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NAME    [Toc]    [Back]

       tar - Manipulates tape archives

SYNOPSIS    [Toc]    [Back]

       tar     function_key[bBfFEhilLmpPsSvVwzn]    [n    |    o]
       [option_argument...] [-e exception]...  [-C  directory]...

       tar  -function_key[options]  [option_argument]...  [n | o]
       [option_argument...] [-e exception]...  [-C  directory]...

       The  tar  command  saves  and restores multiple files on a
       single file (usually a magnetic tape, but it  can  be  any


       [Tru64  UNIX]  The  syntax of the tar command has recently
       changed.  The  minus  sign  (-)  at  the  beginning  of  a
       key/option set is no longer optional.  If tar sees a minus
       sign in front of an option that requires an argument,  tar
       expects the argument to follow the option immediately.  In
       order to use the original tar syntax in existing  scripts,
       you  must  remove  the  minus sign if more than one option
       requiring an argument is given.  Consider this command  in
       the old form: tar -xbfp 20 /dev/ntape/tape0

       Under  the  new  implementation,  this command becomes tar
       xbfp 20 /dev/ntape/tape0

       or tar -xb 20 -f /dev/ntape/tape0 -p

STANDARDS    [Toc]    [Back]

       Interfaces documented on this reference  page  conform  to
       industry standards as follows:

       tar:  XCU5.0

       Refer to the standards(5) reference page for more information
 about industry standards and associated tags.

FUNCTION KEYS    [Toc]    [Back]

       [Tru64 UNIX]  The function performed by tar  is  specified
       by  one  of  the  following  key  letters:  Creates  a new
       archive.  When writing to a tape device, tar  begins  from
       the  current tape position.  Writes the named files at the
       end of the specified archive.  If the archive is on  tape,
       tar  expects  that the tape is currently positioned to the
       beginning of the  archive.   Lists  the  contents  of  the
       archive. If the file argument does not restrict the operation
 to one or more specific  directories  or  files,  tar
       lists  all  of  the  file  names in the archive.  Adds the
       named files to the tape, if  the  files  are  not  already
       there  or  if  they were modified since last copied to the
       tape.  Extracts the named files from the tape.  If a named
       file  matches  a  directory whose contents were written to
       the tape, this directory is (recursively) extracted.   The
       owner, modification time, and mode are restored (if possible).
  If no file argument is given, the entire content of
       the tape is extracted.  If multiple entries specifying the
       same file are on the tape, the  last  one  overwrites  all
       earlier ones.

OPTIONS    [Toc]    [Back]

       [Tru64 UNIX]  The following options can be used with function
 keys: The tar command uses the next argument  as  the
       blocking  factor  for  tape  records.  The  default  is 20
       (larger values can be specified at the risk of creating  a
       tape  archive  that some systems' tape drives might not be
       able to restore).  Use this option only with raw  magnetic
       tape  archives. The block size is determined automatically
       when  reading  tapes  (key  letters  x  and  t).    [Tru64
       UNIX]  Forces  input  and  output blocking to the blocking
       factor (see the b option).  The B option  exists  so  that
       tar  can  work  across  a communications channel where the
       blocking cannot be maintained.  [Tru64 UNIX]  The tar command
 uses the next argument, exception, as the name of the
       file to be excluded from the archive.  Processes  extended
       headers,  allowing you to archive or extract extended UIDs
       and GIDs, long filenames,  link-names,  large  files,  and
       long  user  and  group names The tar command uses the next
       argument  as  the  name  of   the   archive   instead   of
       /dev/ntape/tapen. (See the entry for the n option.) If the
       name of the file is - (dash), tar writes to standard  output
  or  reads from standard input, whichever is appropriate.
  Thus, tar can be used as the head or tail of a  filter
 chain.  The tar utility can also be used to move hierarchies
 with the command: cd fromdir; tar cf  -  .  |  (cd
       todir;  tar xpf -) [Tru64 UNIX]  Checks certain file names
       before archiving.   Source  Code  Control  System  (SCCS),
       Revision  Control  System  (RCS),  files named core, errs,
       a.out, and files  ending  in  are  not  archived.   [Tru64
       UNIX]  Forces tar to follow symbolic links as if they were
       normal files or directories.  Normally, tar does not  follow
 symbolic links, but instead saves the link text in the
       archive.  [Tru64 UNIX]  Ignores checksum errors.  The  tar
       command  writes  a  file  header containing a checksum for
       each file in the archive.  When this option is not  specified,
  the  system  verifies  the  contents  of the header
       blocks by recomputing the checksum and stops with a directory
  checksum  error  when  a mismatch occurs.  When this
       option is specified, tar logs the  error  and  then  scans
       forward until it finds a valid header block.  This permits
       restoring  files  from  later  volumes  of  a  multivolume
       archive   without   reading   earlier   volumes.    [Tru64
       UNIX]  Tells tar to complain if it cannot resolve  all  of
       the  links  to  the  files  dumped.  If this option is not
       specified,  no  error  messages   are   printed.    [Tru64
       UNIX]  Tries  to  create  a symbolic link if tar is unsuccessful
 in its attempt to  link  (hard  link)  two  files.
       Tells tar not to restore the modification times. The modification
 time is the time of extraction.  This  is  always
       the  case  with  symbolic links.  [Tru64 UNIX]  Allows tar
       headers to be created with file names that cannot be nullterminated
  if  they  are  exactly  the maximum length (as
       specified in POSIX).  This option  is  mutually  exclusive
       with  the o option (that is, new versus old).  When specified,
 each of these options turns off the  other;  neither
       option  is turned on by default, however.  The o option is
       provided for backward compatibility.  Specify this  option
       if the archive is to be restored on a system with an older
       version of tar.  On output, tar normally  places  information
  specifying  owner  and  modes  of directories in the
       archive.  Former versions of tar, when  encountering  this
       information  will  give  an error message of the following
       form: name: cannot create

              [Tru64 UNIX]  This option suppresses the  directory
              information.  It  also  prevents  archiving special
              files and FIFOs that earlier versions of tar  would
              not  be  able to extract properly. (Although anyone
              can archive special files,  only  a  user  who  has
              mknod   kernel  authorization  (who  has  superuser
              authority) can extract them from the archives).

              When o is used for reading, it causes the extracted
              file to take on the User and Group ID (UID and GID)
              of the user running the program, rather than  those
              of  the tape.  This is the default for the ordinary

              [Tru64 UNIX]  This  option  is  mutually  exclusive
              with  the  n  option (that is, new vs.  old).  When
              specified, each of  these  options  turns  off  the
              other; neither option is turned on by default, however.
  [Tru64 UNIX]  Restores files to their original
 modes, ignoring the present umask.  Set-user-ID
              and sticky information will also be restored if the
              user is superuser (has chown kernel authorization).
              [Tru64 UNIX]  Specifies the prefix that  is  to  be
              stripped  off  of  the  file  names  archived to or
              extracted from tape.   (See  also  the  s  option).
              [Tru64  UNIX]  Tells  tar  to strip off any leading
              slashes from pathnames during extraction.  This  is
              useful  when restoring a tape that was created on a
              system with  a  different  file  system  structure.
              (See  also  the P option.)  [Tru64 UNIX]  The named
              file immediately following this option  contains  a
              list  of  file  names  separated by newlines.  This
              list is added to (c function key, r  function  key)
              or  extracted  from  (x  function key) the archive.
              The -R option is incompatible with the  -C  option.
              [Tru64  UNIX]  Specifies  the  number  of  512-byte
              blocks per volume (first form), independent of  the
              tape  blocking  factor.   You  can also specify the
              size of the tape in feet, and  optionally  density,
              by  using  the second form.  Feet are assumed to be
              11 inches long to  be  conservative.   This  option
              lets  you  deal  more  easily with multivolume tape
              archives, where tar must be able to  determine  how
              many blocks fit on each volume.

              [Tru64 UNIX]  Tape drives vary in density capabilities.
  The density argument is used in  the  amount
              of  data  that tar can fit on a tape.  Normally tar
              does its work silently.   The  v  (verbose)  option
              makes  tar print the name of each file it processes
              as specified by the function key.  With the t function
 key, the verbose option gives more information
              about the  tape  entries  than  just  their  names.
              [Tru64 UNIX]  Prevents any extended attributes from
              being archived with associated files.  This  option
              is particularly useful for archiving files that are
              to be restored with previous versions  of  tar  and
              cpio.   Causes  tar to print the action to be taken
              followed by the name of the file, and then to  wait
              for  the  user's  confirmation. If a word beginning
              with y, or the locale's definition of  an  affirmative
  response,  is given, the action is performed.
              If any other input is given, the action is not performed.
  [Tru64 UNIX]  Positions the tape after the
              EOF marker on extraction or listing.  The z  option
              lets  the user extract or list tapes that have multiple
 archives on them one after the other  without
              error  as a result of the tape not being positioned
              correctly  for  the  next  extraction  or  listing.
              [Tru64  UNIX]  Selects  /dev/ntape/tapen (the variable
 n means 0-9) as the tape drive  on  which  the
              tape   is   mounted.    The   default  is  drive  0
              (/dev/ntape/tape0).  [Tru64 UNIX]  Adds the following
  argument  to  a list of exception strings that
              prevent files whose names match exactly from  being
              archived. When used with the -C option, the list of
              exceptions becomes relative to each new  directory.
              [Tru64 UNIX]  If a file name is preceded by -C, tar
              performs a chdir() to that file name.  This  allows
              multiple  directories not related by a close common
              parent to be archived using  short  relative  pathnames.
    For   example,   to  archive  files  from
              /usr/include and from /etc, one might use the  following
  command  line:  tar  c -C /usr/include . -C
              /etc .

              [Tru64 UNIX]  Therefore, if you do not  specify  an
              absolute  file  name,  the  file name is considered
              relative to the previous -C  directory.   When  you
              specify  this  option multiple times on the command
              line, make sure to specify subsequent  -C  directories
 relative to the preceding -C directories.

              [Tru64  UNIX]  If  an  error occurs while trying to
              change to the requested directory, subsequent  file
              names  on  the  command  line that are not absolute
              (that is, have no leading /  (slash))  are  skipped
              until the next -C option is specified.

       [Tru64  UNIX]  Only the -e and -C options must be preceded
       by a - (dash) and can be specified more  than  once  on  a
       single  command  line  or  interspersed within the list of
       file names.  All other options must be specified  together
       (with  no  separating  spaces) before -e, -C, and the file
       list.  For all options that require arguments,  the  arguments
  must follow the string of options and be ordered in
       the same way as the specified options.

       [Tru64 UNIX]  Previous restrictions on the  tar  command's
       ability  to  properly  handle  blocked  archives have been

DESCRIPTION    [Toc]    [Back]

       The tar command is used to save and restore data from traditional
 format tar archives.

       [Tru64  UNIX]  The  actions of tar on a trusted system are
       controlled by the  way  the  Information  System  Security
       Officer  (ISSO) has set up the Device Assignment database.
       Refer to the detailed description of import and export  in
       the Security.

       The  actions of the tar command are controlled by a string
       containing, at most, one function key and possibly one  or
       more  options.   Other arguments to tar are file or directory
 names specifying which files to dump or restore.   In
       all  cases,  appearance  of a directory name refers to the
       files and (recursively) subdirectories of that  directory.

       The   LC_MESSAGES   variable   determines   the   locale's
       equivalent of y or n (for yes/no responses).

   Security Restrictions    [Toc]    [Back]
       [Tru64 UNIX]  You must have the tape command authorization
       to  import  or  export  data  to removable media (magnetic
       tapes, and so on). A full discussion of security  restrictions
  is  contained  in the sU_NOMAP. You cannot directly
       access device files used for  import  and  export  on  the
       trusted system.

       [Tru64  UNIX]  Do  not  use  the  tar  command to transfer
       directory hierarchies; use the mltape command instead.

NOTES    [Toc]    [Back]

       The tar command is  marked  as  LEGACY  in  XCU  Issue  5.
       [Tru64  UNIX]  There  is  no way to ask for the nth occurrence
 of a file.  [Tru64 UNIX]  Tape  errors  are  handled
       ungracefully.   [Tru64  UNIX]  The u function can be slow.
       [Tru64 UNIX]  The current limit on file name length is 256
       bytes.   The current limit on file links (hard or soft) is
       100 bytes.  [Tru64 UNIX]  There is no way  selectively  to
       follow  symbolic  links.   [Tru64  UNIX]  When  extracting
       tapes created with the r or u functions, directory modification
   times   might   not  be  set  correctly.   [Tru64
       UNIX]  After encountering tape write errors,  tar  queries
       the  operator about performing a rewrite.  If the operator
       requests a rewrite, a rewind is performed, followed by  an
       attempt  to  rewrite the data.  In the event the no-rewind
       device is used, the user should always load a new tape  to
       avoid  the  possibility  of overwriting previously written
       archives.  [Tru64 UNIX]  Socket files  are  ignored  while
       archiving through thetar.

EXIT STATUS    [Toc]    [Back]

       The following exit values are returned: Successful completion.
  An error occurred.

EXAMPLES    [Toc]    [Back]

       To create a tar archive to device /dev/ntape/tape0, enter:
       tar cvfb /dev/ntape/tape0 20 -e ./foo -C /usr/glenn . \ -e
       ./bar -e ./logs/logfile -C /usr/gaston .

              The preceding command  line  specifies  a  blocking
              factor  of  20.  The resulting archive contains all
              files and directories in /usr/glenn except for file
              and all files and directories in /usr/gaston except
              for files To create a tar archive as a  disk  file,
              enter:  tar  cvf  /tmp/mybackup.tar -e $HOME/zeugma

              The preceding command line uses  the  f  option  to
              create a tar archive named mybackup.tar in the /tmp
              directory.  The archive contains  the  user's  home
              directory and its contents, including all subdirectories
 and files except the zeugma subdirectory and
              its  contents, which are excluded by the -e (exception)
 option.  The following example  extracts  one
              directory  'APXUSRGD'  (whose  path in the supp.tar
              archive   is   strips   off   the    path    prefix
              (./DOCS/HTML/SUPPDOCS/) and stores the directory in
              the   users's   current   directory:    tar    Pxvf


       The following environment variables affect  the  execution
       of tar: Provides a default value for the internationalization
 variables that are unset or null. If LANG is unset or
       null,  the  corresponding value from the default locale is
       used. If any of the internationalization variables contain
       an  invalid setting, the utility behaves as if none of the
       variables had been defined.  If set to a non-empty  string
       value,  overrides the values of all the other internationalization
 variables.  Determines the locale for the interpretation
 of sequences of bytes of text data as characters
       (for example, single-byte as opposed to multibyte  characters
  in arguments).  Determines the locale for the format
       and contents of diagnostic messages  written  to  standard
       error.   Determines  the  format  of date and time strings
       output when listing the contents of  an  archive.   Determines
  the location of message catalogs for the processing
       of LC_MESSAGES.  Determines the time zone used  with  date
       and time strings.

FILES    [Toc]    [Back]

       Device  name  used with the n option.  Temporary file used
       with the u function.

SEE ALSO    [Toc]    [Back]

       Commands:  cpio(1), pax(1)

       Functions:  chdir(2), umask(2)

       Files:  tar(4)

       Standards:  standards(5)


[ Back ]
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