551:") natively, without the use of 7z, using the "-J" switch. The resulting file extension is ".tar.xz" or ".txz" and not ".tar.7z". This method of compression has been adopted with many distributions for packaging, such as Arch, Debian (deb), Fedora (rpm) and Slackware. (The older "lzma" format is less efficient.) On the other hand, it is important to note, that tar does not save the filesystem encoding, which means that tar compressed filenames can become unreadable if decompressed on a different computer.
1318:
36:
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1298:
554:
The 7z format does not allow extraction of some "broken files"—that is (for example) if one has the first segment of a series of 7z files, 7z cannot give the start of the files within the archive—it must wait until all segments are downloaded. The 7z format also lacks recovery records, making it
453:
processors, jump targets are 'normalized' before compression by changing relative position into absolute values. For x86, this means that near jumps, calls and conditional jumps (but not short jumps and conditional jumps) are converted from the machine language "jump 1655 bytes backwards" style
519:
for the passphrase more difficult. Current GPU-based, and custom hardware attacks limit the effectiveness of this particular method of key stretching, so it is still important to choose a strong password. The 7z format provides the option to encrypt the filenames of a 7z archive.
464:
BCJ2– Pre-processor for 32-bit x86 executables. BCJ2 is an improvement on BCJ, adding additional x86 jump/call instruction processing. Near jump, near call, conditional near jump targets are split out and compressed separately in another
716:
Compared to LZMA1, LZMA2 adds support for LZMA_SYNC_FLUSH, uncompressed chunks (smaller expansion when trying to compress uncompressible data), possibility to change lc/lp/pb in the middle of encoding, and some other internal
355: – Dmitry Shkarin's 2002 PPMdH (PPMII (Prediction by Partial matching with Information Inheritance) and cPPMII (complicated PPMII)) with small changes: PPMII is an improved version of the 1984
206:
The 7z file format specification is distributed with 7-Zip's source code since 2015. The specification can be found in plain text format in the 'doc' sub-directory of the source code distribution.
401:
A suite of recompression tools called
AdvanceCOMP contains a copy of the DEFLATE encoder from the 7-Zip implementation; these utilities can often be used to further compress the size of existing
454:
notation to normalized "jump to address 5554" style notation; all jumps to 5554, perhaps a common subroutine, are thus encoded identically, making them more compressible.
511:
hash function. The SHA-256 is executed 2 (524288) times, which causes a significant delay on slow PCs before compression or extraction starts. This technique is called
793:
461: – Converter for 32-bit x86 executables. Normalise target addresses of near jumps and calls from relative distances to absolute destinations.
328:
1342:
261:, where multiple files of like type are compressed within a single stream, in order to exploit the combined redundancy inherent in similar files.
733:
978:
884:
543:), and hence can be inappropriate for backup/archival purposes. A workaround on UNIX-like systems for this is to convert data to a
828:
309:
algorithm, using a sliding dictionary up to 4 GB in length for duplicate string elimination. The LZ stage is followed by
547:
before compressing with 7z. But GNU tar (common in many UNIX environments) can also compress with the LZMA2 algorithm ("
703:
772:
200:
192:
146:
631:
331: – modified version of LZMA providing better multithreading support and less expansion of incompressible data.
761:
414:
1215:
352:
660:
1301:
877:
593:
338:
1029:
500:
231:
1352:
983:
789:
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compressor features displacement compression for 32-bit x86 executables and IA-64 executables, and the
1252:
410:
382:
356:
271:
Support for multi-part archives : e.g. xxx.7z.001, xxx.7z.002, ... (see the context menu items
1347:
1321:
870:
221:, modular architecture that allows any compression, conversion, or encryption method to be stacked.
102:
1311:
598:
67:
529:
225:
729:
1049:
568:
1297:
483:
runtime executable file compressor includes support for working with 16-bit values within
433:
preprocessors included, so that later stages are able to achieve greater compression: For
8:
1242:
1064:
540:
176:
22:
937:
917:
516:
265:
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and pre-processing algorithms. The 7z format initially appeared as implemented by the
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Similar executable pre-processing technology is included in other software; the
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512:
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370:
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853:
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306:
196:
150:
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389:. 7-Zip contains a from-scratch DEFLATE encoder that frequently beats the
314:
290:
allows additional future compression methods to be added to the standard.
191:
archiver. The 7-Zip program is publicly available under the terms of the
1059:
857:
623:
564:
503:
algorithm with a 256-bit key. The key is generated from a user-supplied
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218:
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504:
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235:
184:
55:
1008:
907:
758:
450:
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to re-assemble an archive from a set of multi-part component files).
35:
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963:
656:
560:
548:
245:
91:
862:
1127:
1122:
508:
446:
442:
362:
341:
algorithm. Bzip2 uses two reversible transformations; BWT, then
251:
973:
953:
770:"Stronger Key Derivation via Sequential Memory-Hard Functions"
1092:
958:
588:
471: – delta filter, basic preprocessor for multimedia data.
397:
version in compression size, but at the expense of CPU usage.
334:
188:
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1200:
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1117:
993:
988:
968:
912:
537:
533:
430:
402:
394:
378:
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in
December 2008. The latest stable version of 7-Zip and
1283:
1137:
1097:
1039:
559:
unless used in conjunction with external solutions, like
484:
480:
434:
386:
298:
The following compression methods are currently defined:
790:"GNU tar 1.34: 8.1 Using Less Space through Compression"
846:
373:. Deflate is found in several file formats including
349:
for symbol reduction (the actual compression element).
214:
The 7z format provides the following main features:
689:
687:
161:
1334:
684:
878:
575:files also lack a recovery feature while the
630:Data Compression Newsletter. 30 April 2003.
209:
16:Family of archive file formats used by 7-Zip
748:
244:Large file support (up to approximately 16
228:(depending on the compression method used).
1307:
885:
871:
365: – Standard algorithm based on 32 kB
651:
649:
420:
821:Data compression: the complete reference
818:
681:LZMA SDK, "DOC" directory, 7zFormat.txt
195:. The LZMA SDK 4.62 was placed in the
1343:Computer-related introductions in 1999
1335:
646:
293:
264:Compression and encryption of archive
866:
663:from the original on 27 February 2015
282:Support for custom codec plugin DLLs.
706:from the original on 8 February 2010
634:from the original on 28 October 2008
1262:Document packaging and distribution
1168:Software packaging and distribution
892:
779:. presented at BSDCan'09, May 2009.
616:
13:
812:
736:from the original on 22 March 2019
693:
68:Uniform Type Identifier (UTI)
14:
1364:
838:
796:from the original on 2 April 2015
624:"A Few Questions for Igor Pavlov"
359:(prediction by partial matching).
193:GNU Lesser General Public License
147:GNU Lesser General Public License
1317:
1316:
1306:
1296:
507:using an algorithm based on the
179:that supports several different
82:'7', 'z', 0xBC, 0xAF, 0x27, 0x1C
34:
782:
722:
675:
523:
1:
609:
594:Comparison of archive formats
528:The 7z format does not store
490:
425:The LZMA SDK comes with the
7:
582:
536:owner/group permissions or
305: – A variation of the
241:Zip 2.0 (Legacy) Encryption
114:; 25 years ago
61:application/x-7z-compressed
10:
1369:
1279:Open Packaging Conventions
657:"History of 7-zip changes"
20:
1292:
1261:
1166:
1018:Archiving and compression
1017:
946:
900:
823:. Springer. p. 241.
357:PPM compression algorithm
339:Burrows–Wheeler transform
210:Features and enhancements
156:
136:
126:
108:
98:
86:
76:
66:
54:
42:
33:
571:. By way of comparison,
56:Internet media type
819:Salomon, David (2007).
599:List of archive formats
495:The 7z format supports
72:org.7-zip.7-zip-archive
1274:OEBPS Container Format
530:filesystem permissions
515:and is used to make a
421:Pre-processing filters
203:SDK is version 24.05.
775:14 April 2019 at the
337: – The standard
90:2 bytes (roughly 18
21:For other uses, see
764:28 May 2019 at the
730:"7-zip source code"
294:Compression methods
275:to create them and
177:archive file format
30:
23:7Z (disambiguation)
1353:Russian inventions
1269:OEB Package Format
768:. As presented in
517:brute-force search
226:compression ratios
44:Filename extension
28:
1330:
1329:
830:978-1-84628-602-5
288:open architecture
259:solid compression
170:
169:
99:Developed by
1360:
1320:
1319:
1310:
1309:
1300:
947:Compression only
887:
880:
873:
864:
863:
850:
849:
847:Official website
834:
806:
805:
803:
801:
786:
780:
752:
746:
745:
743:
741:
726:
720:
719:
713:
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700:liblzma bindings
691:
682:
679:
673:
672:
670:
668:
653:
644:
643:
641:
639:
620:
604:Open file format
579:format has one.
569:error-correction
557:data degradation
277:Combine Files...
181:data compression
175:is a compressed
166:
163:
142:
131:Data compression
122:
120:
115:
38:
31:
27:
1368:
1367:
1363:
1362:
1361:
1359:
1358:
1357:
1348:Archive formats
1333:
1332:
1331:
1326:
1288:
1257:
1238:Package (macOS)
1162:
1013:
942:
896:
894:Archive formats
891:
845:
844:
841:
831:
815:
813:Further reading
810:
809:
799:
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788:
787:
783:
777:Wayback Machine
766:Wayback Machine
753:
749:
739:
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723:
709:
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694:Collin, Lasse.
692:
685:
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109:Initial release
87:Size limitation
62:
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901:Archiving only
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839:External links
837:
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755:Colin Percival
747:
721:
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596:
591:
584:
581:
555:vulnerable to
525:
522:
513:key stretching
492:
489:
487:binary files.
473:
472:
469:Delta encoding
466:
462:
422:
419:
399:
398:
371:Huffman coding
360:
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347:Huffman coding
332:
326:
311:entropy coding
295:
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284:
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269:
262:
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248:, or 2 bytes).
242:
239:
229:
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211:
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168:
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158:
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133:
128:
127:Type of format
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29:7z file format
15:
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795:
791:
785:
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771:
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763:
760:
756:
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735:
731:
725:
718:
717:improvements.
705:
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697:
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652:
650:
633:
629:
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619:
615:
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566:
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558:
552:
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546:
545:tar bitstream
542:
539:
535:
531:
521:
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510:
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498:
488:
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478:
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448:
445:(PPC), IA-64
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428:
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408:
404:
396:
392:
388:
384:
380:
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368:
364:
361:
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354:
351:
348:
344:
343:Move to front
340:
336:
333:
330:
327:
324:
320:
316:
312:
308:
304:
301:
300:
299:
291:
289:
286:The format's
281:
278:
274:
273:Split File...
270:
267:
263:
260:
256:
253:
250:
247:
243:
240:
237:
233:
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223:
220:
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207:
204:
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198:
197:public domain
194:
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182:
178:
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165:
159:
155:
152:
151:Public domain
148:
144:
140:
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107:
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101:
97:
93:
89:
85:
81:
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71:
69:
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59:
57:
53:
47:
45:
41:
37:
32:
24:
19:
1024:
820:
798:. Retrieved
784:
750:
738:. Retrieved
724:
715:
708:. Retrieved
699:
696:"lzma_.lzma"
677:
665:. Retrieved
636:. Retrieved
618:
567:with robust
563:, or within
553:
527:
494:
474:
424:
400:
390:
323:binary trees
315:Markov chain
297:
285:
276:
272:
257:Support for
213:
205:
172:
171:
78:Magic number
18:
858:SourceForge
638:26 December
565:filesystems
524:Limitations
319:range coder
254:file names.
139:Open format
103:Igor Pavlov
1337:Categories
1302:Comparison
628:Dr. Dobb's
610:References
505:passphrase
497:encryption
491:Encryption
236:encryption
185:encryption
1009:Zstandard
710:3 January
561:parchives
532:(such as
499:with the
451:ARM Thumb
393:standard
246:exbibytes
234:-256 bit
1322:Category
1216:Java RAR
964:compress
800:17 March
794:Archived
773:Archived
762:Archived
740:23 March
734:Archived
704:Archived
661:Archived
632:Archived
583:See also
391:de facto
313:using a
92:exabytes
1050:Cabinet
667:10 June
509:SHA-256
465:stream.
447:Itanium
443:PowerPC
417:files.
363:DEFLATE
317:-based
266:headers
252:Unicode
157:Website
117: (
974:Zopfli
954:Brotli
827:
759:scrypt
449:, and
1093:lrzip
959:bzip2
589:7-Zip
413:, or
345:with
335:Bzip2
329:LZMA2
224:High
189:7-Zip
162:7-zip
145:Yes:
1312:List
1253:XBAP
1233:MSIX
1186:APPX
1158:ZPAQ
1128:sitx
1118:rzip
1078:.egg
1073:.dmg
1069:DGCA
994:lzop
989:lzip
979:LZMA
969:gzip
938:WARC
918:shar
913:cpio
825:ISBN
802:2015
742:2018
712:2010
669:2010
640:2009
541:ACLs
538:NTFS
534:UNIX
431:BCJ2
429:and
403:gzip
395:zlib
385:and
379:gzip
369:and
367:LZ77
353:PPMd
321:and
307:LZ77
303:LZMA
219:Open
201:LZMA
164:.org
119:1999
112:1999
1284:PAQ
1248:XAP
1243:RPM
1228:MSI
1221:EAR
1211:WAR
1206:JAR
1201:ipa
1196:HAP
1191:deb
1181:App
1176:apk
1153:ZIP
1148:zoo
1143:Xar
1138:UDA
1134:SQX
1123:sit
1113:RAR
1108:PEA
1103:MPQ
1098:LZX
1088:LHA
1083:kgb
1065:dar
1060:cpt
1055:cfs
1040:ARJ
1035:ARC
1030:ACE
984:LZ4
933:WAD
928:LBR
923:tar
856:on
577:rar
573:zip
501:AES
485:DOS
481:UPX
477:RAR
459:BCJ
439:ARM
435:x86
427:BCJ
415:MNG
411:PNG
407:ZIP
387:PDF
383:PNG
375:ZIP
232:AES
49:.7z
1339::
1045:B1
1025:7z
1004:xz
999:SQ
908:ar
854:7z
792:.
757:.
732:.
714:.
702:.
698:.
686:^
659:.
648:^
626:.
549:xz
441:,
437:,
409:,
405:,
381:,
377:,
183:,
173:7z
149:/
886:e
879:t
872:v
833:.
804:.
744:.
671:.
642:.
325:.
268:.
238:.
141:?
121:)
94:)
25:.
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
