tar(1) DG/UX R4.11MU05 tar(1)
NAME
tar - file archiver
SYNOPSIS
tar c[vwfbknFhLleA[#]] device block volsize incfile [file . . .]
tar c[vwfbknXhLleA[#]] device block volsize excfile [[-I incfile | file] . . . ]
tar r[vwfbknFhLlieA[#]] device block volsize incfile [file . . .]
tar r[vwfbknXhLlieA[#]] device block volsize excfile [[-I incfile | file] . . . ]
tar t[vfbnFieA[#]] device block incfile [file . . .]
tar t[vfbnXieA[#]] device block excfile [[-I incfile | file] . . . ]
tar u[vwfbknFhLlieA[#]] device block volsize incfile [file . . .]
tar u[vwfbknXhLlieA[#]] device block volsize excfile [[-I incfile | file] . . . ]
tar x[vwfbnFieAmop[#]] device block incfile [file . . .]
tar x[vwfbnXieAmop[#]] device block excfile [[-I incfile | file] . . . ]
DESCRIPTION
NOTE: tar on a system with DG/UX information security does not save
security attributes. Thus, the security attributes of files
restored with tar will be set based upon the security
attributes of the restoring process. It is recommended that
dump2(1M) or cpio(1) be used to make a trusted archive.
NOTE: Tape devices are controlled devices, and the non-privileged
user may not have complete access to them. As installed,
systems with DG/UX information security allow all users write
access to tape devices, and only privileged users are allowed
read access. This is because all tape devices are assigned a
MAC range of from IMPLEMENTATION_LO to IMPLEMENTATION_HI. The
system administrator may allow different access by reseting
these values.
tar saves files on an archive medium (such as a floppy diskette or a
tape) and restores them from that medium. Its actions are controlled
by a string of characters containing one function letter (c, r, t, u,
or x), and possibly followed by one or more function modifiers (v, w,
f, b, k, n, F, X, h, L, l, i, e, A, m, o, p, and #). Other arguments
to the command are files (or directory names) specifying which files
are to be dumped or restored. In all cases, appearance of a
directory name refers to the files and (recursively) subdirectories
of that directory.
The function letters are as follows:
c Create a new archive; writing begins at the beginning of the
archive, instead of after the last file.
r Replace. The named files are written on the end of an
existing archive.
t Table. The names of the specified files are listed each time
they occur on the archive. If no files are specified, all
the names in the archive are listed. With the v modifier,
the listing is similar to the format produced by the ls -l
command. [See ls(1).]
u Update. The named files are added to the archive if they are
not already there, or have been modified since last written
on that archive.
x Extract. The named files are extracted from the archive. If
a named file matches a directory whose contents have been
written onto the archive, this directory is (recursively)
extracted. Use the file or directory's relative path when
appropriate, or tar will not find a match. If no files are
specified, the entire contents of the archive are extracted.
If several files with the same name are on the archive, the
last one overwrites all earlier ones.
The modifiers below may be used in addition to the letter that
selects the desired function. Use them in the order shown in the
synopsis.
v Normally, tar does its work silently. The v (verbose)
modifier causes it to print the name of each file it treats,
preceded by the function letter. With the t function letter,
v gives more information about the archive entries than just
the name.
w What. This modifier causes tar to print the action to be
taken, followed by the name of the file, and then wait for
your confirmation. If a word beginning with y is given, the
action is performed. Any other input means no.
f File. This causes tar to use the device argument as the name
of the archive. If f is given, /etc/default/tar is not
searched. If f is omitted, tar will use the device indicated
by the TAPE environment variable, if set; otherwise, it will
use the default values defined in /etc/default/tar. If the
name of the file is -, tar writes to the standard output or
reads from the standard input, whichever is appropriate.
Thus, tar can be used as the head or tail of a pipeline. tar
can also be used to move hierarchies with the command:
cd fromdir; tar cf - . | (cd todir; tar xf -)
b This modifier causes tar to use the block argument as the
blocking factor for archive records. If the device is
selected via an /etc/default/tar entry, the default blocking
factor comes from that entry. If a device other than - is
selected via the f modifier, the default is 32. The maximum
blocking factor is 128. This modifier should not be supplied
when operating on regular archives or block special devices.
The blocking factor is determined automatically when reading
tapes (function letters x and t) unless it is larger than 32.
To read tapes that contain larger records, provide the b
modifier with a larger value.
k This modifier uses the volsize argument as the size, in
kilobytes per volume, for non-tape devices (such as floppy
drives). The argument to k should be a multiple of the
blocking factor; if it isn't, tar will round it down to the
nearest such multiple. A value of 0 for volsize causes
multi-volume mode to be disabled (interpreted as an infinite
volume size).
When restoring from a multi-volume archive, tar prompts for a
new volume only if a split file has been partially restored.
Otherwise tar exits at the end of the volume. If this
happens, run the tar command again for the next volume.
n This modifier must be used when device is not a tape device.
F This modifier uses the incfile argument as a file containing
a list of named files (or directories) to be included. This
modifier may not be used with the X modifier.
X This modifier uses the excfile argument as a file containing
a list of named files (or directories) to be excluded.
Multiple excfile arguments may be used, with one X modifier
per excfile. This modifier may not be used with the F
modifier.
h This modifier causes tar to follow symbolic links as if they
were normal files or directories. Normally tar does not
follow symbolic links.
L This function is identical to that of the h modifier.
l This modifier causes tar to complain if it cannot resolve all
of the links to the files being dumped. If the l modifier is
not specified, no error messages are printed.
i This modifier causes tar to ignore directory checksum errors.
e This modifier causes tar to quit when certain minor errors
are encountered. Examples of "minor errors" are: a filename
that is too long, and a file that changes size while it is
being backed up. Otherwise tar will continue when minor
errors are encountered.
A This modifier causes absolute pathnames for files to be
suppressed. This causes all pathnames to be interpreted as
relative to the current working directory.
m This modifier causes tar to not restore the modification
times. The modification time of the file will be the time of
extraction.
o When tar is run by a user without appropriate privilege,
extracted files take on the user and group identifiers of the
user running the program. This modifier gives a user with
appropriate privilege that same behavior. Normally, when tar
is run by a user with appropriate privilege, extracted files
take on the user and group identifiers that are stored in the
archive.
p This modifier restores the named file arguments to their
original modes, ignoring the present value returned by umask.
[See umask(2).] This modifier is not necessary if the
effective user ID is root, in which case the umask is always
ignored and file modes are restored exactly as they were
recorded in the archive.
[#] This modifier allows you to specify, via the file
/etc/default/tar, the device to be used for creating or
extracting an archive. Specify a number 0 through 9 as the
value of #. tar looks for the ``archive#='' entry in
/etc/default/tar and uses the device name specified there.
In addition to the device name, an entry in /etc/default/tar
specifies the blocking factor and the volume size to be used
for that device. (The b and k modifiers may be used to
override these values.) For example, the default device
entry in /etc/default/tar might look like:
archive0=/dev/rmt/0n 32 150000
where 32 is the blocking factor and 150000 is the volume size
(in kilobytes).
The following option may appear after all arguments corresponding to
function modifiers:
-I The -I option is similar in function to the F modifier. The
argument following -I is assumed to be a file containing a
list of named files (or directories) to be included. Unlike
the F modifier, -I may be used with the X modifier; it may
also be specified more than once on the command line. The -I
option and the F modifier may not be specified together.
FILES
/etc/default/tar
/dev/rmt/*
/tmp/tar*
DIAGNOSTICS
Complains about bad key characters and tape read/write errors.
Complains if insufficient memory is available to hold the link
tables.
SEE ALSO
ar(1), cpio(1), ls(1), umask(2), appropriateprivilege(5), tar(5)
NOTES
tar maintains the block allocation limit of control point
directories.
tar does not maintain the file node allocation limit of control point
directories due to limitations in the tar(5) header format.
The r and u function letters are not supported when writing to tape
drives; they can be used only when writing tar images to disk.
The limit on pathname length is 255 characters (155 characters for
the directory portion and 100 characters for the filename portion).
The block and seek sizes reported when verbose mode (modifier v) is
specified are rounded to the nearest kilobyte.
On a generic DG/UX system, appropriate privilege is granted by having
an effective UID of 0 (root). See the appropriateprivilege(5) man
page for more information.
On a system with DG/UX information security, appropriate privilege is
granted by having one or more specific capabilities enabled in the
effective capability set of the user. See the capdefaults(5) man
page for more information.
Licensed material--property of copyright holder(s)