1STAR(1) Schily´s USER COMMANDS STAR(1)
2
6 star - unique standard tape archiver
7
9 star command [options] [-find] file1 ... filen [find_expr]
10 ustar command [options] [-find] file1 ... filen [find_expr]
11 tar command [options] file1 ... filen
12 star -copy [options] [-find] file1 ... [f_expr] directory
13 star -copy [options] -C from_directory . to_directory
14
16 Star is a very fast tar(1) like tape archiver with improved functional‐
17 ity.
18 Star archives and extracts multiple files to and from a single file
20 called a tarfile. A tarfile is usually a magnetic tape, but it can be
21 any file. In all cases, appearance of a directory name refers to the
22 files and (recursively) subdirectories of that directory.
23 Star's actions are controlled by the mandatory command flags from the
25 list below. The way star acts may be modified by additional options.
26 Note that unpacking tar archives may be a security risk because star
28 may overwrite existing files. See SECURITY NOTES for more information.
29
31 Star includes the first free implementation of POSIX.1-2001 extended
32 tar headers. The POSIX.1-2001 extended tar headers define a new stan‐
33 dard way for going beyond the limitations of the historic tar format.
34 They allow (among others) to archive all UNIX time stamps in sub-second
35 resolution, files of arbitrary size and filenames without length limi‐
36 tation using UNICODE UTF-8 coding for best exchange compatibility.
37 Star by default uses a fifo to optimize data flow from/to tape. This
39 results in a normally streaming tape during the whole backup. See
40 -fifo and fs= option to get information on how to find the best fifo
41 size.
42 Star includes a pattern matcher to control the list of files to be pro‐
44 cessed. This gives a convenient interface for archiving and restoring
45 complex lists of files. In conjunction with the -w flag it is easy to
46 merge a tar archive into an existing file tree. See also -U option. In
47 create mode use the pat= option to specify either select or exclude
48 patterns (depending on the -V flag). In extract or list mode all file
49 type arguments are interpreted as select patterns while the patterns
50 specified with the pat= option may be used as select or exclude pat‐
51 terns (depending on the -V flag). Have a look at the description of
52 the -C option to learn how to fetch files from a list of directories
53 (in create mode) or to distribute files to a list of directories (in
54 extract mode). A substitute option allows ed(1) like pattern substitu‐
55 tion in file names.
56 Star includes an enhanced function that is similar to the find(1) com‐
58 mand (see sfind(1)). This allows to use find expressions, even in
59 extract or list mode, directly on the content on an archive. The
60 extensions to find(1) allow to modify the file metadata.
61 Star includes a sophisticated diff command. Several diff options allow
63 user tailorable functionality. Star won't show you differences you are
64 not interested in. Check the diffopts= option for more details.
65 Star has no limitation on filename length. Pathnames and linknames up
67 to PATH_MAX (1023 bytes with old OS versions and 4095 bytes with
68 POSIX.1-2001) may be archived. Later versions may be able to deal with
69 longer pathnames.
70 Star deals with all 3 times, available for files on UNIX systems if the
72 archive format is either chosen from the star specific formats or is a
73 format that uses POSIX.1-2001 extended headers. This is either done in
74 second resolution by using a star specific POSIX.1-1988 compatible
75 extension or in sub second resolution by using POSIX.1-2001 extended
76 headers. Star is able to store and restore all 3 times (mtime, atime
77 and even ctime). On Solaris 2.x systems, star is able to do backups
78 without changing any of the 3 the times.
79 If used with the H=ustar option, or if called as ustar or tar while the
81 H=headertype option is not used, star is 100% POSIX compliant.
82 Star's default format (if called as star) is xstar and is as posix com‐
84 pliant as possible. Enhancements to the standard that prevent correct
85 extraction of single files when using a different tar implementation
86 that is only POSIX.1-1988 compliant may occur, but they only affect
87 single files with a pathname that is longer than 100+130 chars or when
88 archiving sparse files with the -sparse option in effect. All other
89 files will extract correctly. See the description for the H=headertype
90 option below for more information on archive formats and possible ar‐
91 chive interchange problems.
92 Star makes it easy to repair corrupted filesystems. After a fsck -y has
94 been run on the filesystem, star is able to restore only the missing
95 files automatically. Use then star -diff to check for differences (see
96 EXAMPLES for more information).
97 Star automatically recognizes the type of the archive. Star therefore
99 is able to handle features and properties of different archive types in
100 their native mode, if it knows about the peculiarities of the archive
101 type. See the H=headertype option for more details. To be able to do
102 this, star adds hidden fingerprints to the archive header that allows
103 to recognise all star specific archive formats. The GNU tar format is
104 recognised by the way it deviates from the standard.
105 Star automatically recognizes and handles byte swapped archives. There
107 is no option to manually control byte swapping.
108 Star automatically recognizes and handles compressed archives inside
110 plain files.
111 Star is able to archive and restore Access Control Lists for files
113 using POSIX.1-2001 extended headers.
114
116 In native mode, star is compatible to the command line syntax of a typ‐
117 ical POSIX command and for this reason expects commands and options to
118 start with a single dash (-). In this case, commands and options may be
119 specified separately, all boolean or increment type options may be
120 specified either separately or combined. For compatibility with GNU
121 programs, long options may alternatively start with a double dash. In
122 compatibility mode to POSIX tar, star expects commands and options to
123 appear as one single string that does not start with a dash. In POSIX
124 tar compatibility mode, additional non POSIX options may be specified
125 but must appear after the POSIX options and their args and need to
126 start with a dash.
127 -c Create a new tarfile and write named files into it. Writing
129 starts at the beginning of tarfile. See -v option for informa‐
130 tion on how to increase verbosity while the archive is written.
131 -copy Copy named files to the target directory which is the last file
133 type argument. The target directory must exist. The shorthand
134 -cx instead of -copy is not allowed because this could be a
135 result of a typo.
136 If the option -diff has been specified in addition, star per‐
138 forms a one pass directory tree compare instead of copying
139 files. The shorthand -c -diff instead of -copy -diff is also
140 allowed.
141 On operating systems with slow file I/O (such as Linux), it may
143 help to use -no-fsync in addition, but then star is unable to
144 detect all error conditions; so use with care.
145 If the option -t has been specified in addition, the last file
147 type argument is not a target directory and star is performing a
148 one pass listing instead of copying files. This makes sense as
149 the listing from star may be better readable than the output
150 from ls -lR. The shorthand -c -t or -ct instead of -copy -t is
151 also allowed.
152 The job is by default done in the best archive mode. This
154 implies that it defaults to H=exustar -dump. When in -copy
155 mode, star forks into two processes and data exchange is done
156 via the shared memory from the FIFO. This gives the best possi‐
157 ble performance. Without FIFO, the -copy mode will not work.
158 The list= option, patterns and substitutions apply only to the
160 create side of the copy command.
161 -diff Compare the content and the attributes of the files from the ar‐
163 chive in tarfile to the filesystem. This may also be used to
164 compare two file trees in the filesystem. If you use a set of
165 diffopts that fits your needs, it will give - in many cases - a
166 more readable output than diff -r. If you use star's dump
167 extensions for the tar archive, the -diff option allows to find
168 even if the directory in the file tree contains more files than
169 the archive. This way, it is possible to compare all properties
170 of two file trees in one run. See diffopts for more details.
171 Adding one or more -v options increases the verbosity. With -vv
172 and above, the directory content is compared also if in -dump
173 mode.
174 -n No extraction. Show what star would do, in case the -x command
176 had been specified.
177 -r Replace files in a tarfile. The named files are written to the
179 end of tarfile. This implies that later, the appropriate files
180 will be found more than once on the tarfile.
181 -t Table of contents. List the contents of the tarfile. If the -v
183 flag is used, the listing is similar to the format of ls -l out‐
184 put. With this option, the flags -a, -atime and -ctime have a
185 different meaning if the archive is in star, xstar, xustar,
186 exustar, or pax format. The option -a or -atime lists the
187 access time instead of the modification time, the option -ctime
188 lists the file creation time instead of the modification time.
189 The option -tpath may be used in addition to modify the output
190 so it may be used in shell scripts.
191 -u Update a tarfile. The named files are written to the end of
193 tarfile if they are not already there or if the files are newer
194 than the files of the same name found in the archive. The -r
195 and -u command only work if the tar archives is a regular file
196 or if the tar archive is an unblocked tape that may backspace.
197 -x Extract the named files from the tarfile. If no filename argu‐
199 ment or pattern is specified, the entire content of the tarfile
200 is restored. If the -U flag is not used, star extracts no file
201 which is older than the corresponding file on disk.
202 On operating systems with slow file I/O (such as Linux), it may
204 help to use -no-fsync in addition, but then star is unable to
205 detect all error conditions; so use with care.
206 Except for the shorthands documented above, exactly one of the commands
208 above must be specified.
209 If one or more patterns or substitution commands have been specified,
211 they apply to any of the command listed above. In copy mode, all pat‐
212 terns and substitute commands apply to the create side.
213
216 -help Print a summary of the most important options for star(1).
217 -xhelp Print a summary of the less important options for star(1).
219 -/ Don't strip leading slashes from file names when extracting an
221 archive. Tar archives containing absolute pathnames are usually
222 a bad idea. With other tar implementations, they may possibly
223 never be extracted without clobbering existing files. Star for
224 that reason, by default strips leading slashes from filenames
225 when in extract mode. As it may be impossible to create an ar‐
226 chive where leading slashes have been stripped while retaining
227 correct path names, star does not strip leading slashes in cre‐
228 ate mode.
229 See SECURITY NOTES for more information.
231 -.. Don't skip files that contain /../ in the name. Tar archives
233 containing names with /../ could be used to compromise the sys‐
234 tem. If they are unpacked together with a lot of other files,
235 this would in most cases not even be noticed. For this reason,
236 star by default does not extract files that contain /../ in the
237 name if star is not in interactive mode (see -w option).
238 See SECURITY NOTES for more information.
240 -7z run the input or output through a p7zip pipe - see option -z
242 below.
243 Note that the p7zip program currently does not operate on a pipe
245 but on a /tmp file copy and thus limits the maximum archive
246 size.
247 -0
250 -1
252 -2
254 -3
256 -4
258 -5
260 -6
262 -7 Select an archive entry from /etc/default/star. The format for
264 the archive entries is the same as the format in
265 /etc/default/tar in Solaris.
266 -acl Handle Access Control List (ACL) information in create and
268 extract mode. If -acl has been specified, star is in create
269 mode and the header type is exustar, star will add ACL informa‐
270 tion to the archive using POSIX.1-2001 extended headers. If
271 -acl has been specified and star is in extract mode, star will
272 try to restore ACL information. If there is no ACL information
273 for one or all files in the archive, star will clear the ACL
274 information for the specific file. Note that if -acl has not
275 been specified, star will not handle ACL information at all and
276 files may inherit ACL information from the parent directories.
277 If the -acl option has been specified, star assumes that the -p
278 option has been specified too.
279 artype=headertype
281 Generate a tape archive in headertype format. If this option is
282 used in extract/list mode this forces star to interpret the
283 headers to be of type headertype. As star even in case of a
284 user selected extract archive format does format checking, it
285 may be that you will not be able to unpack a specific archive
286 with all possible forced archive formats. Selecting the old tar
287 format for extraction will always work though. Valid parameter
288 for headertype are:
289 help Print a help message about possible header types.
291 v7tar Old UNIX V7 tar format. This archive format may only
293 store plain files. Pathnames or linknames longer than
294 99 chars may not be archived.
295 If the v7tar format has been selected, star will not
297 use enhancements to the historic UNIX V7 tar format.
298 File size is limited to 2 GB - 2 bytes, uid/gid is
299 limited to 262143. Sparse files will be filled up
300 with zeroes.
301 tar Old BSD UNIX tar format. This archive format may only
303 store plain files, directories and symbolic links.
304 Pathnames or linknames longer than 99 chars may not be
305 archived. See also the -d option as a note to some
306 even older tar implementations.
307 If the tar format has been selected, star will not use
309 enhancements to the historic tar format. File size is
310 limited to 2 GB - 2 bytes, uid/gid is limited to
311 262143. Sparse files will be filled up with zeroes.
312 star Old star standard format. This is an upward/downward
314 compatible enhancement of the old (pre Posix) UNIX tar
315 format. It has been introduced in 1985 and therefore
316 is not Posix compliant. The star format allows to ar‐
317 chive special files (even sockets) and records access
318 time and creation time besides the modification time.
319 Newer versions of the old star format allow very long
320 filenames (100+155 chars and above), linknames > 100
321 chars and sparse files (if -sparse is used). This
322 format is able to copy the device nodes on HP-UX that
323 have 24 bits in the minor device number, which is more
324 then the 21 bits that are possible with the
325 POSIX-1003.1-1988 archive format.
326 The nonstandard extensions are located in the space
328 between the link name and the POSIX file name prefix.
329 As the star format does not use a POSIX magic string,
330 the extensions do not interfere with the POSIX tar
331 formats. The last 4 bytes of the tar header contain a
332 'tar\0' signature.
333 gnutar This is a commonly used, but unfortunately not Posix
335 compliant (although designed after 1987) enhancement
336 to the old tar format. The gnutar format has been
337 defined between 1989 and 1994. Do not use the gnutar
338 archive format unless you want to create an archive
339 for a target system that is known to have only the
340 gnutar program available. The gnutar archive format
341 violates basic rules for any (even the historic) tar
342 archive format, in special when sparse files are
343 archived using the -sparse option. Using the gnutar
344 archive format causes a high risk that the resulting
345 archive may only be read by gnutar or by star. The
346 implementation of the gnutar archive format within
347 star is not complete, but sufficient for most gnutar
348 archives. See NOTES for more information.
349 ustar IEEE/Posix1003/IEC-9945-1-1988 Standard Data Inter‐
351 change format. With this option in effect, star will
352 generate 100% POSIX.1-1988 compliant tar archives.
353 Files with pathnames longer than 100+155 chars or
354 linknames longer than 100 chars may not be archived.
355 If star is called as ustar the default archive format
356 is ustar.
357 If the ustar format has been selected, star will not
359 use enhancements to the POSIX.1-1988 tar format, the
360 archive will be strictly conforming. File size is
361 limited to 8 GB, uid/gid/major/minor is limited to
362 2097151. Sparse files will be filled up with zeroes.
363 pax The IEEE/Posix1003/IEC-9945-1-1988 successor is the
365 POSIX-1003.1-2001 Standard Data Interchange format.
366 It is called the pax archive format.
367 If the pax format has been selected, star will not use
369 enhancements to the POSIX.1-2001 tar format, the ar‐
370 chive will be strictly conforming. File size is
371 unlimited, uid/gid/uname/gidname is unlimited,
372 major/minor is limited to 2097151. Sparse files will
373 be filled up with zeroes.
374 xstar The extended standard tar format has been introduced
376 in 1994. Star uses the xstar format as default ar‐
377 chive format. This is an upward/downward compatible
378 enhancement of the IEEE/Posix1003/IEC-9945-1 Standard
379 Data Interchange format. It allows among others very
380 long filenames (100+130 chars and above) and records
381 access time and creation time. Sparse files will be
382 archived correctly (if -sparse is used).
383 The access time and creation time are stored at the
385 end of the POSIX file name prefix (this limits the
386 prefix to 130 chars). These extensions do not inter‐
387 fere with the POSIX standard as the fields for mtime
388 and ctime field are always separated from the POSIX
389 file name prefix by a null byte. The last 4 bytes of
390 the tar header contain a 'tar\0' signature.
391 The xstar format is the default format when star is
393 neither called as tar nor called as ustar.
394 xustar A new format introduced 1998, that omits the 'tar\0'
396 signature at the end of the tar header. It is other‐
397 wise identical to the xstar format. As some tar
398 implementations do not follow the POSIX rules and com‐
399 pute the checksum for less than 512 bytes of the tar
400 header, this format may help to avoid problems with
401 these broken tar implementations. The main other dif‐
402 ference to the xstar format is that the xustar format
403 uses POSIX.1-2001 extended headers to overcome limita‐
404 tions of the historic tar format while the xstar for‐
405 mat uses proprietary extensions. The xustar format is
406 the default format when star is called as tar.
407 File size is unlimited, uid/gid/uname/gidname is
409 unlimited, major/minor is unlimited. Sparse files
410 will be archived correctly (if -sparse is used).
411 exustar A format similar to the xustar format but with forced
413 POSIX.1-2001 extended headers. If this format is used
414 together with the -acl option, star records Access
415 Control Lists (ACLs) in POSIX.1-2001 extended headers.
416 The exustar format allows to archive all file types
418 but it does not archive more than the POSIX.1-1988 set
419 by default. If the -dump option is used or if star is
420 otherwise on dump mode, star archives all file types
421 and in addition archives more meta data then usual.
422 File size is unlimited, uid/gid/uname/gidname is
424 unlimited, major/minor is unlimited. Sparse files
425 will be archived correctly (if -sparse is used).
426 suntar The extended header format found on Solaris 7/8/9.
428 This format is similar to the pax format but does not
429 handle atime and ctime and in addition uses 'X' as the
430 typeflag for the extended headers instead of the stan‐
431 dard 'x'.
432 File size is unlimited, uid/gid/uname/gidname is
434 unlimited, major/minor is unlimited. Sparse files
435 will be filled up with zeroes.
436 bin The cpio UNIX V7 binary format. This is a format with
438 big interoperability problems. Try to avoid this for‐
439 mat. It is only present to make the scpio command
440 SVr4 compliant.
441 cpio The POSIX.1-1988 cpio format. This format uses octal
443 ascii headers. A similar format is created by calling
444 cpio -o -c on pre SYSVr4 systems and by calling cpio
445 -o -Hodc on SYSVr4 systems. The POSIX.1-1988 cpio
446 format allows a file name length up to 262142 charac‐
447 ters and allows to archive nearly any file type. File
448 size is limited to 8 GB, uid/gid/st_dev is limited to
449 262143. The way major and minor device numbers are
450 stored inside the st_dev field is implementation
451 dependent.
452 Even though this archive format is covered by the
454 POSIX.1-1988 standard, it has a lower portability than
455 the ustar format. Try to avoid the cpio archive for‐
456 mat.
457 odc This archive format is similar to the The POSIX.1-1988
459 cpio format but the file name length is limited to 255
460 characters and the socket file type is not allowed.
461 This archive format has been introduced to allow non
462 POSIX cpio implementations such as the cpio program on
463 SYSV to accept the archive. Use this format whenever
464 you are not sure if the target system offers a fully
465 POSIX compliant cpio program.
466 Even though this archive format is covered by the
468 POSIX.1-1988 standard, it has a lower portability than
469 the ustar format. Try to avoid the odc archive format.
470 asc Tell star to create a cpio archive in the ascii format
472 that is created with cpio -o -c on SYSVr4 systems. It
473 uses extended (32 bit) numbers for uid's, gid's and
474 device numbers but limits the file size to 4 GB - 2
475 bytes although the format has been specified after the
476 POSIX.1-1988 cpio format. Try to avoid the asc ar‐
477 chive format because of its limited portability.
478 crc This format is similar to the asc cpio format but in
480 addition uses a simple byte based checksum called CRC.
481 Try to avoid the crc archive format because of its
482 limited portability.
483 All tar archive formats may be interchanged if the archive con‐
486 tains no files that may not be archived by using the old tar
487 format. Archives in the xstar format may be extracted by any
488 100% POSIX compliant tar implementation if they contain no files
489 with pathnames > 100+130 chars and if they contain no sparse
490 files that have been archived by using the -sparse option.
491 -ask_remove
494 obsoleted by -ask-remove
495 -ask-remove
497 Ask to remove non writable files on extraction. By default,
498 star will not overwrite files that are read only. If this
499 option is in effect, star will ask whether it should remove
500 these files to allow the extraction of a file in the following
501 way:
502 remove 'filename' ? Y(es)/N(o) :
504 -atime, -a
506 Reset access time of files after storing them to tarfile. On
507 Solaris 2.x, (if invoked by root) star uses the _FIOSATIME ioctl
508 to do this. This enables star not to trash the ctime while
509 resetting the atime of the files. If the -atime option is used
510 in conjunction with the list command, star lists access time
511 instead of modification time. (This works only in conjunction
512 with the star, xstar, xustar, exustar, and with the pax format.)
513 Another option to retain the access time for the the files that
514 are going to be archives is to readonly mount a UFS snapshot and
515 to archive files from the mount point of the UFS snapshot.
516 -B Force star to perform multiple reads (if necessary) to fill a
518 block. This option exists so that star can work across the Eth‐
519 ernet, since pipes and sockets return partial blocks even when
520 more data is coming. If star uses stdin as archive file, star
521 behaves as if it has been called with the -B option. For this
522 reason, the option -B in practice is rarely needed.
523 -block-number
525 Print the archive block number (archive offset / 512) at the
526 beginning of each line when in verbose mode. This allows to
527 write backup scripts that archive the offsets for files and that
528 use
529 mt fsr blockno
531 to skip to the tape block number of interest in a fast way if a
533 single file needs to be restored.
534 blocks=#, b=#
536 Set the blocking factor of the tarfile to # times 512 bytes
537 (unless a different multiplication factor has been specified -
538 see bs= option for possible multiplication factors). Changing
539 the blocking factor only makes sense when the archive is located
540 on a real tape device or when the archive is accessed via the
541 remote tape protocol (see f= option below). The default is to
542 use a blocking factor of 20 i.e. 10 kBytes. Increasing the
543 blocksize will speed up the backup. For portability with very
544 old tar implementations (pre BSD 4.2 or pre AT&T SVR4), block‐
545 size should not be more than 10 kBytes. For POSIX.1-1988 com‐
546 patibility, blocksize should be no more than 10 kBytes. For
547 POSIX.1-2001 compatibility, blocksize should be no more than
548 32 kBytes. Most systems also have a hardware limitation for the
549 blocksize, 32 kBytes and 63 kBytes are common limits on many
550 systems. The upper limit in any case is the size of the buffer
551 RAM in the tape drive. Make a test if you want to make sure
552 that the target system will handle the intended blocksize. If
553 you use star for data exchange via tape, it is a good idea to
554 use a blocksize of 10 kBytes unless you are sure that the read‐
555 ing system will handle a larger blocksize. If you use star for
556 backup purposes with recent hardware (e.g. DLT tape drives), a
557 blocksize of 256 kBytes results in sufficient speed and seems to
558 be a good choice. Star allows block sizes up to 2 GByte if the
559 system does not impose a smaller limit. If you want to deter‐
560 mine the blocking factor when reading an unknown tar archive on
561 tape, specify a blocking factor that is higher than the supposed
562 blocking factor of the tape. Star then will determine the
563 blocking factor by reading the first record of the tape and
564 print a message:
565 star: Blocksize = # records.
567 Where # is the blocking factor in multiples of 512 bytes. The
569 blocks= option and the bs= option are equivalent methods to
570 specify the tape block size. The blocks= option is preferred by
571 people who like to use an option that behaves similar to the
572 interface of the historic tar(1) implementations.
573 bs=# Set output block size to #. You may use the same method as in
575 dd(1) and sdd(1). The number representing the size is taken in
576 bytes unless otherwise specified. If a number is followed
577 directly by the letter `.', `w', `b', `k', `m', `g', `t', or
578 `p', the size is multiplied by 1, 2, 512, 1024, 1024*1024,
579 1024*1024*1024, 1024*1024*1024*1024 or 1024*1024*1024*1024*1024.
580 If the size consists of numbers separated by `x' or `*', multi‐
581 plication of the two numbers is performed. Thus bs=7x8k will
582 specify a blocksize of 56 kBytes. Blocksize must be a multiple
583 of 512 bytes. See also the description of the blocks= option
584 for more details on blocksizes. The option bs= is preferred by
585 people who like to use an option that behaves similar to the
586 interface used by dd(1) and sdd(1).
587 -bsdchdir
589 Switch the behavior of the C= option to BSD style. The default
590 behavior of star is to stay in a working directory until a new
591 C= is seen. With BSD tar, the C= option is only related to the
592 next file type argument.
593 -bz run the input or output through a bzip2 pipe - see option -z -Z
595 and -j below. As the -bz the -j the -Z and the -z option are
596 non standard, it makes sense to omit the -bz the -j the -Z and
597 the -z options inside shell scripts if you are going to extract
598 a compressed archive that is located inside a plain file as star
599 will auto detect compression and choose the right decompression
600 option to extract.
601 C=dir
603 -C dir Perform a chdir(2) operation to dir before storing or extracting
605 the next files. In all cases, star will perform the chdir(2)
606 operation relative to the current working directory of the
607 shell.
608 · In list mode (with the -t flag), star ignores all -C
610 options.
611 · In create mode (with the -c, -r and -u flag), star walks
613 through all -C options and file type arguments. While a
614 BSD derived tar(1) implementation goes back to the cur‐
615 rent working directory after storing one file argument
616 that immediately follows the -C option, star changes the
617 directory only if a new -C option follows. To emulate
618 the behavior of a BSD derived tar(1), add a -C . option
619 after the file argument.
620 · In extract mode (with the -x, -n and -diff flag), star
622 builds a pattern list together with corresponding direc‐
623 tories from previous C=dir options and performs a
624 chdir(2) to the corresponding directory of a matching
625 pattern. All pat= options that do not follow a C=dir
626 option are interpreted as if they were preceded by a -C .
627 option. See EXAMPLES for more information.
628 compress-program=name
630 Set a named compress program. The program must compress in a
631 pipe when called without parameters and decompress when run with
632 the -d option in a pipe. This option is otherwise similar to
633 the -z the -j the -Z and the -bz option.
634 -copydlinks
636 Try to recursively copy the content of linked directories
637 instead of creating the link. This is an experimental feature
638 that may help to unpack archives on DOS.
639 -copyhardlinks
641 This option allows to copy hardlinked targets rather than creat‐
642 ing the link. It helps to extract tar files on systems that do
643 not implement hardlinks (e.g. BeOS).
644 -copylinks
646 This option allows to copy both, hard- and symlinked targets
647 rather than creating a link. It helps to extract tar files on
648 systems that do not implement links (e.g. OS/2). To extract and
649 copy all symlinks correctly, you may need to call star twice as
650 star cannot copy files that appear in the archive later than a
651 symlink pointing to them.
652 -copysymlinks
654 This option allows to copy symlinked targets rather than creat‐
655 ing a symbolic link. It helps to extract tar files on systems
656 that do not implement links (e.g. OS/2). To extract and copy
657 all symlinks correctly, you may need to call star twice as star
658 cannot copy files that appear in the archive later than a sym‐
659 link pointing to them.
660 -ctime If used with the list command, this lists ctime rather than
662 mtime if the archive format is star, xstar, xustar, exustar, or
663 pax.
664 If star is run as root and if -ctime is used with the extract
666 command and the same archive formats, this causes star to try to
667 restore even the ctime of a file by generating time storms. You
668 should not do this when in multi user mode because this may con‐
669 fuse programs like cron and the news system. Although star
670 tries to eliminate the accumulative effects of the time storm,
671 there is a tendency for the system clock to slow down a bit.
672 The clock typically lags about one millisecond per extracted
673 file. Use with care and check the system clock after using this
674 feature.
675 If used with the create command this changes the behavior of the
677 newer= option. Star, in this case compares the ctime of all
678 files to the mtime of the stamp file rather then comparing the
679 mtimes of both files.
680 -cumulative
682 A shorthand for -dump-cumulative. See -dump-cumulative for more
683 information.
684 -D Do not descend directories. Normally, star descends the whole
686 tree if it encounters a directory in in its file parameters.
687 The option -D is in effect by default if the list=file option is
688 used. If you like star to descend directories found in the list
689 file, use the -dodesc option (see below).
690 -d Do not store/create directories. Old versions of tar such as
692 published with the seventh edition of UNIX are not able to deal
693 with directories in tar archives. If a tar archive is generated
694 without directories this avoids problems with tar implementa‐
695 tions found on SYSVr3 and earlier. If used during extract, no
696 intermediate missing directories are created.
697 -data-change-warn
699 If the size of a file changes while the file is being archived,
700 treat this condition as a warning only that does not cause a non
701 zero exit code. A warning message is still written if the con‐
702 dition is not otherwise ignored by another rule from an errctl=
703 option. The -data-change-warn option works as if the last error
704 control option was
705 errctl="WARN|GROW|SHRINK *"
707 The -e option or an ABORT entry in a condition set up by errctl=
709 has a higher precedence than the -data-change-warn option. This
710 option is ignored in extract or list mode.
711 -debug Print debug messages. Among other things, this gives debug mes‐
713 sages for header type recognition, tar type properties, EOF
714 recognition, opening of remote archives and fifo internals.
715 diffopts=optlst
717 Comma separated list of diffopts. Valid members in optlst are:
718 help Print a summary of possible members of the diffopts
720 list.
721 ! Invert the meaning of the following string. No comma
723 is needed after the exclamation mark.
724 not Invert the meaning of all members in the diffopts list
726 i.e. exclude all present options from an initially
727 complete set compare list. When using csh(1) you
728 might have problems to use ! due to its strange
729 parser. This is why the not alias exists.
730 perm Compare file permissions. With this option in effect,
732 star compares the low order 12 bits of the st_mode
733 field.
734 mode Same as perm.
736 type Compare file type. Note that star cannot compare the
738 file type in case of a hard link.
739 nlink Compare link count on hardlinks. This only works if
741 the archive is in exustar format and contains star's
742 dump extensions.
743 uid Compare numerical user id of file.
745 gid Compare numerical group id of file.
747 uname Compare ASCII version of user id of file. The user
749 name is mapped via the file /etc/passwd.
750 gname Compare ASCII version of group id of file. The group
752 name is mapped via the file /etc/group.
753 id Shorthand for: uid,gid,uname,gname. Compare all
755 user/group related info of file. Note that this will
756 always find differences if the source and target sys‐
757 tem use different user or group mappings.
758 size Compare file size. Note that star cannot compare the
760 file size in case of a hard link.
761 data Compare content of file. If star already found that
763 the size of the files differ, it will not compare the
764 content anymore. If the size of the files differ,
765 star will always report different data.
766 cont Same as data.
768 rdev Compare major/minor numbers for device nodes.
770 hardlink Compare target of hardlinks.
772 symlink Compare target of symlinks. This evaluates the paths
774 returned by the readlink(2) call.
775 Two symlinks are considered equal, it they either have
777 a characterwise identical link-name, or if they either
778 both use an absolute path name or both use a relative
779 path name and the following is true: Both symlinks
780 point to the same file that must exist or both path‐
781 names look similar enough.
782 sympath Compare the target pathnames of symlinks. This charac‐
784 terwise compares the strings returned from the read‐
785 link(2) call.
786 sparse Compare if either both files are sparse or not. If
788 only one of both files is sparse, then a difference is
789 flagged. This only works with if the archive format
790 is star, xstar, xustar, exustar, or gnutar.
791 atime Compare access time of file. This only works with if
793 the archive format is star, xstar, xustar, exustar, or
794 pax.
795 mtime Compare modification time of file.
797 ctime This only works with if the archive format is star,
799 xstar, xustar, exustar, or pax.
800 lmtime Compare the modification time of symbolic links. By
802 default, star will not compare the modification time
803 of symbolic links as most systems cannot set the modi‐
804 fication time of symbolic links. Star compares lmtime
805 only if mtime is compared also.
806 times Shorthand for: atime,mtime,ctime.
808 dir Compare the content of directories. This only works
810 if the archive is in exustar format and contains
811 star's dump extensions. Together with increased ver‐
812 bose level (-vv) this will print a list of files that
813 are only in the archive and a list of files that are
814 only on the current filesystem.
815 xtimes Shorthand for: atime,mtime,ctime,lmtime.
817 acl Compare access control lists. This only works if the
819 archive is in exustar format and has been created with
820 star's -acl option. You need to specify the -acl
821 option in addition when running the diff.
822 xattr Compare extended file attributes. This only works if
824 the archive is in exustar format and has been created
825 with star's -xattr option. You need to specify the
826 -xattr option in addition when running the diff.
827 fflags Compare extended file flags. This only works if the
829 archive is in exustar format and has been created with
830 star's -xfflags option. You need to specify the
831 -xfflags option in addition when running the diff.
832 If optlst starts with a ! the meaning of all members in optlst
834 is inverted as with the not optlist member. In this case, star
835 starts with a complete list that includes atime and lmtime.
836 Reasonable diff options to use when comparing against a copy of
837 a directory tree are diffopts=!atime,ctime,lmtime.
838 If diffopts are not specified, star compares everything but the
840 access time of the files and the modification time of symbolic
841 links.
842 dir-group=group
844 If star extracts archives as root, this option allows to control
845 the group id of intermediate directories created by star.
846 dir-owner=user
848 If star extracts archives as root, this option allows to control
849 the owner of intermediate directories created by
850 -dirmode
852 If in create mode (i.e. when storing files to archive), star
853 stores directories past the corresponding files. This guarantees
854 that even old tar implementations without a directory cache will
855 be able to restore the correct times of directories. The option
856 -dirmode should only be used if the archive needs to be
857 extracted by an old tar implementation. If star is used to
858 extract an archive that has been created with -dirmode the
859 directories will not get an old time stamp unless the option -U
860 is used while extracting the archive.
861 -dodesc
863 Force star to descend directories found in a list=file. See
864 also the -D option above.
865 -dump Allows to create archives with the same number of attributes as
867 an archive that has been created with the level= option but
868 without the restrictions that apply to a true dump.
869 The resultant archive may be seen as a level-less dump which
871 includes similar attributes as a level 0 dump but may span more
872 than a single file system and does not need to use a -C option.
873 It has been originally introduced to make it easier to implement
874 a star version that supports true incremental dumps, but it is
875 kept as it gives additional benefits. Star currently sets the
876 archive type to exustar and, in addition archives more inode
877 meta data inside POSIX.1-2001 extended headers. See also level=
878 option and the section INCREMENTAL BACKUPS for more information
879 on true incremental dumps.
880 -dump-cumulative
882 instructs star to perform incremental dumps relatively to the
883 last incremental dump of the same level. Incremental dumps with
884 a level higher than 0 are normally done relatively to the con‐
885 tent of a previous dump with lower level. If incremental dumps
886 and restores are going to be used to synchronize filesystem con‐
887 tent, every successive incremental dump will increase in size if
888 -dump-cumulative is not used. See section SYNCHRONIZING
889 FILESYSTEMS for more information.
890 dumpdate=name
893 Tells star to use the mtime of the time stamp file name instead
894 of using the start time of star. This is needed when star is
895 run on file system snapshots. If star would use the the start
896 time with snapshots, all files that have been modified between
897 the setup of the snapshot and the start of star would be missing
898 on the backup.
899 -dumpmeta
901 changes the behavior of star in incremental dump mode. If
902 -dumpmeta is used and only the inode change time (st_ctime) of a
903 file has been updated since the last incremental dump, star will
904 archive only the meta data of the file (e.g. uid, permissions,
905 ...) but not the file content. Using -dumpmeta will result in
906 smaller incremental dumps, but files that have been created
907 between two incrementals and set to an old date in st_mtime
908 (e.g. as a result from a tar extract) will not be archived with
909 full content. Using -dumpmeta thus may result in incomplete
910 incremental dumps, use with extreme care.
911 -e Exit immediately with exit status -3 (253) if any unexpected
913 error occurs. The -e option works as if the last error control
914 option was
915 errctl="ABORT|ALL|DIFF *"
917 This allows to use the errctl= option together with the -e
919 option and thus to ignore some error conditions while aborting
920 on all other conditions.
921 errctl= name
923 errctl= error control spec
925 Add the content from file name to the error control definitions
926 or add error control spec to the error control definitions.
927 More than one error control file and more than one error control
928 spec as well as a mixture of both forms is possible.
929 The reason for using error control is to make star quiet about
931 error conditions that are known to be irrelevant on the quality
932 of the archive or restore run or to tell star to abort on cer‐
933 tain error conditions instead of trying to continue with the ar‐
934 chive.
935 A typical reason to use error control is to suppress warnings
937 about growing log files while doing a backup on a live file sys‐
938 tem. Another typical reason to use error control is to tell
939 star to abort if e.g. a file could not be archived instead of
940 continuing to archive other files from a list.
941 The error control file contains a set of lines, each starting
943 with a list of error conditions to be ignored followed by white
944 space followed by a file name pattern (see match(1) or pat‐
945 match(3) for more information). The error control spec uses the
946 same syntax as a single line from the error control file. If
947 the file name pattern needs to start with white space, use a
948 backslash to escape the start of the file name. It is not possi‐
949 ble to have new line characters in the file name pattern. When‐
950 ever an error situation is encountered, star checks the lines in
951 the error control file starting from the top. If the current
952 error condition is listed on a line in the error control file,
953 then star checks whether the pattern on the rest of the line
954 matches the current file name. If this is the case, star uses
955 the current error control specification to control the current
956 error condition.
957 The list of error conditions to be handled may use one or more
959 (in this case separated by a '|' character) identifiers from the
960 list below:
961 ABORT If this meta condition is included in an error con‐
963 dition, star aborts (exits) as soon as possible
964 after this error condition has been seen instead of
965 making star quiet about the condition. This error
966 condition flag may only be used together with at
967 another error condition or a list of error condi‐
968 tions (separated by a '|' character).
969 WARN If this meta condition is included in an error con‐
971 dition, star prints the warning about the error con‐
972 dition but the error condition does not affect the
973 exit code of star and the error statistics (which is
974 printed to the end) does not include the related
975 errors. This error condition flag may only be used
976 together with at another error condition or a list
977 of error conditions (separated by a '|' character).
978 The WARN meta condition has a lower precedence than
979 ABORT.
980 DIFF Suppress output in case that star -diff did
982 encounter any differences.
983 ALL This is a shortcut for all error conditions below.
985 STAT Suppress warnings that star could not stat(2) a
987 file.
988 GETACL Suppress warnings about files on which star had
990 problems to retrieve the ACL information.
991 OPEN Suppress warnings about files that could not be
993 opened.
994 READ Suppress warnings read errors on files.
996 WRITE Suppress warnings write errors on files.
998 READLINK Suppress warnings readlink(2) errors on symbolic
1000 links.
1001 GROW Suppress warnings about files that did grow while
1003 they have been archived.
1004 SHRINK Suppress warnings about files that did shrink while
1006 they have been archived.
1007 MISSLINK Suppress warnings about files for which star was
1009 unable to archive all hard links.
1010 NAMETOOLONG Suppress warnings about files that could not be
1012 archived because the name of the file is too long
1013 for the archive format.
1014 FILETOOBIG Suppress warnings about files that could not be
1016 archived because the size of the file is too big for
1017 the archive format.
1018 SPECIALFILE Suppress warnings about files that could not be
1020 archived because the file type is not supported by
1021 the archive format.
1022 GETXATTR Suppress warnings about files on that star could not
1024 retrieve the extended file attribute information.
1025 SETTIME Suppress warnings about files on that star could not
1027 set the time information during extraction.
1028 SETMODE Suppress warnings about files on that star could not
1030 set the access modes during extraction.
1031 SECURITY Suppress warnings about files that have been skipped
1033 on extraction because they have been considered to
1034 be a security risk. This currently applies to all
1035 files that have a '/../' sequence inside when -..
1036 has not been specified.
1037 LSECURITY Suppress warnings about links that have been skipped
1039 on extraction because they have been considered to
1040 be a security risk. This currently applies to all
1041 link names that start with '/' or have a '/../'
1042 sequence inside when -secure-links has been speci‐
1043 fied. In this case, star tries to match the link
1044 name against the pattern in the error control file.
1045 SAMEFILE Suppress warnings about links that have been skipped
1047 on extraction because source and target of the link
1048 are pointing to the same file. If star would not
1049 skip these files, it would end up with removing the
1050 file completely. In this case, star tries to match
1051 the link name against the pattern in the error con‐
1052 trol file.
1053 BADACL Suppress warnings access control list conversion
1055 problems.
1056 SETACL Suppress warnings about files on that star could not
1058 set the ACL information during extraction.
1059 SETXATTR Suppress warnings about files on that star could not
1061 set the extended file attribute information during
1062 extraction.
1063 If a specific error condition is ignored, then the error condition is
1065 not only handled in a silent way but also excluded from the error sta‐
1066 tistics that are printed at the end of the star run.
1067 Be very careful when using error control as you may ignore any error
1069 condition. If you ignore the wrong error conditions, you may not be
1070 able to see real problems anymore.
1071 -exclude-from name
1073 Exclude from named file, this is an alias for the -X option. See
1074 -X option for more information.
1075 -F,-FF ...
1077 Fast and simple exclude option for create mode. With one -F
1078 argument, star ignores all directories called SCCS and RCS.
1079 With two -F arguments, star in addition ignores all files called
1080 core errs a.out all files ending with .o. OBJ/. With three -F
1081 arguments, star ignores all sub trees starting from a directory
1082 that includes a file .mirror or .exclude and all object files
1083 and files called core errs a.out all files ending with .o. With
1084 four -F arguments, star ignores all sub trees starting from a
1085 directory that includes a file .mirror or .exclude the latter
1086 files are excluded too as well as and all object files and files
1087 called core errs a.out all files ending with .o. With five -F
1088 arguments, star in addition again excludes all directories
1089 called SCCS and RCS.
1090 -fifo Use a fifo to optimize data flow from/to tarfile. This option
1092 is in effect by default (it may be changed at compile time).
1093 The default fifo size is 8 MBytes on all platforms except Linux
1094 versions that do not support mmap() (4 MB because kernels before
1095 2.4 did not handle big shared memory areas) and Sun/mc68000 (1
1096 MB). This will star make even work on a tiny machine like a Sun
1097 3/50. The fifo size may be modified with the fs= option. A rule
1098 of dumb for the fifo size is to use more than the buffer size of
1099 the tape drive and less then half of the real memory of the
1100 machine. A good choice would be to use a fifo size between 8
1101 and 256 MB. This may increase backup speed up to 5% compared to
1102 the speed achieved with the default fifo size. Note that with a
1103 DLT drive that gives 12MB/s transfer rate, a fifo of 256 MB size
1104 will keep the tape at least streaming in units of 20 seconds.
1105 All options that start with the -f sequence are sensitive to
1106 typo problems, see BUGS section for more information.
1107 -fifostats
1109 Print fifo statistics at the end of a star run when the fifo has
1110 been in effect. All options that start with the -f sequence are
1111 sensitive to typo problems, see BUGS section for more informa‐
1112 tion.
1113 file=tarfilename, f=tarfilename
1115 Use tarfilename as the name for the tar archive. Currently up to
1116 100 file= options are possible. Specifying more then one file=
1117 option make sense in multi volume mode. In this case star will
1118 use the next name in the list every time a media change is
1119 needed. To make star behave consistent with the single file
1120 case, star loops over the list of known archive files. Note
1121 that if star is installed suid root and the first tarfile is a
1122 remote archive, only the connection to this archive will be cre‐
1123 ated with root privileges. After this connection has been
1124 established as root, star switches back to the id of the caller.
1125 If any of the other archives in the list is located on a differ‐
1126 ent host, star will not be able to open this archive later on,
1127 unless run by root.
1128 Star normally uses stdin/stdout for the tar archive because the
1130 most common way to use star is in conjunction with pipes. If
1131 star is installed suid root or if it has been called by root,
1132 tarfilename may be in remote syntax: user@host:filename as in
1133 rcp(1) even if invoked by non root users. See SUID NOTES for
1134 more information.
1135 To make a file local although it includes a colon (:), the file‐
1137 name must start with: '/', './' or '../'
1138 Note that if star talks to an old rmt remote tape server that
1140 does not support symbolic open modes, it does not open a remote
1141 tape with the O_CREAT open flag because this would be extremely
1142 dangerous. If the rmt server on the other side is the rmt
1143 server that comes with star or the GNU rmt server, star may use
1144 the symbolic mode for the open flags. Only the symbolic open
1145 modes allow to send all possible open modes in a portable way to
1146 remote tape servers.
1147 It is recommended to use the rmt server that comes with star.
1149 It is the only rmt server that gives platform independent com‐
1150 patibility with BSD, Sun and GNU rmt clients and it includes
1151 security features that may be set up in /etc/default/rmt. All
1152 options that start with the -f sequence are sensitive to typo
1153 problems, see BUGS section for more information.
1154 See ENVIRONMENT section for information on how to use ssh(1) to
1156 create a remote tape server connection.
1157 Note that if file=- has been specified, it is no longer possible
1159 to use the -find -exec primary.
1160 -find This option acts a separator. If it is used, all star options
1162 must be to the left of the -find option. To the right of the
1163 -find option, star accepts the find command line syntax only.
1164 The find expression acts as a filter between the source of file
1166 names and the consumer, which may either be the archiving engine
1167 or list/extract engine. If the find expression evaluated as
1168 TRUE, then the related file is selected for processing, other‐
1169 wise it is omited.
1170 In order to make the evaluation of the find expression more con‐
1172 venient, star implements additional find primaries that have
1173 side effects on the file meta data. Star implements the follow‐
1174 ing additional find primaries:
1175 -chgrp gname
1177 The primary always evaluates as true; it sets the group
1178 of the file to gname.
1179 -chmod mode
1181 The primary always evaluates as true; it sets the permis‐
1182 sions of the file to mode. Octal and symbolic permis‐
1183 sions are accepted for mode as with chmod(1).
1184 -chown uname
1186 The primary always evaluates as true; it sets the owner
1187 of the file to uname.
1188 -false The primary always evaluates as false; it allows to make
1190 the result of the full expression different from the
1191 result of a part of the expression.
1192 -true The primary always evaluates as true; it allows to make
1194 the result of the full expression different from the
1195 result of a part of the expression.
1196 The command line:
1198 star -c f=o.tar -find . ( -type d -ls -o false ) -o ! -type d
1200 lists all directories and archives all non-directories to the
1202 archive o.tar.
1203 The command line:
1205 star -c f=o.tar -find . ( -type d -chown root -o true )
1207 archives all directories so they appear to be owned by root in
1209 the archive, all non-directories are archived as they are in the
1210 file system.
1211 Note that the -ls, -exec and the -ok primary cannot be used if
1213 stdin or stdout has been redirected by the list=- of by the
1214 file=- options.
1215 -force_hole
1217 obsoleted by -force-hole
1218 -force-hole
1220 Try to extract all files with holes. This even works with files
1221 that are created without the -sparse option. Star, in this case
1222 examines the content of the files in the archive and replaces
1223 writes to parts containing binary zeroes with seeks. This option
1224 should be used with extreme care because you sometimes get in
1225 trouble when files get unattended holes. All options that start
1226 with the -f sequence are sensitive to typo problems, see BUGS
1227 section for more information.
1228 -force_remove
1230 obsoleted by -force-remove
1231 -force-remove
1233 Force to remove non writable files on extraction. By default,
1234 star will not overwrite files that are read only. If this
1235 option is in effect, star will silently remove these files to
1236 allow the extraction of a file. All options that start with the
1237 -f sequence are sensitive to typo problems, see BUGS section for
1238 more information.
1239 -force-restore
1241 Force an incremental restore even if the incremental dump is
1242 only a partial dump. See -wtardumps, level= and section INCRE‐
1243 MENTAL BACKUPS for more information.
1244 fs=# Set fifo size to #. See bs= for the possible syntax. The
1246 default size of the fifo is 1 Mbyte on Sun mc68000 systems, 4
1247 Mbytes on non mmap() aware Linux systems and 8 Mbytes on all
1248 other systems. See -fifo option for hints on using the right
1249 fifo size.
1250 fs-name=mount_point
1253 Use mount_point when recording information in /etc/tardumps and
1254 when comparing against information in /etc/tardumps for incre‐
1255 mental backups. This makes sense when backups are made using
1256 file system snapshots and allows /etc/tardumps and the archive
1257 to contain the real name of the file system instead of the tem‐
1258 porary mount point that is used for the snapshot device.
1259 H=headertype
1262 See artype=headertype option. Note that POSIX.1-2001 defines an
1263 option -H that follows symbolic links that have been encountered
1264 on the command line. For this reason, the old star option
1265 H=headertype option may go away in the future even though this
1266 option has been in use by cpio since 1989.
1267 -h, -L Follow symbolic links as if they were files. Normally star will
1269 not follow symbolic links but stores their values in tarfile.
1270 See also the -L option.
1271 -hardlinks
1273 In extract mode, this option tells star to try to create a
1274 hardlink whenever a symlink is encountered in the archive. In
1275 create mode, this option tells star to try to archive a hardlink
1276 whenever a symlink is encountered in the file system.
1277 -hpdev Allow 24 bits for the minor device number using 8 octal digits.
1279 Note that although it allows to create tar archives that can be
1280 read with HP-UX tar, this creates tar archives which violate
1281 POSIX.1-1988. This option is only needed if you like to use a
1282 POSIX.1-1988 based archive format that does not include exten‐
1283 sions. If you use the xstar format, star will use a base 256
1284 extension that allows bigger major/minor numbers by default, if
1285 you use the xustar or the exustar format there is no limitation
1286 at all as these formats use POSIX.1-2001 extended headers to ar‐
1287 chive the major/minor numbers by default.
1288 -i Ignore checksum errors on tar headers. If this option is speci‐
1290 fied, star will not exit if a header with a bad checksum is
1291 found but search for the next valid header.
1292 -install
1294 Carefully replace existing files when extracting files. This is
1295 done similar to install(1) by first extracting the files into a
1296 temporary name and renaming the file to the final name after the
1297 extraction of that file was successful.
1298 As star by default does not remove non-empty directories, an
1300 install that needs to remove existing non-empty directories may
1301 also need the options -force-remove and -remove-recursive.
1302 -j run the input or output through a bzip2 pipe - see option -z -Z
1304 and -bz below. As the -bz the -j the -Z and the -z option are
1305 non standard, it makes sense to omit the -bz the -j the -Z and
1306 the -z options inside shell scripts if you are going to extract
1307 a compressed archive that is located inside a plain file as star
1308 will auto detect compression and choose the right decompression
1309 option to extract.
1310 -keep-nonempty-dirs
1312 Do not complain about trying to remove nonempty directories in
1313 case that -remove-recursive has not been specified.
1314 -keep_old_files
1316 obsoleted by -keep-old-files
1317 -keep-old-files, -k
1319 Keep existing files rather than restoring them from tarfile.
1320 This saves files from being clobbered even if tarfile contains a
1321 more recent version of the corresponding file.
1322 See SECURITY NOTES for more information.
1324 -L, -h Follow symbolic links as if they were files. Normally star will
1326 not follow symbolic links but stores their values in tarfile.
1327 See also the -h option.
1328 -l Do not print a warning message if not all links to hard linked
1330 files could be dumped. This option is evaluated in the opposite
1331 way to historic tar(1) implementations and to POSIX.1. POSIX.1
1332 requests that by default no warning messages will be printed and
1333 -l will enable warning messages when not all links could be
1334 archived.
1335 level=dumplevel
1337 Set level for incremental dumps. This option is used to switch
1338 star into true incremental dump mode.
1339 In true incremental dump mode, a -C option which is followed by
1341 the name a mount point and a dot ('.') as starting directory
1342 name is required. Only a single file system may be handled at a
1343 time. If the directory following the -C option is not referring
1344 to a root directory of a file system, the dump is called a par‐
1345 tial dump. If the directory following the -C option is refer‐
1346 ring to a root directory of a file system and no other restric‐
1347 tions apply that exclude certain files from the dump, the dump
1348 is called a full dump.
1349 By default, the tardumps database is not written. See also the
1351 tardumps=name and -wtardumps options and the section INCREMENTAL
1352 BACKUPS for more information.
1353 -link-dirs
1355 When in create mode, try to find hard linked directories. Using
1356 -link-dirs will force star to keep track of all directories that
1357 will go into the archive and thus causes a lot more memory to be
1358 allocated than in the default case.
1359 If you like to extract a cpio archive that contains hard linked
1361 directories, you also need to specify -link-dirs in extract or
1362 diff mode. This is needed because many cpio implementations
1363 create buggy archives with respect to hard links. If star would
1364 look for hard linked directories in all cases, it would detect
1365 many pseudo hard links to directories. Use -link-dirs with care
1366 if you extract cpio archives.
1367 Note that not all filesystem allow to create hard links to
1369 directories. Also note that even though a non-root user is able
1370 detect and archive hard linked directories, all known operating
1371 systems require the extraction to be done as root in order to be
1372 able to create or remove hard links to directories. For this
1373 reason its only recommended to use this option when doing accu‐
1374 rate backups and when hard links to directories are expected.
1375 When the option -link-dirs is not used and hard links to direc‐
1377 tories are present, the appendant sub-tree will appear more than
1378 once on the archive and star will print Linkcount below zero
1379 warnings for non directory hard links inside the sub-tree.
1380 list=filename
1382 Read filenames for store/create/list/diff command from filename.
1383 The file filename must contain a list of path names, each on a
1384 separate line. This option implies the -D option. To force
1385 star to descend directories, use the -dodesc option in this
1386 case. See also the -X option.
1387 Note that if list=- has been specified, it is no longer possible
1389 to use the -find -exec primary.
1390 -lowmem
1392 Try to run with reduced memory requirements. This causes star
1393 to default to 1 MB of FIFO memory. Instead of allocating memory
1394 to hold the directory content and reading the directory at once,
1395 star reads the directory name by name. This may cause star to
1396 close the directory if it rans out of file descriptors because
1397 of deeply nested directories. If a directory then does not sup‐
1398 port telldir(3)/seekdir(3), star will fail.
1399 -lzo run the input or output through a lzop pipe - see option -z
1401 below.
1402 -M, -xdev
1404 Do not descend mount points. This is useful when doing backups
1405 of complete file systems. See NOTES for more information.
1406 -m Do not restore access and modification time. (Access time is
1408 only available if star is reading star, xstar, xustar, exustar,
1409 or pax archives). If star extracts other archive types, the -m
1410 flag only refers to the modification time.
1411 -match-tree
1414 If in create mode a pattern does not match a directory, and
1415 -match-tree has been specified, the whole directory tree is
1416 excluded from the archive and from further directory scans. By
1417 default, star excludes the directory but still recursively scans
1418 the content of this directory as complex patterns could allow
1419 files inside the directory tree to match. Using -match-tree
1420 allows to efficiently exclude whole trees from scanning. This
1421 helps to avoid scannings directory trees that are on remote file
1422 systems or contain excessive bad blocks.
1423 maxsize=#
1425 Do not store files in tarfile if they are bigger than #. See
1426 bs= for the possible syntax. By default, the number is multi‐
1427 plied by 1024, so the value counts in units of kBytes. If the
1428 size specifier ends with a valid multiplication character (e.g
1429 '.' for bytes or 'M' for MB) the specified size is used as spec‐
1430 ified and not multiplied by 1024. See bs= option for all possi‐
1431 ble multipliers.
1432 -meta In create mode, -meta causes star to archive all meta data of
1434 the file (e.g. uid, permissions, ...) but not the file content.
1435 In extract mode, it causes star to restore all meta data but not
1436 the file content. In addition, in extract mode no plain file,
1437 special file or directory will be created. Meta files are
1438 needed to support incremental backups.
1439 Warning: Do not try to extract star archives containing meta
1441 files using other tar implementations if they are not aware of
1442 the meta file extensions of star. Star tries to force all tar
1443 implementations that are not standard compliant to abort. Star
1444 also tries to make all non POSIX.1-2001 compliant tar implemen‐
1445 tations unable to find a valid filename. However when other
1446 POSIX.1-2001 aware tar implementations come up and don't know
1447 about meta files, they will destroy files on disk.
1448 The problems result from the only current fallback in the POSIX
1450 standard that tells tar implementations to treat all unknown
1451 file types as if they were plain files. As meta files are needed
1452 for incremental backups, I am looking for people and companies
1453 who like to support me to be able to add the meta file concept
1454 to the POSIX.1-2005 standard.
1455 -modebits
1457 This options allows you to create tar archives that include more
1458 than 12 bits from st_mode. Note this create tar archives that
1459 violate POSIX but some tar implementations insist in reading
1460 such nonstandard archives.
1461 -multivol
1463 Switch to multi volume mode. In multi volume mode, there will
1464 be no logical EOF marker written to the end of a single tape. If
1465 -multivol is used in read mode, a hard EOF on input (if not pre‐
1466 ceded by a logical EOF) triggers a medium change operation.
1467 Specifying -multivol tells star to split files across volumes if
1469 needed. This way, a virtual archive is created that spans more
1470 than one medium. Multi volume mode is needed whenever it is not
1471 possible to split the archiving or extracting into several logi‐
1472 cally independent tasks. This is true for e.g. incremental
1473 dump/restore operations where inode numbers need to be traced
1474 for the whole task.
1475 When tsize=# has been specified, but star is not in multi volume
1477 mode, files cannot be split across volumes.
1478 When -multivol has been specified in create mode together with
1480 tsize=# then a media change is initiated exactly after an amount
1481 of tsize data has been written. When -multivol has been speci‐
1482 fied in create mode and tsize=# has not been specified, then the
1483 medium change is triggered by a EOT condition from writing the
1484 medium. This allows to use media where the size cannot be known
1485 in advance (e.g. tapes with build in compression); it does not
1486 work if the EOT condition is not returned in sync with the
1487 related write operation. For this reason, it is expected that
1488 data buffering inside a device driver cannot be used.
1489 Depending on the selected archive format, star writes a volume
1491 header at the beginning of a new medium. This medium header
1492 allows to verify the correct volume after a change during read
1493 back. It is recommended to use the exustar format for best
1494 results. In create mode, -multivol is only supported for ar‐
1495 chives types that allow to write reliable multi volume header
1496 information.
1497 See tsize=# option for more information.
1499 Note that -multivol is an interactive option that prevents star
1501 from being used in non-interactive environments. If you like to
1502 use it in a non-interactive environment, you need to specify
1503 new-volume-script=script in addition in order to automate the
1504 media change procedure.
1505 newer=filename
1507 Do not store files to tarfile if their modification time is not
1508 newer than the modification time of filename. See -ctime option
1509 for changing this behavior.
1510 -newest
1512 In conjunction with the list command this lists you only the
1513 newest file in tarfile.
1514 -newest_file
1516 obsoleted by -newest-file
1517 -newest-file
1519 In conjunction with the list command this lists you only the
1520 newest regular file in tarfile.
1521 new-volume-script=script
1523 Call script at end of each tape if in multi volume mode. If
1524 this option is not in effect, star will ask the user to confirm
1525 the volume change. The script is called with two parameters.
1526 The first parameter is the next volume number and the second
1527 parameter is the next archive file name.
1528 -nodump
1530 If this option is set, star will not dump files that have the
1531 nodump flag set. Note that this currently only works on BSD-4.4
1532 derivates and on Linux. On Linux, using this option will cause
1533 a performance degradation (the system time increases by 10%)
1534 because of the unlucky kernel interface.
1535 -no-dirslash
1537 Do not add a slash to the end of directory names if writing to
1538 an archive. Historic tar archive formats did only allow to
1539 specify plain files and hard links. Around 1980, BSD added a
1540 feature to specify a directory on tape by adding a slash to the
1541 end of the name. POSIX.1-1988 defined the first official tar ar‐
1542 chive format that had a clean method to specify the type of a
1543 directory. As old tar formats need the slash to recognize a
1544 directory, -no-dirslash may not be used if archives should be
1545 compatible with the old tar format.
1546 -no_fifo
1548 obsoleted by -no-fifo
1549 -no-fifo
1551 Don't use a fifo to optimize data flow from/to tarfile. Cur‐
1552 rently the -fifo option is used as default. (This may be changed
1553 at compile time.)
1554 -no-fsync
1556 Do not call fsync(2) for each file that has been extracted from
1557 the archive. Using -no-fsync may speed up extraction on operat‐
1558 ing systems with slow file I/O (such as Linux), but includes the
1559 risk that star may not be able to detect extraction problems
1560 that occur after the call to close(2). A typical cause for such
1561 problems is a NFS file system that fills up before the buffer
1562 cache is synced or a write error that occurs while the buffer
1563 cache is synced. There may be other reasons. Use with extreme
1564 care.
1565 -nochown, -o
1567 Do not restore owner and group of files. This may be used if
1568 super user privileges are needed to overwrite existing files but
1569 the local ownership of the existing files should not change.
1570 -no-p Do not restore files and directories to their original permis‐
1572 sions. This option is needed only if star is called by the
1573 super user and the permissions should not be restored from the
1574 archive. See also the -p option. The -p options has a higher
1575 precedence than the -no-p option.
1576 -no_statistics
1578 obsoleted by -no-statistics
1579 -no-statistics
1581 Do not print statistic messages at the end of a star run.
1582 -no-xheader
1584 Do not create or extract POSIX.1-2001 extended headers. This
1585 option may be used if you like to read an archive with broken
1586 extended headers.
1587 -not, -V
1589 Invert the meaning of the pattern list. i.e. use those files
1590 which do not match any of the pattern. Note that this option
1591 only applies to patterns that have been specified via the pat‐
1592 tern=pattern or pat=pattern option. Patterns specified as file
1593 type arguments will not be affected.
1594 -notarg, -pax-c
1596 Match all file or archive members except those specified by the
1597 pattern or file operands.
1598 -nowarn
1600 Do not print warning messages. This sometimes is useful to make
1601 the output more readable (e.g. when hundreds of files that are
1602 going to be extracted are not newer in the archive then on the
1603 filesystem).
1604 -numeric
1606 Use the numeric user/group fields in the listing rather than the
1607 default. The default allows to list the ASCII version of
1608 user/group of the file and to extract the owners of the files
1609 based on numeric values rather than the names. In create mode,
1610 no user/groups names are put on the archive. The -numeric
1611 option also applies when ACLs are going to be archived or
1612 extracted.
1613 -O Be compatible to old versions of tar. If star is invoked with
1615 this option, star generates archives which are fully compatible
1616 with old UNIX tar archives. If in extract mode, star ignores any
1617 additional info in the headers. This implies neither that ar‐
1618 chives generated with this option are binary equal with archives
1619 generated by old tar versions nor that star is trying to compre‐
1620 hend all bugs that are found in old tar versions. The bug in
1621 old tar versions that cause a reversal of a space and a NULL
1622 byte in the checksum field is not repeated. If you want to have
1623 signed checksums you have to specify the -singed-checksum option
1624 too. If you want directories not to be archived in order to be
1625 compatible to very old historic tar archives, you need to spec‐
1626 ify the -d option too.
1627 This option is superseeded by the H=headertype option.
1629 -o, -nochown
1631 Do not restore owner and group of files. This may be used if
1632 super user privileges are needed to overwrite existing files but
1633 the local ownership of the existing files should not change.
1634 -onull, -nullout
1636 Do not actually write to the archive but compute and add the
1637 sizes. This is useful when trying to figure out if a tape may
1638 hold the current backup. Please only use the -onull option as
1639 it is a similar option as used by the sdd(1) command.
1640 -P Allow star to write a partial record as the last record. Nor‐
1642 mally, star writes each record with the same size. This option
1643 is useful on unblocked tapes i.e. cartridge tapes like QIC tapes
1644 as well as with archives that are located in files. If you use
1645 this option on local files, the size of the archive will be
1646 smaller. If you use this option on cartridge tapes, is makes
1647 sure that later - in extract mode - star will read up to the end
1648 of file marker on the tape and the next call to star will read
1649 from the next archive on the same tape.
1650 -p Restore files and directories to their original permissions.
1652 Without this option, they are created using the permissions in
1653 the archive and the present umask(2). If star is called by the
1654 super user, star behaves as if it has been called with the -p
1655 option. See also -no-p option. If the archive contains Access
1656 Control Lists (ACLs) in POSIX.1-2001 extended headers, star will
1657 restore the access control lists from the archive for files if
1658 the -acl option is specified. If the option -acl has not been
1659 specified, ACLs are not restored at all.
1660 pattern=pattern, pat=pattern
1662 Set matching pattern to pattern. A maximum of 100 pattern=pat
1663 options may be specified. As each pattern is unlimited in
1664 length, this is no real limitation. If more than one pattern is
1665 specified, a file matches if any of the specified pattern
1666 matches. Patterns may be used in create mode to select or
1667 exclude files from the list of file type arguments or the files
1668 located in a sub tree of a file type argument directory. By
1669 default, star scans the whole directory tree underneath a direc‐
1670 tory that is in the argument list. This may be modified by using
1671 the -match-tree option. In extract or list mode, all file type
1672 arguments are interpreted to be select pattern and all option
1673 type patterns may be either select or exclude patterns depending
1674 on the presence or absence of the -not option. If you use file
1675 type select patterns, they work exactly like the method used by
1676 other (non pattern aware) tar(1) implementations. File type
1677 select patterns do not offer pattern matching but allow to
1678 restore subtrees. To extract a complete sub tree from the
1679 directory dir with star using the pattern= option, use pattern=
1680 dir/\* if you like to select a subtree by using the historic
1681 method, use dir as file type argument. If you only like to
1682 extract the directory itself, use dir/ as file type argument.
1683 See manual page for match(1) for more details of the pattern
1684 matcher. All patterns are selection patterns by default. To
1685 make them exclude patterns, use the -not or the -V option.
1686 pkglist=file
1688 This is (for now) an internal interface for the Schily Source
1689 Package System (sps). It only works in create mode and behaves
1690 similar to the list= option, but it allows to overwrite the per‐
1691 missions, the uid and gid values from the content of the
1692 pkglist= file. Each line from the pkglist= file contains a file
1693 name followed by the permission, a user name and a group name.
1694 The permission is an octal character string. Each value that is
1695 not used to overwrite the original values may be replaced by a
1696 '?'. The fields are separated by spaces, so the pkglist= option
1697 does not allow files that contain newline or space characters.
1698 -pax-c, -notarg
1700 Match all file or archive members except those specified by the
1701 pattern or file operands.
1702 -pax-H Follow symbolic links that have been encountered on the command
1704 line. If the referenced file does not exist, the file informa‐
1705 tion and type will be for the link itself. If the link is ref‐
1706 erencing a file type that cannot be archived with the current
1707 archive format, the file information and type will be for the
1708 link itself.
1709 -pax-i Do interactive renaming in a way that has been defined for POSIX
1711 pax. Star will print the original filename and prompt for a
1712 reply. If you type just RETURN, than the file is skipped. If
1713 you type '.', then the original file name is retained. If you
1714 type anything else, then this is taken as the new file name.
1715 Note that -pax-i is an interactive option that prevents star
1717 from being used in non-interactive environments.
1718 -pax-L Follow symbolic links. If the referenced file does not exist,
1720 the file information and type will be for the link itself. If
1721 the link is referencing a file type that cannot be archived with
1722 the current archive format, the file information and type will
1723 be for the link itself.
1724 -pax-ls
1726 Switch listing format to the format defined for POSIX pax and
1727 ls.
1728 -pax-match
1730 Allow file type arguments to be recognised as regular expres‐
1731 sions in a way that has been defined for POSIX pax.
1732 -pax-n Allow each pattern to match only once. If a pattern matches a
1734 directors, then the whole sub tree matches the pattern.
1735 -pax-p string
1737 PAX style privileges string. Several characters (each has its
1738 own meaning). The following characters are defined:
1739 a Do not preserve file access times. This option is cur‐
1741 rently ignored.
1742 e Preserve the user ID, group ID, file mode bits. This is
1744 equivalent to calling star -p -acl -xfflags.
1745 m Do not preserve file modification times. This is cur‐
1747 rently equivalent to calling star -m.
1748 o Preserve the user ID and group ID. This is the default
1750 for star if called as root.
1751 p Preserve the file mode bits. This is equivalent to call‐
1753 ing star -p.
1754 -prinodes
1756 Print inode numbers in verbose list mode if the archive contains
1757 inode numbers.
1758 -print-artype
1760 Check the type of the archive, print the archive and compression
1761 type on a single line and exit.
1762 -qic24 Set tape volume size to 61440 kBytes. See tsize=# option for
1764 more information.
1765 -qic120
1767 Set tape volume size to 128000 kBytes. See tsize=# option for
1768 more information.
1769 -qic150
1771 Set tape volume size to 153600 kBytes. See tsize=# option for
1772 more information.
1773 -qic250
1775 Set tape volume size to 256000 kBytes. See tsize=# option for
1776 more information.
1777 -qic525
1779 Set tape volume size to 512500 kBytes. See tsize=# option for
1780 more information.
1781 -read0 Read null terminated file names from the file specified with the
1783 list= option.
1784 -refresh_old_files
1786 obsoleted by -refresh-old-files
1787 -refresh-old-files
1789 -refresh
1791 Do not create new files. Only already existing files may be
1792 overwritten from tarfile if either newer versions are present in
1793 the archive or if the -U flag is used. This allows to overwrite
1794 files by more recent files from an archive that contains more
1795 files than the target directory should contain. The option
1796 -refresh-old-files is the same as the -refresh option.
1797 -remove_first
1799 obsoleted by -remove-first
1800 -remove-first
1802 Remove files before extraction. If this option is in effect,
1803 star will remove files before extracting a file from the ar‐
1804 chive. This is needed if you want to change the file type or if
1805 you need to break a hard link. If you do not use either
1806 -ask-remove or -force-remove together with -remove-first, this
1807 option is useless and no files will be removed.
1808 -remove_recursive
1810 obsoleted by -remove-recursive
1811 -remove-recursive
1813 Remove files recursive. If removing of a file is permitted,
1814 star will only remove files, specials and empty directories. If
1815 this option is in effect, star will be allowed to recursively
1816 removes non empty directories too.
1817 -restore
1819 switches star into true incremental restore mode. A file named
1820 star-symtable and a directory named star-tmpdir is created in
1821 the root directory of the file system where the extraction takes
1822 place. If -restore has been specified, star behaves as if -xdot
1823 has been specified too. See also level= option and section
1824 INCREMENTAL BACKUPS for more information.
1825 Note: Do not use the -restore option if you only like to restore
1827 a single file or a list of selected files.
1828 -S Do not store/create special files. A special files is any file
1830 except plain files, symbolic links and directories. You need to
1831 be super user to extract special files.
1832 -s replstr
1834 Modify file or archive member names named by a pattern according
1835 to the substitution expression replstr. The format of replstr
1836 is:
1837 -s /old/new/[gp]
1839 The old pattern may use regular expressions and the new string
1841 may contain the special character '&'. The character '&' is sub‐
1842 stituted by the string that matches the old pattern. The
1843 optional trailing 'g' means global substitution. If 'g' is not
1844 used, a substitution pattern is only used once on a name. If
1845 the optional trailing 'p' is used, the substitution is printed
1846 to standard error.
1847 Up to 100 substitute options may be used. If more than one sub‐
1849 stitute option has been specified, star will loop over all sub‐
1850 stitute patterns until one matches.
1851 If the name substitutes to the empty string, the file is
1853 skipped.
1854 -secure-links
1856 Do not extract hard links or symbolic links if the link name
1857 (the target of the link) starts with a slash (/) or if /../ is
1858 contained in the link name. Tar archives containing such links
1859 could be used to compromise the system. If they are unpacked
1860 together with a lot of other files, this may not even be
1861 noticed.
1862 As the usability of a tar archiver would be limited if
1864 -secure-links checking would be done by default, star makes link
1865 checking optional.
1866 If you unpacked a tar archive using the -secure-links and did
1868 not get a security warning at the end of the star run, all files
1869 and links have been extracted. If you get a warning, you should
1870 unpack the archive a second time and specify the options -k, -w
1871 and -nowarn in addition to the options used for the first run.
1872 See SECURITY NOTES for more information.
1873 -shm Use System V shared memory for fifo. Normally star is compiled
1875 to use mapped /dev/zero pages for the fifo, if the operating
1876 system supports this. If star is compiled to have both code for
1877 mapped pages and for System V shared memory, star will use
1878 shared memory instead of the default. If the -help menu doesn't
1879 show the -shm flag you have no choice. When using System V
1880 shared memory, you may have to raise the system's internal limit
1881 for shared memory resources to get enough shared memory for
1882 star.
1883 -signed_checksum
1885 obsoleted by -signed-checksum
1886 -signed-checksum
1888 Use signed chars to calculate checksums. This violates the tar
1889 specs but old versions of tar derived from the seventh edition
1890 of UNIX are implemented in this way. Note: Only filenames and
1891 linknames containing chars with the most significant bit set may
1892 trigger this problem because all other fields only contain 7 bit
1893 ASCII characters, octal digits or binary zeroes.
1894 -silent
1896 Suppress informational messages like foobar is sparse.
1897 -sparse
1899 Handle files with holes effectively on store/create. Note that
1900 sparse files may not be archived this way if the archive format
1901 is tar, ustar, suntar, pax, or any cpio variant. On Solaris-2.3
1902 ... Solaris-2.5.1 there is a special ioctl() called _FIOAI that
1903 allows root to get the allocation info more efficiently. On
1904 Solaris 11 there is an enhanced lseek(2) call with addidional
1905 whence values SEEK_HOLE and SEEK_DATA that allow to find holes
1906 in an efficient way. Other operating systems lack support to
1907 get the real allocation list and force star to scan the files to
1908 look for blocks that only contain null characters. This may
1909 star cause to assume more holes to be present than the number
1910 that the file really contains.
1911 -symlinks
1913 This option tells star in extract mode to try to create a sym‐
1914 link whenever a hardlink is encountered in the archive.
1915 -T If the option file= or f= is omitted and the -T option is
1917 present, star will use the device indicated by the TAPE environ‐
1918 ment variable, if set.
1919 tardumps=name
1921 Set the file name for tar dump dates database to name. The
1922 default name is /etc/tardumps. Use in combination with the
1923 level= option to create true incremental dumps. See also -wtar‐
1924 dumps option and section INCREMENTAL BACKUPS for more informa‐
1925 tion.
1926 -time Print timing info. See DIAGNOSTICS for more information.
1928 -to_stdout
1930 obsoleted by -to-stdout
1931 -to-stdout
1933 Extract files to stdout. This option may be used to extract
1934 tarfiles containing tarfiles (see examples below).
1935 -tpath Use this option together with the -t option or with -cv (verbose
1937 create) to get only a list of the pathnames of the files in the
1938 archive. This may be used in shell scripts to generate a name
1939 list. If used together with the -diff option, star will only
1940 print the names of the files that differ. A second run of star
1941 may then be used to restore all files that had differences to
1942 the archive. Use the list= option to specify the namelist in
1943 this case.
1944 tsize=#
1946 Set tape volume size to # to enable multi volume tape support.
1947 The value refers to the archive size without compression. See
1948 bs= for the possible syntax. By default, the number is multi‐
1949 plied by 512, so the value counts in units of 512 byte blocks.
1950 If the size specifier ends with a valid multiplication character
1951 (e.g '.' for bytes or 'M' for MB) the specified size is used as
1952 specified and not multiplied by 512. With this option in
1953 effect, star is able to archive filesystems that are bigger then
1954 the tape size. If the option tsize=# without -multivol then no
1955 file will be split across volumes and each volume may in theory
1956 be read back separately. Files that do not fit on a single tape
1957 may not be stored in this mode. If -multivol has been specified
1958 in addition, star will split files when the maximum allowed tape
1959 size has been reached. If the tape volume size is not a multi‐
1960 ple of the tape block size, the tape volume size is silently
1961 rounded down to a value that is a multiple of the tape block
1962 size.
1963 See -multivol option for more information.
1965 -U Restore files unconditionally. By default, an older file from
1967 the archive will not replace a corresponding newer file on disk.
1968 umask=mask
1970 Set star's umask to mask. This allows to control the permis‐
1971 sions for intermediate directories that are created by star in
1972 extract mode. See also -p option.
1973 -v Increment verbose level by one. This normally results in more
1975 output during operation. See also in the description for the -t
1976 flag. Normally, star does its work silently. If the verbose
1977 level is 2 or more and star is in create or update mode, star
1978 will produce a listing to the format of the ls -l output.
1979 -V, -not
1981 Invert the meaning of the pattern list. i.e. use those files
1982 which do not match any of the pattern. Note that this option
1983 only applies to patterns that have been specified via the pat‐
1984 tern=pattern or pat=pattern option. Patterns specified as file
1985 type arguments will not be affected.
1986 -version
1988 Print version information and exit.
1989 VOLHDR=name
1991 Use name to generate a volume header.
1992 -w Do interactive creation, extraction or renaming. For every file
1994 that matches the list of patterns and that has a more recent
1995 modification time in the tar archive (if in extract mode and the
1996 -U option is not specified) star prints its name and asks:
1997 get/put ? Y(es)/N(o)/C(hange name) :
1999 You may answer either `N' for No or <Return> to skip this file.
2001 If you answer `Y' the file is extracted or archived on tape with
2002 its original name. If you answer `C', you are prompted for a
2003 new name. This name is used for the filename on disk if star is
2004 in extract mode or for the archive name if star is in create
2005 mode.
2006 See SECURITY NOTES for more information.
2008 Note that -w is an interactive option that prevents star from being
2010 used in non-interactive environments.
2011 -wready
2013 This option tells Star to wait up to two minutes for the drive
2014 to become ready. It has been added as a hack for a bug in the
2015 SunOS/Solaris st device driver. This driver has problems to
2016 sense the loading time with Exabyte drives with factory set‐
2017 tings. It also makes sense to use -wready if multiple remote
2018 backups are made. In this case, the remote connection is closed
2019 while the remote tape server is still writing a file mark. If
2020 another remote backup is initiated before the old remote server
2021 did finish to write the file mark, it would be impossible to
2022 open the tape driver unless -wready is specified to tell star to
2023 wait for the drive to become ready again.
2024 -wtardumps
2026 Tell star to update the file that contains the tar dump dates
2027 data base if in dump mode. If the dump is not a full dump, the
2028 tar dump dates data base file is not written. See also tar‐
2029 dumps=name and -C option or INCREMENTAL BACKUPS section for more
2030 information.
2031 -X filename
2033 Use the file filename as a file containing a list of path names
2034 to be excluded from the store/create/list/diff operation. The
2035 file filename must contain a list of path names, each on a sepa‐
2036 rate line. Be careful with white space and note that path names
2037 in the list may not contain new lines. Multiple -X options may
2038 be used. Each argument must refer to a file containing path
2039 names. The -X option has precedence before other options that
2040 select files to be included in the operation. See also list=
2041 option.
2042 -xattr
2044 -xattr-linux
2046 Store and extract extended file attributes as found on Linux
2047 systems. This option only makes sense when creating or extract‐
2048 ing exustar archives as it is based on POSIX.1-2001 extended tar
2049 headers.
2050 The method used in the current implementation could be used to
2052 store and extract extended file attributes from BSD too. Note
2053 that the current implementation is not generic enough to cover
2054 more general extended file attribute implementations as found on
2055 Solaris. If star starts to implement a method that covers
2056 extended file attributes on Solaris, the new method will be used
2057 then -xattr has been specified and -xattr-linux will refer to
2058 the old method. The method used with -xattr-linux may go away
2059 in the future.
2060 xdebug=#, xd=#
2062 Set extended debug level to #.
2063 -xdev, -M
2065 Do not descend mount points. This is useful when doing backups
2066 of complete file systems. See NOTES for more information.
2067 -xdir Extract directories even if the corresponding directories on the
2069 archive are not newer. This is useful when for some reason, the
2070 directories are recorded after their content (see -dirmode
2071 option), or when the permissions of some directories must be set
2072 in any case. As the classical UNIX cpio program does not imple‐
2073 ment delayed directory permission and time stamp setting, cpio
2074 users often create archives in reverse order (directories past
2075 their content). For this reason, it makes sense to use -xdir
2076 while extracting cpio archives.
2077 -xdot Unconditionally extract the first directory in the archive if
2079 the name of this directory is either '.' or './'. This helps to
2080 extract archives in an expected way if the target directory is a
2081 newly created empty directory. As this directory is newer than
2082 the top level directory in the archive, star would usually skip
2083 this directory during extraction. The effect of this directory
2084 is as if -xdir has been specified but is switched off after the
2085 first directory has been found.
2086 -xfflags
2088 Store and extract extended file flags as found on BSD and Linux
2089 systems. This option only makes sense when creating or extract‐
2090 ing exustar archives as it is based on POSIX.1-2001 extended tar
2091 headers. See NOTES section for problems with -xfflags on Linux
2092 systems.
2093 -Z run the input or output through a compress pipe - see option -z
2095 below.
2096 -z run the input or output through a gzip pipe. This is currently
2098 a quick and dirty hack, that mainly will cover the most common
2099 usage to compress the tar output if it is a file. No reblocking
2100 will be done, so this option will currently only make sense on
2101 plain files. As the -bz the -j the -Z and the -z option are non
2102 standard, it makes sense to omit the -bz the -j the -Z and the
2103 -z options inside shell scripts if you are going to extract a
2104 compressed archive that is located inside a plain file as star
2105 will auto detect compression and choose the right decompression
2106 option to extract. The environment variable STAR_COMPRESS_FLAG
2107 may be used to specify one option for gzip. If you want to
2108 write write compressed archives to tape, you should use
2109 star -c . | gzip | sdd ibs=4k obs=32k -fill of=/dev/rmt/1bn
2110 or
2111 star -c . | gzip | sdd ibs=4k obs=32k -fill ovsize=60m
2112 of=/dev/rmt/1bn
2113 if the tape can hold 60 MB.
2114
2116 Star is able to back up file system in full and incremental mode. To
2117 allow incremental backups, the file system must implement POSIX seman‐
2118 tics.
2119 To be more verbose:
2121 · The filesystem needs to uniquely identify files by the two num‐
2123 bers st_dev (The device ID of the device containing the file)
2124 and st_ino (The file serial number). If a file is renamed,
2125 these numbers need to be retained. Both numbers need to be a
2126 cardinal scalar that is expressible in a decimal number.
2127 · The filesystem needs to implement at least two time stamps,
2129 st_mtime the file's last modification time and st_ctime the
2130 file's last status change time. Both time stamps need to be
2131 dealt with as documented by the POSIX standard. Both numbers
2132 need to be a cardinal scalar that is expressible in a decimal
2133 number.
2134 · The filesystem needs to allow to rename files and directories by
2136 either calling rename(2), or link(2) and unlink(2).
2137 · The filesystem needs to honor and preserve the case of file
2139 names.
2140 The incremental backup method used by star depends on comparing the
2142 time stamps of all files against the time of the last backup. Note that
2143 this method only works correctly if the level 0 backup and all higher
2144 level incrementals include the whole file system. As star archives all
2145 inode meta data, star is able to detect renamed files by comparing the
2146 inode numbers of all files while in incremental restore mode.
2147 Detecting renamed files only works if star, while in backup mode, scans
2149 the whole file system tree for each full and incremental backup. This
2150 will work in case no files are excluded and the dump starts at the root
2151 directory of a file system. In case that no files are renamed from
2152 excluded parts to included parts, partial backups may be taken also.
2153 Partial backups only make sense if a complete directory sub tree is
2154 excluded (e.g. by using the pat= option) or if a partial backup starts
2155 at a sub directory that is not the root directory of the file system.
2156 To create a level 0 dump call:
2158 star -c -xdev -sparse -acl -link-dirs level=0 -wtardumps \
2160 f=archive-name -C /filestem-mount-point .
2161 To create a level 1 dump call:
2163 star -c -xdev -sparse -acl -link-dirs level=1 -wtardumps \
2165 f=archive-name -C /filestem-mount-point .
2166 Backups from live filesystems should be avoided. On operating systems
2168 that support file system snapshots, backups should be made from a read-
2169 only mount of a snapshot. Be careful that all files that have been cre‐
2170 ated between setting up a snapshot and starting an incremental backup
2171 may be missing from all backups unless the dumpdate=name option is
2172 used.
2173 If the system that is going to be backed up is not acting as a file
2175 server, it makes sense to shut down all services that may result in
2176 inconsistent file states before setting up the filesystem snapshot.
2177 After the filesystem snapshot has been set up, the services may be
2178 restarted.
2179 If the the system that is going to be backed up is acting as a file
2181 server, it may be that services on remote clients cause inconsistent
2182 file states unless all such services that remotely access files are
2183 shut down before the snapshot is set up.
2184 Star includes options that help to deal with file system snapshots.
2186 The following example backs up a file system on Solaris using a file
2187 system snapshot:
2188 echo > /tmp/snapstamp
2190 mount -r `fssnap -F ufs -o \
2192 backing-store=/var/tmp/EXPORT-NFS.snap /export/nfs` /mnt
2193 star -c -xdev -sparse -acl -link-dirs level=0 -wtardumps \
2195 f=archive-name dumpdate=/tmp/snapstamp \
2196 fs-name=/export/nfs -C /mnt .
2197 First a file with a current time stamp is created, then a snapshot for
2199 /export/nfs is created and mounted on /mnt. The following star command
2200 then creates a level 0 backup from the file system using the time the
2201 snapshot was created and the original mount point of the file system
2202 for /etc/tardumps and the archive header.
2203 Note that if the backup is done on a live file system, it may be unre‐
2205 liable. A typical problem problem in this context is caused by growing
2206 log files. As growing files are not a real problem with backups, the
2207 best way of dealing with growing files is to set up a star error con‐
2208 trol file (see errctl= option) and to tell star to ignore growing
2209 files.
2210
2212 Full (level 0) dumps should be made on a regular base (e.g. once a
2213 month). As a full dump may take a long time and takes a lot of tape,
2214 it is wise to make higher level incremental dumps with shorter inter‐
2215 vals. The next table shows a dump level list that may be used if
2216 monthly full dumps take place:
2217 Sun Mon Tue Wed Thu Fri
2219 Week 1: 0 10 10 10 10 5
2220 Week 2: 10 10 10 10 10 5
2221 Week 3: 10 10 10 10 10 5
2222 Week 4: 10 10 10 10 10 5
2223 The level 9 dumps made between Monday and Friday accumulate all changes
2225 made within the week. If you don't like this, use the following backup
2226 schedule:
2227 Sun Mon Tue Wed Thu Fri
2229 Week 1: 0 20 30 40 50 5
2230 Week 2: 10 20 30 40 50 5
2231 Week 3: 10 20 30 40 50 5
2232 Week 4: 10 20 30 40 50 5
2233 Note that in this case, 7 dumps need to be restored if the a crash hap‐
2235 pens at the worst case date (just before the Friday dump in week 2 or
2236 later).
2237
2240 Incremental restores should be made to an empty file system (except for
2241 the lost+found directory). Star is currently unable to perform incre‐
2242 mental restores to a file system that contains active mount points.
2243 The incremental restore procedure starts with restoring the last full
2245 (level 0) dump. Then the latest incremental dump of each dump level
2246 (with ascending order of dump levels) need to be restored.
2247 Let us assume the first example from the section BACKUP SCHEDULES for
2249 the backup schedule. If a disk crash happens before the Thursday dump
2250 of week 3 has been made, the following restore procedure needs to be
2251 applied:
2252 level 0
2254 starting with an empty disk, the full (level 0) dump from week 1
2255 is restored.
2256 level 5
2258 after the level 0 restore has been finished, the level 5 dump
2259 from Friday in week 2 is restored.
2260 level 10
2262 after the level 5 restore has been finished, the level 10 dump
2263 from Wednesday in week 3 is restored.
2264 The disk now contains the same files as it did when the level 9 dump
2266 has been made on Wednesday of week 3.
2267 To extract a level 0 dump call:
2269 cd /filestem-mount-point
2271 star -xpU -restore f=archive-name
2272 This creates the directory star-tmpdir and the database star-symtable
2274 in the root directory of the new file system. Subsequent restores with
2275 higher level backups depend on these files.
2276 To extract a level 1 (or higher) dump call:
2278 cd /filestem-mount-point
2280 star -xpU -restore f=archive-name
2281 Note that the environment variable STAR_DEBUG exists, star does not
2283 remove files with link count 1 that have been removed between incremen‐
2284 tal dumps. These files are moved to the directory star-tmpdir. Before
2285 you start to extract the next incremental, you need to remove all files
2286 in star-tmpdir.
2287
2290 Star may be used to synchronize filesystem content. To do this, an
2291 initial copy of the current content of the source filesystem needs to
2292 be performed first.
2293 To create an initial copy of a filesystem call:
2295 star -c -xdev -sparse -acl -link-dirs level=0 -wtardumps \
2297 -C /filestem-mount-point . | \
2298 star -xpU -restore -C /extract-target-dir
2299 In order to perform subsequent synchronization of the target filesystem
2301 with the content of the source filesystem, a modified incremental
2302 dump/restore procedure may be used.
2303 To copy incremental content of a filesystem call:
2305 star -c -xdev -sparse -acl -link-dirs level=1 -wtardumps \
2307 -cumulative -C /filestem-mount-point . | \
2308 star -xpU -restore -C /extract-target-dir
2309 Note that like with backups in general, copies from a live filesystem
2311 should be avoided. On operating systems that support file system snap‐
2312 shots, copies should be made from a read-only mount of a snapshot. Be
2313 careful that all files that have been created between setting up a
2314 snapshot and starting an incremental copy may be missing from all
2315 copies unless the dumpdate=name option is used.
2316 See section INCREMENTAL BACKUPS to learn how to modify the command line
2318 in case file system snapshots are used.
2319
2321 If star handles a signal, it first prints the statistics. Star handles
2322 the following signals:
2323 SIGINT usually generated by ^C from the controlling tty. Upon
2325 receipt of a SIGINT, star prints statistics and exits. If in
2326 create mode i.e. storing files to archive, star finishes with
2327 the current file to ensure that no partial file is written to
2328 the archive, write an eof record and then exits.
2329 SIGHUP not to be generated from a tty. The actions are the same as
2331 upon receipt of a SIGINT.
2332 SIGQUIT usually generated by ^\ from the controlling tty. Upon
2334 receipt of a SIGQUIT, star prints statistics and continues
2335 with the current operation. This is useful to watch the
2336 progress of the current operation.
2337
2339 The following exit values are returned:
2340 0 All files were processed successfully.
2342 -3 / 253
2344 Star has been called with the option -e, or the errctl= option
2345 has been used to mark the current error fatal.
2346 -2 / 254
2348 One or more files could not be processed successfully.
2349 -1 / 255
2351 Command line parsing error.
2352 >0 Other positive exit codes: The errno of the call that caused the
2354 fatal error.
2355
2357 To get a listing in a way similar to ls -l one might use:
2358 example% star -tv f=/dev/rmt/1bn
2360 The same command as listed above in a POSIX tar command line syntax
2362 compliant way is:
2363 example% star tvf /dev/rmt/1mbn
2365 To copy the directory tree in /home/someuser to the directory /home/fs
2367 use:
2368 example% (cd /home/someuser; star -c .) | (cd /home/fs ; star -xp)
2370 or by using the change directory option of star:
2372 example% star -c -C /home/someuser . | star -xp -C /home/fs
2374 Note that both examples above are not the optimum way to copy a direc‐
2376 tory tree. A more efficient way to copy a directory tree is to use the
2377 -copy option.
2378 example% star -copy -p -xdot -C /home/someuser . /home/fs
2380 To copy a file tree including the Access Control List entries for all
2382 files and to correctly copy sparse (holey) files use:
2383 example% star -copy -p -xdot -acl -sparse -C /home/someuser . /home/fs
2385 To compare the content of a tape to the filesystem one might use:
2387 example% star -diff -v f=/dev/rmt/1bn
2389 To compare two directory trees one might use:
2391 example% star -c . | star -C todir -diff -v diffopts=!times
2393 or better by using a method similar to the -copy method above:
2395 example% star -c -diff -v diffopts=!times -C fromdir . todir
2397 To compare all properties of two file trees, use:
2399 example% star -c -diff -vv -dump -acl -sparse -C fromdir . todir
2401 To extract a backup of the /usr tree without all files residing below
2403 /usr/openwin one might use:
2404 example% star -xp -V pat=openwin/\* f=/dev/rmt/1bn
2406 To extract all .c files to src, all .o files to obj and all other files
2408 to /tmp one might use:
2409 example% star -xp -C src '*.c' -C obj '*.o' -C /tmp '*' f=/dev/rmt/1bn
2411 To extract files from a zipped tar archive that is located on a read
2413 only filesystem e.g. a CD while having the shell's working directory on
2414 the CD one might use:
2415 example% star -zxp -C /tmp f=star-1.1.tar.gz
2417 to extract the files from the tar archive to the /tmp directory.
2419 To backup a list of files generated by the find(1) command:
2421 example% find . find_options -print | star -c list=- f=/dev/rmt/1bn
2423 Note that this does not work if the file names from output of the find
2425 command include new line characters.
2426 To extract a tarfile that contains a tarfile one might use:
2428 example% star -x -to-stdout f=/dev/rmt/1bn pat=pat | star -xp
2430 Pat, in this case should match the tarfile in the tarfile on tape that
2432 should be extracted.
2433 To make a backup of the root filesystem to a tape drive connected to a
2435 remote machine, one might use:
2436 example# cd /
2438 example# star -cM fs=128m bs=63k f=tape@remotehost:/dev/rmt/1bn .
2439 You need a line in /etc/passwd like the following to enable this:
2441 tape:NP:60001:60001:Tape:/etc/tapehome:/opt/schily/sbin/rmt
2443 And a .rhosts file in /etc/tapehome to allow remote connections from
2445 the appropriate hosts. Make sure that the file /etc/default/rmt exists
2446 and allows remote access to the requested tape drive.
2447 To use a ssh(1) connection for a backup to a remote tape server, one
2449 might use:
2450 example# env RSH=/usr/bin/ssh star -cM fs=128m bs=63k
2452 f=tape@remotehost:/dev/rmt/1bn .
2453 To repair a corrupted filesystem for which no recent backup exists, do
2456 the following:
2457 example# fsck -y /filesys
2459 example# mount /filesys
2460 example# cd /filesys
2461 example# star -xpk f=/dev/rmt/1bn
2462 example# mt -f /dev/rmt/1bn rewind
2463 example# star -diff -v diffopts=!times f=/dev/rmt/1bn
2464 Now check the differences and decide whether to restore additional
2466 files. This may be done by generating a list containing the needed
2467 filenames and using the list= option or by using the interactive mode
2468 (see -w option).
2469 If you want a list that only contains all filenames from files with
2471 differences you may use:
2472 example# star -diff -tpath diffopts=!times f=/dev/rmt/1bn
2474 If you are looking for files that changed the type or the access per‐
2476 mission because this is a common case on still corrupted files, use:
2477 example# star -diff -tpath diffopts=type,perm f=/dev/rmt/1bn
2479 If you like to archive all directories only that are part of the direc‐
2481 tory tree under ".", use:
2482 example# star -c f=archive-name -find . -type d
2484 If you like to archive all files as owner root and group root and make
2486 all files world readable in the archive, use:
2487 example# star -c f=archive-name -find . -chown root -chgrp root
2489 -chmod o+r
2490 If you like to list all files in an archive in a way like sfind(1),
2492 instead of the way used by star, use:
2493 example# star -t f=archive-name -find . -ls -false
2495
2498 STAR_COMPRESS_FLAG
2499 If you like star to always create compressed files that use max‐
2500 imum compression, you may set the environment variable STAR_COM‐
2501 PRESS_FLAG to -9.
2502 STAR_DEBUG
2504 If this environment variable is present, star will not remove
2505 temporary files from ./star-tmpdir. The files in this directory
2506 are files that have been removed by users before the last incre‐
2507 mental dump did take place on the master filesystem.
2508 STAR_FIFOSIZE
2510 If you like to by default let star use a different fifo size,
2511 set this environment variable to the desired size.
2512 TAPE Unlike other tar(1) implementations, star defaults to use
2514 stdin/stdout for the archive. If you like star to use the file
2515 name from the TAPE environment instead, you need to specify the
2516 -T option too.
2517 RSH If the RSH environment is present, the remote connection will
2519 not be created via rcmd(3) but by calling the program pointed to
2520 by RSH. Use e.g. RSH=/usr/bin/ssh to create a secure shell
2521 connection.
2522 Note that this forces star to create a pipe to the rsh(1) pro‐
2524 gram and disallows star to directly access the network socket to
2525 the remote server. This makes it impossible to set up perfor‐
2526 mance parameters and slows down the connection compared to a
2527 root initiated rcmd(3) connection.
2528 See BUGS section for more information.
2530 RMT If the RMT environment is present, the remote tape server will
2532 not be the program /etc/rmt but the program pointed to by RMT.
2533 Note that the remote tape server program name will be ignored if
2534 you log in using an account that has been created with a remote
2535 tape server program as login shell.
2536
2538 /etc/default/star
2539 Default values can be set for the following options in
2540 /etc/default/star. For example: CDR_FIFOSIZE=64m
2541 STAR_FIFOSIZE
2543 Sets the default size of the FIFO (see also fs=# option).
2544 STAR_FIFOSIZE_MAX
2546 Sets the maximum size of the FIFO (see also fs=# option).
2547 Setting STAR_FIFOSIZE_MAX in /etc/default/star allows to
2548 overwrite global values from backup scripts for machines
2549 with less memory.
2550 archive0=
2552 archive1=
2554 archive2=
2556 archive3=
2558 archive4=
2560 archive5=
2562 archive6=
2564 archive7=
2566 Archive entries for the -[0..7] option.
2567 A correct archive?= line has 3..4 space separated
2569 entries. The first is the device entry (e.g. ar‐
2570 chive0=/dev/tape). The second is the blocking factor in
2571 512 byte units. The third is the maximum media size in
2572 1024 byte units. If this entry contains a 0, then the
2573 media size is unlimited. The fourth entry is optional.
2574 If it contains a 'n' or a 'N', then the archive device is
2575 not a tape.
2576 Examples:
2578 archive0=/dev/tape 512 0 y
2580 archive1=/dev/fd0 1 1440 n
2581 archive2=/dev/rmt/0mbn 512 0
2582 If the default file does not need to be shared with the
2584 tar program from Solaris, any number may be used like a
2585 generic size option like bs=.
2586 Example:
2588 archive0=/dev/tape 256k 40G y
2590 /etc/tardumps
2592 The default name for the dump level archive. The default name is
2593 used whenever the tardumps=name option has not been specified.
2594 The file is written or updated when -wtardumps is used.
2595 The file holds one or more lines, each specifying a dump level
2597 entry. Each dump level entry starts with a mount point name
2598 followed by a TAB and one or more spaces, followed by the deci‐
2599 mal dump level, a space and the dump time.
2600 If the dump level is directly followed by a 'P', then the dump
2602 refers to a partial dump (a dump that does not include the whole
2603 filesystem).
2604 The dump time itself includes the decimal representation of the
2606 UTC seconds since Jan 01 1970, a space and the textual local
2607 time representation of the dump time.
2608 The numerical decimal dump time representation may be followed
2610 by a dot and a sub second value. The textual local time repre‐
2611 sentation is for informational use by humans only and not evalu‐
2612 ated by star.
2613 ./star-symtable
2615 Contains a database that is needed in incremental restore mode.
2616 ./star-symdump
2618 Contains an intermediate dump of restore database after a fatal
2619 error condition was met during an incremental restore operation.
2620 ./star-tmpdir
2622 Is the temporary directory that is used as intermediate file
2623 storage by star if in incremental restore mode.
2624 ./star-lock
2626 Is a lock file created by star when doing an incremental
2627 restore. If this file is present, it prevents star from running
2628 another incremental restore operation. This helps to avoid more
2629 than one restore operation at a time (e.g. from a cron script).
2630 /dev/tty
2632 Is used for the intercative user interface.
2633
2635 spax(1), suntar(1), scpio(1), tar(1), cpio(1), pax(1), rcp(1), mt(1),
2636 rmt(1), match(1), dd(1), sdd(1), rsh(1), ssh(1), star(4/5), rcmd(3),
2637 fssnap(1m)
2638
2640 star: f records + p bytes (total of x bytes = d.nnk).
2641 The number of full records, the number of bytes in partial records and
2643 the total amount of data in KBytes.
2644 star: Total time x.yyysec (z kBytes/sec)
2646 The time used and the transfer speed from/to the archive.
2648 If there have been non fatal errors during the archive processing, star
2650 will display a delayed error summary before exiting.
2651
2654 The command line syntax for the tar command (as defined in SUSv2 -
2655 UNIX-98) deviates from the command line syntax defined for all other
2656 commands. While the POSIX command line syntax requests all options to
2657 start with a dash (-) and allows to either write options separately or
2658 combined (in case of boolean flags), the tar command line syntax
2659 requires all options to be combined into a single string that does not
2660 start with a dash. Star by default assumes a command line syntax like
2661 a typical POSIX command and includes a compatibility mode that allows
2662 to specify a command line syntax as documented for the UNIX-98 tar com‐
2663 mand. If you believe that you found a bug in the way star parses the
2664 command line, please first check your command line for correctness
2665 before you make a bug report for star.
2666 If you like to write portable shell scripts that call tar, use the
2668 UNIX-98 tar command line syntax (i.e. a single option string and no
2669 dash), choose the commands and options from the following set of char‐
2670 acters ( rxtuc vxfblmo ) and check the shell script with both, your
2671 local tar and star for correct behavior. It you expect the script to
2672 call gnutar, do not include the -o option as gnutar implements this
2673 option in a way that violates UNIX-98.
2674 Star strips leading ./ sequences from pathnames. This lets star in many
2676 cases store longer pathnames than other implementations.
2677 The POSIX.1-1988 method (ustar format) of storing files with pathnames
2679 that are longer than 100 chars has some limitations:
2680 The name field (100 chars) an inserted slash (`/') and the pre‐
2682 fix field (155 chars) produce the pathname of the file. When
2683 recreating the original filename, name and prefix are concate‐
2684 nated, using a slash character in the middle. If a pathname does
2685 not fit in the space provided or may not be split at a slash
2686 character so that the parts will fit into 100 + 155 chars, the
2687 file may not be archived. Linknames longer than 100 chars may
2688 not be archived too.
2689 The star, xstar, xustar, exustar, pax, and gnutar archive formats don't
2691 have these limitations. While gnutar uses a method that makes it impos‐
2692 sible for other tar implementations (except star) to restore filenames
2693 that are longer than 100 chars, the xstar, xustar, exustar and pax ar‐
2694 chive format uses a method that allows an POSIX.1-1988 compliant way of
2695 storing filenames, if the POSIX method would allow this. When the ar‐
2696 chive format is xustar, exustar or pax very long filenames are stored
2697 using extended headers from the POSIX.1-2001 standard.
2698 Some buggy tar implementations will generate incorrect filenames during
2700 a restore operation if the archive contains pathnames or linknames of
2701 exactly 100 chars length.
2702 Star adds a tar signature in the last four bytes of each tar header if
2704 the archive format is star or xstar. This is no problem with the star
2705 archive format as it is an extension of the old pre POSIX.1-1988 tar
2706 format. On the other side, the xstar archive format claims to be as
2707 POSIX.1-1988 compliant as possible. Inserting this tar signature is a
2708 minor deviation from the standard that has the last 12 bytes of each
2709 header reserved for future use. On the other side, tar implementations
2710 such as some pax implementations that only compute checksums on the
2711 first 500 bytes of the header are violating the standard that requests
2712 the checksum to be computed on all 512 bytes of the tar header. All tar
2713 implementations that are 100% Posix compliant will be able to extract
2714 xstar archives as long as no new standard is defined that claims the
2715 last 12 bytes of the header for a different use. But then the ustar
2716 version number should be changed from `00' to `01'. Now, that the
2717 POSIX-2001 standard has been accepted, it is even predictable that all
2718 extensions to the standard tar format will go into the POSIX.1-2001
2719 extended headers which are extensible to include any feature without
2720 future limitation. The only known tar implementation that also uses
2721 the last 12 bytes of the tar header is Sun's tar which uses these 12
2722 bytes for files that are split over several archives. Such archives
2723 created by Sun's tar are not readable by the buggy pax implementation
2724 too. The Sun extension is not incompatible to the star signature
2725 because Sun expects an octal number at the beginning of the 12 byte
2726 field which is a null character in the star case.
2727 Star uses these four bytes since 1985 without problems. If you need a
2729 100% POSIX.1-1988 and 100% POSIX.1-2001 compliant tar archive, you may
2730 use the xustar, exustar or the pax archive format. The probability of
2731 falsely detecting other tar formats as xustar or exustar format however
2732 is higher.
2733 There is no way to ask for the n-th occurrence of a file.
2735 The way EOF is handled by star differs, whether the fifo is in effect
2737 or not. If the fifo is not used, star stops reading the archive if it
2738 encounters a logical EOF record in the archive. If the fifo is used,
2739 star may read until the fifo is full or until the real EOF mark on tape
2740 is reached. How much data star actually reads depends on the time when
2741 the star foreground process sends a fifo shutdown signal to the back‐
2742 ground fifo read process.
2743 Gnu tar often creates tar archives with incorrect logical EOF marks.
2745 The standard requires two blocks that are completely zeroed, whereas
2746 gnutar often only adds one of them.
2747 Old versions of tar found on SYSVr3 and earlier cannot read tar ar‐
2749 chives with a blocksize greater than 10 kBytes.
2750 The method of storing sparse files currently used with the star and
2752 xstar format is not guaranteed to be used in later versions of star.
2753 If the author decides to change this method, later versions of star may
2754 not be able to restore sparse files from tar archives made by the cur‐
2755 rent version of star.
2756 Some tar implementations violate the standard in using only the first
2758 500 Bytes of the header for checksum computation. These tar implementa‐
2759 tions will not accept star and xstar type tar archives.
2760 Sun's Solaris 2.x tar implementation violates the Posix standard. Tar
2762 archives generated by star cause Sun's tar to print tar: impossible
2763 file type messages. You may ignore these messages.
2764 Gnutar's dumpdirs are non standard and are currently not implemented.
2766 If gnutar archives sparse files with more than four holes, it produces
2768 archives that violate the standard in a way that prevents other tar
2769 implementations to read these archives. Star knows about that and is
2770 able to handle these gnutar archives.
2771 The filetype N (LF_NAMES) from gnutar (an obsolete method of storing
2773 long names) will never be implemented.
2774 Note that on operating systems (like DOS) that do not implement real
2776 pipes, star implements compression via a temporary file. Using com‐
2777 pression thus is limited by the maximum file size and the available
2778 disk space.
2779 The extended file flags implementation (see -xfflags option) on Linux
2781 is buggy by design. In order to retrieve the needed information, every
2782 file needs to be opened. If the /dev directory is included in create
2783 mode, every possible driver will be loaded which may hang the system
2784 for a long time. In the worst case, unwanted side effects from opening
2785 devices (such as causing tape drives to rewind the media) may be
2786 caused.
2787
2790 If you unpack a tar archive in a non empty directory, any file in that
2791 directory may be overwritten unless you specify the -k option. If the
2792 archive contains symbolic links or hard links, star may even overwrite
2793 files outside the current directory. If the directory where the ar‐
2794 chive is been unpacked is not empty and contains contains symbolic
2795 links or hard links to directories outside that directory, star may
2796 also overwrite files outside the current directory. As many other com‐
2797 mands, star usually has all possible permissions when run as root.
2798 Unpacking archives as root thus may have fatal results to any file on
2799 your system. Be very careful when you try to extract an archive that
2800 has not been created by you. It is possible to create hand crafted tar
2801 archives that may overwrite critical files (like /etc/passwd) on your
2802 system. In addition all tar archives that have been created with the
2803 list= option and tar archives where the C= option was not specified
2804 before all file type arguments may be critical.
2805 A good advise is to extract all doubtful archives as non root in an
2807 empty directory and to specify the -secure-links option. If you get a
2808 warning, you should unpack the archive a second time and specify the
2809 options -k, -w and -nowarn in addition to the options used for the
2810 first run.
2811
2813 If star is installed suid root, star is able to make connections to
2814 remote archives for non root users. This is done by using the rcmd(3)
2815 interface to get a connection to a rmt(1) server.
2816 Star resets its effective uid back to the real user id immediately
2818 after setting up the remote connection to the rmt server and before
2819 opening any other file.
2820 If star has not been installed suid root and not called by root, it
2822 will try to create the remote connection via rsh(1) or ssh(1) (in case
2823 the environment RSH has been set to ssh). Note that in this case, the
2824 throughput to the remote tape server will be much lower than with a
2825 connection that has been initiated via rcmd(3).
2826
2828 If star is running on a large file aware platform, star is able to han‐
2829 dle files up to 8 GB in a mode that is compliant to the POSIX.1-1988
2830 ustar format. With a nonstandard star specific extension, up to 95 bits
2831 may be used to code the filesize. This will handle files up to
2832 200,000,000 TB. With the new POSIX.1-2001 extended headers used by the
2833 xustar, exustar and pax format, any filesize may be archived.
2834
2836 The fact that the -f option has to be implemented in a way that is com‐
2837 patible with old tar implementations gives several problems. The
2838 options -fifostats, -force-hole, -force-remove and -fifo interfere with
2839 the -f option and the fact that they exist prevents users from using
2840 filenames like e.g. ifo using the traditional way where the filename
2841 directly follows the string -f without any space between the option
2842 name and the file name. However, there is no problem to use a file
2843 named ifo by by calling -f ifo, f=ifo, -f=ifo or -f= ifo. Be careful
2844 not to make typos with the above options. The result could be that a
2845 file is created as a result of the mistyped option.
2846 There is currently no way to set the fifo lowwater and highwater marks.
2848 There is currently no way to automatically delete files in the target
2850 file tree if they are obsolete. Star should implement something simi‐
2851 lar to gnutar's dumpdirs.
2852 If not invoked by the super user star may not be able to extract files
2854 if they reside in read only directories.
2855 Star is not able to make a complete backup of a filesystem if files are
2857 hidden by a mount that is in effect on a directory of this filesystem.
2858 This may be avoided in case of the ufs filesystem if the backup is made
2859 off a ufs snapshot (see the man page for fssnap(1m) It could be avoided
2860 for any filesystem if the loopback filesystem had an option that tells
2861 lofs not to traverse mountpoints.
2862 For now (late 2002), we know that the following programs are broken and
2864 do not implement signal handling correctly:
2865 rsh on SunOS-5.0...SunOS-5.9
2867 ssh from ssh.com
2869 ssh from openssh.org
2871 Sun already did accept a bug report for rsh(1)/[22mssh(1). Openssh.org
2873 accepted and fixed a bug for their implementation of ssh(1).
2874 If you use star to create a remote connection via an unfixed rsh(1) or
2876 ssh(1), be prepared that terminal generated signals may interrupt the
2877 remote connection.
2878
2881 Star was first created in 1982 to extract tapes on a UNIX clone that
2882 had no tar command. In 1985 the first fully functional version has
2883 been released as mtar.
2884 When the old star format extensions have been introduced in 1985, it
2886 was renamed to star (Schily tar). In 1994, Posix 1003.1-1988 exten‐
2887 sions were added and star was renamed to star (Standard tar).
2888
2891 Joerg Schilling
2892 Seestr. 110
2893 D-13353 Berlin
2894 Germany
2895 Mail bugs and suggestions to:
2897 schilling@fokus.fraunhofer.de or js@cs.tu-berlin.de or
2899 joerg@schily.isdn.cs.tu-berlin.de
2900Joerg Schilling 07/06/29 STAR(1)