesktop.org/wiki/Software/dbus

       lftp backend (needed for ftp, ftps, fish [over ssh] - also supports
       sftp, webdav[s])
              LFTP Client - http://lftp.yar.ru/

       MEGA backend (only works for accounts created prior to November 2018)
       (mega.nz)
              megatools client - https://github.com/megous/megatools

       MEGA v2 and v3 backend (works for all MEGA accounts) (mega.nz)
              MEGAcmd client - https://mega.nz/cmd

       multi backend
              Multi -- store to more than one backend
              (also see A NOTE ON MULTI BACKEND ) below.

       ncftp backend (ftp, select via ncftp+ftp://)
              NcFTP - http://www.ncftp.com/

       OneDrive backend (Microsoft OneDrive)
              python-requests-oauthlib - https://github.com/requests/requests-
              oauthlib

       Par2 Wrapper Backend
              par2cmdline - http://parchive.sourceforge.net/

       pydrive backend
              PyDrive -- a wrapper library of google-api-python-client -
              https://pypi.python.org/pypi/PyDrive
              (also see A NOTE ON PYDRIVE BACKEND ) below.

       rclone backend
              rclone - https://rclone.org/

       rsync backend
              rsync client binary - http://rsync.samba.org/

       ssh paramiko backend (default)
              paramiko (SSH2 for python) -
              http://pypi.python.org/pypi/paramiko (downloads);
              http://github.com/paramiko/paramiko (project page)
              pycrypto (Python Cryptography Toolkit) -
              http://www.dlitz.net/software/pycrypto/

       ssh pexpect backend(legacy)
              sftp/scp client binaries OpenSSH - http://www.openssh.com/
              Python pexpect module -
              http://pexpect.sourceforge.net/pexpect.html

       swift backend (OpenStack Object Storage)
              Python swiftclient module - https://github.com/openstack/python-
              swiftclient/
              Python keystoneclient module -
              https://github.com/openstack/python-keystoneclient/

       webdav backend
              certificate authority database file for ssl certificate
              verification of HTTPS connections -
              http://curl.haxx.se/docs/caextract.html
              (also see A NOTE ON SSL CERTIFICATE VERIFICATION).
              Python kerberos module for kerberos authentication -
              https://github.com/02strich/pykerberos

       MediaFire backend
              MediaFire Python Open SDK -
              https://pypi.python.org/pypi/mediafire/

       xorriso backend
              xorriso - https://www.gnu.org/software/xorriso/

AUTHOR
       Original Author - Ben Escoto <bescoto@stanford.edu>

       Current Maintainer - Kenneth Loafman <kenneth@loafman.com>

       Continuous Contributors
              Edgar Soldin, Mike Terry
       Most backends were contributed individually.  Information about their
       authorship may be found in the according file's header.
       Also we'd like to thank everybody posting issues to the mailing list or
       on launchpad, sending in patches or contributing otherwise. Duplicity
       wouldn't be as stable and useful if it weren't for you.
       A special thanks goes to rsync.net, a Cloud Storage provider with
       explicit support for duplicity, for several monetary donations and for
       providing a special "duplicity friends" rate for their offsite backup
       service.  Email info@rsync.net for details.

SEE ALSO
       python(1), rdiff(1).

Version 2.2.3                   March 20, 2024                    DUPLICITY(1)