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 star is
173 reading a tar archive that has been created in -dump 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 here
481 as CRC. This algorithm is simple Sum32 -- not a poly‐
482 nomial CRC. Try to avoid the crc archive format
483 because of its limited portability.
484 All tar archive formats may be interchanged if the archive con‐
487 tains no files that may not be archived by using the old tar
488 format. Archives in the xstar format may be extracted by any
489 100% POSIX compliant tar implementation if they contain no files
490 with pathnames > 100+130 chars and if they contain no sparse
491 files that have been archived by using the -sparse option.
492 -ask_remove
495 obsoleted by -ask-remove
496 -ask-remove
498 Ask to remove non writable files on extraction. By default,
499 star will not overwrite files that are read only. If this
500 option is in effect, star will ask whether it should remove
501 these files to allow the extraction of a file in the following
502 way:
503 remove 'filename' ? Y(es)/N(o) :
505 -atime, -a
507 Reset access time of files after storing them to tarfile. On
508 Solaris 2.x, (if invoked by root) star uses the _FIOSATIME ioctl
509 to do this. This enables star not to trash the ctime while
510 resetting the atime of the files. If the -atime option is used
511 in conjunction with the list command, star lists access time
512 instead of modification time. (This works only in conjunction
513 with the star, xstar, xustar, exustar, and with the pax format.)
514 Another option to retain the access time for the the files that
515 are going to be archives is to readonly mount a UFS snapshot and
516 to archive files from the mount point of the UFS snapshot.
517 -B Force star to perform multiple reads (if necessary) to fill a
519 block. This option exists so that star can work across the Eth‐
520 ernet, since pipes and sockets return partial blocks even when
521 more data is coming. If star uses stdin as archive file, star
522 behaves as if it has been called with the -B option. For this
523 reason, the option -B in practice is rarely needed.
524 -block-number
526 Print the archive block number (archive offset / 512) at the
527 beginning of each line when in verbose mode. This allows to
528 write backup scripts that archive the offsets for files and that
529 use
530 mt fsr blockno
532 to skip to the tape block number of interest in a fast way if a
534 single file needs to be restored.
535 blocks=#, b=#
537 Set the blocking factor of the tarfile to # times 512 bytes
538 (unless a different multiplication factor has been specified -
539 see bs= option for possible multiplication factors). Changing
540 the blocking factor only makes sense when the archive is located
541 on a real tape device or when the archive is accessed via the
542 remote tape protocol (see f= option below). The default is to
543 use a blocking factor of 20 i.e. 10 kBytes. Increasing the
544 blocksize will speed up the backup. For portability with very
545 old tar implementations (pre BSD 4.2 or pre AT&T SVR4), block‐
546 size should not be more than 10 kBytes. For POSIX.1-1988 com‐
547 patibility, blocksize should be no more than 10 kBytes. For
548 POSIX.1-2001 compatibility, blocksize should be no more than
549 32 kBytes. Most systems also have a hardware limitation for the
550 blocksize, 32 kBytes and 63 kBytes are common limits on many
551 systems. The upper limit in any case is the size of the buffer
552 RAM in the tape drive. Make a test if you want to make sure
553 that the target system will handle the intended blocksize. If
554 you use star for data exchange via tape, it is a good idea to
555 use a blocksize of 10 kBytes unless you are sure that the read‐
556 ing system will handle a larger blocksize. If you use star for
557 backup purposes with recent hardware (e.g. DLT tape drives), a
558 blocksize of 256 kBytes results in sufficient speed and seems to
559 be a good choice. Star allows block sizes up to 2 GByte if the
560 system does not impose a smaller limit. If you want to deter‐
561 mine the blocking factor when reading an unknown tar archive on
562 tape, specify a blocking factor that is higher than the supposed
563 blocking factor of the tape. Star then will determine the
564 blocking factor by reading the first record of the tape and
565 print a message:
566 star: Blocksize = # records.
568 Where # is the blocking factor in multiples of 512 bytes. The
570 blocks= option and the bs= option are equivalent methods to
571 specify the tape block size. The blocks= option is preferred by
572 people who like to use an option that behaves similar to the
573 interface of the historic tar(1) implementations.
574 bs=# Set output block size to #. You may use the same method as in
576 dd(1) and sdd(1). The number representing the size is taken in
577 bytes unless otherwise specified. If a number is followed
578 directly by the letter `.', `w', `b', `k', `m', `g', `t', or
579 `p', the size is multiplied by 1, 2, 512, 1024, 1024*1024,
580 1024*1024*1024, 1024*1024*1024*1024 or 1024*1024*1024*1024*1024.
581 If the size consists of numbers separated by `x' or `*', multi‐
582 plication of the two numbers is performed. Thus bs=7x8k will
583 specify a blocksize of 56 kBytes. Blocksize must be a multiple
584 of 512 bytes. See also the description of the blocks= option
585 for more details on blocksizes. The option bs= is preferred by
586 people who like to use an option that behaves similar to the
587 interface used by dd(1) and sdd(1).
588 -bsdchdir
590 Switch the behavior of the C= option to BSD style. The default
591 behavior of star is to stay in a working directory until a new
592 C= is seen. With BSD tar, the C= option is only related to the
593 next file type argument.
594 -bz run the input or output through a bzip2 pipe - see option -z -Z
596 and -j below. As the -bz the -j the -Z and the -z option are
597 non standard, it makes sense to omit the -bz the -j the -Z and
598 the -z options inside shell scripts if you are going to extract
599 a compressed archive that is located inside a plain file as star
600 will auto detect compression and choose the right decompression
601 option to extract.
602 C=dir
604 -C dir Perform a chdir(2) operation to dir before storing or extracting
606 the next files. In all cases, star will perform the chdir(2)
607 operation relative to the current working directory of the
608 shell.
609 · In list mode (with the -t flag), star ignores all -C
611 options.
612 · In create mode (with the -c, -r and -u flag), star walks
614 through all -C options and file type arguments. While a
615 BSD derived tar(1) implementation goes back to the cur‐
616 rent working directory after storing one file argument
617 that immediately follows the -C option, star changes the
618 directory only if a new -C option follows. To emulate
619 the behavior of a BSD derived tar(1), add a -C . option
620 after the file argument.
621 · In extract mode (with the -x, -n and -diff flag), star
623 builds a pattern list together with corresponding direc‐
624 tories from previous C=dir options and performs a
625 chdir(2) to the corresponding directory of a matching
626 pattern. All pat= options that do not follow a C=dir
627 option are interpreted as if they were preceded by a -C .
628 option. See EXAMPLES for more information.
629 compress-program=name
631 Set a named compress program. The program must compress in a
632 pipe when called without parameters and decompress when run with
633 the -d option in a pipe. This option is otherwise similar to
634 the -z the -j the -Z and the -bz option.
635 -copydlinks
637 Try to recursively copy the content of linked directories
638 instead of creating the link. This is an experimental feature
639 that may help to unpack archives on DOS.
640 -copyhardlinks
642 This option allows to copy hardlinked targets rather than creat‐
643 ing the link. It helps to extract tar files on systems that do
644 not implement hardlinks (e.g. BeOS).
645 -copylinks
647 This option allows to copy both, hard- and symlinked targets
648 rather than creating a link. It helps to extract tar files on
649 systems that do not implement links (e.g. OS/2). To extract and
650 copy all symlinks correctly, you may need to call star twice as
651 star cannot copy files that appear in the archive later than a
652 symlink pointing to them.
653 -copysymlinks
655 This option allows to copy symlinked targets rather than creat‐
656 ing a symbolic link. It helps to extract tar files on systems
657 that do not implement links (e.g. OS/2). To extract and copy
658 all symlinks correctly, you may need to call star twice as star
659 cannot copy files that appear in the archive later than a sym‐
660 link pointing to them.
661 -cpio-statistics
663 Instead of the star flavor of the statistics, print statistics
664 in cpio flavor.
665 -ctime If used with the list command, this lists ctime rather than
667 mtime if the archive format is star, xstar, xustar, exustar, or
668 pax.
669 If star is run as root and if -ctime is used with the extract
671 command and the same archive formats, this causes star to try to
672 restore even the ctime of a file by generating time storms. You
673 should not do this when in multi user mode because this may con‐
674 fuse programs like cron and the news system. Although star
675 tries to eliminate the accumulative effects of the time storm,
676 there is a tendency for the system clock to slow down a bit.
677 The clock typically lags about one millisecond per extracted
678 file. Use with care and check the system clock after using this
679 feature.
680 If used with the create command this changes the behavior of the
682 newer= option. Star, in this case compares the ctime of all
683 files to the mtime of the stamp file rather then comparing the
684 mtimes of both files.
685 -cumulative
687 A shorthand for -dump-cumulative. See -dump-cumulative for more
688 information.
689 -D Do not descend directories when in create mode. Normally, star
691 descends the whole tree if it encounters a directory in in its
692 file parameters. The option -D is in effect by default if the
693 list=file option is used. If you like star to descend directo‐
694 ries found in the list file, use the -dodesc option (see below).
695 -d Do not store/create directories. Old versions of tar such as
697 published with the seventh edition of UNIX are not able to deal
698 with directories in tar archives. If a tar archive is generated
699 without directories this avoids problems with tar implementa‐
700 tions found on SYSVr3 and earlier. If used during extract, no
701 intermediate missing directories are created.
702 -data-change-warn
704 If the size of a file changes while the file is being archived,
705 treat this condition as a warning only that does not cause a non
706 zero exit code. A warning message is still written if the con‐
707 dition is not otherwise ignored by another rule from an errctl=
708 option. The -data-change-warn option works as if the last error
709 control option was
710 errctl="WARN|GROW|SHRINK *"
712 The -e option or an ABORT entry in a condition set up by errctl=
714 has a higher precedence than the -data-change-warn option. This
715 option is ignored in extract or list mode.
716 -debug Print debug messages. Among other things, this gives debug mes‐
718 sages for header type recognition, tar type properties, EOF
719 recognition, opening of remote archives and fifo internals.
720 diffopts=optlst
722 Comma separated list of diffopts. Valid members in optlst are:
723 help Print a summary of possible members of the diffopts
725 list.
726 ! Invert the meaning of the following string. No comma
728 is needed after the exclamation mark.
729 not Invert the meaning of all members in the diffopts list
731 i.e. exclude all present options from an initially
732 complete set compare list. When using csh(1) you
733 might have problems to use ! due to its strange
734 parser. This is why the not alias exists.
735 perm Compare file permissions. With this option in effect,
737 star compares the low order 12 bits of the st_mode
738 field.
739 mode Same as perm.
741 symperm Compare permissions even in case the target file on
743 the local filesystem is a symbolic link. By default,
744 star will not compare the permission of symbolic links
745 as most systems cannot set the permission of symbolic
746 links. Star compares symperm only if perm is compared
747 also.
748 type Compare file type. Note that star cannot compare the
750 file type in case of a hard link.
751 nlink Compare link count on hardlinks. This only works if
753 the archive is in exustar format and contains star's
754 dump extensions.
755 uid Compare numerical user id of file.
757 gid Compare numerical group id of file.
759 uname Compare ASCII version of user id of file. The user
761 name is mapped via the file /etc/passwd.
762 gname Compare ASCII version of group id of file. The group
764 name is mapped via the file /etc/group.
765 id Shorthand for: uid,gid,uname,gname. Compare all
767 user/group related info of file. Note that this will
768 always find differences if the source and target sys‐
769 tem use different user or group mappings.
770 size Compare file size. Note that star cannot compare the
772 file size in case of a hard link.
773 data Compare content of file. If star already found that
775 the size of the files differ, it will not compare the
776 content anymore. If the size of the files differ,
777 star will always report different data.
778 cont Same as data.
780 rdev Compare major/minor numbers for device nodes.
782 hardlink Compare target of hardlinks.
784 symlink Compare target of symlinks. This evaluates the paths
786 returned by the readlink(2) call.
787 Two symlinks are considered equal, it they either have
789 a characterwise identical link-name, or if they either
790 both use an absolute path name or both use a relative
791 path name and the following is true: Both symlinks
792 point to the same file that must exist or both path‐
793 names look similar enough.
794 sympath Compare the target pathnames of symlinks. This charac‐
796 terwise compares the strings returned from the read‐
797 link(2) call.
798 sparse Compare if either both files are sparse or not. If
800 only one of both files is sparse, then a difference is
801 flagged. This only works with if the archive format
802 is star, xstar, xustar, exustar, or gnutar.
803 atime Compare access time of file. This only works with if
805 the archive format is star, xstar, xustar, exustar, or
806 pax.
807 mtime Compare modification time of file.
809 ctime This only works with if the archive format is star,
811 xstar, xustar, exustar, or pax.
812 lmtime Compare the modification time even in case the target
814 file on the local filesystem is a symbolic link. By
815 default, star will not compare the modification time
816 of symbolic links as most systems cannot set the modi‐
817 fication time of symbolic links. Star compares lmtime
818 only if mtime is compared also.
819 times Shorthand for: atime,mtime,ctime.
821 dir Compare the content of directories. This only works
823 if the archive is in exustar format and contains
824 star's dump extensions. Together with increased ver‐
825 bose level (-vv) this will print a list of files that
826 are only in the archive and a list of files that are
827 only on the current filesystem.
828 xtimes Shorthand for: atime,mtime,ctime,lmtime.
830 acl Compare access control lists. This only works if the
832 archive is in exustar format and has been created with
833 star's -acl option. You need to specify the -acl
834 option in addition when running the diff.
835 xattr Compare extended file attributes. This only works if
837 the archive is in exustar format and has been created
838 with star's -xattr option. You need to specify the
839 -xattr option in addition when running the diff.
840 fflags Compare extended file flags. This only works if the
842 archive is in exustar format and has been created with
843 star's -xfflags option. You need to specify the
844 -xfflags option in addition when running the diff.
845 If optlst starts with a ! the meaning of all members in optlst
847 is inverted as with the not optlist member. In this case, star
848 starts with a complete list that includes atime and lmtime.
849 Reasonable diff options to use when comparing against a copy of
850 a directory tree are diffopts=!atime,ctime,lmtime.
851 If diffopts are not specified, star compares everything but the
853 access time of the files and the modification time of symbolic
854 links.
855 dir-group=group
857 If star extracts archives as root, this option allows to control
858 the group id of intermediate directories created by star.
859 dir-owner=user
861 If star extracts archives as root, this option allows to control
862 the owner of intermediate directories created by
863 -dirmode
865 If in create mode (i.e. when storing files to archive), star
866 stores directories past the corresponding files. This guarantees
867 that even old tar implementations without a directory cache will
868 be able to restore the correct times of directories. The option
869 -dirmode should only be used if the archive needs to be
870 extracted by an old tar implementation. If star is used to
871 extract an archive that has been created with -dirmode the
872 directories will not get an old time stamp unless the option -U
873 is used while extracting the archive.
874 -dodesc
876 Force star to descend directories found in a list=file. See
877 also the -D option above. The -dodesc option only works in cre‐
878 ate mode.
879 -dump Allows to create archives with the same number of attributes as
881 an archive that has been created with the level= option but
882 without the restrictions that apply to a true dump.
883 The resultant archive may be seen as a level-less dump which
885 includes similar attributes as a level 0 dump but may span more
886 than a single file system and does not need to use a -C option.
887 It has been originally introduced to make it easier to implement
888 a star version that supports true incremental dumps, but it is
889 kept as it gives additional benefits. Star currently sets the
890 archive type to exustar and, in addition archives more inode
891 meta data inside POSIX.1-2001 extended headers. See also level=
892 option and the section INCREMENTAL BACKUPS for more information
893 on true incremental dumps.
894 -dump-cumulative
896 instructs star to perform incremental dumps relatively to the
897 last incremental dump of the same level. Incremental dumps with
898 a level higher than 0 are normally done relatively to the con‐
899 tent of a previous dump with lower level. If incremental dumps
900 and restores are going to be used to synchronize filesystem con‐
901 tent, every successive incremental dump will increase in size if
902 -dump-cumulative is not used. See section SYNCHRONIZING
903 FILESYSTEMS for more information.
904 dumpdate=name
907 Tells star to use the mtime of the time stamp file name instead
908 of using the start time of star. This is needed when star is
909 run on file system snapshots. If star would use the the start
910 time with snapshots, all files that have been modified between
911 the setup of the snapshot and the start of star would be missing
912 on the backup.
913 -dumpmeta
915 changes the behavior of star in incremental dump mode. If
916 -dumpmeta is used and only the inode change time (st_ctime) of a
917 file has been updated since the last incremental dump, star will
918 archive only the meta data of the file (e.g. uid, permissions,
919 ...) but not the file content. Using -dumpmeta will result in
920 smaller incremental dumps, but files that have been created
921 between two incrementals and set to an old date in st_mtime
922 (e.g. as a result from a tar extract) will not be archived with
923 full content. Using -dumpmeta thus may result in incomplete
924 incremental dumps, use with extreme care.
925 -e Exit immediately with exit status -3 (253) if any unexpected
927 error occurs. The -e option works as if the last error control
928 option was
929 errctl="ABORT|ALL|DIFF *"
931 This allows to use the errctl= option together with the -e
933 option and thus to ignore some error conditions while aborting
934 on all other conditions.
935 errctl= name
937 errctl= error control spec
939 Add the content from file name to the error control definitions
940 or add error control spec to the error control definitions.
941 More than one error control file and more than one error control
942 spec as well as a mixture of both forms is possible.
943 The reason for using error control is to make star quiet about
945 error conditions that are known to be irrelevant on the quality
946 of the archive or restore run or to tell star to abort on cer‐
947 tain error conditions instead of trying to continue with the ar‐
948 chive.
949 A typical reason to use error control is to suppress warnings
951 about growing log files while doing a backup on a live file sys‐
952 tem. Another typical reason to use error control is to tell
953 star to abort if e.g. a file could not be archived instead of
954 continuing to archive other files from a list.
955 The error control file contains a set of lines, each starting
957 with a list of error conditions to be ignored followed by white
958 space followed by a file name pattern (see match(1) or pat‐
959 match(3) for more information). The error control spec uses the
960 same syntax as a single line from the error control file. If
961 the file name pattern needs to start with white space, use a
962 backslash to escape the start of the file name. It is not possi‐
963 ble to have new line characters in the file name pattern. When‐
964 ever an error situation is encountered, star checks the lines in
965 the error control file starting from the top. If the current
966 error condition is listed on a line in the error control file,
967 then star checks whether the pattern on the rest of the line
968 matches the current file name. If this is the case, star uses
969 the current error control specification to control the current
970 error condition.
971 The list of error conditions to be handled may use one or more
973 (in this case separated by a '|' character) identifiers from the
974 list below:
975 ABORT If this meta condition is included in an error con‐
977 dition, star aborts (exits) as soon as possible
978 after this error condition has been seen instead of
979 making star quiet about the condition. This error
980 condition flag may only be used together with at
981 another error condition or a list of error condi‐
982 tions (separated by a '|' character).
983 WARN If this meta condition is included in an error con‐
985 dition, star prints the warning about the error con‐
986 dition but the error condition does not affect the
987 exit code of star and the error statistics (which is
988 printed to the end) does not include the related
989 errors. This error condition flag may only be used
990 together with at another error condition or a list
991 of error conditions (separated by a '|' character).
992 The WARN meta condition has a lower precedence than
993 ABORT.
994 DIFF Suppress output in case that star -diff did
996 encounter any differences.
997 ALL This is a shortcut for all error conditions below.
999 STAT Suppress warnings that star could not stat(2) a
1001 file.
1002 GETACL Suppress warnings about files on which star had
1004 problems to retrieve the ACL information.
1005 OPEN Suppress warnings about files that could not be
1007 opened.
1008 READ Suppress warnings read errors on files.
1010 WRITE Suppress warnings write errors on files.
1012 READLINK Suppress warnings readlink(2) errors on symbolic
1014 links.
1015 GROW Suppress warnings about files that did grow while
1017 they have been archived.
1018 SHRINK Suppress warnings about files that did shrink while
1020 they have been archived.
1021 MISSLINK Suppress warnings about files for which star was
1023 unable to archive all hard links.
1024 NAMETOOLONG Suppress warnings about files that could not be
1026 archived because the name of the file is too long
1027 for the archive format.
1028 FILETOOBIG Suppress warnings about files that could not be
1030 archived because the size of the file is too big for
1031 the archive format.
1032 SPECIALFILE Suppress warnings about files that could not be
1034 archived because the file type is not supported by
1035 the archive format.
1036 GETXATTR Suppress warnings about files on that star could not
1038 retrieve the extended file attribute information.
1039 SETTIME Suppress warnings about files on that star could not
1041 set the time information during extraction.
1042 SETMODE Suppress warnings about files on that star could not
1044 set the access modes during extraction.
1045 SECURITY Suppress warnings about files that have been skipped
1047 on extraction because they have been considered to
1048 be a security risk. This currently applies to all
1049 files that have a '/../' sequence inside when -..
1050 has not been specified.
1051 LSECURITY Suppress warnings about links that have been skipped
1053 on extraction because they have been considered to
1054 be a security risk. This currently applies to all
1055 link names that start with '/' or have a '/../'
1056 sequence inside when -secure-links has been speci‐
1057 fied. In this case, star tries to match the link
1058 name against the pattern in the error control file.
1059 SAMEFILE Suppress warnings about links that have been skipped
1061 on extraction because source and target of the link
1062 are pointing to the same file. If star would not
1063 skip these files, it would end up with removing the
1064 file completely. In this case, star tries to match
1065 the link name against the pattern in the error con‐
1066 trol file.
1067 BADACL Suppress warnings access control list conversion
1069 problems.
1070 SETACL Suppress warnings about files on that star could not
1072 set the ACL information during extraction.
1073 SETXATTR Suppress warnings about files on that star could not
1075 set the extended file attribute information during
1076 extraction.
1077 If a specific error condition is ignored, then the error condition is
1079 not only handled in a silent way but also excluded from the error sta‐
1080 tistics that are printed at the end of the star run.
1081 Be very careful when using error control as you may ignore any error
1083 condition. If you ignore the wrong error conditions, you may not be
1084 able to see real problems anymore.
1085 -exclude-from name
1087 Exclude from named file, this is an alias for the -X option. See
1088 -X option for more information.
1089 -F,-FF ...
1091 Fast and simple exclude option for create mode. With one -F
1092 argument, star ignores all directories called SCCS and RCS.
1093 With two -F arguments, star in addition ignores all files called
1094 core errs a.out all files ending with .o. OBJ/. With three -F
1095 arguments, star ignores all sub trees starting from a directory
1096 that includes a file .mirror or .exclude and all object files
1097 and files called core errs a.out all files ending with .o. With
1098 four -F arguments, star ignores all sub trees starting from a
1099 directory that includes a file .mirror or .exclude the latter
1100 files are excluded too as well as and all object files and files
1101 called core errs a.out all files ending with .o. With five -F
1102 arguments, star in addition again excludes all directories
1103 called SCCS and RCS.
1104 -fifo Use a fifo to optimize data flow from/to tarfile. This option
1106 is in effect by default (it may be changed at compile time).
1107 The default fifo size is 8 MBytes on all platforms except Linux
1108 versions that do not support mmap() (4 MB because kernels before
1109 2.4 did not handle big shared memory areas) and Sun/mc68000 (1
1110 MB). This will star make even work on a tiny machine like a Sun
1111 3/50. The fifo size may be modified with the fs= option. A rule
1112 of dumb for the fifo size is to use more than the buffer size of
1113 the tape drive and less then half of the real memory of the
1114 machine. A good choice would be to use a fifo size between 8
1115 and 256 MB. This may increase backup speed up to 5% compared to
1116 the speed achieved with the default fifo size. Note that with a
1117 DLT drive that gives 12MB/s transfer rate, a fifo of 256 MB size
1118 will keep the tape at least streaming in units of 20 seconds.
1119 All options that start with the -f sequence are sensitive to
1120 typo problems, see BUGS section for more information.
1121 -fifostats
1123 Print fifo statistics at the end of a star run when the fifo has
1124 been in effect. All options that start with the -f sequence are
1125 sensitive to typo problems, see BUGS section for more informa‐
1126 tion.
1127 file=tarfilename, f=tarfilename
1129 Use tarfilename as the name for the tar archive. Currently up to
1130 100 file= options are possible. Specifying more then one file=
1131 option make sense in multi volume mode. In this case star will
1132 use the next name in the list every time a media change is
1133 needed. To make star behave consistent with the single file
1134 case, star loops over the list of known archive files. Note
1135 that if star is installed suid root and the first tarfile is a
1136 remote archive, only the connection to this archive will be cre‐
1137 ated with root privileges. After this connection has been
1138 established as root, star switches back to the id of the caller.
1139 If any of the other archives in the list is located on a differ‐
1140 ent host, star will not be able to open this archive later on,
1141 unless run by root.
1142 Star normally uses stdin/stdout for the tar archive because the
1144 most common way to use star is in conjunction with pipes. If
1145 star is installed suid root or if it has been called by root,
1146 tarfilename may be in remote syntax: user@host:filename as in
1147 rcp(1) even if invoked by non root users. See SUID NOTES for
1148 more information.
1149 To make a file local although it includes a colon (:), the file‐
1151 name must start with: '/', './' or '../'
1152 Note that if star talks to an old rmt remote tape server that
1154 does not support symbolic open modes, it does not open a remote
1155 tape with the O_CREAT open flag because this would be extremely
1156 dangerous. If the rmt server on the other side is the rmt
1157 server that comes with star or the GNU rmt server, star may use
1158 the symbolic mode for the open flags. Only the symbolic open
1159 modes allow to send all possible open modes in a portable way to
1160 remote tape servers.
1161 It is recommended to use the rmt server that comes with star.
1163 It is the only rmt server that gives platform independent com‐
1164 patibility with BSD, Sun and GNU rmt clients and it includes
1165 security features that may be set up in /etc/default/rmt. All
1166 options that start with the -f sequence are sensitive to typo
1167 problems, see BUGS section for more information.
1168 See ENVIRONMENT section for information on how to use ssh(1) to
1170 create a remote tape server connection.
1171 Note that if file=- has been specified, it is no longer possible
1173 to use the -find -exec primary.
1174 -find This option acts a separator. If it is used, all star options
1176 must be to the left of the -find option. To the right of the
1177 -find option, star accepts the find command line syntax only.
1178 The find expression acts as a filter between the source of file
1180 names and the consumer, which may either be the archiving engine
1181 or list/extract engine. If the find expression evaluated as
1182 TRUE, then the related file is selected for processing, other‐
1183 wise it is omited.
1184 In order to make the evaluation of the find expression more con‐
1186 venient, star implements additional find primaries that have
1187 side effects on the file meta data. Star implements the follow‐
1188 ing additional find primaries:
1189 -chgrp gname
1191 The primary always evaluates as true; it sets the group
1192 of the file to gname.
1193 -chmod mode
1195 The primary always evaluates as true; it sets the permis‐
1196 sions of the file to mode. Octal and symbolic permis‐
1197 sions are accepted for mode as with chmod(1).
1198 -chown uname
1200 The primary always evaluates as true; it sets the owner
1201 of the file to uname.
1202 -false The primary always evaluates as false; it allows to make
1204 the result of the full expression different from the
1205 result of a part of the expression.
1206 -true The primary always evaluates as true; it allows to make
1208 the result of the full expression different from the
1209 result of a part of the expression.
1210 The command line:
1212 star -c f=o.tar -find . ( -type d -ls -o false ) -o ! -type d
1214 lists all directories and archives all non-directories to the
1216 archive o.tar.
1217 The command line:
1219 star -c f=o.tar -find . ( -type d -chown root -o true )
1221 archives all directories so they appear to be owned by root in
1223 the archive, all non-directories are archived as they are in the
1224 file system.
1225 Note that the -ls, -exec and the -ok primary cannot be used if
1227 stdin or stdout has been redirected by the list=- of by the
1228 file=- options.
1229 -force_hole
1231 obsoleted by -force-hole
1232 -force-hole
1234 Try to extract all files with holes. This even works with files
1235 that are created without the -sparse option. Star, in this case
1236 examines the content of the files in the archive and replaces
1237 writes to parts containing binary zeroes with seeks.
1238 If used together with the -sparse option in create mode, star
1240 assumes all files to be sparse and archives files with blocks of
1241 nulls as sparse files.
1242 This option should be used with extreme care because you some‐
1244 times get in trouble when files get unattended holes. All
1245 options that start with the -f sequence are sensitive to typo
1246 problems, see BUGS section for more information.
1247 -force_remove
1249 obsoleted by -force-remove
1250 -force-remove
1252 Force to remove non writable files on extraction. By default,
1253 star will not overwrite files that are read only. If this
1254 option is in effect, star will silently remove these files to
1255 allow the extraction of a file. All options that start with the
1256 -f sequence are sensitive to typo problems, see BUGS section for
1257 more information.
1258 -force-restore
1260 Force an incremental restore even if the incremental dump is
1261 only a partial dump. See -wtardumps, level= and section INCRE‐
1262 MENTAL BACKUPS for more information.
1263 fs=# Set fifo size to #. See bs= for the possible syntax. The
1265 default size of the fifo is 1 Mbyte on Sun mc68000 systems, 4
1266 Mbytes on non mmap() aware Linux systems and 8 Mbytes on all
1267 other systems. See -fifo option for hints on using the right
1268 fifo size.
1269 fs-name=mount_point
1272 Use mount_point when recording information in /etc/tardumps and
1273 when comparing against information in /etc/tardumps for incre‐
1274 mental backups. This makes sense when backups are made using
1275 file system snapshots and allows /etc/tardumps and the archive
1276 to contain the real name of the file system instead of the tem‐
1277 porary mount point that is used for the snapshot device.
1278 H=headertype
1281 See artype=headertype option. Note that POSIX.1-2001 defines an
1282 option -H that follows symbolic links that have been encountered
1283 on the command line. For this reason, the old star option
1284 H=headertype option may go away in the future even though this
1285 option has been in use by cpio since 1989.
1286 -h, -L Follow symbolic links as if they were files. Normally star will
1288 not follow symbolic links but stores their values in tarfile.
1289 See also the -L option.
1290 -hardlinks
1292 In extract mode, this option tells star to try to create a
1293 hardlink whenever a symlink is encountered in the archive. In
1294 create mode, this option tells star to try to archive a hardlink
1295 whenever a symlink is encountered in the file system.
1296 -hpdev Allow 24 bits for the minor device number using 8 octal digits.
1298 Note that although it allows to create tar archives that can be
1299 read with HP-UX tar, this creates tar archives which violate
1300 POSIX.1-1988. This option is only needed if you like to use a
1301 POSIX.1-1988 based archive format that does not include exten‐
1302 sions. If you use the xstar format, star will use a base 256
1303 extension that allows bigger major/minor numbers by default, if
1304 you use the xustar or the exustar format there is no limitation
1305 at all as these formats use POSIX.1-2001 extended headers to ar‐
1306 chive the major/minor numbers by default.
1307 -i Ignore checksum errors on tar headers. If this option is speci‐
1309 fied, star will not exit if a header with a bad checksum is
1310 found but search for the next valid header.
1311 -install
1313 Carefully replace existing files when extracting files. This is
1314 done similar to install(1) by first extracting the files into a
1315 temporary name and renaming the file to the final name after the
1316 extraction of that file was successful.
1317 As star by default does not remove non-empty directories, an
1319 install that needs to remove existing non-empty directories may
1320 also need the options -force-remove and -remove-recursive.
1321 -j run the input or output through a bzip2 pipe - see option -z -Z
1323 and -bz below. As the -bz the -j the -Z and the -z option are
1324 non standard, it makes sense to omit the -bz the -j the -Z and
1325 the -z options inside shell scripts if you are going to extract
1326 a compressed archive that is located inside a plain file as star
1327 will auto detect compression and choose the right decompression
1328 option to extract.
1329 -keep-nonempty-dirs
1331 Do not complain about trying to remove nonempty directories in
1332 case that -remove-recursive has not been specified.
1333 -keep_old_files
1335 obsoleted by -keep-old-files
1336 -keep-old-files, -k
1338 Keep existing files rather than restoring them from tarfile.
1339 This saves files from being clobbered even if tarfile contains a
1340 more recent version of the corresponding file.
1341 See SECURITY NOTES for more information.
1343 -L, -h Follow symbolic links as if they were files. Normally star will
1345 not follow symbolic links but stores their values in tarfile.
1346 See also the -h option.
1347 -l Do not print a warning message if not all links to hard linked
1349 files could be dumped. This option is evaluated in the opposite
1350 way to historic tar(1) implementations and to POSIX.1. POSIX.1
1351 requests that by default no warning messages will be printed and
1352 -l will enable warning messages when not all links could be
1353 archived.
1354 level=dumplevel
1356 Set level for incremental dumps. This option is used to switch
1357 star into true incremental dump mode. The dumplevel may be in
1358 the range between 0..99.
1359 In true incremental dump mode, a -C option which is followed by
1361 the name a mount point and a dot ('.') as starting directory
1362 name is required. Only a single file system may be handled at a
1363 time. If the directory following the -C option is not referring
1364 to a root directory of a file system, the dump is called a par‐
1365 tial dump. If the directory following the -C option is refer‐
1366 ring to a root directory of a file system and no other restric‐
1367 tions apply that exclude certain files from the dump, the dump
1368 is called a full dump.
1369 By default, the tardumps database is not written. See also the
1371 tardumps=name and -wtardumps options and the section INCREMENTAL
1372 BACKUPS for more information.
1373 -link-data
1375 In create mode, include the data for files even if these files
1376 are hard links. This feature in create mode is currently only
1377 available for the exustar archive format and only in case
1378 -sparse has not been specified.
1379 In extract mode, allow star to deal with data in hard linked
1381 files even if the standard would not allow this for the used ar‐
1382 chive format.
1383 -link-dirs
1385 When in create mode, try to find hard linked directories. Using
1386 -link-dirs will force star to keep track of all directories that
1387 will go into the archive and thus causes a lot more memory to be
1388 allocated than in the default case.
1389 If you like to extract a cpio archive that contains hard linked
1391 directories, you also need to specify -link-dirs in extract or
1392 diff mode. This is needed because many cpio implementations
1393 create buggy archives with respect to hard links. If star would
1394 look for hard linked directories in all cases, it would detect
1395 many pseudo hard links to directories. Use -link-dirs with care
1396 if you extract cpio archives.
1397 Note that not all filesystem allow to create hard links to
1399 directories. Also note that even though a non-root user is able
1400 detect and archive hard linked directories, all known operating
1401 systems require the extraction to be done as root in order to be
1402 able to create or remove hard links to directories. For this
1403 reason its only recommended to use this option when doing accu‐
1404 rate backups and when hard links to directories are expected.
1405 When the option -link-dirs is not used and hard links to direc‐
1407 tories are present, the appendant sub-tree will appear more than
1408 once on the archive and star will print Linkcount below zero
1409 warnings for non directory hard links inside the sub-tree.
1410 list=filename
1412 Read filenames for store/create/list/diff command from filename.
1413 The file filename must contain a list of path names, each on a
1414 separate line. This option implies the -D option. To force
1415 star to descend directories, use the -dodesc option in this
1416 case. See also the -X option.
1417 Note that if list=- has been specified, it is no longer possible
1419 to use the -find -exec primary.
1420 -lowmem
1422 Try to run with reduced memory requirements. This causes star
1423 to default to 1 MB of FIFO memory. Instead of allocating memory
1424 to hold the directory content and reading the directory at once,
1425 star reads the directory name by name. This may cause star to
1426 close the directory if it rans out of file descriptors because
1427 of deeply nested directories. If a directory then does not sup‐
1428 port telldir(3)/seekdir(3), star will fail.
1429 -lzip run the input or output through a lzip pipe - see option -z
1431 below.
1432 -lzo run the input or output through a lzop pipe - see option -z
1434 below.
1435 -M, -xdev
1437 Do not descend mount points. This is useful when doing backups
1438 of complete file systems. See NOTES for more information.
1439 -m Do not restore access and modification time. (Access time is
1441 only available if star is reading star, xstar, xustar, exustar,
1442 or pax archives). If star extracts other archive types, the -m
1443 flag only refers to the modification time.
1444 -match-tree
1447 If in create mode a pattern does not match a directory, and
1448 -match-tree has been specified, the whole directory tree is
1449 excluded from the archive and from further directory scans. By
1450 default, star excludes the directory but still recursively scans
1451 the content of this directory as complex patterns could allow
1452 files inside the directory tree to match. Using -match-tree
1453 allows to efficiently exclude whole trees from scanning. This
1454 helps to avoid scannings directory trees that are on remote file
1455 systems or contain excessive bad blocks.
1456 maxsize=#
1458 Do not store files in tarfile if they are bigger than #. See
1459 bs= for the possible syntax. By default, the number is multi‐
1460 plied by 1024, so the value counts in units of kBytes. If the
1461 size specifier ends with a valid multiplication character (e.g
1462 '.' for bytes or 'M' for MB) the specified size is used as spec‐
1463 ified and not multiplied by 1024. See bs= option for all possi‐
1464 ble multipliers.
1465 -meta In create mode, -meta causes star to archive all meta data of
1467 the file (e.g. uid, permissions, ...) but not the file content.
1468 In extract mode, it causes star to restore all meta data but not
1469 the file content. In addition, in extract mode no plain file,
1470 special file or directory will be created. Meta files are
1471 needed to support incremental backups.
1472 Warning: Do not try to extract star archives containing meta
1474 files using other tar implementations if they are not aware of
1475 the meta file extensions of star. Star tries to force all tar
1476 implementations that are not standard compliant to abort. Star
1477 also tries to make all non POSIX.1-2001 compliant tar implemen‐
1478 tations unable to find a valid filename. However when other
1479 POSIX.1-2001 aware tar implementations come up and don't know
1480 about meta files, they will destroy files on disk.
1481 The problems result from the only current fallback in the POSIX
1483 standard that tells tar implementations to treat all unknown
1484 file types as if they were plain files. As meta files are needed
1485 for incremental backups, I am looking for people and companies
1486 who like to support me to be able to add the meta file concept
1487 to the POSIX.1-2005 standard.
1488 -modebits
1490 This options allows you to create tar archives that include more
1491 than 12 bits from st_mode. Note this create tar archives that
1492 violate POSIX but some tar implementations insist in reading
1493 such nonstandard archives.
1494 -multivol
1496 Switch to multi volume mode. In multi volume mode, there will
1497 be no logical EOF marker written to the end of a single tape. If
1498 -multivol is used in read mode, a hard EOF on input (if not pre‐
1499 ceded by a logical EOF) triggers a medium change operation.
1500 Specifying -multivol tells star to split files across volumes if
1502 needed. This way, a virtual archive is created that spans more
1503 than one medium. Multi volume mode is needed whenever it is not
1504 possible to split the archiving or extracting into several logi‐
1505 cally independent tasks. This is true for e.g. incremental
1506 dump/restore operations where inode numbers need to be traced
1507 for the whole task.
1508 When tsize=# has been specified, but star is not in multi volume
1510 mode, files cannot be split across volumes.
1511 When -multivol has been specified in create mode together with
1513 tsize=# then a media change is initiated exactly after an amount
1514 of tsize data has been written. When -multivol has been speci‐
1515 fied in create mode and tsize=# has not been specified, then the
1516 medium change is triggered by a EOT condition from writing the
1517 medium. This allows to use media where the size cannot be known
1518 in advance (e.g. tapes with build in compression); it does not
1519 work if the EOT condition is not returned in sync with the
1520 related write operation. For this reason, it is expected that
1521 data buffering inside a device driver cannot be used.
1522 Depending on the selected archive format, star writes a volume
1524 header at the beginning of a new medium. This medium header
1525 allows to verify the correct volume after a change during read
1526 back. It is recommended to use the exustar format for best
1527 results. In create mode, -multivol is only supported for ar‐
1528 chives types that allow to write reliable multi volume header
1529 information.
1530 See tsize=# option for more information.
1532 Note that -multivol is an interactive option that prevents star
1534 from being used in non-interactive environments. If you like to
1535 use it in a non-interactive environment, you need to specify
1536 new-volume-script=script in addition in order to automate the
1537 media change procedure.
1538 newer=filename
1540 Do not store files to tarfile if their modification time is not
1541 newer than the modification time of filename. See -ctime option
1542 for changing this behavior.
1543 -newest
1545 In conjunction with the list command this lists you only the
1546 newest file in tarfile.
1547 -newest_file
1549 obsoleted by -newest-file
1550 -newest-file
1552 In conjunction with the list command this lists you only the
1553 newest regular file in tarfile.
1554 new-volume-script=script
1556 Call script at end of each tape if in multi volume mode. If
1557 this option is not in effect, star will ask the user to confirm
1558 the volume change. The script is called with two parameters.
1559 The first parameter is the next volume number and the second
1560 parameter is the next archive file name.
1561 -nodump
1563 If this option is set, star will not dump files that have the
1564 nodump flag set. Note that this currently only works on BSD-4.4
1565 derivates and on Linux. On Linux, using this option will cause
1566 a performance degradation (the system time increases by 10%)
1567 because of the unlucky kernel interface.
1568 -no-dirslash
1570 Do not add a slash to the end of directory names if writing to
1571 an archive. Historic tar archive formats did only allow to
1572 specify plain files and hard links. Around 1980, BSD added a
1573 feature to specify a directory on tape by adding a slash to the
1574 end of the name. POSIX.1-1988 defined the first official tar ar‐
1575 chive format that had a clean method to specify the type of a
1576 directory. As old tar formats need the slash to recognize a
1577 directory, -no-dirslash may not be used if archives should be
1578 compatible with the old tar format.
1579 -no_fifo
1581 obsoleted by -no-fifo
1582 -no-fifo
1584 Don't use a fifo to optimize data flow from/to tarfile. Cur‐
1585 rently the -fifo option is used as default. (This may be changed
1586 at compile time.)
1587 -no-fsync
1589 Do not call fsync(2) for each file that has been extracted from
1590 the archive. Using -no-fsync may speed up extraction on operat‐
1591 ing systems with slow file I/O (such as Linux), but includes the
1592 risk that star may not be able to detect extraction problems
1593 that occur after the call to close(2). A typical cause for such
1594 problems is a NFS file system that fills up before the buffer
1595 cache is synced or a write error that occurs while the buffer
1596 cache is synced. There may be other reasons. Use with extreme
1597 care.
1598 -nochown, -o
1600 Do not restore owner and group of files. This may be used if
1601 super user privileges are needed to overwrite existing files but
1602 the local ownership of the existing files should not change.
1603 -no-p Do not restore files and directories to their original permis‐
1605 sions. This option is needed only if star is called by the
1606 super user and the permissions should not be restored from the
1607 archive. See also the -p option. The -p options has a higher
1608 precedence than the -no-p option.
1609 -no_statistics
1611 obsoleted by -no-statistics
1612 -no-statistics
1614 Do not print statistic messages at the end of a star run.
1615 -no-xheader
1617 Do not create or extract POSIX.1-2001 extended headers. This
1618 option may be used if you like to read an archive with broken
1619 extended headers.
1620 -not, -V
1622 Invert the meaning of the pattern list. i.e. use those files
1623 which do not match any of the pattern. Note that this option
1624 only applies to patterns that have been specified via the pat‐
1625 tern=pattern or pat=pattern option. Patterns specified as file
1626 type arguments will not be affected.
1627 -notarg, -pax-c
1629 Match all file or archive members except those specified by the
1630 pattern or file operands.
1631 -nowarn
1633 Do not print warning messages. This sometimes is useful to make
1634 the output more readable (e.g. when hundreds of files that are
1635 going to be extracted are not newer in the archive then on the
1636 filesystem).
1637 -numeric
1639 Use the numeric user/group fields in the listing rather than the
1640 default. The default allows to list the ASCII version of
1641 user/group of the file and to extract the owners of the files
1642 based on numeric values rather than the names. In create mode,
1643 no user/groups names are put on the archive. The -numeric
1644 option also applies when ACLs are going to be archived or
1645 extracted.
1646 -O Be compatible to old versions of tar. If star is invoked with
1648 this option, star generates archives which are fully compatible
1649 with old UNIX tar archives. If in extract mode, star ignores any
1650 additional info in the headers. This implies neither that ar‐
1651 chives generated with this option are binary equal with archives
1652 generated by old tar versions nor that star is trying to compre‐
1653 hend all bugs that are found in old tar versions. The bug in
1654 old tar versions that cause a reversal of a space and a NULL
1655 byte in the checksum field is not repeated. If you want to have
1656 signed checksums you have to specify the -signed-checksum option
1657 too. If you want directories not to be archived in order to be
1658 compatible to very old historic tar archives, you need to spec‐
1659 ify the -d option too.
1660 This option is superseeded by the H=headertype option.
1662 -o, -nochown
1664 Do not restore owner and group of files. This may be used if
1665 super user privileges are needed to overwrite existing files but
1666 the local ownership of the existing files should not change.
1667 -onull, -nullout
1669 Do not actually write to the archive but compute and add the
1670 sizes. This is useful when trying to figure out if a tape may
1671 hold the current backup. Please only use the -onull option as
1672 it is a similar option as used by the sdd(1) command.
1673 -P Allow star to write a partial record as the last record. Nor‐
1675 mally, star writes each record with the same size. This option
1676 is useful on unblocked tapes i.e. cartridge tapes like QIC tapes
1677 as well as with archives that are located in files. If you use
1678 this option on local files, the size of the archive will be
1679 smaller. If you use this option on cartridge tapes, is makes
1680 sure that later - in extract mode - star will read up to the end
1681 of file marker on the tape and the next call to star will read
1682 from the next archive on the same tape.
1683 -p Restore files and directories to their original permissions.
1685 Without this option, they are created using the permissions in
1686 the archive and the present umask(2). If star is called by the
1687 super user, star behaves as if it has been called with the -p
1688 option. See also -no-p option. If the archive contains Access
1689 Control Lists (ACLs) in POSIX.1-2001 extended headers, star will
1690 restore the access control lists from the archive for files if
1691 the -acl option is specified. If the option -acl has not been
1692 specified, ACLs are not restored at all.
1693 pattern=pattern, pat=pattern
1695 Set matching pattern to pattern. A maximum of 100 pattern=pat
1696 options may be specified. As each pattern is unlimited in
1697 length, this is no real limitation. If more than one pattern is
1698 specified, a file matches if any of the specified pattern
1699 matches. Patterns may be used in create mode to select or
1700 exclude files from the list of file type arguments or the files
1701 located in a sub tree of a file type argument directory. By
1702 default, star scans the whole directory tree underneath a direc‐
1703 tory that is in the argument list. This may be modified by using
1704 the -match-tree option. In extract or list mode, all file type
1705 arguments are interpreted to be select pattern and all option
1706 type patterns may be either select or exclude patterns depending
1707 on the presence or absence of the -not option. If you use file
1708 type select patterns, they work exactly like the method used by
1709 other (non pattern aware) tar(1) implementations. File type
1710 select patterns do not offer pattern matching but allow to
1711 restore subtrees. To extract a complete sub tree from the
1712 directory dir with star using the pattern= option, use pattern=
1713 dir/\* if you like to select a subtree by using the historic
1714 method, use dir as file type argument. If you only like to
1715 extract the directory itself, use dir/ as file type argument.
1716 See manual page for match(1) for more details of the pattern
1717 matcher. All patterns are selection patterns by default. To
1718 make them exclude patterns, use the -not or the -V option.
1719 pkglist=file
1721 This is (for now) an internal interface for the Schily Source
1722 Package System (sps). It only works in create mode and behaves
1723 similar to the list= option, but it allows to overwrite the per‐
1724 missions, the uid and gid values from the content of the
1725 pkglist= file. Each line from the pkglist= file contains a file
1726 name followed by the permission, a user name and a group name.
1727 The permission is an octal character string. Each value that is
1728 not used to overwrite the original values may be replaced by a
1729 '?'. The fields are separated by spaces, so the pkglist= option
1730 does not allow files that contain newline or space characters.
1731 -pax-c, -notarg
1733 Match all file or archive members except those specified by the
1734 pattern or file operands.
1735 -pax-H Follow symbolic links that have been encountered on the command
1737 line. If the referenced file does not exist, the file informa‐
1738 tion and type will be for the link itself. If the link is ref‐
1739 erencing a file type that cannot be archived with the current
1740 archive format, the file information and type will be for the
1741 link itself.
1742 -pax-i Do interactive renaming in a way that has been defined for POSIX
1744 pax. Star will print the original filename and prompt for a
1745 reply. If you type just RETURN, than the file is skipped. If
1746 you type '.', then the original file name is retained. If you
1747 type anything else, then this is taken as the new file name.
1748 Note that -pax-i is an interactive option that prevents star
1750 from being used in non-interactive environments.
1751 -pax-L Follow symbolic links. If the referenced file does not exist,
1753 the file information and type will be for the link itself. If
1754 the link is referencing a file type that cannot be archived with
1755 the current archive format, the file information and type will
1756 be for the link itself.
1757 -pax-ls
1759 Switch listing format to the format defined for POSIX pax and
1760 ls.
1761 -pax-match
1763 Allow file type arguments to be recognised as regular expres‐
1764 sions in a way that has been defined for POSIX pax.
1765 -pax-n Allow each pattern to match only once. If a pattern matches a
1767 directors, then the whole sub tree matches the pattern.
1768 -pax-p string
1770 PAX style privileges string. Several characters (each has its
1771 own meaning). The following characters are defined:
1772 a Do not preserve file access times. This option is cur‐
1774 rently ignored.
1775 e Preserve the user ID, group ID, file mode bits. This is
1777 equivalent to calling star -p -acl -xfflags.
1778 m Do not preserve file modification times. This is cur‐
1780 rently equivalent to calling star -m.
1781 o Preserve the user ID and group ID. This is the default
1783 for star if called as root.
1784 p Preserve the file mode bits. This is equivalent to call‐
1786 ing star -p.
1787 -prinodes
1789 Print inode numbers in verbose list mode if the archive contains
1790 inode numbers.
1791 -print-artype
1793 Check the type of the archive, print the archive and compression
1794 type on a single line and exit.
1795 -qic24 Set tape volume size to 61440 kBytes. See tsize=# option for
1797 more information.
1798 -qic120
1800 Set tape volume size to 128000 kBytes. See tsize=# option for
1801 more information.
1802 -qic150
1804 Set tape volume size to 153600 kBytes. See tsize=# option for
1805 more information.
1806 -qic250
1808 Set tape volume size to 256000 kBytes. See tsize=# option for
1809 more information.
1810 -qic525
1812 Set tape volume size to 512500 kBytes. See tsize=# option for
1813 more information.
1814 -read0 Read null terminated file names from the file specified with the
1816 list= option.
1817 -refresh_old_files
1819 obsoleted by -refresh-old-files
1820 -refresh-old-files
1822 -refresh
1824 Do not create new files. Only already existing files may be
1825 overwritten from tarfile if either newer versions are present in
1826 the archive or if the -U flag is used. This allows to overwrite
1827 files by more recent files from an archive that contains more
1828 files than the target directory should contain. The option
1829 -refresh-old-files is the same as the -refresh option.
1830 -remove_first
1832 obsoleted by -remove-first
1833 -remove-first
1835 Remove files before extraction. If this option is in effect,
1836 star will remove files before extracting a file from the ar‐
1837 chive. This is needed if you want to change the file type or if
1838 you need to break a hard link. If you do not use either
1839 -ask-remove or -force-remove together with -remove-first, this
1840 option is useless and no files will be removed.
1841 -remove_recursive
1843 obsoleted by -remove-recursive
1844 -remove-recursive
1846 Remove files recursive. If removing of a file is permitted,
1847 star will only remove files, specials and empty directories. If
1848 this option is in effect, star will be allowed to recursively
1849 removes non empty directories too.
1850 -restore
1852 switches star into true incremental restore mode. A file named
1853 star-symtable and a directory named star-tmpdir is created in
1854 the root directory of the file system where the extraction takes
1855 place. If -restore has been specified, star behaves as if -xdot
1856 has been specified too. See also level= option and section
1857 INCREMENTAL BACKUPS for more information.
1858 Note: Do not use the -restore option if you only like to restore
1860 a single file or a list of selected files.
1861 -S Do not store/create special files. A special files is any file
1863 except plain files, symbolic links and directories. You need to
1864 be super user to extract special files.
1865 -s replstr
1867 Modify file or archive member names named by a pattern according
1868 to the substitution expression replstr. The format of replstr
1869 is:
1870 -s /old/new/[gp]
1872 The old pattern may use regular expressions and the new string
1874 may contain the special character '&'. The character '&' is sub‐
1875 stituted by the string that matches the old pattern. The
1876 optional trailing 'g' means global substitution. If 'g' is not
1877 used, a substitution pattern is only used once on a name. If
1878 the optional trailing 'p' is used, the substitution is printed
1879 to standard error.
1880 Up to 100 substitute options may be used. If more than one sub‐
1882 stitute option has been specified, star will loop over all sub‐
1883 stitute patterns until one matches.
1884 If the name substitutes to the empty string, the file is
1886 skipped.
1887 -secure-links
1889 Do not extract hard links or symbolic links if the link name
1890 (the target of the link) starts with a slash (/) or if /../ is
1891 contained in the link name. Tar archives containing such links
1892 could be used to compromise the system. If they are unpacked
1893 together with a lot of other files, this may not even be
1894 noticed.
1895 As the usability of a tar archiver would be limited if
1897 -secure-links checking would be done by default, star makes link
1898 checking optional.
1899 If you unpacked a tar archive using the -secure-links and did
1901 not get a security warning at the end of the star run, all files
1902 and links have been extracted. If you get a warning, you should
1903 unpack the archive a second time and specify the options -k, -w
1904 and -nowarn in addition to the options used for the first run.
1905 See SECURITY NOTES for more information.
1906 -shm Use System V shared memory for fifo. Normally star is compiled
1908 to use mapped /dev/zero pages for the fifo, if the operating
1909 system supports this. If star is compiled to have both code for
1910 mapped pages and for System V shared memory, star will use
1911 shared memory instead of the default. If the -help menu doesn't
1912 show the -shm flag you have no choice. When using System V
1913 shared memory, you may have to raise the system's internal limit
1914 for shared memory resources to get enough shared memory for
1915 star.
1916 -signed_checksum
1918 obsoleted by -signed-checksum
1919 -signed-checksum
1921 Use signed chars to calculate checksums. This violates the tar
1922 specs but old versions of tar derived from the seventh edition
1923 of UNIX are implemented in this way. Note: Only filenames and
1924 linknames containing chars with the most significant bit set may
1925 trigger this problem because all other fields only contain 7 bit
1926 ASCII characters, octal digits or binary zeroes.
1927 -silent
1929 Suppress informational messages like foobar is sparse.
1930 -sparse
1932 Handle files with holes effectively on store/create. Note that
1933 sparse files may not be archived this way if the archive format
1934 is tar, ustar, suntar, pax, or any cpio variant. On Solaris-2.3
1935 ... Solaris-2.5.1 there is a special ioctl() called _FIOAI that
1936 allows root to get the allocation info more efficiently. On
1937 Solaris 11 there is an enhanced lseek(2) call with addidional
1938 whence values SEEK_HOLE and SEEK_DATA that allow to find holes
1939 in an efficient way. Other operating systems lack support to
1940 get the real allocation list and force star to scan the files to
1941 look for blocks that only contain null characters. This may
1942 star cause to assume more holes to be present than the number
1943 that the file really contains.
1944 -symlinks
1946 This option tells star in extract mode to try to create a sym‐
1947 link whenever a hardlink is encountered in the archive.
1948 -T If the option file= or f= is omitted and the -T option is
1950 present, star will use the device indicated by the TAPE environ‐
1951 ment variable, if set.
1952 tardumps=name
1954 Set the file name for tar dump dates database to name. The
1955 default name is /etc/tardumps. Use in combination with the
1956 level= option to create true incremental dumps. See also -wtar‐
1957 dumps option and section INCREMENTAL BACKUPS for more informa‐
1958 tion.
1959 -time Print timing info. See DIAGNOSTICS for more information.
1961 -to_stdout
1963 obsoleted by -to-stdout
1964 -to-stdout
1966 Extract files to stdout. This option may be used to extract
1967 tarfiles containing tarfiles (see examples below).
1968 -tpath Use this option together with the -t option or with -cv (verbose
1970 create) to get only a list of the pathnames of the files in the
1971 archive. This may be used in shell scripts to generate a name
1972 list. If used together with the -diff option, star will only
1973 print the names of the files that differ. A second run of star
1974 may then be used to restore all files that had differences to
1975 the archive. Use the list= option to specify the namelist in
1976 this case.
1977 tsize=#
1979 Set tape volume size to # to enable multi volume tape support.
1980 The value refers to the archive size without compression. See
1981 bs= for the possible syntax. By default, the number is multi‐
1982 plied by 512, so the value counts in units of 512 byte blocks.
1983 If the size specifier ends with a valid multiplication character
1984 (e.g '.' for bytes or 'M' for MB) the specified size is used as
1985 specified and not multiplied by 512. With this option in
1986 effect, star is able to archive filesystems that are bigger then
1987 the tape size. If the option tsize=# without -multivol then no
1988 file will be split across volumes and each volume may in theory
1989 be read back separately. Files that do not fit on a single tape
1990 may not be stored in this mode. If -multivol has been specified
1991 in addition, star will split files when the maximum allowed tape
1992 size has been reached. If the tape volume size is not a multi‐
1993 ple of the tape block size, the tape volume size is silently
1994 rounded down to a value that is a multiple of the tape block
1995 size.
1996 See -multivol option for more information.
1998 -U Restore files unconditionally. By default, an older file from
2000 the archive will not replace a corresponding newer file on disk.
2001 umask=mask
2003 Set star's umask to mask. This allows to control the permis‐
2004 sions for intermediate directories that are created by star in
2005 extract mode. See also -p option.
2006 -v Increment verbose level by one. This normally results in more
2008 output during operation. See also in the description for the -t
2009 flag. Normally, star does its work silently. If the verbose
2010 level is 2 or more and star is in create or update mode, star
2011 will produce a listing to the format of the ls -l output.
2012 -V, -not
2014 Invert the meaning of the pattern list. i.e. use those files
2015 which do not match any of the pattern. Note that this option
2016 only applies to patterns that have been specified via the pat‐
2017 tern=pattern or pat=pattern option. Patterns specified as file
2018 type arguments will not be affected.
2019 -version
2021 Print version information and exit.
2022 VOLHDR=name
2024 Use name to generate a volume header.
2025 -w Do interactive creation, extraction or renaming. For every file
2027 that matches the list of patterns and that has a more recent
2028 modification time in the tar archive (if in extract mode and the
2029 -U option is not specified) star prints its name and asks:
2030 get/put ? Y(es)/N(o)/C(hange name) :
2032 You may answer either `N' for No or <Return> to skip this file.
2034 If you answer `Y' the file is extracted or archived on tape with
2035 its original name. If you answer `C', you are prompted for a
2036 new name. This name is used for the filename on disk if star is
2037 in extract mode or for the archive name if star is in create
2038 mode.
2039 See SECURITY NOTES for more information.
2041 Note that -w is an interactive option that prevents star from being
2043 used in non-interactive environments.
2044 -wready
2046 This option tells Star to wait up to two minutes for the drive
2047 to become ready. It has been added as a hack for a bug in the
2048 SunOS/Solaris st device driver. This driver has problems to
2049 sense the loading time with Exabyte drives with factory set‐
2050 tings. It also makes sense to use -wready if multiple remote
2051 backups are made. In this case, the remote connection is closed
2052 while the remote tape server is still writing a file mark. If
2053 another remote backup is initiated before the old remote server
2054 did finish to write the file mark, it would be impossible to
2055 open the tape driver unless -wready is specified to tell star to
2056 wait for the drive to become ready again.
2057 -wtardumps
2059 Tell star to update the file that contains the tar dump dates
2060 data base if in dump mode. If the dump is not a full dump, the
2061 tar dump dates data base file is not written. See also tar‐
2062 dumps=name and -C option or INCREMENTAL BACKUPS section for more
2063 information.
2064 -X filename
2066 Use the file filename as a file containing a list of path names
2067 to be excluded from the store/create/list/diff operation. The
2068 file filename must contain a list of path names, each on a sepa‐
2069 rate line. Be careful with white space and note that path names
2070 in the list may not contain new lines. Multiple -X options may
2071 be used. Each argument must refer to a file containing path
2072 names. The -X option has precedence before other options that
2073 select files to be included in the operation. See also list=
2074 option.
2075 -xattr
2077 -xattr-linux
2079 Store and extract extended file attributes as found on Linux
2080 systems. This option only makes sense when creating or extract‐
2081 ing exustar archives as it is based on POSIX.1-2001 extended tar
2082 headers.
2083 The method used in the current implementation could be used to
2085 store and extract extended file attributes from BSD too. Note
2086 that the current implementation is not generic enough to cover
2087 more general extended file attribute implementations as found on
2088 Solaris. If star starts to implement a method that covers
2089 extended file attributes on Solaris, the new method will be used
2090 then -xattr has been specified and -xattr-linux will refer to
2091 the old method. The method used with -xattr-linux may go away
2092 in the future.
2093 xdebug=#, xd=#
2095 Set extended debug level to #.
2096 -xdev, -M
2098 Do not descend mount points. This is useful when doing backups
2099 of complete file systems. See NOTES for more information.
2100 -xdir Extract directories even if the corresponding directories on the
2102 archive are not newer. This is useful when for some reason, the
2103 directories are recorded after their content (see -dirmode
2104 option), or when the permissions of some directories must be set
2105 in any case. As the classical UNIX cpio program does not imple‐
2106 ment delayed directory permission and time stamp setting, cpio
2107 users often create archives in reverse order (directories past
2108 their content). For this reason, it makes sense to use -xdir
2109 while extracting cpio archives.
2110 -xdot Unconditionally extract the first directory in the archive if
2112 the name of this directory is either '.' or './'. This helps to
2113 extract archives in an expected way if the target directory is a
2114 newly created empty directory. As this directory is newer than
2115 the top level directory in the archive, star would usually skip
2116 this directory during extraction. The effect of this directory
2117 is as if -xdir has been specified but is switched off after the
2118 first directory has been found.
2119 -xfflags
2121 Store and extract extended file flags as found on BSD and Linux
2122 systems. This option only makes sense when creating or extract‐
2123 ing exustar archives as it is based on POSIX.1-2001 extended tar
2124 headers. See NOTES section for problems with -xfflags on Linux
2125 systems.
2126 -xmeta Extract meta files as if they were files. Meta files in ar‐
2128 chives are plain files that do not contain any content data in
2129 the archive. They may be created by using the -meta option in
2130 star's create mode. Existing files are not overwritten. If a
2131 file is missing, a zero sized file is created. If the option
2132 -meta is used together with the option -force-hole, missing
2133 plain files are created as sparse empty files of the original
2134 size.
2135 -xz run the input or output through a xz pipe - see option -z below.
2137 -Z run the input or output through a compress pipe - see option -z
2139 below.
2140 -z run the input or output through a gzip pipe. This is currently
2142 a quick and dirty hack, that mainly will cover the most common
2143 usage to compress the tar output if it is a file. No reblocking
2144 will be done, so this option will currently only make sense on
2145 plain files. As the -bz the -j the -Z and the -z option are non
2146 standard, it makes sense to omit the -bz the -j the -Z and the
2147 -z options inside shell scripts if you are going to extract a
2148 compressed archive that is located inside a plain file as star
2149 will auto detect compression and choose the right decompression
2150 option to extract. The environment variable STAR_COMPRESS_FLAG
2151 may be used to specify one option for gzip. If you want to
2152 write write compressed archives to tape, you should use
2153 star -c . | gzip | sdd ibs=4k obs=32k -fill of=/dev/rmt/1bn
2154 or
2155 star -c . | gzip | sdd ibs=4k obs=32k -fill ovsize=60m
2156 of=/dev/rmt/1bn
2157 if the tape can hold 60 MB.
2158
2160 Star is able to back up file system in full and incremental mode. To
2161 allow incremental backups, the file system must implement POSIX seman‐
2162 tics.
2163 To be more verbose:
2165 · The filesystem needs to uniquely identify files by the two num‐
2167 bers st_dev (The device ID of the device containing the file)
2168 and st_ino (The file serial number). If a file is renamed,
2169 these numbers need to be retained. Both numbers need to be a
2170 cardinal scalar that is expressible in a decimal number.
2171 · The filesystem needs to implement at least two time stamps,
2173 st_mtime the file's last modification time and st_ctime the
2174 file's last status change time. Both time stamps need to be
2175 dealt with as documented by the POSIX standard. Both numbers
2176 need to be a cardinal scalar that is expressible in a decimal
2177 number.
2178 · The filesystem needs to allow to rename files and directories by
2180 either calling rename(2), or link(2) and unlink(2).
2181 · The filesystem needs to honor and preserve the case of file
2183 names.
2184 The incremental backup method used by star depends on comparing the
2186 time stamps of all files against the time of the last backup. Note that
2187 this method only works correctly if the level 0 backup and all higher
2188 level incrementals include the whole file system. As star archives all
2189 inode meta data, star is able to detect renamed files by comparing the
2190 inode numbers of all files while in incremental restore mode.
2191 Detecting renamed files only works if star, while in backup mode, scans
2193 the whole file system tree for each full and incremental backup. This
2194 will work in case no files are excluded and the dump starts at the root
2195 directory of a file system. In case that no files are renamed from
2196 excluded parts to included parts, partial backups may be taken also.
2197 Partial backups only make sense if a complete directory sub tree is
2198 excluded (e.g. by using the pat= option) or if a partial backup starts
2199 at a sub directory that is not the root directory of the file system.
2200 To create a level 0 dump call:
2202 star -c -xdev -sparse -acl -link-dirs level=0 -wtardumps \
2204 f=archive-name -C /filestem-mount-point .
2205 To create a level 1 dump call:
2207 star -c -xdev -sparse -acl -link-dirs level=1 -wtardumps \
2209 f=archive-name -C /filestem-mount-point .
2210 Do not forget the dot at the end of the command line that specifies the
2212 directory to start the operation.
2213 Backups from live filesystems should be avoided. On operating systems
2215 that support file system snapshots, backups should be made from a read-
2216 only mount of a snapshot. Be careful that all files that have been cre‐
2217 ated between setting up a snapshot and starting an incremental backup
2218 may be missing from all backups unless the dumpdate=name option is
2219 used.
2220 If the system that is going to be backed up is not acting as a file
2222 server, it makes sense to shut down all services that may result in
2223 inconsistent file states before setting up the filesystem snapshot.
2224 After the filesystem snapshot has been set up, the services may be
2225 restarted.
2226 If the the system that is going to be backed up is acting as a file
2228 server, it may be that services on remote clients cause inconsistent
2229 file states unless all such services that remotely access files are
2230 shut down before the snapshot is set up.
2231 Star includes options that help to deal with file system snapshots.
2233 The following example backs up a file system on Solaris using a file
2234 system snapshot:
2235 echo > /tmp/snapstamp
2237 mount -r `fssnap -F ufs -o \
2239 backing-store=/var/tmp/EXPORT-NFS.snap /export/nfs` /mnt
2240 star -c -xdev -sparse -acl -link-dirs level=0 -wtardumps \
2242 f=archive-name dumpdate=/tmp/snapstamp \
2243 fs-name=/export/nfs -C /mnt .
2244 First a file with a current time stamp is created, then a snapshot for
2246 /export/nfs is created and mounted on /mnt. The following star command
2247 then creates a level 0 backup from the file system using the time the
2248 snapshot was created and the original mount point of the file system
2249 for /etc/tardumps and the archive header.
2250 Note that if the backup is done on a live file system, it may be unre‐
2252 liable. A typical problem problem in this context is caused by growing
2253 log files. As growing files are not a real problem with backups, the
2254 best way of dealing with growing files is to set up a star error con‐
2255 trol file (see errctl= option) and to tell star to ignore growing
2256 files.
2257
2259 Full (level 0) dumps should be made on a regular base (e.g. once a
2260 month). As a full dump may take a long time and takes a lot of tape,
2261 it is wise to make higher level incremental dumps with shorter inter‐
2262 vals. The next table shows a dump level list that may be used if
2263 monthly full dumps take place:
2264 Sun Mon Tue Wed Thu Fri
2266 Week 1: 0 10 10 10 10 5
2267 Week 2: 10 10 10 10 10 5
2268 Week 3: 10 10 10 10 10 5
2269 Week 4: 10 10 10 10 10 5
2270 The level 10 dumps made between Monday and Friday accumulate all
2272 changes made within the week. If you don't like this, use the following
2273 backup schedule:
2274 Sun Mon Tue Wed Thu Fri
2276 Week 1: 0 20 30 40 50 5
2277 Week 2: 10 20 30 40 50 5
2278 Week 3: 10 20 30 40 50 5
2279 Week 4: 10 20 30 40 50 5
2280 Note that in this case, 7 dumps need to be restored if the a crash hap‐
2282 pens at the worst case date (just before the Friday dump in week 2 or
2283 later).
2284
2287 Incremental restores should be made to an empty file system (except for
2288 the lost+found directory). Star is currently unable to perform incre‐
2289 mental restores to a file system that contains active mount points.
2290 The incremental restore procedure starts with restoring the last full
2292 (level 0) dump. Then the latest incremental dump of each dump level
2293 (with ascending order of dump levels) need to be restored.
2294 Let us assume the first example from the section BACKUP SCHEDULES for
2296 the backup schedule. If a disk crash happens before the Thursday dump
2297 of week 3 has been made, the following restore procedure needs to be
2298 applied:
2299 level 0
2301 starting with an empty disk, the full (level 0) dump from week 1
2302 is restored.
2303 level 5
2305 after the level 0 restore has been finished, the level 5 dump
2306 from Friday in week 2 is restored.
2307 level 10
2309 after the level 5 restore has been finished, the level 10 dump
2310 from Wednesday in week 3 is restored.
2311 The disk now contains the same files as it did when the level 10 dump
2313 has been made on Wednesday of week 3.
2314 To extract a level 0 dump call:
2316 cd /filestem-mount-point
2318 star -xpU -restore f=archive-name
2319 This creates the directory star-tmpdir and the database star-symtable
2321 in the root directory of the new file system. Subsequent restores with
2322 higher level backups depend on these files.
2323 To extract a level 1 (or higher) dump call:
2325 cd /filestem-mount-point
2327 star -xpU -restore f=archive-name
2328 Note that the environment variable STAR_DEBUG exists, star does not
2330 remove files with link count 1 that have been removed between incremen‐
2331 tal dumps. These files are moved to the directory star-tmpdir. Before
2332 you start to extract the next incremental, you need to remove all files
2333 in star-tmpdir.
2334
2337 Star may be used to synchronize filesystem content. To do this, an
2338 initial copy of the current content of the source filesystem needs to
2339 be performed first.
2340 To create an initial copy of a filesystem call:
2342 star -c -xdev -sparse -acl -link-dirs level=0 -wtardumps \
2344 -C /filestem-mount-point . | \
2345 star -xpU -restore -C /extract-target-dir
2346 In order to perform subsequent synchronization of the target filesystem
2348 with the content of the source filesystem, a modified incremental
2349 dump/restore procedure may be used.
2350 To copy incremental content of a filesystem call:
2352 star -c -xdev -sparse -acl -link-dirs level=1 -wtardumps \
2354 -cumulative -C /filestem-mount-point . | \
2355 star -xpU -restore -C /extract-target-dir
2356 Note that like with backups in general, copies from a live filesystem
2358 should be avoided. On operating systems that support file system snap‐
2359 shots, copies should be made from a read-only mount of a snapshot. Be
2360 careful that all files that have been created between setting up a
2361 snapshot and starting an incremental copy may be missing from all
2362 copies unless the dumpdate=name option is used.
2363 See section INCREMENTAL BACKUPS to learn how to modify the command line
2365 in case file system snapshots are used.
2366
2368 If star handles a signal, it first prints the statistics. Star handles
2369 the following signals:
2370 SIGINT usually generated by ^C from the controlling tty. Upon
2372 receipt of a SIGINT, star prints statistics and exits. If in
2373 create mode i.e. storing files to archive, star finishes with
2374 the current file to ensure that no partial file is written to
2375 the archive, write an eof record and then exits.
2376 SIGHUP not to be generated from a tty. The actions are the same as
2378 upon receipt of a SIGINT.
2379 SIGQUIT usually generated by ^\ from the controlling tty. Upon
2381 receipt of a SIGQUIT, star prints statistics and continues
2382 with the current operation. This is useful to watch the
2383 progress of the current operation.
2384
2386 The following exit values are returned:
2387 0 All files were processed successfully.
2389 -3 / 253
2391 Star has been called with the option -e, or the errctl= option
2392 has been used to mark the current error fatal.
2393 -2 / 254
2395 One or more files could not be processed successfully.
2396 -1 / 255
2398 Command line parsing error.
2399 >0 Other positive exit codes: The errno of the call that caused the
2401 fatal error.
2402
2404 To get a listing in a way similar to ls -l one might use:
2405 example% star -tv f=/dev/rmt/1bn
2407 The same command as listed above in a POSIX tar command line syntax
2409 compliant way is:
2410 example% star tvf /dev/rmt/1mbn
2412 To copy the directory tree in /home/someuser to the directory /home/fs
2414 use:
2415 example% (cd /home/someuser; star -c .) | (cd /home/fs ; star -xp)
2417 or by using the change directory option of star:
2419 example% star -c -C /home/someuser . | star -xp -C /home/fs
2421 Note that both examples above are not the optimum way to copy a direc‐
2423 tory tree. A more efficient way to copy a directory tree is to use the
2424 -copy option.
2425 example% star -copy -p -xdot -C /home/someuser . /home/fs
2427 To copy a file tree including the Access Control List entries for all
2429 files and to correctly copy sparse (holey) files use:
2430 example% star -copy -p -xdot -acl -sparse -C /home/someuser . /home/fs
2432 To compare the content of a tape to the filesystem one might use:
2434 example% star -diff -v f=/dev/rmt/1bn
2436 To compare two directory trees one might use:
2438 example% star -c . | star -C todir -diff -v diffopts=!times
2440 or better by using a method similar to the -copy method above:
2442 example% star -c -diff -v diffopts=!times -C fromdir . todir
2444 To compare all properties of two file trees, use:
2446 example% star -c -diff -vv -dump -acl -sparse -C fromdir . todir
2448 To extract a backup of the /usr tree without all files residing below
2450 /usr/openwin one might use:
2451 example% star -xp -V pat=openwin/\* f=/dev/rmt/1bn
2453 To extract all .c files to src, all .o files to obj and all other files
2455 to /tmp one might use:
2456 example% star -xp -C src '*.c' -C obj '*.o' -C /tmp '*' f=/dev/rmt/1bn
2458 To extract files from a zipped tar archive that is located on a read
2460 only filesystem e.g. a CD while having the shell's working directory on
2461 the CD one might use:
2462 example% star -zxp -C /tmp f=star-1.1.tar.gz
2464 to extract the files from the tar archive to the /tmp directory.
2466 To backup a list of files generated by the find(1) command:
2468 example% find . find_options -print | star -c list=- f=/dev/rmt/1bn
2470 Note that this does not work if the file names from output of the find
2472 command include new line characters.
2473 To extract a tarfile that contains a tarfile one might use:
2475 example% star -x -to-stdout f=/dev/rmt/1bn pat=pat | star -xp
2477 Pat, in this case should match the tarfile in the tarfile on tape that
2479 should be extracted.
2480 To make a backup of the root filesystem to a tape drive connected to a
2482 remote machine, one might use:
2483 example# cd /
2485 example# star -cM fs=128m bs=63k f=tape@remotehost:/dev/rmt/1bn .
2486 You need a line in /etc/passwd like the following to enable this:
2488 tape:NP:60001:60001:Tape:/etc/tapehome:/opt/schily/sbin/rmt
2490 And a .rhosts file in /etc/tapehome to allow remote connections from
2492 the appropriate hosts. Make sure that the file /etc/default/rmt exists
2493 and allows remote access to the requested tape drive.
2494 To use a ssh(1) connection for a backup to a remote tape server, one
2496 might use:
2497 example# env RSH=/usr/bin/ssh star -cM fs=128m bs=63k
2499 f=tape@remotehost:/dev/rmt/1bn .
2500 To repair a corrupted filesystem for which no recent backup exists, do
2503 the following:
2504 example# fsck -y /filesys
2506 example# mount /filesys
2507 example# cd /filesys
2508 example# star -xpk f=/dev/rmt/1bn
2509 example# mt -f /dev/rmt/1bn rewind
2510 example# star -diff -v diffopts=!times f=/dev/rmt/1bn
2511 Now check the differences and decide whether to restore additional
2513 files. This may be done by generating a list containing the needed
2514 filenames and using the list= option or by using the interactive mode
2515 (see -w option).
2516 If you want a list that only contains all filenames from files with
2518 differences you may use:
2519 example# star -diff -tpath diffopts=!times f=/dev/rmt/1bn
2521 If you are looking for files that changed the type or the access per‐
2523 mission because this is a common case on still corrupted files, use:
2524 example# star -diff -tpath diffopts=type,perm f=/dev/rmt/1bn
2526 If you like to archive all directories only that are part of the direc‐
2528 tory tree under ".", use:
2529 example# star -c f=archive-name -find . -type d
2531 If you like to archive all files as owner root and group root and make
2533 all files world readable in the archive, use:
2534 example# star -c f=archive-name -find . -chown root -chgrp root
2536 -chmod o+r
2537 If you like to list all files in an archive in a way like sfind(1),
2539 instead of the way used by star, use:
2540 example# star -t f=archive-name -find . -ls -false
2542
2545 STAR_COMPRESS_FLAG
2546 If you like star to always create compressed files that use max‐
2547 imum compression, you may set the environment variable STAR_COM‐
2548 PRESS_FLAG to -9.
2549 STAR_DEBUG
2551 If this environment variable is present, star will not remove
2552 temporary files from ./star-tmpdir. The files in this directory
2553 are files that have been removed by users before the last incre‐
2554 mental dump did take place on the master filesystem.
2555 STAR_FIFOSIZE
2557 If you like to by default let star use a different fifo size,
2558 set this environment variable to the desired size.
2559 TAPE Unlike other tar(1) implementations, star defaults to use
2561 stdin/stdout for the archive. If you like star to use the file
2562 name from the TAPE environment instead, you need to specify the
2563 -T option too.
2564 RSH If the RSH environment is present, the remote connection will
2566 not be created via rcmd(3) but by calling the program pointed to
2567 by RSH. Use e.g. RSH=/usr/bin/ssh to create a secure shell
2568 connection.
2569 Note that this forces star to create a pipe to the rsh(1) pro‐
2571 gram and disallows star to directly access the network socket to
2572 the remote server. This makes it impossible to set up perfor‐
2573 mance parameters and slows down the connection compared to a
2574 root initiated rcmd(3) connection.
2575 See BUGS section for more information.
2577 RMT If the RMT environment is present, the remote tape server will
2579 not be the program /etc/rmt but the program pointed to by RMT.
2580 Note that the remote tape server program name will be ignored if
2581 you log in using an account that has been created with a remote
2582 tape server program as login shell.
2583
2585 /etc/default/star
2586 Default values can be set for the following options in
2587 /etc/default/star. For example: CDR_FIFOSIZE=64m
2588 STAR_FIFOSIZE
2590 Sets the default size of the FIFO (see also fs=# option).
2591 STAR_FIFOSIZE_MAX
2593 Sets the maximum size of the FIFO (see also fs=# option).
2594 Setting STAR_FIFOSIZE_MAX in /etc/default/star allows to
2595 overwrite global values from backup scripts for machines
2596 with less memory.
2597 archive0=
2599 archive1=
2601 archive2=
2603 archive3=
2605 archive4=
2607 archive5=
2609 archive6=
2611 archive7=
2613 Archive entries for the -[0..7] option.
2614 A correct archive?= line has 3..4 space separated
2616 entries. The first is the device entry (e.g. ar‐
2617 chive0=/dev/tape). The second is the blocking factor in
2618 512 byte units. The third is the maximum media size in
2619 1024 byte units. If this entry contains a 0, then the
2620 media size is unlimited. The fourth entry is optional.
2621 If it contains a 'n' or a 'N', then the archive device is
2622 not a tape.
2623 Examples:
2625 archive0=/dev/tape 512 0 y
2627 archive1=/dev/fd0 1 1440 n
2628 archive2=/dev/rmt/0mbn 512 0
2629 If the default file does not need to be shared with the
2631 tar program from Solaris, any number may be used like a
2632 generic size option like bs=.
2633 Example:
2635 archive0=/dev/tape 256k 40G y
2637 /etc/tardumps
2639 The default name for the dump level archive. The default name is
2640 used whenever the tardumps=name option has not been specified.
2641 The file is written or updated when -wtardumps is used.
2642 The file holds one or more lines, each specifying a dump level
2644 entry. Each dump level entry starts with a mount point name
2645 followed by a TAB and one or more spaces, followed by the deci‐
2646 mal dump level, a space and the dump time.
2647 If the dump level is directly followed by a 'P', then the dump
2649 refers to a partial dump (a dump that does not include the whole
2650 filesystem).
2651 The dump time itself includes the decimal representation of the
2653 UTC seconds since Jan 01 1970, a space and the textual local
2654 time representation of the dump time.
2655 The numerical decimal dump time representation may be followed
2657 by a dot and a sub second value. The textual local time repre‐
2658 sentation is for informational use by humans only and not evalu‐
2659 ated by star.
2660 ./star-symtable
2662 Contains a database that is needed in incremental restore mode.
2663 ./star-symdump
2665 Contains an intermediate dump of restore database after a fatal
2666 error condition was met during an incremental restore operation.
2667 ./star-tmpdir
2669 Is the temporary directory that is used as intermediate file
2670 storage by star if in incremental restore mode.
2671 ./star-lock
2673 Is a lock file created by star when doing an incremental
2674 restore. If this file is present, it prevents star from running
2675 another incremental restore operation. This helps to avoid more
2676 than one restore operation at a time (e.g. from a cron script).
2677 /dev/tty
2679 Is used for the intercative user interface.
2680
2682 spax(1), tar(1), cpio(1), pax(1), rcp(1), mt(1), rmt(8), match(1),
2683 dd(1), sdd(1), rsh(1), ssh(1), star(4), rcmd(3), fssnap(1m)
2684
2686 star: f records + p bytes (total of x bytes = d.nnk).
2687 The number of full records, the number of bytes in partial records and
2689 the total amount of data in KBytes.
2690 star: Total time x.yyysec (z kBytes/sec)
2692 The time used and the transfer speed from/to the archive.
2694 If there have been non fatal errors during the archive processing, star
2696 will display a delayed error summary before exiting.
2697
2700 The command line syntax for the tar command (as defined in SUSv2 -
2701 UNIX-98) deviates from the command line syntax defined for all other
2702 commands. While the POSIX command line syntax requests all options to
2703 start with a dash (-) and allows to either write options separately or
2704 combined (in case of boolean flags), the tar command line syntax
2705 requires all options to be combined into a single string that does not
2706 start with a dash. Star by default assumes a command line syntax like
2707 a typical POSIX command and includes a compatibility mode that allows
2708 to specify a command line syntax as documented for the UNIX-98 tar com‐
2709 mand. If you believe that you found a bug in the way star parses the
2710 command line, please first check your command line for correctness
2711 before you make a bug report for star.
2712 If you like to write portable shell scripts that call tar, use the
2714 UNIX-98 tar command line syntax (i.e. a single option string and no
2715 dash), choose the commands and options from the following set of char‐
2716 acters ( rxtuc vxfblmo ) and check the shell script with both, your
2717 local tar and star for correct behavior. It you expect the script to
2718 call gnutar, do not include the -o option as gnutar implements this
2719 option in a way that violates UNIX-98.
2720 Star strips leading ./ sequences from pathnames. This lets star in many
2722 cases store longer pathnames than other implementations.
2723 The POSIX.1-1988 method (ustar format) of storing files with pathnames
2725 that are longer than 100 chars has some limitations:
2726 The name field (100 chars) an inserted slash (`/') and the pre‐
2728 fix field (155 chars) produce the pathname of the file. When
2729 recreating the original filename, name and prefix are concate‐
2730 nated, using a slash character in the middle. If a pathname does
2731 not fit in the space provided or may not be split at a slash
2732 character so that the parts will fit into 100 + 155 chars, the
2733 file may not be archived. Linknames longer than 100 chars may
2734 not be archived too.
2735 The star, xstar, xustar, exustar, pax, and gnutar archive formats don't
2737 have these limitations. While gnutar uses a method that makes it impos‐
2738 sible for other tar implementations (except star) to restore filenames
2739 that are longer than 100 chars, the xstar, xustar, exustar and pax ar‐
2740 chive format uses a method that allows an POSIX.1-1988 compliant way of
2741 storing filenames, if the POSIX method would allow this. When the ar‐
2742 chive format is xustar, exustar or pax very long filenames are stored
2743 using extended headers from the POSIX.1-2001 standard.
2744 Some buggy tar implementations will generate incorrect filenames during
2746 a restore operation if the archive contains pathnames or linknames of
2747 exactly 100 chars length.
2748 Star adds a tar signature in the last four bytes of each tar header if
2750 the archive format is star or xstar. This is no problem with the star
2751 archive format as it is an extension of the old pre POSIX.1-1988 tar
2752 format. On the other side, the xstar archive format claims to be as
2753 POSIX.1-1988 compliant as possible. Inserting this tar signature is a
2754 minor deviation from the standard that has the last 12 bytes of each
2755 header reserved for future use. On the other side, tar implementations
2756 such as some pax implementations that only compute checksums on the
2757 first 500 bytes of the header are violating the standard that requests
2758 the checksum to be computed on all 512 bytes of the tar header. All tar
2759 implementations that are 100% Posix compliant will be able to extract
2760 xstar archives as long as no new standard is defined that claims the
2761 last 12 bytes of the header for a different use. But then the ustar
2762 version number should be changed from `00' to `01'. Now, that the
2763 POSIX-2001 standard has been accepted, it is even predictable that all
2764 extensions to the standard tar format will go into the POSIX.1-2001
2765 extended headers which are extensible to include any feature without
2766 future limitation. The only known tar implementation that also uses
2767 the last 12 bytes of the tar header is Sun's tar which uses these 12
2768 bytes for files that are split over several archives. Such archives
2769 created by Sun's tar are not readable by the buggy pax implementation
2770 too. The Sun extension is not incompatible to the star signature
2771 because Sun expects an octal number at the beginning of the 12 byte
2772 field which is a null character in the star case.
2773 Star uses these four bytes since 1985 without problems. If you need a
2775 100% POSIX.1-1988 and 100% POSIX.1-2001 compliant tar archive, you may
2776 use the xustar, exustar or the pax archive format. The probability of
2777 falsely detecting other tar formats as xustar or exustar format however
2778 is higher.
2779 There is no way to ask for the n-th occurrence of a file.
2781 The way EOF is handled by star differs, whether the fifo is in effect
2783 or not. If the fifo is not used, star stops reading the archive if it
2784 encounters a logical EOF record in the archive. If the fifo is used,
2785 star may read until the fifo is full or until the real EOF mark on tape
2786 is reached. How much data star actually reads depends on the time when
2787 the star foreground process sends a fifo shutdown signal to the back‐
2788 ground fifo read process.
2789 Gnu tar often creates tar archives with incorrect logical EOF marks.
2791 The standard requires two blocks that are completely zeroed, whereas
2792 gnutar often only adds one of them.
2793 Old versions of tar found on SYSVr3 and earlier cannot read tar ar‐
2795 chives with a blocksize greater than 10 kBytes.
2796 The method of storing sparse files currently used with the star and
2798 xstar format is not guaranteed to be used in later versions of star.
2799 If the author decides to change this method, later versions of star may
2800 not be able to restore sparse files from tar archives made by the cur‐
2801 rent version of star.
2802 Some tar implementations violate the standard in using only the first
2804 500 Bytes of the header for checksum computation. These tar implementa‐
2805 tions will not accept star and xstar type tar archives.
2806 Sun's Solaris 2.x tar implementation violates the Posix standard. Tar
2808 archives generated by star cause Sun's tar to print tar: impossible
2809 file type messages. You may ignore these messages.
2810 Gnutar's dumpdirs are non standard and are currently not implemented.
2812 If gnutar archives sparse files with more than four holes, it produces
2814 archives that violate the standard in a way that prevents other tar
2815 implementations to read these archives. Star knows about that and is
2816 able to handle these gnutar archives.
2817 The filetype N (LF_NAMES) from gnutar (an obsolete method of storing
2819 long names) will never be implemented.
2820 Note that on operating systems (like DOS) that do not implement real
2822 pipes, star implements compression via a temporary file. Using com‐
2823 pression thus is limited by the maximum file size and the available
2824 disk space.
2825 The extended file flags implementation (see -xfflags option) on Linux
2827 is buggy by design. In order to retrieve the needed information, every
2828 file needs to be opened. If the /dev directory is included in create
2829 mode, every possible driver will be loaded which may hang the system
2830 for a long time. In the worst case, unwanted side effects from opening
2831 devices (such as causing tape drives to rewind the media) may be
2832 caused.
2833
2836 If you unpack a tar archive in a non empty directory, any file in that
2837 directory may be overwritten unless you specify the -k option. If the
2838 archive contains symbolic links or hard links, star may even overwrite
2839 files outside the current directory. If the directory where the ar‐
2840 chive is been unpacked is not empty and contains contains symbolic
2841 links or hard links to directories outside that directory, star may
2842 also overwrite files outside the current directory. As many other com‐
2843 mands, star usually has all possible permissions when run as root.
2844 Unpacking archives as root thus may have fatal results to any file on
2845 your system. Be very careful when you try to extract an archive that
2846 has not been created by you. It is possible to create hand crafted tar
2847 archives that may overwrite critical files (like /etc/passwd) on your
2848 system. In addition all tar archives that have been created with the
2849 list= option and tar archives where the C= option was not specified
2850 before all file type arguments may be critical.
2851 A good advise is to extract all doubtful archives as non root in an
2853 empty directory and to specify the -secure-links option. If you get a
2854 warning, you should unpack the archive a second time and specify the
2855 options -k, -w and -nowarn in addition to the options used for the
2856 first run.
2857
2859 If star is installed suid root, star is able to make connections to
2860 remote archives for non root users. This is done by using the rcmd(3)
2861 interface to get a connection to a rmt(8) server.
2862 Star resets its effective uid back to the real user id immediately
2864 after setting up the remote connection to the rmt server and before
2865 opening any other file.
2866 If star has not been installed suid root and not called by root, it
2868 will try to create the remote connection via rsh(1) or ssh(1) (in case
2869 the environment RSH has been set to ssh). Note that in this case, the
2870 throughput to the remote tape server will be much lower than with a
2871 connection that has been initiated via rcmd(3).
2872
2874 If star is running on a large file aware platform, star is able to han‐
2875 dle files up to 8 GB in a mode that is compliant to the POSIX.1-1988
2876 ustar format. With a nonstandard star specific extension, up to 95 bits
2877 may be used to code the filesize. This will handle files up to
2878 200,000,000 TB. With the new POSIX.1-2001 extended headers used by the
2879 xustar, exustar and pax format, any filesize may be archived.
2880
2882 The fact that the -f option has to be implemented in a way that is com‐
2883 patible with old tar implementations gives several problems. The
2884 options -fifostats, -force-hole, -force-remove and -fifo interfere with
2885 the -f option and the fact that they exist prevents users from using
2886 filenames like e.g. ifo using the traditional way where the filename
2887 directly follows the string -f without any space between the option
2888 name and the file name. However, there is no problem to use a file
2889 named ifo by by calling -f ifo, f=ifo, -f=ifo or -f= ifo. Be careful
2890 not to make typos with the above options. The result could be that a
2891 file is created as a result of the mistyped option.
2892 There is currently no way to set the fifo lowwater and highwater marks.
2894 There is currently no way to automatically delete files in the target
2896 file tree if they are obsolete. Star should implement something simi‐
2897 lar to gnutar's dumpdirs.
2898 If not invoked by the super user star may not be able to extract files
2900 if they reside in read only directories.
2901 Star is not able to make a complete backup of a filesystem if files are
2903 hidden by a mount that is in effect on a directory of this filesystem.
2904 This may be avoided in case of the ufs filesystem if the backup is made
2905 off a ufs snapshot (see the man page for fssnap(1m) It could be avoided
2906 for any filesystem if the loopback filesystem had an option that tells
2907 lofs not to traverse mountpoints.
2908 For now (late 2002), we know that the following programs are broken and
2910 do not implement signal handling correctly:
2911 rsh on SunOS-5.0...SunOS-5.9
2913 ssh from ssh.com
2915 ssh from openssh.org
2917 Sun already did accept a bug report for rsh(1)/[22mssh(1). Openssh.org
2919 accepted and fixed a bug for their implementation of ssh(1).
2920 If you use star to create a remote connection via an unfixed rsh(1) or
2922 ssh(1), be prepared that terminal generated signals may interrupt the
2923 remote connection.
2924
2927 Star was first created in 1982 to extract tapes on a UNIX clone that
2928 had no tar command. In 1985 the first fully functional version has
2929 been released as mtar.
2930 When the old star format extensions have been introduced in 1985, it
2932 was renamed to star (Schily tar). In 1994, Posix 1003.1-1988 exten‐
2933 sions were added and star was renamed to star (Standard tar).
2934
2937 Joerg Schilling
2938 Seestr. 110
2939 D-13353 Berlin
2940 Germany
2941 Mail bugs and suggestions to:
2943 schilling@fokus.fraunhofer.de or js@cs.tu-berlin.de or
2945 joerg@schily.isdn.cs.tu-berlin.de
2946Joerg Schilling 11/04/12 STAR(1)