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       dar - disk archive


       dar [-c | -x | -l | -d | -t | -C | -+] [<path>/]<basename> [options]

       dar -h

       dar -V


       dar  is  a full featured backup tool, aimed for disks (floppy, CD-R(W),
       DVD-R(W), zip, jazz, etc.)

       dar can store a  backup  in  several  files  (called  "slices"  in  the
       following)  of  a  given  size,  eventually  pausing  or running a user
       command/script before starting the  next  slice.  This  can  allow  for
       example, the burning of the last generated slice on a CD-R, or changing
       a floppy disk before continuing on  the  next  one.   Like  its  grand-
       brother,  the great "tar" command, dar may also use compression, at the
       difference that compression is used inside the archive to  be  able  to
       have  compressed  slices  of  the  defined size. But the most important
       feature of dar is its ability to make differential  backups.  In  other
       words,  backups  that contain only new files or files that have changed
       from a backup of reference.  Moreover  with  differential  backup,  dar
       also stores files that have been deleted since the backup of reference.
       Thus, when restoring, first a full backup, then additional differential
       backups,  at each restoration you get the exact state of the filesystem
       at the time of the backup. And of course, the reference backup may be a
       full or a differential backup itself.

       dar  is  the  first  backup  program  I know that can also remove files
       during restoration!  By  the  way,  in  this  document,  "archive"  and
       "backup" mean the same thing, and are used interchangeably.

       Unlike  the  tar  command,  dar  is  not suited for directly writing to
       tapes. So keep using tar for tape archives. Because,  even  when  using
       dar  to  write  a  slice  on a tape, you will loose all the interest of
       another feature of dar which is its ability to directly access  any  of
       the  archived  files,  even  when compression is used. This way, and in
       contrast to the tar command, dar is able to extract a given  file  much
       faster  from  a  backup  and  to  also recover files that follow a data
       corruption  (loosing  only  the  file  in  which  data  corruption  has

       This,   of  course,  has  its  limitations,  in  particular  when  data
       corruption occurs in the vital part of the backup, i.e. the  few  first
       bytes of each slice or the last part of the archive (the catalogue). In
       case you need to store archives on a  bad  quality  medium,  you  could
       protect  each  slice with a Parchive recovery file. (see NOTES for more
       information about Parchive, and how to transparently run Parchive  from

       Slices  have  a base name given on the command line, which is completed
       by a dot, a number, a dot and the extension (dar) to form  a  filename.
       On the command line you will never have to give the full file name of a

       Let’s take an example:
                           considering the base name "joe", dar will make  one
                           or   several  slices  during  backup  process.  The
                           filenames  with  of  these  slices  are:  joe.1.dar
                           joe.2.dar  ...  joe.10.dar ... etc.  If you want to
                           extract, list, or use this backup as reference, you
                           will  only  have to use the base name, which is the
                           string "joe" in this example.



       Important note: Not all system actually support long options  (Solaris,
       FreeBSD,  ...).  For  example  --create  will not be available on these
       systems, and you will have to use -c instead. In the same way, not  all
       system  do  support  optional arguments (FreeBSD without GNU getopt for
       example), you then need to explicitly give the argument, for example in
       place  of  "-z"  you  will  need to give "-z 9", see "EXPLICIT OPTIONAL
       ARGUMENTS" paragraph near the end of this document.

       -c, --create [<path>/]<basename>
                           creates a backup with the name based on <basename>.
                           All  the  slices  will  be created in the directory
                           <path> if specified, else in the current directory.
                           If  the  destination  filesystem  is  too  small to
                           contain all the slices of the backup, the -p option
                           (pausing  before  starting  new slices) might be of
                           interest. Else, in the case the filesystem is full,
                           dar will suspend the operation, asking for the user
                           to make free space, then continue its operation. To
                           make free space, the only thing you cannot do is to
                           touch the slice being written. If the  filename  is
                           "-"  *and* no slice is asked for (no -s option) the
                           archive is produced on the standard output allowing
                           the  user  to  send the resulting archive through a

       -x, --extract [<path>/]<basename>
                           extracts files from the given  backup.  Slices  are
                           expected  to  be in the current directory or in the
                           directory given by <path>. It is also  possible  to
                           use symbolic links to gather slices that are not in
                           the same  directory.  Path  may  also  point  to  a
                           removable  device (floppy, CD, etc.), in this case,
                           to be able to mount/unmount the  device,  you  must
                           not launch dar from that directory. In other words,
                           the current directory must not  be  that  directory
                           (see tutorial for details).

       -l, --list [<path>/]<basename>
                           lists  the contents of the given backup. In general
                           dar will only require the first and the last  slice
                           of the archive.

       -t, --test [<path>/]<basename>
                           checks   the   backup   integrity.   Even   without
                           compression, dar is able to  detect  at  least  one
                           error  per file in the archive, thanks to a 16 bits
                           CRC recorded per file  in  the  catalogue.  If  one
                           error has occurred in a file stored in the archive,
                           dar will report it in 100% of  all  cases.  If  two
                           errors have occurred, dar will see them in 93,8% of
                           the cases. If three errors occurred, dar  will  see
                           them  in  100%  of  the  cases. If four errors have
                           occurred, dar will see them in 90.6% of the  cases,

       -d, --diff [<path>/]<basename>
                           compares  saved  files  in the backup with those in
                           the filesystem.

       -C, --isolate [<path>/]<basename>
                           isolate a catalogue from its archive. The  argument
                           is  the  basename of the file that will contain the
                           catalogue. The -A option is mandatory here to  give
                           the  name  of  the archive to extract the catalogue
                           from. Slicing is available (-s -S -p -b  etc.).  If
                           the  filename is "-" *and* no slice is asked (no -s
                           option) the catalogue is produced on  the  standard
                           output,  allowing  the  user  to send the resulting
                           catalogue through a pipe. Note  that  there  is  no
                           difference  in  concept  between a catalogue and an
                           archive.  Thus  you  can  do  all  operation  on  a
                           catalogue, in particular take it as reference for a
                           differential archive. A catalogue produced with  -C
                           is  just  like  a  differential  archive done right
                           after a full backup, (no data in it).

       -+, --merge [<path>/]<basename>
                           create a subset archive from one  or  two  existing
                           archives   (the   resulting  archive  name  is  the
                           argument to this command). The dar  file  selection
                           mechanism  (see  below)  let  the user decide which
                           files will be present in the resulting archive  and
                           which one will be ignored. This option thus let the
                           user merge two archives in a  single  one  (with  a
                           filtering  mechanism  that  accepts  all files), as
                           well as this option let the user create  a  smaller
                           archive  which  data  is  taken  from  one  or  two
                           archives of reference. Note that  at  no  time  the
                           contents  of the archives of reference is extracted
                           to real files and directories: this is  an  archive
                           to  archive transfer, thus you may lack support for
                           Extended Attribute while you will be able to  fully
                           manipulate  files  with  their  Extended Attributes
                           from one archive  to  the  resulting  one.  If  the
                           basename  is  "-"  *and*  no  slice is asked (no -s
                           option), the archive is produced on standard output
                           allowing  the  user  to  send the resulting archive
                           through a pipe.  The  first  mandatory  archive  of
                           reference  if  provided  thanks  to  the -A option,
                           while the second "auxiliary" (and optional) archive
                           of  reference  is provided thanks to the -@ option.
                           Note that in  the  current  status,  the  resulting
                           archive  contains  all  files  from  the  mandatory
                           archive  of  reference  (that  matched   the   file
                           selection   mechanism)   plus  those  file  of  the
                           auxiliary archive that are not already  present  in
                           the mandatory archive of reference. In other words,
                           no overwriting is possible, a more complex  way  to
                           solve   conflicts  will  take  place  in  a  future
                           version. Last by default, archive data selected for
                           merging  is  uncompressed,  and re-compressed. Thus
                           the  merging  operation  can  be  used  to   change
                           compression  algorithm  of given archive as well as
                           change its encryption. But, for better  performance
                           it  is  also possible thanks to the -ak option (see
                           below the -ak option  for  usage  restrictions)  to
                           merge   files  keeping  them  compressed,  thus  no
                           decompression/re-compression is performed  at  all,
                           which make the operation faster.

       -h, --help          displays help usage.

       -V, --version       displays version information.


       -v, --verbose[=s[kipped]]
                           verbose output. --verbose and --verbose=skipped are
                           independent. --verbose=skipped displays  the  files
                           being  excluded by filters, while --verbose display
                           actions under process.

       -q, --quiet         Suppress the final statistics report. If no verbose
                           output  is  asked  beside  this  option, nothing is
                           displayed if the operation succeeds.

       -b, --beep          makes  the  terminal  ring  when  user  action   is
                           required  (like  for  example the creation of a new
                           slice using the -p option)

       -n, --no-overwrite  do not allow overwriting of any file or slice.

       -w, --no-warn       Do not warn before overwriting file  or  slice.  By
                           default  (no  -n  and no -w) overwriting is allowed
                           but a warning is  issued  before  proceeding.  This
                           option may receive ’a’ as argument:

       -wa, --no-warn=all  This  implies  the  -w  option, and means that over
                           avoiding warning for  file  overwriting,  DAR  also
                           avoid signaling a file about to be removed when its
                           type is not the expected one. File are removed when
                           they  have  been  recorded  as  deleted  since  the
                           archive  of  reference.  At  restoration   of   the
                           differential  archive,  if a file of the given name
                           exists, it is remove, but  if  the  type  does  not
                           match  the file that was present at the time of the
                           archive of reference (directory, plain file,  fifo,
                           socket,  char  or block device, etc.), a warning is
                           normally issued to prevent the  accidental  removal
                           of  data  that  was  not  saved  in  the  backup of
                           reference. (See also -k option)

       -R, --fs-root <path>
                           The path points to the  directory  tree  containing
                           all   the  files  that  will  be  enrolled  in  the
                           operation (backup, restoration or  comparison).  By
                           default  the  current  directory is used. All other
                           paths used in -P or -g options on the command  line
                           are  and  must  be  relative  to  this  path (or to
                           current directory if -R is not present). Note  that
                           -R is useless for testing (-t option) isolation (-C
                           option) and merging (-+ option)

       -X, --exclude <mask>
                           The mask is a string with wild cards (like * and ?)
                           which   is  applied  to  filenames  which  are  not
                           directories. If a given file matches the  mask,  it
                           is  excluded  from the operation. By default (no -X
                           on the command line), no file is excluded from  the
                           operation.  -X  may be present several times on the
                           command line, in that  case  a  file  will  not  be
                           considered for the given operation if it matches at
                           least one -X mask.

       -I, --include <mask>
                           The mask is applied  to  filenames  which  are  not
                           directories.  If  a given file matches the mask and
                           does not match any mask given with -X, the file  is
                           selected  for  the operation. By default (no -I and
                           no -X on the command line), all files are  included
                           for  the operation. -I may be present several times
                           on the command line, in that  case  all  file  that
                           match one of the -I mask will be considered for the
                           given operation, if they do not also match  one  of
                           the -X mask.

       -P, --prune <path>  Do not consider file or directory sub-tree given by
                           the path. -P may be present  several  time  on  the
                           command  line.  The  difference with -X is that the
                           mask is not applied only to the filename, but  also
                           include  the  path.  Moreover  it  applies  also to
                           directories (-X does not). By default (no -P on the
                           command-line), no sub-tree or file is excluded from
                           the operation,  and  all  the  directory  tree  (as
                           indicated  by  -R  option) is considered. Note that
                           <path> may contains wild-cards  like  *  or  ?  see
                           glob(7) man page for more informations.

       -g, --go-into <path>
                           Files  or  directory  to  only  take in account, as
                           opposed to -P. -g may be present  several  time  on
                           command-line.  Same thing here, the difference with
                           -I is that the mask is applied to the path+filename
                           and also concerns directories. By default all files
                           under the -R directory are considered. Else, if one
                           or more -g option is given, just those are selected
                           (if they do not match any  -P  option).  All  paths
                           given   this   way  must  be  relative  to  the  -R
                           directory. This is equivalent as giving <path>  out
                           of  any  option.  Warning, -g option cannot receive
                           wild-cards, these would not be interpreted.

       -[, --include-from-file <listing_file>
                           Files listed in the listing file are  included  for
                           the   operation.   No   wild   card  expression  is
                           interpreted in the listing file, the null character
                           is  not  allowed and the carriage return is used to
                           separate file names (one file name per line).  Note
                           that this option applies to any files and directory
                           exactly as -g does, with  an  important  difference
                           however:  -g option only uses relative paths to the
                           root directory (the directory  given  with  the  -R
                           option),  while  -[  can use absolute path as well.
                           Another  difference  is  when  the  argument  is  a
                           directory  -g  will  include all the subdirectories
                           under that directory, while when the same entry  is
                           found  in  a  listing  file  given  to -[ only that
                           directory will  be  included,  no  subdirectory  or
                           subfile  would  be  enrolled in the backup, with -[
                           you need to list the exact set of file you want  to
                           backup.  You  can thus generate a listing file with
                           the ’find / -print >  somefile’  command  and  give
                           ’somefile’  as  argument  to  -[  option. Note that
                           however, dar will not save  files  out  of  the  -R
                           given root directory tree.

       -], --exclude-from-file <listing_file>
                           Files  listed in the listing file are excluded from
                           the operation. If a directory is listed in the file
                           all  its contents is excluded (unless using ordered
                           method  and  another  mask  includes  some  of  its
                           subfiles  or  subdirectories).  This  option is the
                           opposite of -[ and acts the same was as  -P  option
                           does  (in  particular  it  is compared to the whole
                           path+filename   and   applies    to    files    and
                           directories). As for -[ option, -] listing file can
                           contain absolute paths,  but  wild  cards  are  not
                           expanded, neither.

       File selection in brief:

       As  seen  above, -I -X -P, -g, -[ and -] options are used to select the
       files to operate on. -I and -X only use the name of files  and  do  not
       apply to directories, while -P, -g -[ and -] use the filename *and* the
       path, they *do* apply to directories.

       since version 2.2.0 two modes of interpretation of these options exist.
       The normal original method and the ordered method:

              the normal method is the default:
                   A  directory is elected for operation if no -P or -] option
                   excludes it. If at least one -g or -[ option is  given  one
                   command  line,  one -g option must cover it, else it is not
                   elected for operation. If a directory is not  selected,  no
                   recursion  is done in it (the directory is pruned). For non
                   directories files, the same is true (P, -g, -[  and  -]  do
                   apply)  and  a  second  test  must also be satisfied: no -X
                   option must exclude the filename, and if at  least  one  -I
                   option  is  given, one must match the given filename (using
                   or not wild-cards).

              the ordered method (when -am option is given on command-line):
                   The ordered method takes care  of  the  order  of  presence
                   between  -X  and -I in one hand and of -P, -g, -[ and -] in
                   the other hand (note that  it  has  also  the  same  action
                   concerning  EA  selection when using -u and -U options, but
                   that’s no more file selection). In the ordered  method  the
                   last  argument  take precedence over all the previous ones,
                   let’s take an example:

                   -X "*.mp?" -I "*.mp3" -I "toto*"
                        Here dar will include all files except  file  of  name
                        "*.mp?"  (those  ending  with  "mpX"  where  X  is any
                        character), but it will however include  those  ending
                        with  ".mp3".  It  will  also include files which name
                        begin by "toto" whatever  they  end  with.  This  way,
                        "toto.mp2"  will be saved (while it matches "*.mp?" it
                        also begins by "toto") as well as "toto.txt"  as  well
                        as "joe.mp3" (while it matches "*.mp?" it also ends by
                        "mp3"). But will not be saved  "joe.mp2"  (because  it
                        does not begin by "toto", nor ends by "mp3", and match
                        "*.mp?" mask). As we see the last option  (-I  or  -X)
                        overcomes  the  previous  one.  -P,  -g, -[ and -] act
                        together the same but as seen above they do  not  only
                        act  on filename, but on the whole path+filename. Note
                        that (-g, -P, -[, -]) and (-X ,  -I)  are  independent
                        concerning  their relative order. You can mix -X -I -g
                        -P -] -[ in any order, what will be important  is  the
                        relative  positions  of  -X  options  compared  to  -I
                        options, and the relative positions of -g -[ -] and -P
                        options between them.

              In  logical  terms,  if <prev_mask> is the mask generated by all
              previous mask on the command line, -I <mask> generates  the  new
              following   mask:  <prev_mask>  or  <mask>  .  While  -X  <mask>
              generates the new following mask: <prev_mask>  and  not  <mask>.
              This  is  recursive  each time you add a -I or -X option. Things
              work the same with -P, -g, -[ and -] options.
       This ends the file selection  explication  let’s  continue  with  other

       -u, --exclude-ea <mask>
                           Do  not  consider the Extended Attributes (EA) that
                           are matched by the given mask. By  default,  no  EA
                           are  excluded,  if  the  support  for  EA  has been
                           activated at compilation time. This option  can  be
                           used multiple times.

       -U, --include-ea <mask>
                           Do  only consider the EA that match the given mask.
                           By default, all EA are included  if  no  -u  or  -U
                           option  is  present  and  if the support for EA has
                           been activated at compilation time. This option can
                           be  used  multiple  times. See also the -am and -ae
                           options, they also apply to -U and -u  options  and
                           read below the Note concerning EA.

       Note concerning Extended Attributes (EA)

              Support  for  EA  must  be  activated  at  compilation time (the
              configure script tries to do so  if  your  system  has  all  the
              required support for that). Thus you can get two binaries of dar
              (of the same version), one supporting EA and another which  does
              not  (dar  -V  to  see  whether  EA  support  is activated). The
              archives they produce are the same  and  can  be  read  by  each
              other. The only difference is that the binary without EA support
              is not able to save or restore EAs, but is still  able  to  test
              them and list their presence.

              Since version 2.3.x the name of EA include the namespace for dar
              be able to consider any type of EA (not only "system" and "user"
              as  previously).  Thus  the  two previous options -u and -U have
              changed and now take an argument which is a mask applied  to  EA
              names   written  in  the  following  form  where
              "namespace" is for example "user". Note that the mask may or may
              not  include  the  dot  (.)  and  match arbitrary part of the EA
              namespace+name, just remind that masks will be  applied  to  the
              "" global string.

              the  -am  flag  here  also  enables  the  ordered method, for EA
              selection too.  The  ordered  versus  normal  method  have  been
              explained  above  in the file selection note, with some examples
              using -X and -I. Here this is the same with  -U  and  -u,  (just
              replace   -X   by  -u  and  -I  by  -U  and  remember  that  the
              corresponding mask will apply to Extended Attribute selection in
              place of file selection).

              Another  point,  independently  of the -am option the -ae option
              can be used at restoration time only. If set,  when  a  file  is
              about  to  be  overwritten,  all  EA will be first erased before
              restoring  those  selected  for  restoration  in   the   archive
              (according  to  the -U and -u options given). If not set, the EA
              of the existing file will be overwritten, those  extra  EA  that
              are  not  in  the archive or are not selected for restoration in
              regard to the -u and -U options will be preserved. If  you  have
              not  used  any  -u/-U  option at backup time and want to restore
              from a set of full/differential backups the EA exactly  as  they
              were,  you  have  to  use  -ae  for  dar  removes  the EA before
              overwriting their set of EA as stored in  the  archive.  Without
              -ae  option  dar will simply add EA to existing ones, thus get a
              different set of EA for a give file than those recorded  at  the
              time of the backup.

              Last   point   the  -acase  and  -an  options  alters  the  case
              sensitivity of the  -U and -u masks  that  follow  them  on  the
              command-line/included  files  as  they do for -I, -X, -P, -g, -[
              and -] as well. Very last point ;-), by  default  during  backup
              dar  set back the atime after having read each file (see -aa/-ac
              options), this has as side effect to modify the  ctime  date  of
              each file. But ctime change is used by dar to detect EA changes.
              In brief, the next time you backup a file that had  to  be  read
              (thus which contents changed), its EA will be saved even if they
              had not changed. To avoid this slide effect, you can use the -ac
       This  ends  the Extended Attribute selection explication let’s continue
       with other options.

       -i, --input <path>  is available when reading from  pipe  (basename  is
                           "-"  for -x, -l, -t, -d or for -A when -c, -C or -+
                           is used). When reading from pipe, standard input is
                           used,   but  with  this  option,  the  file  <path>
                           (usually a  named  pipe)  is  used  instead.   This
                           option  is to receive output from dar_slave program
                           (see doc/NOTES for examples of use).

       -o, --output <path> is available when reading from  pipe  (basename  is
                           "-"  for -x, -l, -t, -d or for -A when -c, -C or -+
                           is used). When reading from pipe,  standard  output
                           is used to send request to dar_slave, but with this
                           option, the file <path> (usually a named  pipe)  is
                           used  instead.  When  standard  output is used, all
                           messages  goes  to   standard   error   (not   only
                           interactive  messages).  See doc/NOTES for examples
                           of use.

       -O, --comparison-field[=<flag>]
                           When comparing with the archive  of  reference  (-c
                           -A)  during  a differential backup, when extracting
                           (-x)  or  when  comparing  (-d)  do  only  consider
                           certain fields. The available flags are:

                           ignore-owner   all  fields  are  considered  except
                                          ownership.   This is useful when dar
                                          is used by a non-privileged user. It
                                          will not consider a file has changed
                                          just   because   of  a  uid  or  gid
                                          mismatch and at restoration dar will
                                          not   even   try  to  set  the  file

                           mtime          only    inode    type    and    last
                                          modification  date  is considered as
                                          well as  inode  specific  attributes
                                          like  file  size  for  plain  files.
                                          Ownership is ignored, permission  is
                                          ignored.      During     comparison,
                                          difference    on    ownership     or
                                          permission   is   ignored   and   at
                                          restoration time dar will not try to
                                          set   the   inode   permission   and

                           inode-type     Only the inode type  is  considered.
                                          Ownership,  permission and dates are
                                          ignored. Inode  specific  attributes
                                          are still considered (like file size
                                          for plain  files).  Thus  comparison
                                          will    ignore    differences    for
                                          ownership, permission, and dates and
                                          at  restoration  dar will not try to
                                          set the  ownership,  permission  and

       When  no  flag  is  provided  to  this option, -O option acts as if the
       "ignore-owner" flag was set, which is the behavior in older releases (<
       2.3.0).  Note  also  that  for  backward  compatibility, --ignore-owner
       option still exists and is now  just  an  alias  to  the  --comparison-
       field=ignore-owner  option.  Of  course if this option is not used, all
       fields are used for comparison or restoration.

       -H[num], --hour[=num]
                           if -H is used, two dates are  considered  equal  if
                           they  differ  from  a  integer number of hours, and
                           that number is less than or equal to [num]. If  not
                           specified  num  defaults  to  1.  This is used when
                           making   a   differential   backup,   to    compare
                           last_modification    date   of   inodes,   and   at
                           restoration time if the  -r  option  (restore  only
                           more  recent  files) is used. This is to workaround
                           some filesystems (like Samba filesystem) that seems
                           to change the dates of files after having gone from
                           or to daylight saving time (winter/summer time).

       -E, --execute <string>
                           the string is a user command-line  to  be  launched
                           between  slices. For reading (thus using -t, -d, -l
                           or -x options), the command is executed before  the
                           slice  is  read  or even asked, for writing instead
                           (thus using -c, -C or -+ option),  the  command  is
                           executed  once  the  slice has been completed. Some
                           substitution string can be used in the string:

                           %%        will be replaced by %

                           %p        will be replaced by the slice path

                           %b        will be replaced by the slice basename

                           %n        will be replaced by the slice number  (to
                                     be  read  or  just written). For reading,
                                     dar  often  needs  the  last  slice,  but
                                     initially it does not know its number. If
                                     it  cannot  be  found  in   the   current
                                     directory,  the user command-line is then
                                     called with %n equal  to  0.  This  is  a
                                     convenient way to inform the user command
                                     to provide the last slice. If after it is
                                     still  not present, dar asks the user (as
                                     usually) with a message on the  terminal.
                                     Once  the  last  slice is found, the user
                                     command-line is  called  a  second  time,
                                     with  %n  equal  to the value of the last
                                     slice number.

                           %e        will be replaced by the  slice  extension
                                     (always substituted by "dar")

                           %c        will be replaced by the context. Actually
                                     three  possible  values  exist:   "init",
                                     "operation"    and   "last_slice".   When
                                     reading   an   archive   for    (testing,
                                     extraction,   diff,   listing,  or  while
                                     reading the  archive  of  reference,  see
                                     below  the -F option), the "init" context
                                     takes place from the beginning up to  the
                                     time  the  catalogue  is  retrieved. On a
                                     multiple slice archive this correspond to
                                     the  first  slice request and to the last
                                     slice requests. After, that  point  comes
                                     the  "operation" context.  While creating
                                     an  archive,  the   context   is   always
                                     "operation"  except  when  the last slice
                                     has  been  created,  in  which  case  the
                                     context is set to "last_slice".
       Several  -E  option can be given, given commands will then be called in
       the order they appear on the command line, and included files.

       -F, --execute-ref <string>
                           same as -E but is applied  between  slices  of  the
                           reference archive (-A option).

       -K, --key [[<algo>]:]<string>
                           encrypt/decrypt the archive using the <algo> cipher
                           with the <string>  as  pass  phrase.  An  encrypted
                           archive can only be read if the same pass phrase is
                           given.  Available  ciphers  are  "blowfish"  (alias
                           "bf") for strong encryption and "scrambling" (alias
                           "scram") for a very weak encryption. By default  if
                           no  <algo>  or no ’:’ is given, the blowfish cipher
                           is assumed. If your password contains a column  ’:’
                           you  need to specify the cipher to use (or at least
                           use the initial ’:’ which is equivalent to  ’bf:’).
                           If  the  <string>  is empty the pass phrase will be
                           asked  at  execution  time.  Thus,   the   smallest
                           argument  that  -K  can  receive is ’:’ which means
                           blowfish cipher  with  the  pass  phrase  asked  at
                           execution time.

       With  release  2.3.4  a better implementation of the blowfish algorithm
       has been used within dar, while recent version can  transparently  read
       older  implementation  (using  ’bf’  cipher) you can create new archive
       with   this   old   weakened   blowfish   implementation   using    the
       ’blowfish_weak’  or  ’bfw’  cipher. Note that this way of encryption is
       strong but weakened by frequent IV collision (same Initial Vectors used
       often).  This  feature  is  kept  available for those using old openssl
       library that do not provide all the header required  to  implement  the
       new blowfish implementation.

       Note  that  giving  the pass phrase as argument to -K (or -J see below)
       may let other users learn pass phrase (thanks to the ps, or top program
       for  examples).  It is thus wise to either use an empty pass which will
       make dar ask the pass phrase at when needed, or use -K (or  -J  option)
       from  an  Dar  Command  File  (see  -B  option),  assuming  it  has the
       appropriated permission to avoid other users reading it.

       -J, --key-ref [[<algo>]:]<string>
                           same as -K but the given key is used to decrypt the
                           archive of reference (given with -A option).

       -#, --crypto-block <size>
                           to  be  able to randomly access data in an archive,
                           it is not encrypted globally but  block  by  block.
                           You  can define the encryption block size thanks to
                           this argument which default to  10240  bytes.  Note
                           that  syntax  used  for -s option is also available
                           here. Note also that crypto-block is stored as a 32
                           bits  integer thus value larger than 4GB will cause
                           an error. Note last, that the block size given here
                           must   be  provided  when  reading  this  resulting
                           archive (through the -* or -# options).  If  it  is
                           not  the  correct  one,  the  archive  will  not be
                           possible to decrypt, it is thus safe  to  keep  the
                           default value (and not use at all the -# option).

       -*, --crypto-block-ref <size>
                           same  as  --crypto-block  but  for  the  archive of
                           reference (same default value).

       -B, --batch <filename>
                           You can put in the file any option or  argument  as
                           used  on  command  line,  that will be parsed as if
                           they were in place of the "-B  <filename>"  option.
                           This  way  you  can  overcome the command line size
                           limitation. Commands in the file may be disposed on
                           several  lines,  and  -B  option  can  also be used
                           inside files,  leading  a  file  to  include  other
                           files.  But an error occurs in case of loop (a file
                           includes  itself)  and  DAR   aborts   immediately.
                           Comments  are now allowed, and must start by a hash
                           ‘#’ character on each line. Note that for a line to
                           be considered as comment the hash character must be
                           the first character of the line (space or  tab  can
                           still  precede  the  hash).  See Conditional Syntax
                           bellow for a  more  rich  syntax  in  configuration

       -N, --noconf        Do  not try to read neither ~/.darrc nor /etc/darrc
                           configuration files. See files section bellow.

       -e, --empty         Do not perform any action (backup,  restoration  or
                           merging),  displays  all  messages as if it was for
                           real ("dry run" action).

       -aSI, --alter=SI[-unit[s]]
                           when using k M G T E Z Y prefixes to define a size,
                           use  the  SI  meaning:  multiple of 10^3 (a Mega is

       -abinary, --alter=binary[-unit[s]]
                           when using k M G T E Z Y prefixes to define a size,
                           use   the   historical  computer  science  meaning:
                           multiple of 2^10  (a Mega is 1,048,576).

       The --alter=SI and --alter=binary options can be used several times  on
       the  command  line.  They  affect all prefixes which follow, even those
       found in files included by the -B option, up to the next --alter=binary
       or  --alter=SI  occurrence.  Note  that if in a file included by the -B
       option, an --alter=binary or --alter=SI is encountered, it affects  all
       the  following  prefixes,  even  those  outside the included files. For
       example, when running with the parameters "-B some.dcf -s 1K",  1K  may
       be  equal  to  1000  or 1024, depending on --alter=binary or --alter=SI
       being  present  in  the  some.dcf  file.   By   default   (before   any
       --alter=SI/binary option is reached), binary interpretation of prefixes
       is done, for compatibility with older versions.

       -Q                  Do not display an initial warning  on  stderr  when
                           not  launched from a terminal (when launched from a
                           cronjob for example). This means that all questions
                           to  the user will be answered with ’no’, which most
                           of the time will abort  the  program.  Please  note
                           that   this   option   cannot   be   used   in  the
                           configuration file, it must be given on the command
                           line.  Since version 2.2.2, giving this option also
                           forces the non-interactive mode,  even  if  dar  is
                           launched  from  a  terminal. This makes it possible
                           for dar to run in the background. When you do, it’s
                           recommended  to  redirect  stdout  and/or  sterr to

       -aa, --alter=atime  when reading a filesystem, while doing a backup (-c
                           option)  or  comparing  (-d  option) by default dar
                           tries to be as much transparent  as  possible,  and
                           set back the last access time (atime) of read files
                           and directories, as if they  have  not  been  read.
                           But,  preserving  atime  of  read files, make their
                           ctime to be changed (last inode change).  There  is
                           no possibility to preserve both atime and ctime. If
                           you want to overcome the default original  behavior
                           of  dar  and  want  to  keep  ctime  unchanged, the
                           --alter=atime is for you.  Some  security  software
                           rely  on  the  ctime  to  be  preserved, some other
                           software rely on the atime  to  be  preserved  like
                           leafnode NNTP caching software.

       -ac, --alter=ctime  set   back   the  date  alteration  to  ctime  (see
                           --alter=atime above), this is the default behavior.
                           The  use  of  this  switch  is  to override the -aa
                           option in dar configuration files  or  command-line
                           (see  -B option). From -aa and -ac the one which is
                           last parsed from  command-line  or  included  files
                           takes the win.

       -am, --alter=mask   set the ordered mode for mask. This affects the way
                           -I and -X options are interpreted, as well  as  -g,
                           -P, -[ and -] options, -Z and -Y options and -U and
                           -u options. It can take any place on  the  command-
                           line  and  can  be  placed  only once. See the file
                           selection in brief paragraph above for  a  detailed
                           explanation of this option.

       -an, --alter=no-case
                           set  the  filters  in  case  insensitive mode. This
                           concerns only masks  specified  after  this  option
                           (see  also  -acase  option below). This changes the
                           behavior of -I, -X, -g,  -P,  -Z,  -Y,  -u  and  -U

       -acase, --alter=case
                           set  back  to  case sensitive mode for filters. All
                           following masks are case sensitive, up  to  end  of
                           parsing  or up to the next -an option. This changes
                           the behavior of -I, -X, -g, -P, -Z, -Y, -u  and  -U

       -ar, --alter=regex  set  the  filters  to  be  interpreted  as  regular
                           expressions (man regex(7) ) instead of the  default
                           glob  expression  (man  glob(7) ) This modifies the
                           -I, -X, -g, -P, -Z, -Y,  -u  and  -U  options  that
                           follows  up  to  an  eventual  -ag option (see just
                           below). Note that for -P and -g options, the  given
                           mask  matches  the  relative path part of the files
                           path: Let’s take  an  example,  assuming  you  have
                           provided  /usr/local  to  the  -R  option, the mask
                           "^foo$"     will     replaced     internally     by
                           "^/usr/local/foo$"  while  the  mask "foo$" will be
                           replaced internally by "^/usr/local/.*foo$".

       -ag, --alter=glob   This option returns to glob expressions mode (which
                           is  the default) after an -ar option has been used,
                           this applies to any -I, -X, -g, -P, -Z, -Y, -u  and
                           -U  options  that  follow up to an eventual new -ar
                           option (see just above).

       -j, --jog           when virtual memory is exhausted, ask user to  make
                           room  before  trying  to continue. By default, when
                           memory  is  exhausted  dar  aborts.  Note  that  on
                           several system, when memory is exhausted the kernel
                           is likely to kill the process that failed to obtain
                           virtual  memory,  thus on some systems, dar may not
                           be able to ask user for what to do when  memory  is

       SAVING, ISOLATION AND MERGING OPTIONS (to use with -c, -C or -+)

       -z[level], --gzip[=level]
                           compresses  within  slices using gzip algorithm (if
                           not specified, no compression  is  performed).  The
                           compression  level  (an  integer  from  1  to 9) is
                           optional,  and  is  9  by  default,  which  is  max
                           compression/slow  processing.  At  the  opposite, 1
                           means less compression and faster processing.

       -y[level], --bzip2[=level]
                           compresses using bzip2 algorithm. See -z above  for
                           usage details.

       -s, --slice <number>
                           Size  of  the  slices  in  bytes.  If the number is
                           appended by k (or K), M, G, T, P E, Z or Y the size
                           is  in  kilobytes, megabytes, gigabytes, terabytes,
                           petabytes,  exabytes,  zettabytes   or   yottabytes
                           respectively. Example: "20M" means 20 megabytes, by
                           default, it is  the  same  as  giving  20971520  as
                           argument  (see  also -aSI and -abinary options). If
                           -s is not present the backup will be written  to  a
                           single slice whatever the size of the backup may be
                           (there is probably some filesystem limitation, thus
                           you  might  expect  problems  for  file size over 2
                           gigabytes, depending on your filesystem,  but  this
                           is not a limitation of dar).

       -S, --first-slice <number>
                           -S  gives  the size of the first slice which may be
                           chosen  independently  of  the  size  of  following
                           slices.  This  option  needs -s and by default, the
                           size of the first slice is the same as the  one  of
                           the following slices.

       -p [<integer>], --pause[=<integer>]
                           pauses before writing to a new slice (this requires
                           -s). By default there is no pause, all  slices  are
                           written in the same directory, up to the end of the
                           backup or until the filesystem  is  full.  In  this
                           later  case,  the  user  is informed of the lack of
                           disk space and dar stops for user action.  As  soon
                           as  some  disk  space  is  available,  the user can
                           continue the backup. The optional integer that this
                           option can receive tells dar to only pause very ’n’
                           slice. Giving 3 for ’n’ will make  dar  pause  only
                           after  slices 3, 6, 9 and so on. If this integer is
                           not specified, the behavior is as if ’1’ was  given
                           as argument which makes dar pause after each slice.

       -A, --ref [<path>]/<basename>
                           specifies  the  archive   to   use   as   reference
                           (mandatory  with  -C).  By default (default is only
                           possible with -c option) no archive is used and all
                           files  are  saved  (in  regards  to -I -X -P and -g
                           options). All slices of the  reference  backup  are
                           expected  to  be  on  the  same  directory given by
                           <path> or the current directory by default. Usually
                           only  the  first and the last slice are required to
                           extract the catalogue of  reference.  If  necessary
                           the  use of symbolic links is also possible here to
                           gather slices  that  do  not  reside  in  the  same
                           directory. You can also point <path> to a floppy or
                           any other mounted directory, because dar will pause
                           and  ask  the  user for required slices if they are
                           not present. The argument to  -A  may  be  of  four
                            -  An  existing  archive  basename,  which will be
                           taken as reference
                            - a dash ("-") which implies the use of -o and  -i
                           options, this allows the archive of reference to be
                           read from a pair of pipes  with  dar_slave  at  the
                           other  ends.  Dar_slave can be run through ssh on a
                           remote host for example.
                            - a plus sign ("+") which makes the  reference  be
                           the current directory status (not available with -+
                           option: merging). In other  word,  no  file’s  data
                           will  be  saved,  just  the  current  status of the
                           inodes will be recorded in the catalogue.  This  is
                           like  an extracted catalogue form a full backup, it
                           can be taken for further reference  without  having
                           to  make  the  full  backup itself. This feature is
                           known as the "snapshot" backup.
                            - a <date>, if -af option has been  placed  before
                           -A  on the command-line (or in a included file, see
                           -B option). For more about  that  feature  see  -af
                           option below.

       -@, --aux-ref [<path>]/<basename>
                           specifies  an  auxiliary archive of reference. This
                           option is only available with -+ option  (merging).
                           Over  -A  option which is mandatory with -+ option,
                           you may give a second archive of  reference  thanks
                           to  the  -%  option.  This  allows one to merge two
                           archive in a single one. See also -$, -~ and -% for
                           other   options  concerning  auxiliary  archive  of

       -$, --aux-key [[<algo>]:]<string>
                           same  as  -J  but  for  the  auxiliary  archive  of
                           reference (-@ option).

       -~, --aux-execute <string>
                           same  as  -F  but  for  the  auxiliary  archive  of
                           reference (-@ option).

       -%, --aux-crypto-block <size>
                           same  as  -*  but  for  the  auxiliary  archive  of
                           reference (-@ option).

       -D, --empty-dir     When  excluding directories either explicitly using
                           -P or -] options, or implicitly by giving a  -g  or
                           -[  options (a directory is excluded if it does not
                           match mask given with -g options or -[ options) dar
                           does  not  store  anything about these. But with -D
                           option, dar stores them as empty directories.  This
                           can  be  useful,  if  excluding a mount point (like
                           /proc or /dev/pts). At restoration time,  dar  will
                           then  recreate  these  directories  (if necessary).
                           This option has no meaning with -C and  is  ignored
                           in that case.

       -Z, --exclude-compression <mask>
                           Filenames  covered by this mask are not compressed.
                           It is only useful with -z or -y.  By  default,  all
                           file  are compressed (if compression is used). This
                           option can be used several times, in  that  case  a
                           file  that  matches  one of the -Z mask will not be

       -Y, --include-compression <mask>
                           Filenames covered by this mask (and not covered  by
                           -Z)  are  the  only  to  be  compressed. It is only
                           available with -z no -y. By default all  files  are
                           compressed.  This option can be used several times,
                           in that case all files that match  one  of  the  -Y
                           will be compressed, if they do not also match on of
                           the -Z masks. The ordered method here  applies  too
                           when  activated (with -am option), it works exactly
                           the same as -I and -X options, but  apply  to  file
                           compression, not file selection.

       -m, --mincompr <number>
                           files  which  size  is below this value will not be
                           compressed. If -m is not specified it is equivalent
                           to  giving  -m  100  as  argument.  If  you want to
                           compress all file whatever their size is  you  thus
                           need  to  type  -m  0 on the command line. The same
                           number extensions as those used with -s or  -S  are
                           available  here, if you want to specify the size in
                           kilobyte, megabyte, gigabyte etc.

       -ak, --alter=keep-compressed
                           During merging operation,  keep  files  compressed,
                           this  has several restrictions : -z, -y, -Z, -Y, -m
                           are ignored, if two archives  have  to  be  merged,
                           both must use the same compression algorithm or one
                           of them must not use compression at all (this  last
                           restriction  will  probably  disappear  in  a  next
                           version). The advantage of this option is a greater
                           speed  of  execution  (compression  is  usually CPU

       -af, --alter=fixed-date
                           Modify the -A option behavior, making it  receiving
                           a    <date>   as   argument   in   place   of   the
                           [<path>]/<basename> default argument. The <date> is
                           used  to  define  which  file  to  save (file which
                           modification is newer or equal to <date>) and which
                           to  consider  unchanged  (those older than <date>).
                           This option has  only  a  sense  when  creating  an
                           archive (not when merging or isolating).

       <date> must be a date in the following possible formats:
        - a number of second since Jan 1st, 1970
        -        a        date        in        the       following       form

       Here are some examples of date:

              2005/11/19-19:38:48 Which is 38 past 7 PM and  48  seconds,  the
              19th of November 2005

              20:20 Which is 8 PM of the current day

              2-00:08  Which  is  8  past  noon, the second day of the current

              2/2-14:59 Which is 1 to 3 PM, the 2nd of February in the current

       --nodump            do  not save files which have the ’d’ flag set (see
                           chattr(1) lsattr(1) ext2 commands). This option may
                           not  be  available  if  the  system  dar  has  been
                           compiled on did not provide support for ext2 flags.
                           Note  that  this option does nothing with -+ option
                           (merging)  as  no  filesystem  is  used  for   that

       -G, --on-fly-isolate [<path>]/<basename>
                           When  creating  a backup (-c option) or merging two
                           backups (-+ option), -G option perform a  catalogue
                           isolation  of  the  resulting archive. This step is
                           done after the backup/merging  has  completed.  The
                           on-fly  isolation  is  compressed with bzip2 (using
                           compression  level  9),  and  is  a  single  sliced
                           archive  without  encryption.  Due  to command-line
                           exiguity, it is not possible to change  compression
                           algo,  slice  size or encryption scheme for the on-
                           fly isolation.  If  you  need  a  more  complicated
                           isolation, either look for a GUI over libdar, or do
                           a normal (not on-fly) isolation (By the way  it  is
                           possible  to isolate an already isolated catalogue,
                           this is equivalent to  a  copy,  but  you  can  add
                           encryption,  change  compression,  change  slicing,
                           etc.), you can also use dar_xform if you only  want
                           to  change  slices  size  (this  is  faster  as  no
                           decompression/re-compression is done).

       -M, --no-mount-points
                           stay in the same filesystem as the  root  directory
                           (see  -R  option),  subdirectory  that are mounting
                           points for other filesystems will not be  saved  or
                           saved  empty  if -D option is used (useless with -+

       -, ,  --cache-directory-tagging
                           don’t save contents of  directories  that  use  the
                           Cache     Directory     Tagging    Standard.    See
                           details. (this option is useless with -+ option)

       RESTORATION OPTIONS (to use with -x)

       -k, --no-deleted    Do  not  delete  files that have been deleted since
                           the backup of reference (file overwriting can still
                           occur).  By default, files that have been destroyed
                           since the backup of reference  are  deleted  during
                           restoration,   but   a  warning  is  issued  before
                           proceeding, except if -w is used. If -n is used, no
                           file  will be deleted (nor overwritten), thus -k is
                           useless when using -n.

       -r, --recent        restore only files that are absent or  more  recent
                           than  those present in filesystem. -r is useless if
                           -n is present.

       -f, --flat          do not restore directory structure. All  file  will
                           be  restored  in  the directory given to -R, if two
                           files of the same name have  to  be  restored,  the
                           usual   scheme   for   warning   (-w   option)  and
                           overwriting (-n option) is used. No  rename  scheme
                           is  planned  actually. When this option is set, dar
                           does not remove files  that  have  been  stored  as
                           deleted  since  last backup. (-f implicitly implies

       -ae, --alter=erase_ea
                           Drop all existing EA of files present in filesystem
                           that  will  have  to  be  restored.  This  way, the
                           restored files will have the exact set of  EA  they
                           had  at  the  time of the backup. If this option is
                           not given, a file  to  restore  will  have  its  EA
                           overwritten  by  those present in the backup and if
                           some  extra  EAs  are  present  they  will   remain
                           untouched.   See   the   Note  concerning  Extended
                           Attributes (EA) above for  a  detailed  explanation
                           about this behavior.

       TESTING AND DIFFERENCE OPTIONS (to use with -t or -d)

       No specific option, but all general options are available except -n and
       -w which are useless, as testing and comparing only read data.

       LISTING OPTIONS (to use with -l)

       -T, --list-format=<normal | tree | xml>, --tree-format
                           By default, listing provides a tar-like output (the
                           ’normal’  output).  You can however get a tree-like
                           output (the ’tree’ output)  or  an  XML  structured
                           output  (the  ’xml’  output).  Providing -T without
                           argument gives the same  as  providing  the  ’tree’
                           argument  to  it.  The  option  --tree-format is an
                           alias     to      --list-format=tree      (backward
                           compatibility).   Note   that  the  files  doc/dar-
                           catalog-*.dtd define the format of the  XML  output
                           listing   (This   file   is  also  installed  under

       -as, --alter=saved  list only saved files

       -I and -X           can be used to filter file to list  base  on  their
                           name  (is ignored when --list-format=tree is used).
                           Note that -P and -g options are not available while

       Else  only  -v  and  -b  from  general options are useful. Note that -v
       displays an archive summary first, where a lot of information about the
       archive can be obtained.

       displayed fields

                 [data]    possible values are [     ] or [Saved] or [InRef] .
                           [     ] means that the  data  has  not  been  saved
                           because   there   is  no  change  since  backup  of
                           reference. [Saved] means that  the  data  has  been
                           saved, and thus this archive is able to restore the
                           file. [InRef] is used when  isolating  a  catalogue
                           from  an  archive and means that the file was saved
                           in the reference archive.

                 [EA]      possible values are " " (empty string) or  [      ]
                           or   [InRef]  or  [Saved].  It  Shows  if  Extended
                           Attributes are present  and  saved  ([Saved]),  are
                           present  but  not saved ([     ]) which means there
                           is no change since backup of reference, or if there
                           is  no  EA  saved  for  this  file  (empty string).
                           [InRef] is used when isolating a catalogue from  an
                           archive  and  means  that the file was saved in the
                           reference archive.

                 [compr]   possible values are [....%] or [-----] or  [      ]
                           or  [worse].  Shows if the file has been compressed
                           and the compression rate reached  ([...%]),  or  if
                           the  file is stored without compression ([    ] see
                           -Y and -Z options) or if the file is not subject to
                           compression  because it is not a saved regular file
                           ([----]),  or  if  the  file   takes   more   space
                           compressed than its original size ([worse]), due to
                           compression overhead.

                           see ls man page.

                 user      owner of the file

                 group     group owner of the file

                 size      size  in  byte  of  the  file  (if  compression  is
                           enabled,   the   real   size   in  the  archive  is
                           "compression rate" time smaller).

                 date      the last modification date of the  file.  The  last
                           access  time  is  also  saved and restored, but not

                 filename  The name of the file.


       When dar has not been compiled with GNU getopt, which is not present by
       default  on  some  systems  like  FreeBSD,  you  may  lack the optional
       arguments syntax. For  example  "-z"  will  create  a  parse  error  on
       command-line,  or  in  -B  configuration  files.  The  solution  is  to
       explicitly give the argument. Here follows a list of explicit  argument
       to use in place of optional ones:

       -z                  must be replaced by -z 9

       -y                  must be replaced by -y 9

       -w                  must be replaced by -w d or -w default

       -H                  must be replaced by -H 1

       important  !  When using GNU getopt(), optional arguments are available
       by sticking the argument to the  short  option:  "-z"  for  example  is
       available  as  well  as  "-z9". But "-z 9" is wrong, it will be read as
       "-z" option and "9", a command line argument (not an argument to the -z
       option). In the other side, when using a non GNU getopt this time, "-z"
       becomes an option that always requires an argument, and thus "-z 9"  is
       read  as "-z" option with "9" as argument, while "-z9" will be rejected
       as a unknown option, and "-z"  alone  will  generate  an  error  as  no
       argument  is  provided.  In  consequences, you need a space between the
       option (like "-z") and its argument (like "9"), when dar does not  rely
       on  a  GNU  getopt()  call,  which  also  imply  you  to explicitly use
       arguments to options listed just above.


       dar exits with the following code:

       0         Operation successful.

       1         Syntax error on command-line.

       2         Error due to a hardware problem or a lack of memory.

       3         Detection of a condition that should never happen, and  which
                 is considered as a bug of the application.

       4         Code  issued  when  the user has aborted the program upon dar
                 question from dar. This also happens when dar is not run from
                 a  terminal (for example launched from crontab) and dar has a
                 question to the user. In that case, dar aborts the  same  way
                 as if the user pressed the escape key at the question prompt.

       5         is returned when an error concerning  the  treated  data  has
                 been  detected.  While  saving,  this is the case when a file
                 could not be opened or read. While restoring, it is the  case
                 when   a  file  could  not  be  created  or  replaced.  While
                 comparing, it is the case when a file in the archive does not
                 match  the  one  in  the filesystem. While testing, it is the
                 case when a file is corrupted in the archive.

       6         an error occurred while executing user command (given with -E
                 or  -F  option). Mainly because the creation of a new process
                 is not possible (process table is full) or the  user  command
                 returned an error code (exit status different of zero).

       7         an  error  has  occurred  when calling a libdar routine. This
                 means  the  caller  (dar  program),  did  not   respect   the
                 specification  of  the  API  (and this can be considered as a
                 particular case of a bug).

       8         the version of dar used is based in  finite  length  integers
                 (it  has  been  compiled  with the option --enable-mode=...).
                 This code is returned when an integer overflow occurred.  use
                 the full version (based in the so called "infinint" class) to
                 avoid this error.

       9         this  code  indicates  an  unknown  error.  I  have  probably
                 forgotten  to  update the exception caching code to take care
                 of new exceptions... this is a minor bug you are  welcome  to

       10        you  have  tried  to  use a feature that has been disabled at
                 compilation time.

       11        some saved files have changed while  dar  was  reading  them,
                 this  may lead the data saved for this file not correspond to
                 a valid state for this file. For example,  if  the  beginning
                 and  the  end of the file have been modified at the same time
                 (while dar is reading it), only the change at the end will be
                 saved  (the  beginning  has already been read), the resulting
                 state of the file as recorded by dar has  never  existed  and
                 may cause problem to the application using it.


       If  dar  receives  a  signal  (see  kill(2)  man page) it will take the
       default behavior which  most  of  the  time  will  abruptly  abort  the
       program, except for the following signals:

       SIGINT    This  signal is generated by the terminal when hitting CTRL-C
                 (with the  terminal’s  default  settings),  it  can  also  be
                 generated with the kill command

       SIGTERM   This  signal is generated by the system when changing of run-
                 level in particular when doing a shutdown,  it  can  also  be
                 generated with the kill command

       SIGHUP    Depending  on  the system, this signal may be sent before the
                 SIGTERM signal at shutdown time, it  can  also  be  generated
                 with the kill command

       SIGQUIT   This  signal is generated by the terminal when hitting CTRL-\
                 (with the  terminal’s  default  settings),  it  can  also  be
                 generated with the kill command

       SIGUSR1   This signal can be generated by the kill command

       SIGUSR2   This signal can be generated by the kill command

       For  those  previous  signals,  two  behavior exit. For SIGHUP, SIGINT,
       SIGQUIT, SIGTERM and SIGUSR1, a delayed termination is done: the backup
       or  isolation  operation  is  stopped, the catalogue is appended to the
       archive  and  the  archive  is  properly  completed  with  the  correct
       terminator string, this way the generated archive is usable, and can be
       used as reference for a differential backup at a later time. Note  that
       if  an on-fly isolation had been asked, it will *not* be performed, and
       no user command will be launched even if dar has  been  configured  for
       (-E option). For SIGUSR2 instead a fast termination is done: in case of
       backup or isolation, the archive is not completed at all,  only  memory
       and mutex are released properly.

       For  both  type  of  termination  and  other  operations than backup or
       isolation, dar’s behavior is the  same:  For  restoration,  all  opened
       directories  are  closed and permissions are set back to their original
       values (if they had  to  be  changed  for  restoration).  For  listing,
       comparison, testing, the program aborts immediately.

       Another  point, when using one of the previous signals, dar will return
       with the  exist  status  4  meaning  that  the  user  has  aborted  the
       operation.  Note  that  answering  "no" to a question from dar may also
       lead dar to exit this way. last, If before the end of the  program  the
       same signal is received a second time, dar will abort immediately.


       $HOME/.darrc  and  /etc/darrc  if  present  are  read for configuration
       option. They share the same syntax as  file  given  to  -B  option.  If
       $HOME/.darrc  is  not  present  and  only  in  that case, /etc/darrc is
       consulted.  You  can  still  launch  /etc/darrc  from  .darrc  using  a
       statement  like  -B /etc/darrc.  None of these file need to be present,
       but if they are they are parsed AFTER any option on  the  command  line
       and  AFTER  included files from the command line (files given to the -B
       option). NOTE: if $HOME is not defined $HOME/.darrc default to  /.darrc
       (at the root of the filesystem).

       Else  you  can  see conditional syntax bellow, and -N option above that
       leads dar to ignore the /etc/darrc and $HOME/.darrc files.


       configuration files (-B option, $HOME/.darrc  and  /etc/darrc)  usually
       contain  a  simple  list  of  command-line arguments, split or not over
       several lines, and eventually mixed with comments (see  -B  option  for
       more).  But, you can also use make-like targets to ask for a particular
       set of commands to be used in certain conditions.

       A condition takes the form of reserved word immediately followed  by  a
       colon  ’:’.  This word + colon must stand alone on its line, eventually
       with spaces or tabs beside it. The available conditions are:

       extract:            all option listed after this condition get used  if
                           previously  on  command  line or file the -x option
                           has been used

       create:             all option listed after this condition get used  if
                           previously  on command line or file (-B option) the
                           -c option has been used

       listing: (or list:) if -l option has been used

       test:               if -t option has been used

       diff:               if -d option has been used

       isolate:            if -C option has been used

       merge:              if -+ option has been used

       all:                in any case

       default:            if no -c, -d, -x, -t, -C, -l  or -+ option has been
                           used at this point of the parsing.

       The  condition stops when the next condition starts, or at End of File.
       The commands inserted before any  condition  are  equivalent  to  those
       inserted after the "all:" condition. Remark : -c -d -x -t -C and -l are
       mutual exclusive, only one of them can be used while calling dar.

       Here is an example of conditional syntax

                # upon creation exclude the
                # following files from compression
              -Z "*.mp3" -Z "*.mpg"


              # this will get read if not
              # command has been set yet
              # thus by default dar shows its version

              # for any command we also ask to be verbose
              # this is added to the previous all: condition

       Last point, you may have several time the same condition (several  all:
       ) for example. They will be concatenated together.


       You  can  find  some  more examples of use in the tutorial, mini-howto,
       sample  scripts,  and  other  related  documentation.  All  these   are
       available in dar’s source package, and are also installed beside dar in
       the  <--prefix>/share/dar  directory.  This   documentation   is   also
       available online at


       dar_xform(1), dar_slave(1), dar_manager(1), dar_cp(1)

       see also TUTORIAL and NOTES files in the documentation.


       dar  cannot  restore  time  of symbolic links. Many (all ?) UNIX do not
       provide any way to do that, the utime() system call  changes  the  file
       pointed to by the link rather than the date of the link itself.

       dar  saves and restores atime and mtime, but cannot restore ctime (last
       inode change), there does not seems to be a standard call  to  do  that
       under UNIX.

       Denis Corbin