TAR(1) User Commands TAR(1)

NAME

tar - create tape archives and add or extract files

SYNOPSIS

tar c[BDeEFhilnopPTvw@/[0-7]][bf][X...][a|j|J|z|Z] [blocksize]
[tarfile] [size] [exclude-file]...
{file | -I include-file | -C directory file}...


tar r[BDeEFhilnTvw@/[0-7]][bf][j|J|z|Z] [blocksize] [tarfile]
[size]
{file | -I include-file | -C directory file}...


tar t[BeFhilnTv[0-7]][f][X...][j|J|z|Z] [tarfile] [size]
[exclude-file]... {file | -I include-file}...


tar u[BDeEFhilnTvw@/[0-7]][bf][j|J|z|Z] [blocksize] [tarfile]
[size] file...


tar x[BeFhilmnopTvw@/[0-7]][f][X...][j|J|z|Z] [tarfile] [size]
[exclude-file]... [-C directory] [file]...

DESCRIPTION

The tar command archives and extracts files to and from a single file
called a tarfile. A tarfile is usually a magnetic tape, but it can be any
file. tar's actions are controlled by the key argument. The key is a
string of characters containing exactly one function letter (c, r, t , u,
or x) and zero or more function modifiers (letters or digits), depending
on the function letter used. The key string contains no SPACE characters.
Function modifier arguments are listed on the command line in the same
order as their corresponding function modifiers appear in the key string.


The -I include-file, -C directory file, and file arguments specify which
files or directories are to be archived or extracted. In all cases,
appearance of a directory name refers to the files and (recursively)
subdirectories of that directory. Arguments appearing within braces ({ })
indicate that one of the arguments must be specified.

OPERANDS

The following operands are supported:

-C directory file

Performs a chdir (see cd(1)) operation on directory and performs the
c (create) or r (replace) operation on file. Use short relative path
names for file. If file is ".", archive all files in directory. This
operand enables archiving files from multiple directories not related
by a close common parent.

This option may also be passed once to x (extract). In this case the
program will chdir to directory after opening the archive, but before
extracting its contents.


-I include-file

Opens include-file containing a list of files, one per line, and
treats it as if each file appeared separately on the command line. Be
careful of trailing white spaces. Also beware of leading white
spaces, since, for each line in the included file, the entire line
(apart from the newline) is used to match against the initial string
of files to include. In the case where excluded files (see X function
modifier) are also specified, they take precedence over all included
files. If a file is specified in both the exclude-file and the
include-file (or on the command line), it is excluded.


file

A path name of a regular file or directory to be archived (when the
c, r or u functions are specified), extracted (x) or listed (t). When
file is the path name of a directory, the action applies to all of
the files and (recursively) subdirectories of that directory.

When a file is archived, and the E flag (see Function Modifiers) is
not specified, the filename cannot exceed 256 characters. In
addition, it must be possible to split the name between parent
directory names so that the prefix is no longer than 155 characters
and the name is no longer than 100 characters. If E is specified, a
name of up to PATH_MAX characters can be specified.

For example, a file whose basename is longer than 100 characters
could not be archived without using the E flag. A file whose
directory portion is 200 characters and whose basename is 50
characters could be archived (without using E) if a slash appears in
the directory name somewhere in character positions 151-156.

Function Letters

The function portion of the key is specified by one of the following
letters:

c

Create. Writing begins at the beginning of the tarfile, instead of at
the end.


r

Replace. The named files are written at the end of the tarfile. A
file created with extended headers must be updated with extended
headers (see E flag under Function Modifiers). A file created without
extended headers cannot be modified with extended headers.


t

Table of Contents. The names of the specified files are listed each
time they occur in the tarfile. If no file argument is specified, the
names of all files and any associated extended attributes in the
tarfile are listed. With the v function modifier, additional
information for the specified files is displayed.


u

Update. The named files are written at the end of the tarfile if they
are not already in the tarfile, or if they have been modified since
last written to that tarfile. An update can be rather slow. A tarfile
created on a 5.x system cannot be updated on a 4.x system. A file
created with extended headers must be updated with extended headers
(see E flag under Function Modifiers). A file created without
extended headers cannot be modified with extended headers.


x

Extract or restore. The named files are extracted from the tarfile
and written to the directory specified in the tarfile, relative to
the current directory. Use the relative path names of files and
directories to be extracted.

Absolute path names contained in the tar archive are unpacked using
the absolute path names, that is, the leading forward slash (/) is
not stripped off.

If a named file matches a directory whose contents has been written
to the tarfile, this directory is recursively extracted. The owner,
modification time, and mode are restored (if possible); otherwise, to
restore owner, you must be the super-user. Character-special and
block-special devices (created by mknod(8)) can only be extracted by
the super-user. If no file argument is specified, the entire content
of the tarfile is extracted. If the tarfile contains several files
with the same name, each file is written to the appropriate
directory, overwriting the previous one. Filename substitution
wildcards cannot be used for extracting files from the archive.
Rather, use a command of the form:

tar xvf ... /dev/rmt/0 `tar tf ... /dev/rmt/0 | \
grep 'pattern' `


When extracting tapes created with the r or u functions, directory
modification times can not be set correctly. These same functions cannot
be used with many tape drives due to tape drive limitations such as the
absence of backspace or append capabilities.


When using the r, u, or x functions or the X function modifier, the named
files must match exactly the corresponding files in the tarfile. For
example, to extract ./thisfile, you must specify ./thisfile, and not
thisfile. The t function displays how each file was archived.

Function Modifiers

The characters below can be used in conjunction with the letter that
selects the desired function.

a

During a create operation autodetect compression based on the archive
suffix.


b blocksize

Blocking Factor. Use when reading or writing to raw magnetic archives
(see f below). The blocksize argument specifies the number of
512-byte tape blocks to be included in each read or write operation
performed on the tarfile. The minimum is 1, the default is 20. The
maximum value is a function of the amount of memory available and the
blocking requirements of the specific tape device involved (see
mtio(4I) for details.) The maximum cannot exceed INT_MAX/512
(4194303).

When a tape archive is being read, its actual blocking factor is
automatically detected, provided that it is less than or equal to the
nominal blocking factor (the value of the blocksize argument, or the
default value if the b modifier is not specified). If the actual
blocking factor is greater than the nominal blocking factor, a read
error results. See Example 5 in EXAMPLES.


B

Block. Force tar to perform multiple reads (if necessary) to read
exactly enough bytes to fill a block. This function modifier enables
tar to work across the Ethernet, since pipes and sockets return
partial blocks even when more data is coming. When reading from
standard input, "-", this function modifier is selected by default to
ensure that tar can recover from short reads.


D

Data change warnings. Used with c, r, or u function letters. Ignored
with t or x function letters. If the size of a file changes while the
file is being archived, treat this condition as a warning instead of
as an error. A warning message is still written, but the exit status
is not affected.


e

Error. Exit immediately with a positive exit status if any unexpected
errors occur.


E

Write a tarfile with extended headers. (Used with c, r, or u function
letters. Ignored with t or x function letters.) When a tarfile is
written with extended headers, the modification time is maintained
with a granularity of microseconds rather than seconds. In addition,
filenames no longer than PATH_MAX characters that could not be
archived without E, and file sizes greater than 8GB, are supported.
The E flag is required whenever the larger files and/or files with
longer names, or whose UID/GID exceed 2097151, are to be archived, or
if time granularity of microseconds is desired.


f

File. Use the tarfile argument as the name of the tarfile. If f is
specified, /etc/default/tar is not searched. If f is omitted, tar
uses the device indicated by the TAPE environment variable, if set.
Otherwise, tar uses the default values defined in /etc/default/tar.
The number matching the archiveN string is used as the output device
with the blocking and size specifications from the file. For example,

tar -c 2/tmp/*


writes the output to the device specified as archive2 in
/etc/default/tar.

If the name of the tarfile is "-", tar writes to the standard output
or reads from the standard input, whichever is appropriate. tar can
be used as the head or tail of a pipeline. tar can also be used to
move hierarchies with the command:

example% cd fromdir; tar cf - .| (cd todir; tar xfBp -)


F

With one F argument, tar excludes all directories named SCCS and RCS
from the tarfile. With two arguments, FF, tar excludes all
directories named SCCS and RCS, all files with .o as their suffix,
and all files named errs, core, and a.out.


h

Follow symbolic links as if they were normal files or directories.
Normally, tar does not follow symbolic links.


i

Ignore directory checksum errors.


j

Use bzip2 for compressing or decompressing the archives.


J

Use xz for compressing or decompressing the archives.


l

Link. Output error message if unable to resolve all links to the
files being archived. If l is not specified, no error messages are
printed.


m

Modify. The modification time of the file is the time of extraction.
This function modifier is valid only with the x function.


n

The file being read is a non-tape device. Reading of the archive is
faster since tar can randomly seek around the archive.


o

Ownership. Assign to extracted files the user and group identifiers
of the user running the program, rather than those on tarfile. This
is the default behavior for users other than root. If the o function
modifier is not set and the user is root, the extracted files takes
on the group and user identifiers of the files on tarfile (see
chown(1) for more information). The o function modifier is only valid
with the x function.


p

Restore the named files to their original modes, and ACLs if
applicable, ignoring the present umask(1). This is the default
behavior if invoked as super-user with the x function letter
specified. If super-user, SETUID, and sticky information are also
extracted, and files are restored with their original owners and
permissions, rather than owned by root. When this function modifier
is used with the c function, ACLs are created in the tarfile along
with other information. Errors occur when a tarfile with ACLs is
extracted by previous versions of tar.


P

Suppress the addition of a trailing "/" on directory entries in the
archive.


T

This modifier is only available if the system is configured with
Trusted Extensions.

When this modifier is used with the function letter c, r, or u for
creating, replacing or updating a tarfile, the sensitivity label
associated with each archived file and directory is stored in the
tarfile.

Specifying T implies the function modifier p.

When used with the function letter x for extracting a tarfile, the
tar program verifies that the file's sensitivity label specified in
the archive equals the sensitivity label of the destination
directory. If not, the file is not restored. This operation must be
invoked from the global zone. If the archived file has a relative
pathname, it is restored to the corresponding directory with the same
label, if available. This is done by prepending to the current
destination directory the root pathname of the zone whose label
equals the file. If no such zone exists, the file is not restored.

Limited support is provided for extracting labeled archives from
Trusted Solaris 8. Only sensitivity labels, and multi-level directory
specifications are interpreted. Privilege specifications and audit
attribute flags are silently ignored. Multilevel directory
specifications including symbolic links to single level directories
are are mapped into zone-relative pathnames if a zone with the same
label is available. This support is intended to facilitate migration
of home directories. Architectural differences preclude the
extraction of arbitrarily labeled files from Trusted Solaris 8 into
identical pathnames in Trusted Extensions. Files cannot be extracted
unless their archived label matches the destination label.


v

Verbose. Output the name of each file preceded by the function
letter. With the t function, v provides additional information about
the tarfile entries. The listing is similar to the format produced by
the -l option of the ls(1) command.


w

What. Output the action to be taken and the name of the file, then
await the user's confirmation. If the response is affirmative, the
action is performed; otherwise, the action is not performed. This
function modifier cannot be used with the t function.


X

Exclude. Use the exclude-file argument as a file containing a list of
relative path names for files (or directories) to be excluded from
the tarfile when using the functions c, x, or t. Be careful of
trailing white spaces. Also beware of leading white spaces, since,
for each line in the excluded file, the entire line (apart from the
newline) is used to match against the initial string of files to
exclude. Lines in the exclude file are matched exactly, so an entry
like "/var" does not exclude the /var directory if tar is backing up
relative pathnames. The entry should read "./var" under these
circumstances. The tar command does not expand shell metacharacters
in the exclude file, so specifying entries like "*.o" does not have
the effect of excluding all files with names suffixed with ".o". If a
complex list of files is to be excluded, the exclude file should be
generated by some means such as the find(1) command with appropriate
conditions.

Multiple X arguments can be used, with one exclude-file per argument.
In the case where included files (see -I include-file operand) are
also specified, the excluded files take precedence over all included
files. If a file is specified in both the exclude-file and the
include-file (or on the command line), it is excluded.


z

Use gzip for compressing or decompressing the archives.


Z

Use compress for compressing or decompressing the archives.


@

Include extended attributes in archive. By default, tar does not
place extended attributes in the archive. With this flag, tar looks
for extended attributes on the files to be placed in the archive and
add them to the archive. Extended attributes go in the archive as
special files with a special type label. When this modifier is used
with the x function, extended attributes are extracted from the tape
along with the normal file data. Extended attribute files can only be
extracted from an archive as part of a normal file extract. Attempts
to explicitly extract attribute records are ignored.


/

Include extended system attributes in archive. By default, tar does
not place extended system attributes in the archive. With this flag,
tar looks for extended system attributes on the files to be placed in
the archive and adds them to the archive. Extended system attributes
go in the archive as special files with a special type label. When
this modifier is used with the x function, extended system attributes
are extracted from the tape along with the normal file data. Extended
system attribute files can only be extracted from an archive as part
of a normal file extract. Attempts to explicitly extract attribute
records are ignored.


[0-7]

Select an alternative drive on which the tape is mounted. The default
entries are specified in /etc/default/tar. If no digit or f function
modifier is specified, the entry in /etc/default/tar with digit "0"
is the default.

USAGE

See largefile(7) for the description of the behavior of tar when
encountering files greater than or equal to 2 Gbyte ( 2^31 bytes).


The automatic determination of the actual blocking factor can be fooled
when reading from a pipe or a socket (see the B function modifier below).


1/4" streaming tape has an inherent blocking factor of one 512-byte
block. It can be read or written using any blocking factor.


This function modifier works for archives on disk files and block special
devices, among others, but is intended principally for tape devices.


For information on tar header format, see archives.h(3HEAD).

EXAMPLES

Example 1: Creating an archive of your home directory

The following is an example using tar to create an archive of your home
directory on a tape mounted on drive /dev/rmt/0:


example% cd
example% tar cvf /dev/rmt/0 .
messages from tar


The c function letter means create the archive. The v function modifier
outputs messages explaining what tar is doing. The f function modifier
indicates that the tarfile is being specified (/dev/rmt/0 in this
example). The dot (.) at the end of the command line indicates the
current directory and is the argument of the f function modifier.


Display the table of contents of the tarfile with the following command:


example% tar tvf /dev/rmt/0


The output is similar to the following for the POSIX locale:


rw-r--r-- 1677/40 2123 Nov 7 18:15 1985 ./test.c
...
example%


The columns have the following meanings:


o column 1 is the access permissions to ./test.c

o column 2 is the user-id/group-id of ./test.c

o column 3 is the size of ./test.c in bytes

o column 4 is the modification date of ./test.c. When the
LC_TIME category is not set to the POSIX locale, a different
format and date order field can be used.

o column 5 is the name of ./test.c


To extract files from the archive:


example% tar xvf /dev/rmt/0
messages from tar
example%


If there are multiple archive files on a tape, each is separated from the
following one by an EOF marker. To have tar read the first and second
archives from a tape with multiple archives on it, the non-rewinding
version of the tape device name must be used with the f function
modifier, as follows:


example% tar xvfp /dev/rmt/0n read first archive from tape
messages from tar
example% tar xvfp /dev/rmt/0n read second archive from tape
messages from tar
example%


Notice that in some earlier releases, the above scenario did not work
correctly, and intervention with mt(1) between tar invocations was
necessary. To emulate the old behavior, use the non-rewind device name
containing the letter b for BSD behavior. See the Close Operations
section of the mtio(4I) manual page.

Example 2: Archiving files from /usr/include and from /etc to default tape

drive 0


To archive files from /usr/include and from /etc to default tape drive 0:


example% tar c -C /usr include -C /etc .


The table of contents from the resulting tarfile would produce output
like the following:


include/
include/a.out.h
and all the other files in /usr/include ...
./chown and all the other files in /etc


To extract all files in the include directory:


example% tar xv include
x include/, 0 bytes, 0 tape blocks \
and all files under include ...

Example 3: Transferring files across the network

The following is an example using tar to transfer files across the
network. First, here is how to archive files from the local machine
(example) to a tape on a remote system (host):


example% tar cvfb - 20 files| \
rsh host dd of=/dev/rmt/0 obs=20b
messages from tar
example%


In the example above, we are creating a tarfile with the c key letter,
asking for verbose output from tar with the v function modifier,
specifying the name of the output tarfile using the f function modifier
(the standard output is where the tarfile appears, as indicated by the
`-' sign), and specifying the blocksize (20) with the b function
modifier. If you want to change the blocksize, you must change the
blocksize arguments both on the tar command and on the dd command.

Example 4: Retrieving files from a tape on the remote system back to the

local system


The following is an example that uses tar to retrieve files from a tape
on the remote system back to the local system:


example% rsh -n host dd if=/dev/rmt/0 bs=20b | \
tar xvBfb - 20 files
messages from tar
example%


In the example above, we are extracting from the tarfile with the x key
letter, asking for verbose output from tar with the v function modifier,
telling tar it is reading from a pipe with the B function modifier,
specifying the name of the input tarfile using the f function modifier
(the standard input is where the tarfile appears, as indicated by the "-"
sign), and specifying the blocksize (20) with the b function modifier.

Example 5: Creating an archive of the home directory

The following example creates an archive of the home directory on
/dev/rmt/0 with an actual blocking factor of 19:


example% tar cvfb /dev/rmt/0 19 $HOME


To recognize this archive's actual blocking factor without using the b
function modifier:


example% tar tvf /dev/rmt/0
tar: blocksize = 19
...


To recognize this archive's actual blocking factor using a larger nominal
blocking factor:


example% tar tvf /dev/rmt/0 30
tar: blocksize = 19
...


Attempt to recognize this archive's actual blocking factor using a
nominal blocking factor that is too small:


example% tar tvf /dev/rmt/0 10
tar: tape read error

ENVIRONMENT VARIABLES

See environ(7) for descriptions of the following environment variables
that affect the execution of tar: LC_COLLATE, LC_CTYPE, LC_MESSAGES,
LC_TIME, TZ, and NLSPATH.


Affirmative responses are processed using the extended regular expression
defined for the yesexpr keyword in the LC_MESSAGES category of the user's
locale. The locale specified in the LC_COLLATE category defines the
behavior of ranges, equivalence classes, and multi-character collating
elements used in the expression defined for yesexpr. The locale specified
in LC_CTYPE determines the locale for interpretation of sequences of
bytes of text data a characters, the behavior of character classes used
in the expression defined for the yesexpr. See locale(7).

EXIT STATUS

The following exit values are returned:

0

Successful completion.


>0

An error occurred.

FILES

/dev/rmt/[0-7][b][n]


/dev/rmt/[0-7]l[b][n]


/dev/rmt/[0-7]m[b][n]


/dev/rmt/[0-7]h[b][n]


/dev/rmt/[0-7]u[b][n]


/dev/rmt/[0-7]c[b][n]


/etc/default/tar

Settings might look like this:
archive0=/dev/rmt/0
archive1=/dev/rmt/0n
archive2=/dev/rmt/1
archive3=/dev/rmt/1n
archive4=/dev/rmt/0
archive5=/dev/rmt/0n
archive6=/dev/rmt/1
archive7=/dev/rmt/1n


/tmp/tar*

ATTRIBUTES

See attributes(7) for descriptions of the following attributes:


+--------------------+-----------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-----------------+
|CSI | Enabled |
+--------------------+-----------------+
|Interface Stability | Committed |
+--------------------+-----------------+

SEE ALSO

ar(1), basename(1), bzip2(1), cd(1), chown(1), compress)(1), cpio(1),
csh(1), dirname(1), find(1), gzip(1), ls(1), mt(1), pax(1), setfacl(1),
umask(1), xz(1), archives.h(3HEAD), mtio(4I), attributes(7), environ(7),
fsattr(7), largefile(7), mknod(8)

DIAGNOSTICS

Diagnostic messages are output for bad key characters and tape read/write
errors, and for insufficient memory to hold the link tables.

NOTES

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


Tape errors are handled ungracefully.


The tar archive format allows UIDs and GIDs up to 2097151 to be stored in
the archive header. Files with UIDs and GIDs greater than this value is
archived with the UID and GID of 60001.


If an archive is created that contains files whose names were created by
processes running in multiple locales, a single locale that uses a full
8-bit codeset (for example, the en_US locale) should be used both to
create the archive and to extract files from the archive.


Neither the r function letter nor the u function letter can be used with
quarter-inch archive tapes, since these tape drives cannot backspace.


Since tar has no options, the standard "--" argument that is normally
used in other utilities to terminate recognition of options is not
needed. If used, it is recognized only as the first argument and is
ignored.


Since -C directory file and -I include-file are multi-argument operands,
any of the following methods can be used to archive or extract a file
named -C or -I:

1. Specify them using file operands containing a / character on
the command line (such as /home/joe/-C or ./-I).

2. Include them in an include file with -I include-file.

3. Specify the directory in which the file resides:

-C directory -C


or

-C directory -I


4. Specify the entire directory in which the file resides:

-C directory .


April 14, 2016 TAR(1)