man tar

TAR(1)                                              GNU TAR Manual                                              TAR(1)

      tar - an archiving utility

  Traditional usage
      tar {A|c|d|r|t|u|x}[GnSkUWOmpsMBiajJzZhPlRvwo] [ARG...]

  UNIX-style usage

      tar -c [-f ARCHIVE] [OPTIONS] [FILE...]

      tar -d [-f ARCHIVE] [OPTIONS] [FILE...]

      tar -t [-f ARCHIVE] [OPTIONS] [MEMBER...]

      tar -r [-f ARCHIVE] [OPTIONS] [FILE...]

      tar -u [-f ARCHIVE] [OPTIONS] [FILE...]

      tar -x [-f ARCHIVE] [OPTIONS] [MEMBER...]

  GNU-style usage
      tar {--catenate|--concatenate} [OPTIONS] ARCHIVE ARCHIVE

      tar --create [--file ARCHIVE] [OPTIONS] [FILE...]

      tar {--diff|--compare} [--file ARCHIVE] [OPTIONS] [FILE...]

      tar --delete [--file ARCHIVE] [OPTIONS] [MEMBER...]

      tar --append [-f ARCHIVE] [OPTIONS] [FILE...]

      tar --list [-f ARCHIVE] [OPTIONS] [MEMBER...]

      tar --test-label [--file ARCHIVE] [OPTIONS] [LABEL...]

      tar --update [--file ARCHIVE] [OPTIONS] [FILE...]

      tar --update [-f ARCHIVE] [OPTIONS] [FILE...]

      tar {--extract|--get} [-f ARCHIVE] [OPTIONS] [MEMBER...]

      This manpage is a short description of GNU tar.  For a detailed discussion, including examples and usage recom‐
      mendations, refer to the GNU Tar Manual available in texinfo format.  If the info reader and the tar documenta‐
      tion are properly installed on your system, the command

          info tar

      should give you access to the complete manual.

      You can also view the manual using the info mode in emacs(1), or find it in various formats online at

      If  any  discrepancies  occur  between  this  manpage and the GNU Tar Manual, the later shall be considered the
      authoritative source.

      GNU tar is an archiving program designed to store multiple files in a single file (an archive), and to  manipu‐
      late such archives.  The archive can be either a regular file or a device (e.g. a tape drive, hence the name of
      the program, which stands for tape archiver), which can be located either on the local or on a remote machine.

  Option styles
      Options to GNU tar can be given in three different styles.  In traditional style, the first argument is a clus‐
      ter  of  option  letters and all subsequent arguments supply arguments to those options that require them.  The
      arguments are read in the same order as the option letters.  Any command  line  words  that  remain  after  all
      options has been processed are treated as non-optional arguments: file or archive member names.

      For example, the c option requires creating the archive, the v option requests the verbose operation, and the f
      option takes an argument that sets the name of the archive to operate upon.  The following command, written  in
      the  traditional  style, instructs tar to store all files from the directory /etc into the archive file etc.tar
      verbosely listing the files being archived:

      tar cfv a.tar /etc

      In UNIX or short-option style, each option letter is prefixed with a single dash,  as  in  other  command  line
      utilities.   If  an  option takes argument, the argument follows it, either as a separate command line word, or
      immediately following the option.  However, if the option takes an optional argument, the argument must  follow
      the option letter without any intervening whitespace, as in -g/tmp/snar.db.

      Any  number  of options not taking arguments can be clustered together after a single dash, e.g. -vkp.  Options
      that take arguments (whether mandatory or optional), can appear at the end of such a cluster, e.g. -vkpf a.tar.

      The example command above written in the short-option style could look like:

      tar -cvf a.tar /etc
      tar -c -v -f a.tar /etc

      In GNU or long-option style, each option begins with two dashes and has a meaningful name, consisting of lower-
      case  letters  and dashes.  When used, the long option can be abbreviated to its initial letters, provided that
      this does not create ambiguity.  Arguments to long options are supplied either as a separate command line word,
      immediately  following  the  option,  or separated from the option by an equals sign with no intervening white‐
      space.  Optional arguments must always use the latter method.

      Here are several ways of writing the example command in this style:

      tar --create --file a.tar --verbose /etc
      or (abbreviating some options):
      tar --cre --file=a.tar --verb /etc

      The options in all three styles can be intermixed, although doing so with old options is not encouraged.

  Operation mode
      The options listed in the table below tell GNU tar what operation it is to perform.  Exactly one of  them  must
      be given.  Meaning of non-optional arguments depends on the operation mode requested.

      -A, --catenate, --concatenate
             Append  archive  to  the  end of another archive.  The arguments are treated as the names of archives to
             append.  All archives must be of the same format as the archive they  are  appended  to,  otherwise  the
             resulting  archive  might  be  unusable with non-GNU implementations of tar.  Notice also that when more
             than one archive is given, the members from archives other than the first one will be accessible in  the
             resulting archive only if using the -i (--ignore-zeros) option.

             Compressed archives cannot be concatenated.

      -c, --create
             Create a new archive.  Arguments supply the names of the files to be archived.  Directories are archived
             recursively, unless the --no-recursion option is given.

      -d, --diff, --compare
             Find differences between archive and file system.  The arguments are optional and specify  archive  mem‐
             bers to compare.  If not given, the current working directory is assumed.

             Delete from the archive.  The arguments supply names of the archive members to be removed.  At least one
             argument must be given.

             This option does not operate on compressed archives.  There is no short option equivalent.

      -r, --append
             Append files to the end of an archive.  Arguments have the same meaning as for -c (--create).

      -t, --list
             List the contents of an archive.  Arguments are optional.  When given, they specify  the  names  of  the
             members to list.

             Test  the  archive  volume  label and exit.  When used without arguments, it prints the volume label (if
             any) and exits with status 0.  When one or more command line arguments are given.  tar compares the vol‐
             ume  label with each argument.  It exits with code 0 if a match is found, and with code 1 otherwise.  No
             output is displayed, unless used together with the -v (--verbose) option.

             There is no short option equivalent for this option.

      -u, --update
             Append files which are newer than the corresponding copy in the archive.  Arguments have the same  mean‐
             ing  as  with  -c  and -r options.  Notice, that newer files don't replace their old archive copies, but
             instead are appended to the end of archive.  The resulting archive can thus contain several  members  of
             the same name, corresponding to various versions of the same file.

      -x, --extract, --get
             Extract  files  from an archive.  Arguments are optional.  When given, they specify names of the archive
             members to be extracted.

             Show built-in defaults for various tar options and exit.  No arguments are allowed.

      -?, --help
             Display a short option summary and exit.  No arguments allowed.

             Display a list of available options and exit.  No arguments allowed.

             Print program version and copyright information and exit.

  Operation modifiers
             Check device numbers when creating incremental archives (default).

      -g, --listed-incremental=FILE
             Handle new GNU-format incremental backups.  FILE is the name of a snapshot file, where tar stores  addi‐
             tional  information which is used to decide which files changed since the previous incremental dump and,
             consequently, must be dumped again.  If FILE does not exist when creating an archive, it will be created
             and all files will be added to the resulting archive (the level 0 dump).  To create incremental archives
             of non-zero level N, create a copy of the snapshot file created during the level  N-1,  and  use  it  as

             When  listing or extracting, the actual contents of FILE is not inspected, it is needed only due to syn‐
             tactical requirements.  It is therefore common practice to use /dev/null in its place.

             Use METHOD to detect holes in sparse files.  This option implies --sparse.  Valid values for METHOD  are
             seek and raw.  Default is seek with fallback to raw when not applicable.

      -G, --incremental
             Handle old GNU-format incremental backups.

             Do not exit with nonzero on unreadable files.

             Set  dump  level  for  created  listed-incremental  archive.  Currently only --level=0 is meaningful: it
             instructs tar to truncate the snapshot file before dumping, thereby forcing a level 0 dump.

      -n, --seek
             Assume the archive is seekable.  Normally tar determines automatically whether the archive can be seeked
             or  not.  This option is intended for use in cases when such recognition fails.  It takes effect only if
             the archive is open for reading (e.g. with --list or --extract options).

             Do not check device numbers when creating incremental archives.

             Assume the archive is not seekable.

             Process only the Nth occurrence of each file in the archive.  This option is valid only when  used  with
             one  of  the  following  subcommands:  --delete, --diff, --extract or --list and when a list of files is
             given either on the command line or via the -T option.  The default N is 1.

             Disable the use of some potentially harmful options.

             Set version of the sparse format to use (implies --sparse).  This option implies --sparse.  Valid  argu‐
             ment  values  are  0.0, 0.1, and 1.0.  For a detailed discussion of sparse formats, refer to the GNU Tar
             Manual, appendix D, "Sparse Formats".  Using info reader, it can be accessed running the following  com‐
             mand: info tar 'Sparse Formats'.

      -S, --sparse
             Handle  sparse  files  efficiently.  Some files in the file system may have segments which were actually
             never written (quite often these are database files created by such systems as DBM).   When  given  this
             option,  tar attempts to determine if the file is sparse prior to archiving it, and if so, to reduce the
             resulting archive size by not dumping empty parts of the file.

  Overwrite control
      These options control tar actions when extracting a file over an existing copy on disk.

      -k, --keep-old-files
             Don't replace existing files when extracting.

             Don't replace existing files that are newer than their archive copies.

             Don't replace existing symlinks to directories when extracting.

             Preserve metadata of existing directories.

             Extract all files into DIR, or, if used without argument, into a subdirectory named by the base name  of
             the archive (minus standard compression suffixes recognizable by --auto-compress).

             Overwrite existing files when extracting.

             Overwrite metadata of existing directories when extracting (default).

             Recursively remove all files in the directory prior to extracting it.

             Remove files from disk after adding them to the archive.

             Don't replace existing files when extracting, silently skip over them.

      -U, --unlink-first
             Remove each file prior to extracting over it.

      -W, --verify
             Verify the archive after writing it.

  Output stream selection

      Ignore subprocess exit codes.

             Treat non-zero exit codes of children as error (default).

      -O, --to-stdout
             Extract files to standard output.

             Pipe  extracted  files to COMMAND.  The argument is the pathname of an external program, optionally with
             command line arguments.  The program will be invoked and the contents of the file being  extracted  sup‐
             plied  to  it  on  its  standard output.  Additional data will be supplied via the following environment

                    Type of the file. It is a single letter with the following meaning:

                            f           Regular file
                            d           Directory
                            l           Symbolic link
                            h           Hard link
                            b           Block device
                            c           Character device

                    Currently only regular files are supported.

                    File mode, an octal number.

                    The name of the file.

                    Name of the file as stored in the archive.

                    Name of the file owner.

                    Name of the file owner group.

                    Time of last access. It is a decimal number, representing seconds since the Epoch.   If  the  ar‐
                    chive  provides  times  with  nanosecond precision, the nanoseconds are appended to the timestamp
                    after a decimal point.

                    Time of last modification.

                    Time of last status change.

                    Size of the file.

                    UID of the file owner.

                    GID of the file owner.

             Additionally, the following variables contain information about tar operation mode and the archive being

                    GNU tar version number.

                    The name of the archive tar is processing.

                    Current blocking factor, i.e. number of 512-byte blocks in a record.

                    Ordinal number of the volume tar is processing (set if reading a multi-volume archive).

                    Format  of the archive being processed.  One of: gnu, oldgnu, posix, ustar, v7.  TAR_SUBCOMMAND A
                    short option (with a leading dash) describing the operation tar is executing.

  Handling of file attributes
             Preserve access times on dumped files, either by restoring the times after reading (METHOD=replace, this
             is the default) or by not setting the times in the first place (METHOD=system)

             Delay  setting  modification times and permissions of extracted directories until the end of extraction.
             Use this option when extracting from an archive which has unusual member ordering.

             Force NAME as group for added files.  If GID is not supplied, NAME can be either a user name or  numeric
             GID.   In  this case the missing part (GID or name) will be inferred from the current host's group data‐

             When used with --group-map=FILE, affects only those files whose owner group is not listed in FILE.

             Read group translation map from FILE.  Empty lines are ignored.  Comments are introduced with # sign and
             extend to the end of line.  Each non-empty line in FILE defines translation for a single group.  It must
             consist of two fields, delimited by any amount of whitespace:


             OLDGRP is either a valid group name or a GID prefixed with +.  Unless NEWGID is  supplied,  NEWGRP  must
             also  be  either  a valid group name or a +GID.  Otherwise, both NEWGRP and NEWGID need not be listed in
             the system group database.

             As a result, each input file with owner group OLDGRP will be stored in archive with owner  group  NEWGRP
             and GID NEWGID.

             Force symbolic mode CHANGES for added files.

             Set  mtime  for added files.  DATE-OR-FILE is either a date/time in almost arbitrary format, or the name
             of an existing file.  In the latter case the mtime of that file will be used.

      -m, --touch
             Don't extract file modified time.

             Cancel the effect of the prior --delay-directory-restore option.

             Extract files as yourself (default for ordinary users).

             Apply the user's umask when extracting permissions from the archive (default for ordinary users).

             Always use numbers for user/group names.

             Force NAME as owner for added files.  If UID is not supplied, NAME can be either a user name or  numeric
             UID.   In  this  case the missing part (UID or name) will be inferred from the current host's user data‐

             When used with --owner-map=FILE, affects only those files whose owner is not listed in FILE.

             Read owner translation map from FILE.  Empty lines are ignored.  Comments are introduced with # sign and
             extend  to  the end of line.  Each non-empty line in FILE defines translation for a single UID.  It must
             consist of two fields, delimited by any amount of whitespace:


             OLDUSR is either a valid user name or a UID prefixed with +.  Unless NEWUID  is  supplied,  NEWUSR  must
             also be either a valid user name or a +UID.  Otherwise, both NEWUSR and NEWUID need not be listed in the
             system user database.

             As a result, each input file owned by OLDUSR will be stored in archive with owner name  NEWUSR  and  UID

      -p, --preserve-permissions, --same-permissions
             extract information about file permissions (default for superuser)

             Same as both -p and -s.

             Try extracting files with the same ownership as exists in the archive (default for superuser).

      -s, --preserve-order, --same-order
             Sort names to extract to match archive

             When  creating  an  archive,  sort  directory entries according to ORDER, which is one of none, name, or

             The default is --sort=none, which stores archive members in the same order as returned by the  operating

             Using --sort=name ensures the member ordering in the created archive is uniform and reproducible.

             Using  --sort=inode reduces the number of disk seeks made when creating the archive and thus can consid‐
             erably speed up archivation.  This sorting order is supported only if the underlying system provides the
             necessary information.

  Extended file attributes
      --acls Enable POSIX ACLs support.

             Disable POSIX ACLs support.

             Enable SELinux context support.

             Disable SELinux context support.

             Enable extended attributes support.

             Disable extended attributes support.

             Specify  the  exclude  pattern  for  xattr  keys.   PATTERN  is  a POSIX regular expression, e.g. --xat‐
             trs-exclude='^user.', to exclude attributes from the user namespace.

             Specify the include pattern for xattr keys.  PATTERN is a POSIX regular expression.

  Device selection and switching
      -f, --file=ARCHIVE
             Use archive file or device ARCHIVE.  If this option is not given, tar will first examine the environment
             variable  `TAPE'.  If it is set, its value will be used as the archive name.  Otherwise, tar will assume
             the compiled-in default.  The default value can be inspected either using the --show-defaults option, or
             at the end of the tar --help output.

             An  archive name that has a colon in it specifies a file or device on a remote machine.  The part before
             the colon is taken as the machine name or IP address, and the part after it as the file or device  path‐
             name, e.g.:


             An optional username can be prefixed to the hostname, placing a @ sign between them.

             By  default,  the  remote  host is accessed via the rsh(1) command.  Nowadays it is common to use ssh(1)
             instead.  You can do so by giving the following command line option:


             The remote machine should have the rmt(8) command installed.  If  its  pathname  does  not  match  tar's
             default, you can inform tar about the correct pathname using the --rmt-command option.

             Archive file is local even if it has a colon.

      -F, --info-script=COMMAND, --new-volume-script=COMMAND
             Run  COMMAND at the end of each tape (implies -M).  The command can include arguments.  When started, it
             will inherit tar's environment plus the following variables:

                    GNU tar version number.

                    The name of the archive tar is processing.

                    Current blocking factor, i.e. number of 512-byte blocks in a record.

                    Ordinal number of the volume tar is processing (set if reading a multi-volume archive).

                    Format of the archive being processed.  One of: gnu, oldgnu, posix, ustar, v7.

                    A short option (with a leading dash) describing the operation tar is executing.

             TAR_FD File descriptor which can be used to communicate the new volume name to tar.

             If the info script fails, tar exits; otherwise, it begins writing the next volume.

      -L, --tape-length=N
             Change tape after writing Nx1024 bytes.  If N is followed by a size suffix (see the subsection Size suf‐
             fixes below), the suffix specifies the multiplicative factor to be used instead of 1024.

             This option implies -M.

      -M, --multi-volume
             Create/list/extract multi-volume archive.

             Use COMMAND instead of rmt when accessing remote archives.  See the description of the -f option, above.

             Use COMMAND instead of rsh when accessing remote archives.  See the description of the -f option, above.

             When  this  option  is used in conjunction with --multi-volume, tar will keep track of which volume of a
             multi-volume archive it is working in FILE.

  Device blocking
      -b, --blocking-factor=BLOCKS
             Set record size to BLOCKSx512 bytes.

      -B, --read-full-records
             When listing or extracting, accept incomplete input records after end-of-file marker.

      -i, --ignore-zeros
             Ignore zeroed blocks in archive.  Normally two consecutive 512-blocks filled with zeroes  mean  EOF  and
             tar  stops reading after encountering them.  This option instructs it to read further and is useful when
             reading archives created with the -A option.

             Set record size.  NUMBER is the number of bytes per record.  It must be multiple of 512.  It can can  be
             suffixed  with  a  size  suffix, e.g. --record-size=10K, for 10 Kilobytes.  See the subsection Size suf‐
             fixes, for a list of valid suffixes.

  Archive format selection
      -H, --format=FORMAT
             Create archive of the given format.  Valid formats are:

             gnu    GNU tar 1.13.x format

             oldgnu GNU format as per tar <= 1.12.

             pax, posix
                    POSIX 1003.1-2001 (pax) format.

             ustar  POSIX 1003.1-1988 (ustar) format.

             v7     Old V7 tar format.

      --old-archive, --portability
             Same as --format=v7.

             Control pax keywords when creating PAX archives (-H pax).  This option is equivalent to the -o option of
             the pax(1)utility.

             Same as --format=posix.

      -V, --label=TEXT
             Create archive with volume name TEXT.  If listing or extracting, use TEXT as a globbing pattern for vol‐
             ume name.

  Compression options
      -a, --auto-compress
             Use archive suffix to determine the compression program.

      -I, --use-compress-program=COMMAND
             Filter data through COMMAND.  It must accept the -d option, for decompression.  The argument can contain
             command line options.

      -j, --bzip2
             Filter the archive through bzip2(1).

      -J, --xz
             Filter the archive through xz(1).

      --lzip Filter the archive through lzip(1).

      --lzma Filter the archive through lzma(1).

      --lzop Filter the archive through lzop(1).

             Do not use archive suffix to determine the compression program.

      -z, --gzip, --gunzip, --ungzip
             Filter the archive through gzip(1).

      -Z, --compress, --uncompress
             Filter the archive through compress(1).

  Local file selection
             Add FILE to the archive (useful if its name starts with a dash).

             Backup before removal.  The CONTROL argument, if supplied, controls the backup policy.  Its valid values

             none, off
                    Never make backups.

             t, numbered
                    Make numbered backups.

             nil, existing
                    Make numbered backups if numbered backups exist, simple backups otherwise.

             never, simple
                    Always make simple backups

             If CONTROL is not given, the value is taken from the VERSION_CONTROL environment variable.  If it is not
             set, existing is assumed.

      -C, --directory=DIR
             Change  to  DIR  before  performing any operations.  This option is order-sensitive, i.e. it affects all
             options that follow.

             Exclude files matching PATTERN, a glob(3)-style wildcard pattern.

             Exclude backup and lock files.

             Exclude contents of directories containing file CACHEDIR.TAG, except for the tag file itself.

             Exclude directories containing file CACHEDIR.TAG and the file itself.

             Exclude everything under directories containing CACHEDIR.TAG

             Before dumping a directory, see if it contains FILE.  If so, read exclusion  patterns  from  this  file.
             The patterns affect only the directory itself.

             Same as --exclude-ignore, except that patterns from FILE affect both the directory and all its subdirec‐

             Exclude contents of directories containing FILE, except for FILE itself.

             Exclude directories containing FILE.

             Exclude everything under directories containing FILE.

             Exclude version control system directories.

             Exclude files that match patterns read from VCS-specific ignore files.  Supported files are: .cvsignore,
             .gitignore, .bzrignore, and .hgignore.

      -h, --dereference
             Follow symlinks; archive and dump the files they point to.

             Follow hard links; archive and dump the files they refer to.

      -K, --starting-file=MEMBER
             Begin at the given member in the archive.

             Work  on  files  whose data changed after the DATE.  If DATE starts with / or . it is taken to be a file
             name; the mtime of that file is used as the date.

             Disable the effect of the previous --null option.

             Avoid descending automatically in directories.

             Do not unquote input file or member names.

             Treat each line read from a file list as if it were supplied in the command  line.   I.e.,  leading  and
             trailing  whitespace  is  removed  and, if the resulting string begins with a dash, it is treated as tar
             command line option.

             This is the default behavior.  The --no-verbatim-files-from option is provided as a way  to  restore  it
             after --verbatim-files-from option.

             This  option  is  positional: it affects all --files-from options that occur after it in, until --verba‐
             tim-files-from option or end of line, whichever occurs first.

             It is implied by the --no-null option.

      --null Instruct subsequent -T options to read null-terminated names  verbatim  (disables  special  handling  of
             names that start with a dash).

             See also --verbatim-files-from.

      -N, --newer=DATE, --after-date=DATE
             Only  store  files newer than DATE.  If DATE starts with / or . it is taken to be a file name; the ctime
             of that file is used as the date.

             Stay in local file system when creating archive.

      -P, --absolute-names
             Don't strip leading slashes from file names when creating archives.

             Recurse into directories (default).

             Backup before removal, override usual suffix.  Default suffix is ~,  unless  overridden  by  environment
             variable SIMPLE_BACKUP_SUFFIX.

      -T, --files-from=FILE
             Get names to extract or create from FILE.

             Unless  specified  otherwise, the FILE must contain a list of names separated by ASCII LF (i.e. one name
             per line).  The names read are handled the same way as  command  line  arguments.   They  undergo  quote
             removal and word splitting, and any string that starts with a - is handled as tar command line option.

             If this behavior is undesirable, it can be turned off using the --verbatim-files-from option.

             The  --null option instructs tar that the names in FILE are separated by ASCII NUL character, instead of
             LF.  It is useful if the list is generated by find(1) -print0 predicate.

             Unquote file or member names (default).

             Treat each line obtained from a file list as a file name, even if it starts with a dash.  File lists are
             supplied  with  the  --files-from (-T) option.  The default behavior is to handle names supplied in file
             lists as if they were typed in the command line, i.e. any names starting with a dash are treated as  tar
             options.  The --verbatim-files-from option disables this behavior.

             This  option  affects  all  --files-from options that occur after it in the command line.  Its effect is
             reverted by the --no-verbatim-files-from} option.

             This option is implied by the --null option.

             See also --add-file.

      -X, --exclude-from=FILE
             Exclude files matching patterns listed in FILE.

  File name transformations
             Strip NUMBER leading components from file names on extraction.

      --transform=EXPRESSION, --xform=EXPRESSION
             Use sed replace EXPRESSION to transform file names.

  File name matching options
      These options affect both exclude and include patterns.

             Patterns match file name start.

             Ignore case.

             Patterns match after any / (default for exclusion).

             Case sensitive matching (default).

             Verbatim string matching.

             Wildcards do not match /.

             Use wildcards (default for exclusion).

             Wildcards match / (default for exclusion).

  Informative output
             Display progress messages every Nth record (default 10).

             Run ACTION on each checkpoint.

             Only set time when the file is more recent than what was given with --mtime.

             Print file time to its full resolution.

             Send verbose output to FILE.

      -l, --check-links
             Print a message if not all links are dumped.

             Disable quoting for characters from STRING.

             Additionally quote characters from STRING.

             Set quoting style for file and member names.  Valid values for STYLE are literal,  shell,  shell-always,
             c, c-maybe, escape, locale, clocale.

      -R, --block-number
             Show block number within archive with each message.

             When listing or extracting, list each directory that does not match search criteria.

      --show-transformed-names, --show-stored-names
             Show file or archive names after transformation by --strip and --transform options.

             Print  total bytes after processing the archive.  If SIGNAL is given, print total bytes when this signal
             is delivered.  Allowed signals are: SIGHUP, SIGQUIT, SIGINT, SIGUSR1, and SIGUSR2.  The SIG  prefix  can
             be omitted.

      --utc  Print file modification times in UTC.

      -v, --verbose
             Verbosely list files processed.

             Enable  or  disable  warning  messages identified by KEYWORD.  The messages are suppressed if KEYWORD is
             prefixed with no- and enabled otherwise.

             Multiple --warning messages accumulate.

             Keywords controlling general tar operation:

             all    Enable all warning messages.  This is the default.

             none   Disable all warning messages.

                    "%s: file name read contains nul character"

                    "A lone zero block at %s"

             Keywords applicable for tar --create:

                    "%s: contains a cache directory tag %s; %s"

                    "%s: File shrank by %s bytes; padding with zeros"

             xdev   "%s: file is on a different filesystem; not dumped"

                    "%s: Unknown file type; file ignored"
                    "%s: socket ignored"
                    "%s: door ignored"

                    "%s: file is unchanged; not dumped"

                    "%s: file is the archive; not dumped"

                    "%s: File removed before we read it"

                    "%s: file changed as we read it"

                    Suppresses warnings about unreadable files or directories. This  keyword  applies  only  if  used
                    together with the --ignore-failed-read option.

             Keywords applicable for tar --extract:

                    "%s: skipping existing file"

                    "%s: implausibly old time stamp %s"
                    "%s: time stamp %s is %s s in the future"

                    "Extracting contiguous files as regular files"

                    "Attempting extraction of symbolic links as hard links"

                    "%s: Unknown file type '%c', extracted as normal file"

                    "Current %s is newer or same age"

                    "Ignoring unknown extended header keyword '%s'"

                    Controls  verbose  description  of failures occurring when trying to run alternative decompressor
                    programs.  This warning is disabled by default (unless --verbose is used).  A common  example  of
                    what you can get when using this warning is:

                    $ tar --warning=decompress-program -x -f archive.Z
                    tar (child): cannot run compress: No such file or directory
                    tar (child): trying gzip

                    This  means  that  tar first tried to decompress archive.Z using compress, and, when that failed,
                    switched to gzip.

                    "Record size = %lu blocks"

             Keywords controlling incremental extraction:

                    "%s: Directory has been renamed from %s"
                    "%s: Directory has been renamed"

                    "%s: Directory is new"

             xdev   "%s: directory is on a different device: not purging"

                    "Malformed dumpdir: 'X' never used"

      -w, --interactive, --confirmation
             Ask for confirmation for every action.

  Compatibility options
      -o     When creating, same as --old-archive.  When extracting, same as --no-same-owner.

  Size suffixes
              Suffix    Units                   Byte Equivalent
              b         Blocks                  SIZE x 512
              B         Kilobytes               SIZE x 1024
              c         Bytes                   SIZE
              G         Gigabytes               SIZE x 1024^3
              K         Kilobytes               SIZE x 1024
              k         Kilobytes               SIZE x 1024
              M         Megabytes               SIZE x 1024^2
              P         Petabytes               SIZE x 1024^5
              T         Terabytes               SIZE x 1024^4
              w         Words                   SIZE x 2

      Tar exit code indicates whether it was able to successfully perform the requested operation, and if  not,  what
      kind of error occurred.

      0      Successful termination.

      1      Some  files  differ.  If tar was invoked with the --compare (--diff, -d) command line option, this means
             that some files in the archive differ from their disk counterparts.  If tar was given one of the  --cre‐
             ate,  --append  or  --update  options,  this  exit  code  means that some files were changed while being
             archived and so the resulting archive does not contain the exact copy of the file set.

      2      Fatal error.  This means that some fatal, unrecoverable error occurred.

      If a subprocess that had been invoked by tar exited with a nonzero exit code, tar itself exits with  that  code
      as  well.  This can happen, for example, if a compression option (e.g. -z) was used and the external compressor
      program failed.  Another example is rmt failure during backup to a remote device.

      bzip2(1), compress(1), gzip(1), lzma(1), lzop(1), rmt(8), symlink(7), tar(5), xz(1).

      Complete tar manual: run info tar or use emacs(1) info mode to read it.

      Online copies of GNU tar documentation in various formats can be found at:

      Report bugs to <>.

      Copyright © 2013 Free Software Foundation, Inc.
      License GPLv3+: GNU GPL version 3 or later <>
      This is free software: you are free to change and redistribute it.  There is NO WARRANTY, to the extent permit‐
      ted by law.

TAR                                                November 16, 2017                                            TAR(1)