1.PU 2.TH bzip2 1 3.SH NAME |
4bzip2, bunzip2 \- a block-sorting file compressor, v1.0.3 |
5.br 6bzcat \- decompresses files to stdout 7.br 8bzip2recover \- recovers data from damaged bzip2 files 9 10.SH SYNOPSIS 11.ll +8 12.B bzip2 --- 387 unchanged lines hidden (view full) --- 400will perform best on machines with very large caches. 401 402.SH CAVEATS 403I/O error messages are not as helpful as they could be. 404.I bzip2 405tries hard to detect I/O errors and exit cleanly, but the details of 406what the problem is sometimes seem rather misleading. 407 |
408This manual page pertains to version 1.0.3 of |
409.I bzip2. 410Compressed data created by this version is entirely forwards and 411backwards compatible with the previous public releases, versions |
4120.1pl2, 0.9.0, 0.9.5, 1.0.0, 1.0.1 and 1.0.2, but with the following |
413exception: 0.9.0 and above can correctly decompress multiple 414concatenated compressed files. 0.1pl2 cannot do this; it will stop 415after decompressing just the first file in the stream. 416 417.I bzip2recover |
418versions prior to 1.0.2 used 32-bit integers to represent 419bit positions in compressed files, so they could not handle compressed 420files more than 512 megabytes long. Versions 1.0.2 and above use |
42164-bit ints on some platforms which support them (GNU supported 422targets, and Windows). To establish whether or not bzip2recover was 423built with such a limitation, run it without arguments. In any event 424you can build yourself an unlimited version if you can recompile it 425with MaybeUInt64 set to be an unsigned 64-bit integer. 426 427 428 429.SH AUTHOR |
430Julian Seward, jsewardbzip.org. |
431 |
432http://www.bzip.org |
433 434The ideas embodied in 435.I bzip2 436are due to (at least) the following 437people: Michael Burrows and David Wheeler (for the block sorting 438transformation), David Wheeler (again, for the Huffman coder), Peter 439Fenwick (for the structured coding model in the original 440.I bzip, 441and many refinements), and Alistair Moffat, Radford Neal and Ian Witten 442(for the arithmetic coder in the original 443.I bzip). 444I am much 445indebted for their help, support and advice. See the manual in the 446source distribution for pointers to sources of documentation. Christian 447von Roques encouraged me to look for faster sorting algorithms, so as to 448speed up compression. Bela Lubkin encouraged me to improve the 449worst-case compression performance. |
450Donna Robinson XMLised the documentation. |
451The bz* scripts are derived from those of GNU gzip. 452Many people sent patches, helped 453with portability problems, lent machines, gave advice and were generally 454helpful. |