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RedHat 9 (Linux i386) - man page for star (redhat section 1)

STAR(1) 			      Schily's USER COMMANDS				  STAR(1)

NAME
       star - unique standard tape archiver

SYNOPSIS
       star  command [ options ] file1 ... filen
       ustar command [ options ] file1 ... filen
       tar   command [ options ] file1 ... filen

DESCRIPTION
       Star is a very fast tar(1) like tape archiver with improved functionality.

       Star  archives  and extracts multiple files to and from a single file called a tarfile.	A
       tarfile is usually a magnetic tape, but it can be any file.  In all cases, appearance of a
       directory name refers to the files and (recursively) subdirectories of that directory.

       Star's actions are controlled by the mandatory command flags from the list below.  The way
       star acts may be modified by additional options.

FEATURES
       Star includes the first free implementation of  POSIX.1-2001  extended  tar  headers.  The
       extended  tar  headers  define  a new standard way for going beyond the limitations of the
       historic tar format.  They allow (among	others)  to  archive  all  UNIX  time  stamps  in
       sub-second  resolution,	files  of  arbitrary size and filenames without length limitation
       using UNICODE UTF-8 coding for best exchange compatibility.

       Star by default uses a fifo to optimize data flow from/to tape. This results in a normally
       streaming  tape	during	the whole backup.  See -fifo and fs= option to get information on
       how to find the best fifo size.

       Star includes a pattern matcher to control the list of files to be processed. This gives a
       convenient  interface  for  archiving and restoring complex lists of files. In conjunction
       with the -w flag it is easy to merge a tar archive into an existing file tree. See also -U
       option.	 In  create mode use the pat= option to specify either select or exclude patterns
       (depending on the -V flag). In extract or list mode all file  type  arguments  are  inter-
       preted as select patterns while the patterns specified with the pat= option may be used as
       select or exclude patterns (depending on the -V flag).  Have a look at the description  of
       the  -C	option to learn how fetch files from a list of directories (in create mode) or to
       distribute files to a list of directories (in extract mode).

       Star includes a sophisticated diff command. Several diff  options  allow  user  tailorable
       functionality.  Star won't show you differences you are not interested in.  Check the dif-
       fopts= option for more details.

       Star has no limitation  on  filename  length.  Pathnames  and  linknames  up  to  PATH_MAX
       (1023 bytes  with old OS versions and 4095 bytes with POSIX.1-2001) may be archived. Later
       versions may be able to deal with longer pathnames.

       Star deals with all 3 times, available for files on UNIX systems if the archive format  is
       either  chosen  from  the  star	specific  formats  or  is a format that uses POSIX.1-2001
       extended headers.  This is either done in second  resolution  by  using	a  star  specific
       POSIX.1-1988  compatible  extension  or	in  sub  second  resolution by using POSIX.1-2001
       extended headers.  Star is able to store and restore all 3 times (mtime,  atime	and  even
       ctime).	On  Solaris 2.x systems, star is able to do backups without changing any of the 3
       the times.

       If used with the H=ustar option, or if called as  ustar	or  tar  while	the  H=headertype
       option is not used, star is 100% POSIX compliant.

       Star's  default format (if called as star) is xstar and is as posix compliant as possible.
       Enhancements to the standard that prevent correct extraction of single files when using	a
       different  tar implementation that is only POSIX.1-1988 compliant may occur, but they only
       affect single files with a pathname that is longer than 100+130 chars  or  when	archiving
       sparse  files  with the -sparse option in effect.  All other files will extract correctly.
       See the description for the H=headertype option below for more information on archive for-
       mats and possible archive interchange problems.

       Star  makes  it	easy to repair corrupted filesystems. After a fsck -y has been run on the
       filesystem, star is able to restore only the missing files automatically.  Use  then  star
       -diff to check for differences (see EXAMPLES for more information).

       Star  automatically  recognizes the type of the archive.  Star therefore is able to handle
       features and properties of different archive types in their native mode, if it knows about
       the  peculiarities of the archive type.	See the H=headertype option for more details.  To
       be able to do this, star adds hidden fingerprints to the archive  header  that  allows  to
       recognise  all  star specific archive formats. The GNU tar format is recognised by the way
       it deviates from the standard.

       Star automatically recognizes and handles byte swapped archives. There  is  no  option  to
       manually control byte swapping.

       Star automatically recognizes and handles compressed archives inside plain files.

       Star  is  able  to  archive  and restore Access Control Lists for files using POSIX.1-2001
       extended headers.

COMMAND
       In native mode, star is compatible to the command line syntax of a typical  POSIX  command
       and  for this reason expects commands and options to start with a single dash (-). In this
       case, commands and options may be specified separately,	all  boolean  or  increment  type
       options	may  be specified either separately or combined.  For compatibility with GNU pro-
       grams, long options may alternatively start with a double dash.	In compatibility mode  to
       POSIX  tar, star expects commands and options to appear as one single string that does not
       start with a dash.  In POSIX tar compatibilitx mode, additional non POSIX options  may  be
       specified  but must appear after the POSIX options and their args and need to start with a
       dash.

       -c     Create a new tarfile and write named files into it.  Writing starts at  the  begin-
	      ning  of tarfile.  See -v option for information on how to increase verbosity while
	      the archive is written.

       -diff  Compare the content and the attributes of the files from the archive in tarfile  to
	      the filesystem.  This may also be used to compare two file trees in the filesystem.
	      If you use a set of diffopts that fits your needs, it will give - in many cases - a
	      more  readable  output than diff -r.  If you use star's dump extensions for the tar
	      archive, the -diff option allows to find even if the directory  in  the  file  tree
	      contains more files than the archive. This way, it is possible to compare all prop-
	      erties of two file trees in one run.  See diffopts for more details.

       -n     No extraction. Show what star would do, in case the -x command had been specified.

       -r     Replace files in a tarfile.  The named files are written to  the	end  of  tarfile.
	      This  implies that later, the appropriate files will be found more than once on the
	      tarfile.

       -t     Table of contents.  List the contents of the tarfile.  If the -v flag is used,  the
	      listing  is similar to the format of ls -l output.  With this option, the flags -a,
	      -atime and -ctime have a different meaning if the archive is in star,  xstar,  xus-
	      tar, exustar, or pax format.  The option -a or -atime lists the access time instead
	      of the modification time, the option -ctime lists the file creation time instead of
	      the modification time.

       -u     Update  a  tarfile.   The named files are written to the end of tarfile if they are
	      not already there or if the files are newer than the files of the same  name  found
	      in  the  archive.  The -r and -u command only work if the tar archives is a regular
	      file or if the tar archive is an unblocked tape that may backspace.

       -x     Extract the named files from the tarfile.  If no filename argument  or  pattern  is
	      specified,  the  entire  content of the tarfile is restored.  If the -U flag is not
	      used, star extracts no file which is older than the corresponding file on disk.

       Exactly one of the commands above must be specified.

       If one or more pattern are specified, they apply to any of the command listed above.

OPTIONS
       -help  Print a summary of the most important options for star(1).

       -xhelp Print a summary of the less important options for star(1).

       -/     Don't strip leading slashes from file names when extracting an  archive.	 Tar  ar-
	      chives containing absolute pathnames are usually a bad idea.  With other tar imple-
	      mentations, they may possibly never be extracted without clobbering existing files.
	      Star  for  that  reason,	by  default strips leading slashes from filenames when in
	      extract mode.  As it may be impossible to create an archive where  leading  slashes
	      have  been stripped while retaining correct path names, star does not strip leading
	      slashes in create mode.

       -acl   Handle Access Control List (ACL) information in create and extract mode.	 If  -acl
	      has  been  specified,  star  is in create mode and the header type is exustar, star
	      will add ACL information to the archive using POSIX.1-2001  extended  headers.   If
	      -acl  has  been specified and star is in extract mode, star will try to restore ACL
	      information. If there is no ACL information for one or all files	in  the  archive,
	      star  will  clear the ACL information for the specific file.  Note that if -acl has
	      not been specified, star will not handle ACL  information  at  all  and  files  may
	      inherit  ACL  information from the parent directories.  If the -acl option has been
	      specified, star assumes that the -p option has been specified too.

       -ask_remove
	      obsoleted by -ask-remove

       -ask-remove
	      Ask to remove non writable files on extraction.  By default, star  will  not  over-
	      write files that are read only.  If this option is in effect, star will ask whether
	      it should remove these files to allow the extraction of a  file  in  the	following
	      way:

		     remove 'filename' ? Y(es)/N(o) :

       -atime, -a
	      Reset  access  time  of  files  after storing them to tarfile.  On Solaris 2.x, (if
	      invoked by root) star uses the _FIOSATIME ioctl to do this. This enables	star  not
	      to trash the ctime while resetting the atime of the files.  If the -atime option is
	      used in conjunction with the list command, star lists access time instead of  modi-
	      fication	time. (This works only in conjunction with the star, xstar, xustar, exus-
	      tar, and with the pax format.)  Another option to retain the access  time  for  the
	      the  files that are going to be archives is to readonly mount a UFS snapshot and to
	      archive files from the mount point of the UFS snapshot.

       -B     Force star to perform multiple reads (if necessary) to fill a block.   This  option
	      exists  so  that	star can work across the Ethernet, since pipes and sockets return
	      partial blocks even when more data is coming.  If star uses stdin as archive  file,
	      star  behaves  as  if  it has been called with the -B option.  For this reason, the
	      option -B in practice is rarely needed.

       -block-number
	      Print the archive block number (archive offset / 512) at the beginning of each line
	      when  in verbose mode. This allows to write backup scripts that archive the offsets
	      for files and that use

		   mt fsr blockno

	      to skip to the tape block number of interest in a fast way if a single  file  needs
	      to be restored.

       blocks=#, b=#
	      Set  the	blocking  factor  of the tarfile to # times 512 bytes (unless a different
	      multiplication factor has been specified - see bs= option for  posible  multiplica-
	      tion  factors).	Changing the blocking factor only makes sense when the archive is
	      located on a real tape device or when the archive is accessed via the  remote  tape
	      protocol (see f= option below).  The default is to use a blocking factor of 20 i.e.
	      10 kBytes.  Increasing the blocksize will speed up  the  backup.	 For  portability
	      with  very old tar implementations (pre BSD 4.2 or pre AT&T SVR4), blocksize should
	      not be more than 10 kBytes.  For POSIX.1-1988 compatibility, blocksize should be no
	      more  than  10 kBytes.  For POSIX.1-2001 compatibility, blocksize should be no more
	      than 32 kBytes.  Most systems also have a hardware limitation  for  the  blocksize,
	      32 kBytes  and 63 kBytes are common limits on many systems.  The upper limit in any
	      case is the size of the buffer RAM in the tape drive.  Make a test if you  want  to
	      make  sure  that	the target system will handle the intended blocksize.  If you use
	      star for data exchange via tape, it is a good idea to use a blocksize of	10 kBytes
	      unless you are sure that the reading system will handle a larger blocksize.  If you
	      use star for backup purposes with recent hardware (e.g. DLT tape drives), a  block-
	      size of 256 kBytes results in sufficient speed and seems to be a good choice.  Star
	      allows block sizes up to 2 GByte if the system does not impose a smaller limit.  If
	      you  want  to  determine the blocking factor when reading an unknown tar archive on
	      tape, specify a blocking factor that is higher than the supposed blocking factor of
	      the tape.  Star then will determine the blocking factor by reading the first record
	      of the tape and print a message:

		     star: Blocksize = # records.

	      Where # is the blocking factor in multiples of 512 bytes.  The blocks=  option  and
	      the  bs= option are equivalent methods to specify the tape block size.  The blocks=
	      option is preferred by people who like to use an option that behaves similar to the
	      interface of the historic tar(1) implementations.

       bs=#   Set  output  block  size to #.  You may use the same method as in dd(1) and sdd(1).
	      The number representing the size is taken in bytes unless otherwise specified.   If
	      a  number  is followed directly by the letter `.', `w', `b', `k', `m', `g', `t', or
	      `p', the size  is  multiplied  by  1,  2,  512,  1024,  1024*1024,  1024*1024*1024,
	      1024*1024*1024*1024  or  1024*1024*1024*1024*1024.  If the size consists of numbers
	      separated by `x' or `*', multiplication of the  two  numbers  is	performed.   Thus
	      bs=7x8k will specify a blocksize of 56 kBytes.  Blocksize must be a multiple of 512
	      bytes.  See also the description of the blocks= option for more details  on  block-
	      sizes.   The  option  bs=  is  preferred	by  people who like to use an option that
	      behaves similar to the interface used by dd(1) and sdd(1).

       -bz    run the input or output through a bzip2 pipe - see option -z below.   As	both  the
	      -bz  and	the -z option are non standard, it makes sense to omit the -bz and the -z
	      inside shell scripts if you are going to	extract  a  compressed	archive  that  is
	      located  inside  a  plain  file as star will auto detect compression and choose the
	      right decompression option to extract.

       C=dir  Perform a chdir(2) operation to dir before storing or extracting	the  next  files.
	      In  all  cases,  star  will  perform the chdir(2) operation relative to the current
	      working directory of the shell.

	      o      In list mode (with the -t flag), star ignores all -C options.

	      o      In create mode (with the -c, -r and -u flag),  star  walks  through  all  -C
		     options  and file type arguments.	While a BSD derived tar(1) implementation
		     goes back to the current working directory after storing one  file  argument
		     that immediately follows the -C option, star changes the directory only if a
		     new -C option follows.  To emulate the behavior of a BSD derived tar(1), add
		     a -C .  option after the file argument.

	      o      In extract mode (with the -x, -n and -diff flag), star builds a pattern list
		     together with corresponding directories from previous C=dir options and per-
		     forms  a chdir(2) to the corresponding directory of a matching pattern.  All
		     pat= options that do not follow a C=dir option are interpreted  as  if  they
		     were preceded by a -C .  option.  See EXAMPLES for more information.

       -copylinks
	      This  option  allows to copy hard/symlinks targets rather than creating a link.  It
	      helps to extract tar files on systems that do not implement links (e.g. OS/2).   To
	      extract  and  copy  all symlinks correctly, you may need to call star twice as star
	      cannot copy files that appear in the archive later than a symlink pointing to them.

       -ctime If used with the list command, this lists ctime rather than mtime  if  the  archive
	      format  is  star, xstar, xustar, exustar, or pax.  If used with the extract command
	      and the same archive formats, this tries to restore even the ctime  of  a  file  by
	      generating  time	storms.   You  should not do this when in multi user mode because
	      this may confuse programs like cron and the news system.	If used with  the  create
	      command  this  changes  the behavior of the newer= option.  Star, in this case com-
	      pares the ctime of all files to the mtime of the stamp file rather  then	comparing
	      the mtimes of both files.

       -D     Do  not  descend directories.  Normally, star descends the whole tree if it encoun-
	      ters a directory in in its file parameters.  The option -D is in effect by  default
	      if  the list=file option is used.  If you like star to descend directories found in
	      the list file, use the -dodesc option (see below).

       -d     Do not store/create directories.	Old versions of tar such as  published	with  the
	      seventh  edition of UNIX are not able to deal with directories in tar archives.  If
	      a tar archive is generated without directories this avoids problems with tar imple-
	      mentations found on SYSVr3 and earlier.

       -debug Print debug messages. Among other things, this gives debug messages for header type
	      recognition, tar type properties, EOF recognition, opening of remote  archives  and
	      fifo internals.

       diffopts=optlst
	      Comma separated list of diffopts.  Valid members in optlst are:

	      help	Print a summary of possible members of the diffopts list.

	      ! 	Invert	the meaning of the following string. No comma is needed after the
			exclamation mark.

	      not	Invert the meaning of all members in the diffopts list i.e.  exclude  all
			present  options from an initially complete set compare list.  When using
			csh(1) you might have problems to use !  due to its strange parser.  This
			is why the not alias exists.

	      perm	Compare  file  permissions. With this option in effect, star compares the
			low order 12 bits of the st_mode field.

	      mode	Same as perm.

	      type	Compare file type.  Note that star cannot compare the file type  in  case
			of a hard link.

	      nlink	Compare  link  count  on hardlinks.  This only works if the archive is in
			exustar format and contains star's dump extensions.

	      uid	Compare numerical user id of file.

	      gid	Compare numerical group id of file.

	      uname	Compare ASCII version of user id of file.  The user name  is  mapped  via
			the file /etc/passwd.

	      gname	Compare  ASCII version of group id of file.  The group name is mapped via
			the file /etc/group.

	      id	Shorthand for: uid,gid,uname,gname.  Compare all user/group related  info
			of  file.   Note that this will always find differences if the source and
			target system use different user or group mappings.

	      size	Compare file size.  Note that star cannot compare the file size  in  case
			of a hard link.

	      data	Compare  content  of  file.   If  star already found that the size of the
			files differ, it will not compare the content anymore.

	      cont	Same as data.

	      rdev	Compare major/minor numbers for device nodes.

	      hardlink	Compare target of hardlinks.

	      symlink	Compare target of symlinks. This evaluates  the  value	returned  by  the
			readlink(2) call.

	      atime	Compare  access time of file.  This only works with if the archive format
			is star, xstar, xustar, exustar, or pax.

	      mtime	Compare modification time of file.

	      ctime	This only works with if the archive format is star, xstar, xustar,  exus-
			tar, or pax.

	      times	Shorthand for: atime,mtime,ctime.

	      dir	Compare the content of directories.  This only works if the archive is in
			exustar format	and  contains  star's  dump  extensions.   Together  with
			increased  verbose  level  (-vv) this will print a list of files that are
			only in the archive and a list of files that  are  only  on  the  current
			filesystem.

	      If  optlst starts with a ! the meaning of all members in optlst is inverted as with
	      the not optlist member.

	      If diffopts are not specified, star compares everything but the access time of  the
	      files.

       -dirmode
	      If  in  create  mode  (i.e. when storing files to archive), star stores directories
	      past the corresponding files. This guarantees that  even	old  tar  implementations
	      without a directory cache will be able to restore the correct times of directories.

       -dodesc
	      Force  star  to  descend	directories found in a list=file.  See also the -D option
	      above.

       -dump  This currently is an experimental option to make it easier to implement a star ver-
	      sion that supports true incremental dumps.  Star currently sets the archive type to
	      exustar and archives more inode meta data inside POSIX.1-2001 extended headers.

       -F,-FF ...
	      Fast and simple exclude option for create mode.  With one -F argument, star ignores
	      all  directories	called	SCCS  and  RCS.   With two -F arguments, star in addition
	      ignores all files called core errs a.out all files ending  with  .o.   OBJ/.   With
	      three  -F  arguments,  star  ignores  all  sub trees starting from a directory that
	      includes a file .mirror or .exclude and all object files and files called core errs
	      a.out all files ending with .o.  With four -F arguments, star ignores all sub trees
	      starting from a directory that includes a file .mirror or .exclude the latter files
	      are  excluded  too as well as and all object files and files called core errs a.out
	      all files ending with .o.  With five -F arguments, star in addition again  excludes
	      all directories called SCCS and RCS.

       -fifo  Use  a  fifo  to	optimize  data flow from/to tarfile.  This option is in effect by
	      default (it may be changed at compile time).  The default fifo size is 8 MBytes  on
	      all  platforms  except Linux versions that do not support mmap() (4 MB because ker-
	      nels before 2.4 did not handle big shared memory areas)  and  Sun/mc68000  (1  MB).
	      This  will star make even work on a tiny machine like a Sun 3/50. The fifo size may
	      be modified with the fs= option. A rule of dumb for the fifo size is  to	use  more
	      than the buffer size of the tape drive and less then half of the real memory of the
	      machine.	A good choice would be to use a fifo size between 8 and 256 MB.  This may
	      increase backup speed up to 5% compared to the speed achieved with the default fifo
	      size. Note that with a DLT drive that gives 12MB/s transfer rate, a fifo of 256  MB
	      size  will  keep	the  tape at least streaming in units of 20 seconds.  All options
	      that start with the -f sequence are sensitive to typo problems,  see  BUGS  section
	      for more information.

       -fifostats
	      Print  fifo  statistics  at the end of a star run when the fifo has been in effect.
	      All options that start with the -f sequence are sensitive  to  typo  problems,  see
	      BUGS section for more information.

       file=tarfilename, f=tarfilename
	      Use  tarfilename as the name for the tar archive. Currently up to 100 file= options
	      are possible. Specifying more then one file= option  make  sense	in  multi  volume
	      mode.  In  this  case  star  will  use the next name in the list every time a media
	      change is needed.  To make star behave consistent with the single file  case,  star
	      loops  over  the	list of known archive files.  Note that if star is installed suid
	      root and the first tarfile is a remote archive, only the connection to this archive
	      will  be created with root privilleges.  After this connection has been established
	      as root, star switches back to the id of the caller.  If any of the other  archives
	      in  the list is located on a different host, star will not be able to open this ar-
	      chive later on, unless run by root.

	      Star normally uses stdin/stdout for the tar archive because the most common way  to
	      use star is in conjunction with pipes.  If star is installed suid root or if it has
	      been called by root, tarfilename may be in remote syntax: user@host:filename as  in
	      rcp(1) even if invoked by non root users.  See SUID NOTES for more information.

	      To  make	a  file  local	although it includes a colon (:), the filename must start
	      with: '/', './' or '../'

	      Note that if star talks to an old rmt remote tape server that does not support sym-
	      bolic open modes, it does not open a remote tape with the O_CREAT open flag because
	      this would be extremely dangerous.  If the rmt server on the other side is the  rmt
	      server  that  comes with star or the GNU rmt server, star may use the symbolic mode
	      for the open flags.  Only the symbolic open modes allow to send all  possible  open
	      modes in a portable way to remote tape servers.

	      It  is  recommended to use the rmt server that comes with star.  It is the only rmt
	      server that gives platform independent compatibility with  BSD,  Sun  and  GNU  rmt
	      clients  and  it includes security features that may be set up in /etc/default/rmt.
	      All options that start with the -f sequence are sensitive  to  typo  problems,  see
	      BUGS section for more information.

       -force_hole
	      obsoleted by -force-hole

       -force-hole
	      Try  to  extract	all files with holes. This even works with files that are created
	      without the -sparse option.  Star, in this case examines the content of  the  files
	      in  the  archive	and replaces writes to parts containing binary zeroes with seeks.
	      This option should be used with extreme care because you sometimes get  in  trouble
	      when  files  get unattended holes.  All options that start with the -f sequence are
	      sensitive to typo problems, see BUGS section for more information.

       -force_remove
	      obsoleted by -force-remove

       -force-remove
	      Force to remove non writable files on extraction.  By default, star will not  over-
	      write  files  that  are read only.  If this option is in effect, star will silently
	      remove these files to allow the extraction of a file.  All options that start  with
	      the  -f sequence are sensitive to typo problems, see BUGS section for more informa-
	      tion.

       fs=#   Set fifo size to #.  See bs= for the possible syntax.  The default size of the fifo
	      is 1 Mbyte on Sun mc68000 systems, 4 Mbytes on non mmap() aware Linux systems and 8
	      Mbytes on all other systems.  See -fifo option for hints on using  the  right  fifo
	      size.

       H=headertype
	      Generate	a  tape  archive  in  headertype  format.   If	this  option  is  used in
	      extract/list mode this forces star to interpret the headers to be of  type  header-
	      type.   As  star even in case of a user selected extract archive format does format
	      checking, it may be that you will not be able to unpack a specific archive with all
	      possible	forced	archive formats. Selecting the old tar format for extraction will
	      always work though.  Valid parameter for headertype are:

	      help	Print a help message about possible header types.

	      tar	Old UNIX tar format.  This archive format may  only  store  plain  files,
			directories  and  symbolic  links.  Pathnames or linknames longer than 99
			chars may not be archived.  See also the -d option as a note to some even
			older tar implementations.

			If  the  tar  format has been selected, star will not use enhancements to
			the historic tar format.  File size is limited to 2 GB - 2 bytes, uid/gid
			is limited to 262143.  Sparse files will be filled up with zeroes.

	      star	Old  star standard format. This is an upward/downward compatible enhance-
			ment of the old (pre Posix) UNIX tar format.  It has been  introduced  in
			1985 and therefore is not Posix compliant.  The star format allows to ar-
			chive special files (even sockets) and records access time  and  creation
			time besides the modification time. Newer versions of the old star format
			allow very long filenames (100+155 chars  and  above),	linknames  >  100
			chars  and sparse files.  This format is able to copy the device nodes on
			HP-UX that have 24 bits in the minor device number, which  is  more  then
			the 21 bits that are possible with the POSIX-1003.1-1988 archive format.

	      gnutar	This  is a commonly used, but unfortunately not Posix compliant (although
			designed after 1987) enhancement to the old tar format.  Do not  use  the
			gnutar	archive  format unless you want to create an archive for a target
			system that is known to have only the gnutar program available.  The gnu-
			tar  archive  format violates basic rules for any (even the historic) tar
			archive format.  Using the gnutar archive format causes a high risk  that
			the  resulting archive may only be read by gnutar or by star.  The imple-
			mentation of the gnutar archive format within star is not  complete,  but
			sufficient for most gnutar archives.  See NOTES for more information.

	      ustar	IEEE/Posix1003/IEC-9945-1-1988	Standard  Data	Interchange format.  With
			this option in effect, star will generate 100% POSIX.1-1988 compliant tar
			archives.   Files  with  pathnames longer than 100+155 chars or linknames
			longer than 100 chars may not be archived.  If star is	called	as  ustar
			the default archive format is ustar.

			If  the ustar format has been selected, star will not use enhancements to
			the POSIX.1-1988 tar format, the archive  will	be  strictly  conforming.
			File  size is limited to 8 GB, uid/gid/major/minor is limited to 2097151.
			Sparse files will be filled up with zeroes.

	      pax	The IEEE/Posix1003/IEC-9945-1-1988 successor, the POSIX-1003.1-2001 Stan-
			dard Data Interchange format.

			If  the  pax  format has been selected, star will not use enhancements to
			the POSIX.1-2001 tar format, the archive  will	be  strictly  conforming.
			File  size  is unlimited, uid/gid/uname/gidname is unlimited, major/minor
			is limited to 2097151.	Sparse files will be filled up with zeroes.

	      xstar	Extended standard tar format.  Star uses the xstar format as default  ar-
			chive  format.	 This is an upward/downward compatible enhancement of the
			IEEE/Posix1003/IEC-9945-1 Standard Data Interchange  format.   It  allows
			among  others  very  long filenames (100+130 chars and above) and records
			access time and creation time.	The xstar format is  the  default  format
			when star is neither called as tar nor called as ustar.

	      xustar	New  format  introduced  1998, that omits the tar signature at the end of
			the tar header. It is otherwise identical to the xstar format.	 As  some
			tar  implementations do not follow the POSIX rules and compute the check-
			sum for less than 512 bytes of the tar header, this format  may  help  to
			avoid problems with these tar implementations.	The main other difference
			to the xstar format is that the format uses POSIX.1-2001 extended headers
			to overcome limitations of the historic tar format while the xstar format
			uses proprietary extensions.  The xustar format  is  the  default  format
			when star is called as tar.

			File  size  is unlimited, uid/gid/uname/gidname is unlimited, major/minor
			is unlimited.  Sparse files will be archived correctly.

	      exustar	A format similar to  the  xustar  format  but  with  forced  POSIX.1-2001
			extended  headers.  If this format is used together with the -acl option,
			star records Access Control Lists (ACLs) in POSIX.1-2001  extended  head-
			ers.

			File  size  is unlimited, uid/gid/uname/gidname is unlimited, major/minor
			is unlimited.  Sparse files will be archived correctly.

	      suntar	The extended header format found on Solaris 7/8. This format  is  similar
			to  the  pax  format  but does not handle atime and ctime and in addition
			uses 'X' as the typeflag for the extended headers instead of the standard
			'x'.

			File  size  is unlimited, uid/gid/uname/gidname is unlimited, major/minor
			is unlimited.  Sparse files will be filled up with zeroes.

	      All tar archive formats may be interchanged if the archive contains no  files  that
	      may  not be archived by using the old tar format.  Archives in the xstar format may
	      be extracted by any 100% POSIX compliant tar  implementation  if	they  contain  no
	      files  with pathnames > 100+130 chars and if they contain no sparse files that have
	      been archived by using the -sparse option.

       -h, -L Follow symbolic links as if they were files.  Normally star will	not  follow  sym-
	      bolic links but stores their values in tarfile.  See also the -L option.

       -hardlinks
	      In extract mode, this option tells star to try to create a hardlink whenever a sym-
	      link is encountered in the archive.  In create mode, this option tells star to  try
	      to archive a hardlink whenever a symlink is encountered in the file system.

       -hpdev Allow 24 bits for the minor device number using 8 octal digits.  Note that although
	      it allows to create tar archives that can be read with HP-UX tar, this creates  tar
	      archives which violate POSIX.1-1988.  This option is only needed if you like to use
	      a POSIX.1-1988 based archive format that does not include extensions.  If  you  use
	      the xstar format, star will use a base 256 extension that allows bigger major/minor
	      numbers by default, if you use the xustar or the exustar format there is no limita-
	      tion  at	all  as  these	formats  use POSIX.1-2001 extended headers to archive the
	      major/minor numbers by default.

       -i     Ignore checksum errors on tar headers.  If this option is specified, star will  not
	      exit if a header with a bad checksum is found but search for the next valid header.

       -I     Obsolete option, otherwise identical to -w.

       -keep_old_files
	      obsoleted by -keep-old-files

       -keep-old-files, -k
	      Keep existing files rather than restoring them from tarfile.  This saves files from
	      being clobbered even if tarfile contains a more recent version of the corresponding
	      file.

       -L, -h Follow  symbolic	links  as if they were files.  Normally star will not follow sym-
	      bolic links but stores their values in tarfile.  See also the -h option.

       -l     Do not print a warning message if not all links  to  hard  linked  files	could  be
	      dumped. This option is evaluated in the opposite way to historic tar(1) implementa-
	      tions and to POSIX.1.  POSIX.1 requests that by default no warning messages will be
	      printed and -l will enable warning messages when not all links could be archived.

       -link-dirs
	      When  in	create	mode, try to find hard linked directories.  Using -link-dirs will
	      force star to keep track of all directories that will go into the archive and  thus
	      causes a lot more memory to be allocated than in the default case.

	      Note  that not all filesystem allow to create hard links to directories.	Also note
	      that even though a non-root user is able detect and archive  hard  linked  directo-
	      ries,  all  known  operating  systems  require the extraction to be done as root in
	      order to be able to create or remove hard links to directories.	For  this  reason
	      its  only  recommended to use this option when doing accurate backups and when hard
	      links to directories are expected.

	      When the option -link-dirs is not used and hard links to directories  are  present,
	      the  appendant  sub-tree	will  appear  more than once on the archive and star will
	      print Linkcount below zero warnings for non directory hard links	inside	the  sub-
	      tree.

       list=filename
	      Read filenames for store/create/list command from filename.  The file filename must
	      contain a list of filenames, each on a separate line.  This option implies  the  -D
	      option.  To force star to descend directories, use the -dodesc option in this case.

       -lowmem
	      Try  to  run with reduced memory requirements.  This causes star to default to 1 MB
	      of FIFO memory.  Instead of allocating memory to hold  the  directory  content  and
	      reading  the  directory  at  once,  star reads the directory name by name. This may
	      cause star to close the directory if it rans out of  file  descriptors  because  of
	      deeply	nested	  directories.	 If   a   directory   then   does   not   support
	      telldir(3)/seekdir(3), star will fail.

       -M     Do not descend mount points.   This  is  useful  when  doing  backups  of  complete
	      filesystems.  See NOTES for more information.

       -m     Do not restore access an modification time.  (Access time is only available if star
	      is reading star, xstar, xustar, exustar, or pax archives). If star  extracts  other
	      archive types, the -m flag only refers to the modification time.

       maxsize=#
	      Do  not store files in tarfile if they are bigger than #.  See bs= for the possible
	      syntax.  By default, the number is multiplied by 1024, so the value counts in units
	      of  kBytes.   If the size specifier ends with a valid multiplication character (e.g
	      '.' for bytes or 'M' for MB) the specified size is used as specified and not multi-
	      plied by 1024.  See bs= option for all possible multipliers.

       -meta  This currently is an experimental option. In create mode, it causes star to archive
	      all meta data of the file (e.g. uid, permissions, ...) bit not the file content. In
	      extract  mode, it causes star to restore all meta data but not the file content. In
	      addition, in extract mode no plain file, special file or directory will be created.
	      Meta files are needed in future star versions that support incremental backups.

	      Warning:	Do not try to extract star archives containing meta files using other tar
	      implementations if they are not aware of the meta file extensions  of  star.   Star
	      tries  to  force	all tar implementations that are not standard compliant to abort.
	      Star also tries to make all non POSIX.1-2001 compliant tar  implementations  unable
	      to find a valid filename. However when other POSIX.1-2001 aware tar implementations
	      come up and don't know about meta files, they will destroy files on disk.

	      The problems result from the only current fallback in the POSIX standard that tells
	      tar implementations to treat all unknown file types as if they were plain files. As
	      meta files are needed for incremental backups, I am looking for people  and  compa-
	      nies  who  like  to  support  me	to  be	able  to add the meta file concept to the
	      POSIX.1-2005 standard.

       -modebits
	      This options allows you to create tar archives that include more than 12 bits  from
	      st_mode.	Note this create tar archives that violate POSIX but some tar implementa-
	      tions insist in reading such nonstandard archives.

       newer=filename
	      Do not store files to tarfile if their modification time is not newer than the mod-
	      ification time of filename.  See -ctime option for changing this behavior.

       -newest
	      In  conjunction  with  the  list	command  this  lists  you only the newest file in
	      tarfile.

       -newest_file
	      obsoleted by -newest-file

       -newest-file
	      In conjunction with the list command this lists you only the newest regular file in
	      tarfile.

       new-volume-script=script
	      Call  script at end of each tape if in multi volume mode.  If this option is not in
	      effect, star will ask the user to confirm the volume change.

       -nodump
	      If this option is set, star will not dump files that have the nodump flag set. Note
	      that  this currently only works on BSD-4.4 derivates and on Linux.  On Linux, using
	      this option will cause a performance degradation (the system time increases by 10%)
	      because of the unlucky kernel interface.

       -no_fifo
	      obsoleted by -no-fifo

       -no-fifo
	      Don't use a fifo to optimize data flow from/to tarfile.  Currently the -fifo option
	      is used as default. (This may be changed at compile time.)

       -nochown, -o
	      Do not restore owner and group of files.	This may be used if super user privileges
	      are  needed  to  overwrite  existing  files but the local ownership of the existing
	      files should not change.

       -no_statistics
	      obsoleted by -no-statistics

       -no-statistics
	      Do not print statistic messages at the end of a star run.

       -not, -V
	      Invert the meaning of the pattern list. i.e. use those files which do not match any
	      of  the  pattern.   Note	that  this option only applies to patterns that have been
	      specified via the pattern=pattern or pat=pattern option. Patterns specified as file
	      type arguments will not be affected.

       -nowarn
	      Do  not  print  warning messages.  This sometimes is useful to make the output more
	      readable (e.g. when hundreds of files that are going to be extracted are not  newer
	      in the archive then on the filesystem).

       -numeric
	      Use  the	numeric  user/group  fields  in the listing rather than the default.  The
	      default allows to list the ASCII version of user/group of the file and  to  extract
	      the  owners  of the files based on numeric values rather than the names.	In create
	      mode, no user/groups names are put  on  the  archive.   The  -numeric  option  also
	      applies when ACLs are going to be archived or extracted.

       -O     Be  compatible  to  old versions of tar.	If star is invoked with this option, star
	      generates archives which are fully compatible with old UNIX  tar	archives.  If  in
	      extract  mode,  star ignores any additional info in the headers.	This implies nei-
	      ther that archives generated with this option are binary equal with archives gener-
	      ated  by	old  tar versions nor that star is trying to comprehend all bugs that are
	      found in old tar versions.  The bug in old tar versions that cause a reversal of	a
	      space  and  a NULL byte in the checksum field is not repeated.  If you want to have
	      signed checksums you have to specify the -singed-checksum option too.  If you  want
	      directories  not	to be archived in order to be compatible to very old historic tar
	      archives, you need to specify the -d option too.

	      This option is superseeded by the H=headertype option.

       -o, -nochown
	      Do not restore owner and group of files.	This may be used if super user privileges
	      are  needed  to  overwrite  existing  files but the local ownership of the existing
	      files should not change.

       -onull, -nullout
	      Do not actually write to the archive but compute and add the sizes.  This is useful
	      when  trying  to figure out if a tape may hold the current backup.  Please only use
	      the -onull option as it is a similar option as used by the sdd(1) command.

       -P     Allow star to write a partial record as the last	record.   Normally,  star  writes
	      each record with the same size.  This option is useful on unblocked tapes i.e. car-
	      tridge tapes like QIC tapes as well as with archives that are located in files.  If
	      you  use	this  option on local files, the size of the archive will be smaller.  If
	      you use this option on cartridge tapes, is makes sure that later - in extract  mode
	      - star will read up to the end of file marker on the tape and the next call to star
	      will read from the next archive on the same tape.

       -p     Restore filemodes of directories. Without this option directories are created using
	      the present umask(2).  If in create mode (i.e. when storing files to archive), star
	      stores directories past the corresponding files. This guarantees that even old  tar
	      implementations  will  be able to restore the correct times of directories.  If the
	      archive contains Access Control Lists (ACLs) in POSIX.1-2001 extended headers, star
	      will restore the access control lists from the archive for files if the -acl option
	      is specified.  If the option -acl has not been specified, ACLs are not restored  at
	      all.

       pattern=pattern, pat=pattern
	      Set matching pattern to pattern.	A maximum of 100 pattern=pat options may be spec-
	      ified.  As each pattern is unlimited in length, this is  no  real  limitation.   If
	      more  than one pattern is specified, a file matches if any of the specified pattern
	      matches.	Patterns may be used in create mode to select or exclude files	from  the
	      list of file type arguments or the files located in a sub tree of a file type argu-
	      ment directory.  In extract or list mode, all file type arguments  are  interpreted
	      to  be  select pattern and all option type patterns may be either select or exclude
	      patterns depending on the presence or absence of the -not option.  If you use  file
	      type  select patterns, they work exactly like the method used by other (non pattern
	      aware) tar(1) implementations.  File type select	patterns  do  not  offer  pattern
	      matching	but  allow  to restore subtrees.  To extract a complete sub tree from the
	      directory dir with star using the pattern= option, use pattern= dir/\* if you  like
	      to  select  a subtree by using the historic method, use dir/ as file type argument.
	      See manual page for match(1) for more details of the pattern matcher.  All patterns
	      are  selection  patterns by default. To make them exclude patterns, use the -not or
	      the -V option.

       -qic24 Set tape volume size to 61440 kBytes.  See tsize=# option for more information.

       -qic120
	      Set tape volume size to 128000 kBytes.  See tsize=# option for more information.

       -qic150
	      Set tape volume size to 153600 kBytes.  See tsize=# option for more information.

       -qic250
	      Set tape volume size to 256000 kBytes.  See tsize=# option for more information.

       -refresh_old_files
	      obsoleted by -refresh-old-files

       -refresh-old-files

       -refresh
	      Do not create new files. Only  already  existing	files  may  be	overwritten  from
	      tarfile  if  either  newer versions are present in the archive or if the -U flag is
	      used.  This allows to overwrite files by more recent files  from	an  archive  that
	      contains	more  files  than  the	target	directory  should  contain.   The  option
	      -refresh-old-files is the same as the -refresh option.

       -remove_first
	      obsoleted by -remove-first

       -remove-first
	      Remove files before extraction.  If this option is  in  effect,  star  will  remove
	      files  before  extracting  a  file from the archive.  This is needed if you want to
	      change the file type or if you need to break a hard link.  If you do not use either
	      -ask-remove  or  -force-remove  together with -remove-first, this option is useless
	      and no files will be removed.

       -remove_recursive
	      obsoleted by -remove-recursive

       -remove-recursive
	      Remove files recursive.  If removing of a file is permitted, star will only  remove
	      files,  specials	and empty directories.	If this option is in effect, star will be
	      allowed to recursively removes non empty directories too.

       -S     Do not store/create special files.  A special files is any file except plain files,
	      symbolic	links  and  directories.   You	need  to be super user to extract special
	      files.

       -shm   Use System V shared memory for fifo.  Normally  star  is	compiled  to  use  mapped
	      /dev/zero  pages	for  the fifo, if the operating system supports this.  If star is
	      compiled to have both code for mapped pages and for System V  shared  memory,  star
	      will  use shared memory instead of the default.  If the -help menu doesn't show the
	      -shm flag you have no choice.  When using System V shared memory, you may  have  to
	      raise  the system's internal limit for shared memory resources to get enough shared
	      memory for star.

       -signed_checksum
	      obsoleted by -signed-checksum

       -signed-checksum
	      Use signed chars to calculate checksums. This violates the tar specs but	old  ver-
	      sions  of tar derived from the seventh edition of UNIX are implemented in this way.
	      Note: Only filenames and linknames containing chars with the most  significant  bit
	      set  may	trigger  this  problem	because all other fields only contain 7 bit ASCII
	      characters, octal digits or binary zeroes.

       -silent
	      Suppress informational messages like foobar is sparse.

       -sparse
	      Handle files with holes effectively on store/create.  Note that  sparse  files  may
	      not  be  archived this way if the archive format is tar, ustar, pax, or suntar.  On
	      Solaris-2.3 ... Solaris-2.5.1 there is a special ioctl() called _FIOAI that  allows
	      root  to	get  the  allocation info more efficiently.  Other operating systems lack
	      support to get the real allocation list and force star to scan the  files  to  look
	      for  blocks  that only contain null characters.  This may star to assume more holes
	      to be present than the number that the file really contains.

       -symlinks
	      This option tells star in extract mode to  try  to  create  a  symlink  whenever	a
	      hardlink is encountered in the archive.

       -T     If  the  option  file= or f= is omitted and the -T option is present, star will use
	      the device indicated by the TAPE environment variable, if set.

       -time  Print timing info.  See DIAGNOSTICS for more information.

       -to_stdout
	      obsoleted by -to-stdout

       -to-stdout
	      Extract files to stdout. This option may be used	to  extract  tarfiles  containing
	      tarfiles (see examples below).

       -tpath Use  this option together with the -t option to get only a list of the pathnames of
	      the files in the archive.  This may be used in shell scripts  to	generate  a  name
	      list.   If  used	together with the -diff option, star will only print the names of
	      the files that differ.  A second run of star may then be used to restore all  files
	      that  had differences to the archive.  Use the list= option to specify the namelist
	      in this case.

       tsize=#
	      Set tape volume size to # to enable multi volume tape support.   See  bs=  for  the
	      possible	syntax.  By default, the number is multiplied by 512, so the value counts
	      in units of 512 byte blocks.  If the size specifier ends with a  valid  multiplica-
	      tion  character  (e.g  '.'  for  bytes or 'M' for MB) the specified size is used as
	      specified and not multiplied by 512.  With this option in effect, star is  able  to
	      archive filesystems that are bigger then the tape size.  Files that do not fit on a
	      single tape may not be stored with the current version of star.

       -U     Restore files unconditionally.  By default, an older file from the archive will not
	      replace a corresponding newer file on disk.

       -v     Increment verbose level by one.  This normally results in more output during opera-
	      tion.  See also in the description for the -t flag.  Normally, star does	its  work
	      silently.   If the verbose level is 2 or more and star is in create or update mode,
	      star will produce a listing to the format of the ls -l output.

       -V, -not
	      Invert the meaning of the pattern list. i.e. use those files which do not match any
	      of  the  pattern.   Note	that  this option only applies to patterns that have been
	      specified via the pattern=pattern or pat=pattern option. Patterns specified as file
	      type arguments will not be affected.

       -version
	      Print version information and exit.

       VOLHDR=name
	      Use name to generate a volume header.

       -w     Do  interactive  creation, extraction or renaming.  For every file that matches the
	      list of patterns and that has a more recent modification time in	the  tar  archive
	      (if  in  extract	mode and the -U option is not specified) star prints its name and
	      asks:

		     get/put ? Y(es)/N(o)/C(hange name) :

	      You may answer either `N' for No or <Return> to skip this file.  If you answer  `Y'
	      the  file  is  extracted or archived on tape with its original name.  If you answer
	      `C', you are prompted for a new name. This name is used for the filename on disk if
	      star is in extract mode or for the archive name if star is in create mode.

       Star   waits  up  to one minute for the drive to become ready if this option is specified.
	      -wready This option tells Star waits up to two minutes  for  the	drive  to  become
	      ready.   It  has	been  added  as  a  hack for a bug in the SunOS/Solaris st device
	      driver. This driver has problems to sense the loading time with Exabyte drives with
	      factory  settings.   It  also makes sense to use -wready if multiple remote backups
	      are made. In this case, the remote connection  is  closed  while	the  remote  tape
	      server  is still writing a file mark.  If another remote backup is initiated before
	      the old remote server did finish to write the file mark, it would be impossible  to
	      open the tape driver unless -wready is specified to tell star to wait for the drive
	      to become ready again.

       -xdir  Extract directories even if the corresponding directories on the	archive  are  not
	      newer.   This  is  useful  when for some reason, the directories are recorded after
	      their content (see -dirmode option), or when the permissions  of	some  directories
	      must be set in any case.

       -xfflags
	      Store  and  extract  extended  file  flags as found on BSD and Linux systems.  This
	      option only makes sense when creating or extracting exustar archives as it is based
	      on POSIX.1-2001 extended tar headers.

       -z     run  the	input or output through a gzip pipe.  This is currently a quick and dirty
	      hack, that mainly will cover the most common usage to compress the tar output if it
	      is  a  file.   No  reblocking will be done, so this option will currently only make
	      sense on plain files.  The environment variable As both the -bz and the  -z  option
	      are non standard, it makes sense to omit the -bz and the -z inside shell scripts if
	      you are going to extract a compressed archive that is located inside a  plain  file
	      as  star	will auto detect compression and choose the right decompression option to
	      extract.	STAR_COMPRESS_FLAG may be used to specify one option for  gzip.   If  you
	      want to write write compressed archives to tape, you should use
	      star -c . | gzip | sdd ibs=4k obs=32k -fill of=/dev/rmt/1bn
	      or
	      star -c . | gzip | sdd ibs=4k obs=32k -fill ovsize=60m of=/dev/rmt/1bn
	      if the tape can hold 60 MB.

SIGNALS
       If star handles a signal, it first prints the statistics.  Star handles the following sig-
       nals:

       SIGINT	 usually generated by ^C from the controlling tty.  Upon  receipt  of  a  SIGINT,
		 star  prints  statistics and exits.  If in create mode i.e. storing files to ar-
		 chive, star finishes with the current file to ensure that  no	partial  file  is
		 written to the archive, write an eof record and then exits.

       SIGHUP	 not  to  be  generated from a tty. The actions are the same as upon receipt of a
		 SIGINT.

       SIGQUIT	 usually generated by ^\ from the controlling tty.  Upon receipt  of  a  SIGQUIT,
		 star  prints statistics and continues with the current operation. This is useful
		 to watch the progress of the current operation.

EXAMPLES
       To get a listing in a way similar to ls -l one might use:

	      example% star -tv f=/dev/rmt/1bn

       The same command as listed above in a POSIX tar command line syntax compliant way is:

	      example% star tvf /dev/rmt/1mbn

       To copy the directory tree in /home/someuser to the directory /home/fs use:

	      example% (cd /home/someuser; star -c .) | (cd /home/fs ; star -xp)

       or by using the change directory option of star:

	      example% star -c -C /home/someuser . | star -xp -C /home/fs

       To copy a file tree including the Access Control List entries for all files use:

	      example% star -c -Hexustar -acl -C /home/someuser . | star -xp -acl -C /home/fs

       To compare the content of a tape to the filesystem one might use:

	      example% star -diff -v f=/dev/rmt/1bn

       To compare two directory trees one might use:

	      example% star -c . | star -C todir -diff -v diffopts=!times

       To compare all properties of two file trees, use:

	      example% star -c -dump -C fromdir . | star -C todir -diff -vv

       To extract a backup of the /usr tree without all files  residing  below	/usr/openwin  one
       might use:

	      example% star -xp -V pat=openwin/\* f=/dev/rmt/1bn

       To  extract all .c files to src, all .o files to obj and all other files to /tmp one might
       use:

	      example% star -xp -C src '*.c' -C obj '*.o' -C /tmp '*' f=/dev/rmt/1bn

       To extract files from a zipped tar archive that is located on a read only filesystem  e.g.
       a CD while having the shell's working directory on the CD one might use:

	      example% star -zxp -C /tmp f=star-1.1.tar.gz

       to extract the files from the tar archive to the /tmp directory.

       To backup a list of files generated by the find(1) command:

	      example% find . find_options -print | star -c list=- f=/dev/rmt/1bn

       Note that this does not work if the file names from output of the find command include new
       line characters.

       To extract a tarfile that contains a tarfile one might use:

	      example% star -x -to-stdout f=/dev/rmt/1bn pat=pat | star -xp

       Pat, in this case should match  the  tarfile  in  the  tarfile  on  tape  that  should  be
       extracted.

       To make a backup of the root filesystem to a tape drive connected to a remote machine, one
       might use:

	      example# cd /
	      example# star -cM fs=128m bs=63k f=tape@remotehost:/dev/rmt/1bn .

       You need a line in /etc/passwd like the following to enable this:

	      tape:NP:60001:60001:Tape:/etc/tapehome:/opt/schily/sbin/rmt

       And a .rhosts file in /etc/tapehome to  allow  remote  connections  from  the  appropriate
       hosts.	Make  sure  that the file /etc/default/rmt exists and allows remote access to the
       requested tape drive.

       To repair a corrupted filesystem for which no recent backup exists, do the following:

	      example# fsck -y /filesys
	      example# mount /filesys
	      example# cd /filesys
	      example# star -xpk f=/dev/rmt/1bn
	      example# mt -f /dev/rmt/1bn rewind
	      example# star -diff -v diffopts=!times f=/dev/rmt/1bn

       Now check the differences and decide whether to restore additional files. This may be done
       by  generating  a  list	containing  the needed filenames and using the list= option or by
       using the interactive mode (see -w option).

       If you want a list that only contains all filenames from files with  differences  you  may
       use:

	      example# star -diff -tpath diffopts=!times f=/dev/rmt/1bn

       If  you	are looking for files that changed the type or the access permission because this
       is a common case on still corrupted files, use:

	      example# star -diff -tpath diffopts=type,perm f=/dev/rmt/1bn

ENVIRONMENT
       STAR_COMPRESS_FLAG
	      If you like star to always create compressed files that  use  maximum  compression,
	      you may set the environment variable STAR_COMPRESS_FLAG to -9.

       STAR_FIFO_SIZE
	      If  you like to by default let star use a different fifo size, set this environment
	      variable to the desired size.

       TAPE   Unlike other tar(1) implementations, star defaults to use stdin/stdout for the  ar-
	      chive.   If  you	like star to use the file name from the TAPE environment instead,
	      you need to specify the -T option too.

FILES
       Currently none except the files implied be the command line from star.

       In future, star may use /etc/default/star to set up global defaults.

SEE ALSO
       tar(1), cpio(1), rcp(1), mt(1), rmt(1), match(1), dd(1), sdd(1), star(4/5), rcmd(3),  fss-
       nap(1m)

DIAGNOSTICS
       star: f records + p bytes (total of x bytes = d.nnk).

       The number of full records, the number of bytes in partial records and the total amount of
       data in KBytes.

       star: Total time x.yyysec (z kBytes/sec)

       The time used and the transfer speed from/to the archive.

       If there have been non fatal errors during the archive processing,  star  will  display	a
       delayed error summary before exiting.

NOTES
       The  POSIX  command  line syntax for the tar command deviates from the command line syntax
       defined for all other commands. While the POSIX command line syntax requests  all  options
       to  start  with	a  dash (-) and allows to either write options separately or combined (in
       case of boolean flags), the POSIX tar command line syntax requires all options to be  com-
       bined  into  a  single  string that does not start with a dash.	Star by default assumes a
       command line syntax like a typical POSIX command and includes a	compatibility  mode  that
       allows  to  specify a command line syntax as documented for the POSIX tar command.  If you
       believe that you found a bug in the way star parses the command line, please  first  check
       your command line for correctness before you make a bug report for star.

       If  you like to write portable shell scripts that call tar, use the POSIX tar command line
       syntax (i.e. a single option string and no dash), choose the commands and options from the
       following  set  of characters ( rxtuc vxfblmo ) and check the shell script with both, your
       local tar and star for correct behavior. It you expect the script to call gnutar,  do  not
       include the -o option as gnutar implements this option in a way that violates POSIX.

       Star strips leading ./ sequences from pathnames. This lets star in many cases store longer
       pathnames than other implementations.

       The POSIX.1-1988 method (ustar format) of storing files with  pathnames	that  are  longer
       than 100 chars has some limitations:

	      The name field (100 chars) an inserted slash (`/') and the prefix field (155 chars)
	      produce the pathname of the file. When recreating the original filename,	name  and
	      prefix  are concatenated, using a slash character in the middle. If a pathname does
	      not fit in the space provided or may not be split at a slash character so that  the
	      parts  will  fit	into  100  +  155 chars, the file may not be archived.	Linknames
	      longer than 100 chars may not be archived too.

       The star, xstar, xustar, exustar, pax, and gnutar archive formats don't have these limita-
       tions.  While  gnutar uses a method that makes it impossible for other tar implementations
       (except star) to restore filenames that are longer than	100  chars,  the  xstar,  xustar,
       exustar	and pax archive format uses a method that allows an POSIX.1-1988 compliant way of
       storing filenames, if the POSIX method would allow this.  When the archive format is  xus-
       tar,  exustar  or  pax  very  long  filenames  are  stored using extended headers from the
       POSIX.1-2001 standard.

       Some buggy tar implementations will generate incorrect filenames during a  restore  opera-
       tion if the archive contains pathnames or linknames of exactly 100 chars length.

       Star  adds a tar signature in the last four bytes of each tar header if the archive format
       is star or xstar.  This is no problem with the star archive format as it is  an	extension
       of  the	old  pre  POSIX.1-1988	tar  format.  On the other side, the xstar archive format
       claims to be as POSIX.1-1988 compliant as possible.  Inserting this  tar  signature  is	a
       minor  deviation  from the standard that has the last 12 bytes of each header reserved for
       future use. On the other side, tar implementations such as some pax  implementations  that
       only  compute  checksums  on  the first 500 bytes of the header are violating the standard
       that requests the checksum to be computed on all 512 bytes of  the  tar	header.  All  tar
       implementations	that  are  100% Posix compliant will be able to extract xstar archives as
       long as no new standard is defined that claims the last 12 bytes of the header for a  dif-
       ferent  use.  But then the ustar version number should be changed from `00' to `01'.  Now,
       that the POSIX-2001 standard has been accepted, it is even predictable that all extensions
       to the standard tar format will go into the POSIX.1-2001 extended headers which are exten-
       sible to include any feature without future limitation.	The only known tar implementation
       that  also uses the last 12 bytes of the tar header is Sun's tar which uses these 12 bytes
       for files that are split over several archives. Such archives created by Sun's tar are not
       readable by the buggy pax implementation too. The Sun extension is not incompatible to the
       star signature because Sun expects an octal number at the beginning of the 12  byte  field
       which is a null character in the star case.

       Star  uses  these four bytes since 1985 without problems.  If you need a 100% POSIX.1-1988
       and 100% POSIX.1-2001 compliant tar archive, you may use the xustar, exustar  or  the  pax
       archive format.	The probability of falsely detecting other tar formats as xustar or exus-
       tar format however is higher.

       There is no way to ask for the n-th occurrence of a file.

       The way EOF is handled by star differs, whether the fifo is in effect or not.  If the fifo
       is  not	used, star stops reading the archive if it encounters a logical EOF record in the
       archive.  If the fifo is used, star may read until the fifo is full or until the real  EOF
       mark  on  tape is reached.  How much data star actually reads depends on the time when the
       star foreground process sends a fifo shutdown signal to the background fifo read process.

       Gnu tar often creates tar  archives  with  incorrect  logical  EOF  marks.   The  standard
       requires  two  blocks  that  are  completely zeroed, whereas gnutar often only adds one of
       them.

       Old versions of tar found on SYSVr3 and earlier cannot read tar archives with a	blocksize
       greater than 10 kBytes.

       The  method  of	storing sparse files currently used with the star and xstar format is not
       guaranteed to be used in later versions of star.  If the author	decides  to  change  this
       method,	later  versions of star may not be able to restore sparse files from tar archives
       made by the current version of star.

       Some tar implementations violate the standard in using only the first  500  Bytes  of  the
       header  for checksum computation. These tar implementations will not accept star and xstar
       type tar archives.

       Sun's Solaris 2.x tar implementation violates the Posix standard. Tar  archives	generated
       by  star cause Sun's tar to print tar: impossible file type messages. You may ignore these
       messages.

       Gnutar's dumpdirs are non standard and are currently not implemented.

       If gnutar archives sparse files with more than four holes, it produces archives that  vio-
       late the standard in a way that prevents other tar implementations to read these archives.
       Star knows about that and is able to handle these gnutar archives.

       The filetype N (LF_NAMES) from gnutar (an obsolete method  of  storing  long  names)  will
       never be implemented.

SUID NOTES
       If  star  is  installed suid root, star is able to make connections to remote archives for
       non root users.	This is done by using the rcmd(3) interface to	get  a	connection  to	a
       rmt(1) server.

       Star  resets  its  effective uid back to the real user id immediately after setting up the
       remote connection to the rmt server and before opening any other file.

LIMITATIONS
       If star is running on a large file aware platform, star is able to handle files up to 8 GB
       in a mode that is compliant to the POSIX.1-1988 ustar format. With a nonstandard star spe-
       cific extension, up to 95 bits may be used to code the filesize.  This will  handle  files
       up  to  200,000,000  TB.   With	the new POSIX.1-2001 extended headers used by the xustar,
       exustar and pax format, any filesize may be archived.

BUGS
       The fact that the -f option has to be implemented in a way that is compatible with old tar
       implementations	 gives	 several   problems.	The   options	-fifostats,  -force-hole,
       -force-remove and -fifo interfere with the -f option and the fact that they exist prevents
       users  from  using  filenames  like e.g.  ifo using the traditional way where the filename
       directly follows the string -f without any space between the  option  name  and	the  file
       name.   However,  there is no problem to use a file named ifo by by calling -f ifo, f=ifo,
       -f=ifo or -f= ifo.  Be careful not to make typos with the above options. The result  could
       be that a file is created as a result of the mistyped option.

       There is currently no way to set the fifo lowwater and highwater marks.

       There  is  currently  no way to automatically delete files in the target file tree if they
       are obsolete.  Star should implement something similar to gnutar's dumpdirs.

       If not invoked by the super user star may not be able to extract files if they  reside  in
       read only directories.

       Star  is not able to make a complete backup of a filesystem if files are hidden by a mount
       that is in effect on a directory of this filesystem.  This may be avoided in case  of  the
       ufs  filesystem	if the backup is made off a ufs snapshot (see the man page for fssnap(1m)
       It could be avoided for any filesystem if the loopback filesystem had an option that tells
       lofs not to traverse mountpoints.

HISTORY
       Star  was  first created in 1982 to extract tapes on a UNIX clone that had no tar command.
       In 1985 the first fully functional version has been released as mtar.

       When the old star format extensions have been introduced in 1985, it was renamed  to  star
       (Schily	tar).	In  1994, Posix 1003.1-1988 extensions were added and star was renamed to
       star (Standard tar).

AUTHOR
       Joerg Schilling
       Seestr. 110
       D-13353 Berlin
       Germany

       Mail bugs and suggestions to:

       schilling@fokus.gmd.de or js@cs.tu-berlin.de or joerg@schily.isdn.cs.tu-berlin.de

Joerg Schilling 			     02/08/10					  STAR(1)


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