|
cannam@89
|
1
|
|
cannam@89
|
2 This is the README for bzip2/libzip2.
|
|
cannam@89
|
3 This version is fully compatible with the previous public releases.
|
|
cannam@89
|
4
|
|
cannam@89
|
5 ------------------------------------------------------------------
|
|
cannam@89
|
6 This file is part of bzip2/libbzip2, a program and library for
|
|
cannam@89
|
7 lossless, block-sorting data compression.
|
|
cannam@89
|
8
|
|
cannam@89
|
9 bzip2/libbzip2 version 1.0.6 of 6 September 2010
|
|
cannam@89
|
10 Copyright (C) 1996-2010 Julian Seward <jseward@bzip.org>
|
|
cannam@89
|
11
|
|
cannam@89
|
12 Please read the WARNING, DISCLAIMER and PATENTS sections in this file.
|
|
cannam@89
|
13
|
|
cannam@89
|
14 This program is released under the terms of the license contained
|
|
cannam@89
|
15 in the file LICENSE.
|
|
cannam@89
|
16 ------------------------------------------------------------------
|
|
cannam@89
|
17
|
|
cannam@89
|
18 Complete documentation is available in Postscript form (manual.ps),
|
|
cannam@89
|
19 PDF (manual.pdf) or html (manual.html). A plain-text version of the
|
|
cannam@89
|
20 manual page is available as bzip2.txt.
|
|
cannam@89
|
21
|
|
cannam@89
|
22
|
|
cannam@89
|
23 HOW TO BUILD -- UNIX
|
|
cannam@89
|
24
|
|
cannam@89
|
25 Type 'make'. This builds the library libbz2.a and then the programs
|
|
cannam@89
|
26 bzip2 and bzip2recover. Six self-tests are run. If the self-tests
|
|
cannam@89
|
27 complete ok, carry on to installation:
|
|
cannam@89
|
28
|
|
cannam@89
|
29 To install in /usr/local/bin, /usr/local/lib, /usr/local/man and
|
|
cannam@89
|
30 /usr/local/include, type
|
|
cannam@89
|
31
|
|
cannam@89
|
32 make install
|
|
cannam@89
|
33
|
|
cannam@89
|
34 To install somewhere else, eg, /xxx/yyy/{bin,lib,man,include}, type
|
|
cannam@89
|
35
|
|
cannam@89
|
36 make install PREFIX=/xxx/yyy
|
|
cannam@89
|
37
|
|
cannam@89
|
38 If you are (justifiably) paranoid and want to see what 'make install'
|
|
cannam@89
|
39 is going to do, you can first do
|
|
cannam@89
|
40
|
|
cannam@89
|
41 make -n install or
|
|
cannam@89
|
42 make -n install PREFIX=/xxx/yyy respectively.
|
|
cannam@89
|
43
|
|
cannam@89
|
44 The -n instructs make to show the commands it would execute, but not
|
|
cannam@89
|
45 actually execute them.
|
|
cannam@89
|
46
|
|
cannam@89
|
47
|
|
cannam@89
|
48 HOW TO BUILD -- UNIX, shared library libbz2.so.
|
|
cannam@89
|
49
|
|
cannam@89
|
50 Do 'make -f Makefile-libbz2_so'. This Makefile seems to work for
|
|
cannam@89
|
51 Linux-ELF (RedHat 7.2 on an x86 box), with gcc. I make no claims
|
|
cannam@89
|
52 that it works for any other platform, though I suspect it probably
|
|
cannam@89
|
53 will work for most platforms employing both ELF and gcc.
|
|
cannam@89
|
54
|
|
cannam@89
|
55 bzip2-shared, a client of the shared library, is also built, but not
|
|
cannam@89
|
56 self-tested. So I suggest you also build using the normal Makefile,
|
|
cannam@89
|
57 since that conducts a self-test. A second reason to prefer the
|
|
cannam@89
|
58 version statically linked to the library is that, on x86 platforms,
|
|
cannam@89
|
59 building shared objects makes a valuable register (%ebx) unavailable
|
|
cannam@89
|
60 to gcc, resulting in a slowdown of 10%-20%, at least for bzip2.
|
|
cannam@89
|
61
|
|
cannam@89
|
62 Important note for people upgrading .so's from 0.9.0/0.9.5 to version
|
|
cannam@89
|
63 1.0.X. All the functions in the library have been renamed, from (eg)
|
|
cannam@89
|
64 bzCompress to BZ2_bzCompress, to avoid namespace pollution.
|
|
cannam@89
|
65 Unfortunately this means that the libbz2.so created by
|
|
cannam@89
|
66 Makefile-libbz2_so will not work with any program which used an older
|
|
cannam@89
|
67 version of the library. I do encourage library clients to make the
|
|
cannam@89
|
68 effort to upgrade to use version 1.0, since it is both faster and more
|
|
cannam@89
|
69 robust than previous versions.
|
|
cannam@89
|
70
|
|
cannam@89
|
71
|
|
cannam@89
|
72 HOW TO BUILD -- Windows 95, NT, DOS, Mac, etc.
|
|
cannam@89
|
73
|
|
cannam@89
|
74 It's difficult for me to support compilation on all these platforms.
|
|
cannam@89
|
75 My approach is to collect binaries for these platforms, and put them
|
|
cannam@89
|
76 on the master web site (http://www.bzip.org). Look there. However
|
|
cannam@89
|
77 (FWIW), bzip2-1.0.X is very standard ANSI C and should compile
|
|
cannam@89
|
78 unmodified with MS Visual C. If you have difficulties building, you
|
|
cannam@89
|
79 might want to read README.COMPILATION.PROBLEMS.
|
|
cannam@89
|
80
|
|
cannam@89
|
81 At least using MS Visual C++ 6, you can build from the unmodified
|
|
cannam@89
|
82 sources by issuing, in a command shell:
|
|
cannam@89
|
83
|
|
cannam@89
|
84 nmake -f makefile.msc
|
|
cannam@89
|
85
|
|
cannam@89
|
86 (you may need to first run the MSVC-provided script VCVARS32.BAT
|
|
cannam@89
|
87 so as to set up paths to the MSVC tools correctly).
|
|
cannam@89
|
88
|
|
cannam@89
|
89
|
|
cannam@89
|
90 VALIDATION
|
|
cannam@89
|
91
|
|
cannam@89
|
92 Correct operation, in the sense that a compressed file can always be
|
|
cannam@89
|
93 decompressed to reproduce the original, is obviously of paramount
|
|
cannam@89
|
94 importance. To validate bzip2, I used a modified version of Mark
|
|
cannam@89
|
95 Nelson's churn program. Churn is an automated test driver which
|
|
cannam@89
|
96 recursively traverses a directory structure, using bzip2 to compress
|
|
cannam@89
|
97 and then decompress each file it encounters, and checking that the
|
|
cannam@89
|
98 decompressed data is the same as the original.
|
|
cannam@89
|
99
|
|
cannam@89
|
100
|
|
cannam@89
|
101
|
|
cannam@89
|
102 Please read and be aware of the following:
|
|
cannam@89
|
103
|
|
cannam@89
|
104 WARNING:
|
|
cannam@89
|
105
|
|
cannam@89
|
106 This program and library (attempts to) compress data by
|
|
cannam@89
|
107 performing several non-trivial transformations on it.
|
|
cannam@89
|
108 Unless you are 100% familiar with *all* the algorithms
|
|
cannam@89
|
109 contained herein, and with the consequences of modifying them,
|
|
cannam@89
|
110 you should NOT meddle with the compression or decompression
|
|
cannam@89
|
111 machinery. Incorrect changes can and very likely *will*
|
|
cannam@89
|
112 lead to disastrous loss of data.
|
|
cannam@89
|
113
|
|
cannam@89
|
114
|
|
cannam@89
|
115 DISCLAIMER:
|
|
cannam@89
|
116
|
|
cannam@89
|
117 I TAKE NO RESPONSIBILITY FOR ANY LOSS OF DATA ARISING FROM THE
|
|
cannam@89
|
118 USE OF THIS PROGRAM/LIBRARY, HOWSOEVER CAUSED.
|
|
cannam@89
|
119
|
|
cannam@89
|
120 Every compression of a file implies an assumption that the
|
|
cannam@89
|
121 compressed file can be decompressed to reproduce the original.
|
|
cannam@89
|
122 Great efforts in design, coding and testing have been made to
|
|
cannam@89
|
123 ensure that this program works correctly. However, the complexity
|
|
cannam@89
|
124 of the algorithms, and, in particular, the presence of various
|
|
cannam@89
|
125 special cases in the code which occur with very low but non-zero
|
|
cannam@89
|
126 probability make it impossible to rule out the possibility of bugs
|
|
cannam@89
|
127 remaining in the program. DO NOT COMPRESS ANY DATA WITH THIS
|
|
cannam@89
|
128 PROGRAM UNLESS YOU ARE PREPARED TO ACCEPT THE POSSIBILITY, HOWEVER
|
|
cannam@89
|
129 SMALL, THAT THE DATA WILL NOT BE RECOVERABLE.
|
|
cannam@89
|
130
|
|
cannam@89
|
131 That is not to say this program is inherently unreliable.
|
|
cannam@89
|
132 Indeed, I very much hope the opposite is true. bzip2/libbzip2
|
|
cannam@89
|
133 has been carefully constructed and extensively tested.
|
|
cannam@89
|
134
|
|
cannam@89
|
135
|
|
cannam@89
|
136 PATENTS:
|
|
cannam@89
|
137
|
|
cannam@89
|
138 To the best of my knowledge, bzip2/libbzip2 does not use any
|
|
cannam@89
|
139 patented algorithms. However, I do not have the resources
|
|
cannam@89
|
140 to carry out a patent search. Therefore I cannot give any
|
|
cannam@89
|
141 guarantee of the above statement.
|
|
cannam@89
|
142
|
|
cannam@89
|
143
|
|
cannam@89
|
144
|
|
cannam@89
|
145 WHAT'S NEW IN 0.9.0 (as compared to 0.1pl2) ?
|
|
cannam@89
|
146
|
|
cannam@89
|
147 * Approx 10% faster compression, 30% faster decompression
|
|
cannam@89
|
148 * -t (test mode) is a lot quicker
|
|
cannam@89
|
149 * Can decompress concatenated compressed files
|
|
cannam@89
|
150 * Programming interface, so programs can directly read/write .bz2 files
|
|
cannam@89
|
151 * Less restrictive (BSD-style) licensing
|
|
cannam@89
|
152 * Flag handling more compatible with GNU gzip
|
|
cannam@89
|
153 * Much more documentation, i.e., a proper user manual
|
|
cannam@89
|
154 * Hopefully, improved portability (at least of the library)
|
|
cannam@89
|
155
|
|
cannam@89
|
156 WHAT'S NEW IN 0.9.5 ?
|
|
cannam@89
|
157
|
|
cannam@89
|
158 * Compression speed is much less sensitive to the input
|
|
cannam@89
|
159 data than in previous versions. Specifically, the very
|
|
cannam@89
|
160 slow performance caused by repetitive data is fixed.
|
|
cannam@89
|
161 * Many small improvements in file and flag handling.
|
|
cannam@89
|
162 * A Y2K statement.
|
|
cannam@89
|
163
|
|
cannam@89
|
164 WHAT'S NEW IN 1.0.0 ?
|
|
cannam@89
|
165
|
|
cannam@89
|
166 See the CHANGES file.
|
|
cannam@89
|
167
|
|
cannam@89
|
168 WHAT'S NEW IN 1.0.2 ?
|
|
cannam@89
|
169
|
|
cannam@89
|
170 See the CHANGES file.
|
|
cannam@89
|
171
|
|
cannam@89
|
172 WHAT'S NEW IN 1.0.3 ?
|
|
cannam@89
|
173
|
|
cannam@89
|
174 See the CHANGES file.
|
|
cannam@89
|
175
|
|
cannam@89
|
176 WHAT'S NEW IN 1.0.4 ?
|
|
cannam@89
|
177
|
|
cannam@89
|
178 See the CHANGES file.
|
|
cannam@89
|
179
|
|
cannam@89
|
180 WHAT'S NEW IN 1.0.5 ?
|
|
cannam@89
|
181
|
|
cannam@89
|
182 See the CHANGES file.
|
|
cannam@89
|
183
|
|
cannam@89
|
184 WHAT'S NEW IN 1.0.6 ?
|
|
cannam@89
|
185
|
|
cannam@89
|
186 See the CHANGES file.
|
|
cannam@89
|
187
|
|
cannam@89
|
188
|
|
cannam@89
|
189 I hope you find bzip2 useful. Feel free to contact me at
|
|
cannam@89
|
190 jseward@bzip.org
|
|
cannam@89
|
191 if you have any suggestions or queries. Many people mailed me with
|
|
cannam@89
|
192 comments, suggestions and patches after the releases of bzip-0.15,
|
|
cannam@89
|
193 bzip-0.21, and bzip2 versions 0.1pl2, 0.9.0, 0.9.5, 1.0.0, 1.0.1,
|
|
cannam@89
|
194 1.0.2 and 1.0.3, and the changes in bzip2 are largely a result of this
|
|
cannam@89
|
195 feedback. I thank you for your comments.
|
|
cannam@89
|
196
|
|
cannam@89
|
197 bzip2's "home" is http://www.bzip.org/
|
|
cannam@89
|
198
|
|
cannam@89
|
199 Julian Seward
|
|
cannam@89
|
200 jseward@bzip.org
|
|
cannam@89
|
201 Cambridge, UK.
|
|
cannam@89
|
202
|
|
cannam@89
|
203 18 July 1996 (version 0.15)
|
|
cannam@89
|
204 25 August 1996 (version 0.21)
|
|
cannam@89
|
205 7 August 1997 (bzip2, version 0.1)
|
|
cannam@89
|
206 29 August 1997 (bzip2, version 0.1pl2)
|
|
cannam@89
|
207 23 August 1998 (bzip2, version 0.9.0)
|
|
cannam@89
|
208 8 June 1999 (bzip2, version 0.9.5)
|
|
cannam@89
|
209 4 Sept 1999 (bzip2, version 0.9.5d)
|
|
cannam@89
|
210 5 May 2000 (bzip2, version 1.0pre8)
|
|
cannam@89
|
211 30 December 2001 (bzip2, version 1.0.2pre1)
|
|
cannam@89
|
212 15 February 2005 (bzip2, version 1.0.3)
|
|
cannam@89
|
213 20 December 2006 (bzip2, version 1.0.4)
|
|
cannam@89
|
214 10 December 2007 (bzip2, version 1.0.5)
|
|
cannam@89
|
215 6 Sept 2010 (bzip2, version 1.0.6)
|
