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-rw-r--r--bzip2.1.preformatted440
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diff --git a/bzip2.1.preformatted b/bzip2.1.preformatted
index 8c4fab1..96b44be 100644
--- a/bzip2.1.preformatted
+++ b/bzip2.1.preformatted
@@ -1,24 +1,20 @@
1 1
2 2
3
4bzip2(1) bzip2(1)
5
6
7NNAAMMEE 3NNAAMMEE
8 bzip2, bunzip2 - a block-sorting file compressor, v0.9.0 4 bzip2, bunzip2 - a block-sorting file compressor, v0.9.5
9 bzcat - decompresses files to stdout 5 bzcat - decompresses files to stdout
10 bzip2recover - recovers data from damaged bzip2 files 6 bzip2recover - recovers data from damaged bzip2 files
11 7
12 8
13SSYYNNOOPPSSIISS 9SSYYNNOOPPSSIISS
14 bbzziipp22 [ --ccddffkkssttvvzzVVLL112233445566778899 ] [ _f_i_l_e_n_a_m_e_s _._._. ] 10 bbzziipp22 [ --ccddffkkqqssttvvzzVVLL112233445566778899 ] [ _f_i_l_e_n_a_m_e_s _._._. ]
15 bbuunnzziipp22 [ --ffkkvvssVVLL ] [ _f_i_l_e_n_a_m_e_s _._._. ] 11 bbuunnzziipp22 [ --ffkkvvssVVLL ] [ _f_i_l_e_n_a_m_e_s _._._. ]
16 bbzzccaatt [ --ss ] [ _f_i_l_e_n_a_m_e_s _._._. ] 12 bbzzccaatt [ --ss ] [ _f_i_l_e_n_a_m_e_s _._._. ]
17 bbzziipp22rreeccoovveerr _f_i_l_e_n_a_m_e 13 bbzziipp22rreeccoovveerr _f_i_l_e_n_a_m_e
18 14
19 15
20DDEESSCCRRIIPPTTIIOONN 16DDEESSCCRRIIPPTTIIOONN
21 _b_z_i_p_2 compresses files using the Burrows-Wheeler block- 17 _b_z_i_p_2 compresses files using the Burrows-Wheeler block
22 sorting text compression algorithm, and Huffman coding. 18 sorting text compression algorithm, and Huffman coding.
23 Compression is generally considerably better than that 19 Compression is generally considerably better than that
24 achieved by more conventional LZ77/LZ78-based compressors, 20 achieved by more conventional LZ77/LZ78-based compressors,
@@ -26,22 +22,22 @@ DDEESSCCRRIIPPTTIIOONN
26 tistical compressors. 22 tistical compressors.
27 23
28 The command-line options are deliberately very similar to 24 The command-line options are deliberately very similar to
29 those of _G_N_U _G_z_i_p_, but they are not identical. 25 those of _G_N_U _g_z_i_p_, but they are not identical.
30 26
31 _b_z_i_p_2 expects a list of file names to accompany the com- 27 _b_z_i_p_2 expects a list of file names to accompany the com-
32 mand-line flags. Each file is replaced by a compressed 28 mand-line flags. Each file is replaced by a compressed
33 version of itself, with the name "original_name.bz2". 29 version of itself, with the name "original_name.bz2".
34 Each compressed file has the same modification date and 30 Each compressed file has the same modification date, per-
35 permissions as the corresponding original, so that these 31 missions, and, when possible, ownership as the correspond-
36 properties can be correctly restored at decompression 32 ing original, so that these properties can be correctly
37 time. File name handling is naive in the sense that there 33 restored at decompression time. File name handling is
38 is no mechanism for preserving original file names, per- 34 naive in the sense that there is no mechanism for preserv-
39 missions and dates in filesystems which lack these con- 35 ing original file names, permissions, ownerships or dates
40 cepts, or have serious file name length restrictions, such 36 in filesystems which lack these concepts, or have serious
41 as MS-DOS. 37 file name length restrictions, such as MS-DOS.
42 38
43 _b_z_i_p_2 and _b_u_n_z_i_p_2 will by default not overwrite existing 39 _b_z_i_p_2 and _b_u_n_z_i_p_2 will by default not overwrite existing
44 files; if you want this to happen, specify the -f flag. 40 files. If you want this to happen, specify the -f flag.
45 41
46 If no file names are specified, _b_z_i_p_2 compresses from 42 If no file names are specified, _b_z_i_p_2 compresses from
47 standard input to standard output. In this case, _b_z_i_p_2 43 standard input to standard output. In this case, _b_z_i_p_2
@@ -49,42 +45,50 @@ DDEESSCCRRIIPPTTIIOONN
49 this would be entirely incomprehensible and therefore 45 this would be entirely incomprehensible and therefore
50 pointless. 46 pointless.
51 47
52 _b_u_n_z_i_p_2 (or _b_z_i_p_2 _-_d ) decompresses and restores all spec- 48 _b_u_n_z_i_p_2 (or _b_z_i_p_2 _-_d_) decompresses all specified files.
53 ified files whose names end in ".bz2". Files without this 49 Files which were not created by _b_z_i_p_2 will be detected and
54 suffix are ignored. Again, supplying no filenames causes 50 ignored, and a warning issued. _b_z_i_p_2 attempts to guess
55 decompression from standard input to standard output. 51 the filename for the decompressed file from that of the
52 compressed file as follows:
53
54 filename.bz2 becomes filename
55 filename.bz becomes filename
56 filename.tbz2 becomes filename.tar
57 filename.tbz becomes filename.tar
58 anyothername becomes anyothername.out
59
60 If the file does not end in one of the recognised endings,
61 _._b_z_2_, _._b_z_, _._t_b_z_2 or _._t_b_z_, _b_z_i_p_2 complains that it cannot
62 guess the name of the original file, and uses the original
63 name with _._o_u_t appended.
64
65 As with compression, supplying no filenames causes decom-
66 pression from standard input to standard output.
56 67
57 _b_u_n_z_i_p_2 will correctly decompress a file which is the con- 68 _b_u_n_z_i_p_2 will correctly decompress a file which is the con-
58 catenation of two or more compressed files. The result is 69 catenation of two or more compressed files. The result is
59 the concatenation of the corresponding uncompressed files. 70 the concatenation of the corresponding uncompressed files.
60 Integrity testing (-t) of concatenated compressed files is 71 Integrity testing (-t) of concatenated compressed files is
61
62
63
64 1
65
66
67
68
69
70bzip2(1) bzip2(1)
71
72
73 also supported. 72 also supported.
74 73
75 You can also compress or decompress files to the standard 74 You can also compress or decompress files to the standard
76 output by giving the -c flag. Multiple files may be com- 75 output by giving the -c flag. Multiple files may be com-
77 pressed and decompressed like this. The resulting outputs 76 pressed and decompressed like this. The resulting outputs
78 are fed sequentially to stdout. Compression of multiple 77 are fed sequentially to stdout. Compression of multiple
79 files in this manner generates a stream containing multi- 78 files in this manner generates a stream containing multi-
80 ple compressed file representations. Such a stream can be 79 ple compressed file representations. Such a stream can be
81 decompressed correctly only by _b_z_i_p_2 version 0.9.0 or 80 decompressed correctly only by _b_z_i_p_2 version 0.9.0 or
82 later. Earlier versions of _b_z_i_p_2 will stop after decom- 81 later. Earlier versions of _b_z_i_p_2 will stop after decom-
83 pressing the first file in the stream. 82 pressing the first file in the stream.
84 83
85 _b_z_c_a_t (or _b_z_i_p_2 _-_d_c ) decompresses all specified files to 84 _b_z_c_a_t (or _b_z_i_p_2 _-_d_c_) decompresses all specified files to
86 the standard output. 85 the standard output.
87 86
87 _b_z_i_p_2 will read arguments from the environment variables
88 _B_Z_I_P_2 and _B_Z_I_P_, in that order, and will process them
89 before any arguments read from the command line. This
90 gives a convenient way to supply default arguments.
91
88 Compression is always performed, even if the compressed 92 Compression is always performed, even if the compressed
89 file is slightly larger than the original. Files of less 93 file is slightly larger than the original. Files of less
90 than about one hundred bytes tend to get larger, since the 94 than about one hundred bytes tend to get larger, since the
@@ -101,121 +105,19 @@ bzip2(1) bzip2(1)
101 corruption going undetected is microscopic, about one 105 corruption going undetected is microscopic, about one
102 chance in four billion for each file processed. Be aware, 106 chance in four billion for each file processed. Be aware,
103 though, that the check occurs upon decompression, so it 107 though, that the check occurs upon decompression, so it
104 can only tell you that that something is wrong. It can't 108 can only tell you that something is wrong. It can't help
105 help you recover the original uncompressed data. You can 109 you recover the original uncompressed data. You can use
106 use _b_z_i_p_2_r_e_c_o_v_e_r to try to recover data from damaged 110 _b_z_i_p_2_r_e_c_o_v_e_r to try to recover data from damaged files.
107 files.
108 111
109 Return values: 0 for a normal exit, 1 for environmental 112 Return values: 0 for a normal exit, 1 for environmental
110 problems (file not found, invalid flags, I/O errors, &c), 113 problems (file not found, invalid flags, I/O errors, &c),
111 2 to indicate a corrupt compressed file, 3 for an internal 114 2 to indicate a corrupt compressed file, 3 for an internal
112 consistency error (eg, bug) which caused _b_z_i_p_2 to panic. 115 consistency error (eg, bug) which caused _b_z_i_p_2 to panic.
113 116
114 117
115MMEEMMOORRYY MMAANNAAGGEEMMEENNTT
116 _B_z_i_p_2 compresses large files in blocks. The block size
117 affects both the compression ratio achieved, and the
118 amount of memory needed both for compression and decom-
119 pression. The flags -1 through -9 specify the block size
120 to be 100,000 bytes through 900,000 bytes (the default)
121 respectively. At decompression-time, the block size used
122 for compression is read from the header of the compressed
123 file, and _b_u_n_z_i_p_2 then allocates itself just enough memory
124 to decompress the file. Since block sizes are stored in
125 compressed files, it follows that the flags -1 to -9 are
126 irrelevant to and so ignored during decompression.
127
128
129
130 2
131
132
133
134
135
136bzip2(1) bzip2(1)
137
138
139 Compression and decompression requirements, in bytes, can
140 be estimated as:
141
142 Compression: 400k + ( 7 x block size )
143
144 Decompression: 100k + ( 4 x block size ), or
145 100k + ( 2.5 x block size )
146
147 Larger block sizes give rapidly diminishing marginal
148 returns; most of the compression comes from the first two
149 or three hundred k of block size, a fact worth bearing in
150 mind when using _b_z_i_p_2 on small machines. It is also
151 important to appreciate that the decompression memory
152 requirement is set at compression-time by the choice of
153 block size.
154
155 For files compressed with the default 900k block size,
156 _b_u_n_z_i_p_2 will require about 3700 kbytes to decompress. To
157 support decompression of any file on a 4 megabyte machine,
158 _b_u_n_z_i_p_2 has an option to decompress using approximately
159 half this amount of memory, about 2300 kbytes. Decompres-
160 sion speed is also halved, so you should use this option
161 only where necessary. The relevant flag is -s.
162
163 In general, try and use the largest block size memory con-
164 straints allow, since that maximises the compression
165 achieved. Compression and decompression speed are virtu-
166 ally unaffected by block size.
167
168 Another significant point applies to files which fit in a
169 single block -- that means most files you'd encounter
170 using a large block size. The amount of real memory
171 touched is proportional to the size of the file, since the
172 file is smaller than a block. For example, compressing a
173 file 20,000 bytes long with the flag -9 will cause the
174 compressor to allocate around 6700k of memory, but only
175 touch 400k + 20000 * 7 = 540 kbytes of it. Similarly, the
176 decompressor will allocate 3700k but only touch 100k +
177 20000 * 4 = 180 kbytes.
178
179 Here is a table which summarises the maximum memory usage
180 for different block sizes. Also recorded is the total
181 compressed size for 14 files of the Calgary Text Compres-
182 sion Corpus totalling 3,141,622 bytes. This column gives
183 some feel for how compression varies with block size.
184 These figures tend to understate the advantage of larger
185 block sizes for larger files, since the Corpus is domi-
186 nated by smaller files.
187
188 Compress Decompress Decompress Corpus
189 Flag usage usage -s usage Size
190
191 -1 1100k 500k 350k 914704
192 -2 1800k 900k 600k 877703
193
194
195
196 3
197
198
199
200
201
202bzip2(1) bzip2(1)
203
204
205 -3 2500k 1300k 850k 860338
206 -4 3200k 1700k 1100k 846899
207 -5 3900k 2100k 1350k 845160
208 -6 4600k 2500k 1600k 838626
209 -7 5400k 2900k 1850k 834096
210 -8 6000k 3300k 2100k 828642
211 -9 6700k 3700k 2350k 828642
212
213
214OOPPTTIIOONNSS 118OOPPTTIIOONNSS
215 --cc ----ssttddoouutt 119 --cc ----ssttddoouutt
216 Compress or decompress to standard output. -c will 120 Compress or decompress to standard output.
217 decompress multiple files to stdout, but will only
218 compress a single file to stdout.
219 121
220 --dd ----ddeeccoommpprreessss 122 --dd ----ddeeccoommpprreessss
221 Force decompression. _b_z_i_p_2_, _b_u_n_z_i_p_2 and _b_z_c_a_t are 123 Force decompression. _b_z_i_p_2_, _b_u_n_z_i_p_2 and _b_z_c_a_t are
@@ -235,7 +137,9 @@ OOPPTTIIOONNSS
235 137
236 --ff ----ffoorrccee 138 --ff ----ffoorrccee
237 Force overwrite of output files. Normally, _b_z_i_p_2 139 Force overwrite of output files. Normally, _b_z_i_p_2
238 will not overwrite existing output files. 140 will not overwrite existing output files. Also
141 forces _b_z_i_p_2 to break hard links to files, which it
142 otherwise wouldn't do.
239 143
240 --kk ----kkeeeepp 144 --kk ----kkeeeepp
241 Keep (don't delete) input files during compression 145 Keep (don't delete) input files during compression
@@ -254,19 +158,12 @@ OOPPTTIIOONNSS
254 figure, at the expense of your compression ratio. 158 figure, at the expense of your compression ratio.
255 In short, if your machine is low on memory (8 159 In short, if your machine is low on memory (8
256 megabytes or less), use -s for everything. See 160 megabytes or less), use -s for everything. See
257 MEMORY MANAGEMENT above. 161 MEMORY MANAGEMENT below.
258
259
260
261
262 4
263
264
265
266
267
268bzip2(1) bzip2(1)
269 162
163 --qq ----qquuiieett
164 Suppress non-essential warning messages. Messages
165 pertaining to I/O errors and other critical events
166 will not be suppressed.
270 167
271 --vv ----vveerrbboossee 168 --vv ----vveerrbboossee
272 Verbose mode -- show the compression ratio for each 169 Verbose mode -- show the compression ratio for each
@@ -281,22 +178,96 @@ bzip2(1) bzip2(1)
281 --11 ttoo --99 178 --11 ttoo --99
282 Set the block size to 100 k, 200 k .. 900 k when 179 Set the block size to 100 k, 200 k .. 900 k when
283 compressing. Has no effect when decompressing. 180 compressing. Has no effect when decompressing.
284 See MEMORY MANAGEMENT above. 181 See MEMORY MANAGEMENT below.
182
183 ---- Treats all subsequent arguments as file names, even
184 if they start with a dash. This is so you can han-
185 dle files with names beginning with a dash, for
186 example: bzip2 -- -myfilename.
187
188 ----rreeppeettiittiivvee--ffaasstt ----rreeppeettiittiivvee--bbeesstt
189 These flags are redundant in versions 0.9.5 and
190 above. They provided some coarse control over the
191 behaviour of the sorting algorithm in earlier ver-
192 sions, which was sometimes useful. 0.9.5 and above
193 have an improved algorithm which renders these
194 flags irrelevant.
195
196
197MMEEMMOORRYY MMAANNAAGGEEMMEENNTT
198 _b_z_i_p_2 compresses large files in blocks. The block size
199 affects both the compression ratio achieved, and the
200 amount of memory needed for compression and decompression.
201 The flags -1 through -9 specify the block size to be
202 100,000 bytes through 900,000 bytes (the default) respec-
203 tively. At decompression time, the block size used for
204 compression is read from the header of the compressed
205 file, and _b_u_n_z_i_p_2 then allocates itself just enough memory
206 to decompress the file. Since block sizes are stored in
207 compressed files, it follows that the flags -1 to -9 are
208 irrelevant to and so ignored during decompression.
285 209
286 ----rreeppeettiittiivvee--ffaasstt 210 Compression and decompression requirements, in bytes, can
287 _b_z_i_p_2 injects some small pseudo-random variations 211 be estimated as:
288 into very repetitive blocks to limit worst-case
289 performance during compression. If sorting runs
290 into difficulties, the block is randomised, and
291 sorting is restarted. Very roughly, _b_z_i_p_2 persists
292 for three times as long as a well-behaved input
293 would take before resorting to randomisation. This
294 flag makes it give up much sooner.
295 212
213 Compression: 400k + ( 8 x block size )
296 214
297 ----rreeppeettiittiivvee--bbeesstt 215 Decompression: 100k + ( 4 x block size ), or
298 Opposite of --repetitive-fast; try a lot harder 216 100k + ( 2.5 x block size )
299 before resorting to randomisation. 217
218 Larger block sizes give rapidly diminishing marginal
219 returns. Most of the compression comes from the first two
220 or three hundred k of block size, a fact worth bearing in
221 mind when using _b_z_i_p_2 on small machines. It is also
222 important to appreciate that the decompression memory
223 requirement is set at compression time by the choice of
224 block size.
225
226 For files compressed with the default 900k block size,
227 _b_u_n_z_i_p_2 will require about 3700 kbytes to decompress. To
228 support decompression of any file on a 4 megabyte machine,
229 _b_u_n_z_i_p_2 has an option to decompress using approximately
230 half this amount of memory, about 2300 kbytes. Decompres-
231 sion speed is also halved, so you should use this option
232 only where necessary. The relevant flag is -s.
233
234 In general, try and use the largest block size memory con-
235 straints allow, since that maximises the compression
236 achieved. Compression and decompression speed are virtu-
237 ally unaffected by block size.
238
239 Another significant point applies to files which fit in a
240 single block -- that means most files you'd encounter
241 using a large block size. The amount of real memory
242 touched is proportional to the size of the file, since the
243 file is smaller than a block. For example, compressing a
244 file 20,000 bytes long with the flag -9 will cause the
245 compressor to allocate around 7600k of memory, but only
246 touch 400k + 20000 * 8 = 560 kbytes of it. Similarly, the
247 decompressor will allocate 3700k but only touch 100k +
248 20000 * 4 = 180 kbytes.
249
250 Here is a table which summarises the maximum memory usage
251 for different block sizes. Also recorded is the total
252 compressed size for 14 files of the Calgary Text Compres-
253 sion Corpus totalling 3,141,622 bytes. This column gives
254 some feel for how compression varies with block size.
255 These figures tend to understate the advantage of larger
256 block sizes for larger files, since the Corpus is domi-
257 nated by smaller files.
258
259 Compress Decompress Decompress Corpus
260 Flag usage usage -s usage Size
261
262 -1 1200k 500k 350k 914704
263 -2 2000k 900k 600k 877703
264 -3 2800k 1300k 850k 860338
265 -4 3600k 1700k 1100k 846899
266 -5 4400k 2100k 1350k 845160
267 -6 5200k 2500k 1600k 838626
268 -7 6100k 2900k 1850k 834096
269 -8 6800k 3300k 2100k 828642
270 -9 7600k 3700k 2350k 828642
300 271
301 272
302RREECCOOVVEERRIINNGG DDAATTAA FFRROOMM DDAAMMAAGGEEDD FFIILLEESS 273RREECCOOVVEERRIINNGG DDAATTAA FFRROOMM DDAAMMAAGGEEDD FFIILLEESS
@@ -314,7 +285,7 @@ RREECCOOVVEERRIINNGG DDAATTAA FFRROOMM DDAAMMAAGGEEDD F
314 285
315 _b_z_i_p_2_r_e_c_o_v_e_r is a simple program whose purpose is to 286 _b_z_i_p_2_r_e_c_o_v_e_r is a simple program whose purpose is to
316 search for blocks in .bz2 files, and write each block out 287 search for blocks in .bz2 files, and write each block out
317 into its own .bz2 file. You can then use _b_z_i_p_2 _-_t to test 288 into its own .bz2 file. You can then use _b_z_i_p_2 -t to test
318 the integrity of the resulting files, and decompress those 289 the integrity of the resulting files, and decompress those
319 which are undamaged. 290 which are undamaged.
320 291
@@ -322,21 +293,9 @@ RREECCOOVVEERRIINNGG DDAATTAA FFRROOMM DDAAMMAAGGEEDD F
322 aged file, and writes a number of files "rec0001file.bz2", 293 aged file, and writes a number of files "rec0001file.bz2",
323 "rec0002file.bz2", etc, containing the extracted blocks. 294 "rec0002file.bz2", etc, containing the extracted blocks.
324 The output filenames are designed so that the use of 295 The output filenames are designed so that the use of
325
326
327
328 5
329
330
331
332
333
334bzip2(1) bzip2(1)
335
336
337 wildcards in subsequent processing -- for example, "bzip2 296 wildcards in subsequent processing -- for example, "bzip2
338 -dc rec*file.bz2 > recovered_data" -- lists the files in 297 -dc rec*file.bz2 > recovered_data" -- lists the files in
339 the "right" order. 298 the correct order.
340 299
341 _b_z_i_p_2_r_e_c_o_v_e_r should be of most use dealing with large .bz2 300 _b_z_i_p_2_r_e_c_o_v_e_r should be of most use dealing with large .bz2
342 files, as these will contain many blocks. It is clearly 301 files, as these will contain many blocks. It is clearly
@@ -351,17 +310,15 @@ PPEERRFFOORRMMAANNCCEE NNOOTTEESS
351 The sorting phase of compression gathers together similar 310 The sorting phase of compression gathers together similar
352 strings in the file. Because of this, files containing 311 strings in the file. Because of this, files containing
353 very long runs of repeated symbols, like "aabaabaabaab 312 very long runs of repeated symbols, like "aabaabaabaab
354 ..." (repeated several hundred times) may compress 313 ..." (repeated several hundred times) may compress more
355 extraordinarily slowly. You can use the -vvvvv option to 314 slowly than normal. Versions 0.9.5 and above fare much
356 monitor progress in great detail, if you want. Decompres- 315 better than previous versions in this respect. The ratio
357 sion speed is unaffected. 316 between worst-case and average-case compression time is in
358 317 the region of 10:1. For previous versions, this figure
359 Such pathological cases seem rare in practice, appearing 318 was more like 100:1. You can use the -vvvv option to mon-
360 mostly in artificially-constructed test files, and in low- 319 itor progress in great detail, if you want.
361 level disk images. It may be inadvisable to use _b_z_i_p_2 to 320
362 compress the latter. If you do get a file which causes 321 Decompression speed is unaffected by these phenomena.
363 severe slowness in compression, try making the block size
364 as small as possible, with flag -1.
365 322
366 _b_z_i_p_2 usually allocates several megabytes of memory to 323 _b_z_i_p_2 usually allocates several megabytes of memory to
367 operate in, and then charges all over it in a fairly ran- 324 operate in, and then charges all over it in a fairly ran-
@@ -376,88 +333,43 @@ PPEERRFFOORRMMAANNCCEE NNOOTTEESS
376 333
377CCAAVVEEAATTSS 334CCAAVVEEAATTSS
378 I/O error messages are not as helpful as they could be. 335 I/O error messages are not as helpful as they could be.
379 _B_z_i_p_2 tries hard to detect I/O errors and exit cleanly, 336 _b_z_i_p_2 tries hard to detect I/O errors and exit cleanly,
380 but the details of what the problem is sometimes seem 337 but the details of what the problem is sometimes seem
381 rather misleading. 338 rather misleading.
382 339
383 This manual page pertains to version 0.9.0 of _b_z_i_p_2_. Com- 340 This manual page pertains to version 0.9.5 of _b_z_i_p_2_. Com-
384 pressed data created by this version is entirely forwards 341 pressed data created by this version is entirely forwards
385 and backwards compatible with the previous public release, 342 and backwards compatible with the previous public
386 version 0.1pl2, but with the following exception: 0.9.0 343 releases, versions 0.1pl2 and 0.9.0, but with the follow-
387 can correctly decompress multiple concatenated compressed 344 ing exception: 0.9.0 and above can correctly decompress
388 files. 0.1pl2 cannot do this; it will stop after decom- 345 multiple concatenated compressed files. 0.1pl2 cannot do
389 pressing just the first file in the stream. 346 this; it will stop after decompressing just the first file
390 347 in the stream.
391 348
392 349 _b_z_i_p_2_r_e_c_o_v_e_r uses 32-bit integers to represent bit posi-
393 350 tions in compressed files, so it cannot handle compressed
394 6 351 files more than 512 megabytes long. This could easily be
395
396
397
398
399
400bzip2(1) bzip2(1)
401
402
403 Wildcard expansion for Windows 95 and NT is flaky.
404
405 _b_z_i_p_2_r_e_c_o_v_e_r uses 32-bit integers to represent bit posi-
406 tions in compressed files, so it cannot handle compressed
407 files more than 512 megabytes long. This could easily be
408 fixed. 352 fixed.
409 353
410 354
411AAUUTTHHOORR 355AAUUTTHHOORR
412 Julian Seward, jseward@acm.org. 356 Julian Seward, jseward@acm.org.
357
413 http://www.muraroa.demon.co.uk 358 http://www.muraroa.demon.co.uk
414 359
415 The ideas embodied in _b_z_i_p_2 are due to (at least) the fol- 360 The ideas embodied in _b_z_i_p_2 are due to (at least) the fol-
416 lowing people: Michael Burrows and David Wheeler (for the 361 lowing people: Michael Burrows and David Wheeler (for the
417 block sorting transformation), David Wheeler (again, for 362 block sorting transformation), David Wheeler (again, for
418 the Huffman coder), Peter Fenwick (for the structured cod- 363 the Huffman coder), Peter Fenwick (for the structured cod-
419 ing model in the original _b_z_i_p_, and many refinements), and 364 ing model in the original _b_z_i_p_, and many refinements), and
420 Alistair Moffat, Radford Neal and Ian Witten (for the 365 Alistair Moffat, Radford Neal and Ian Witten (for the
421 arithmetic coder in the original _b_z_i_p_)_. I am much 366 arithmetic coder in the original _b_z_i_p_)_. I am much
422 indebted for their help, support and advice. See the man- 367 indebted for their help, support and advice. See the man-
423 ual in the source distribution for pointers to sources of 368 ual in the source distribution for pointers to sources of
424 documentation. Christian von Roques encouraged me to look 369 documentation. Christian von Roques encouraged me to look
425 for faster sorting algorithms, so as to speed up compres- 370 for faster sorting algorithms, so as to speed up compres-
426 sion. Bela Lubkin encouraged me to improve the worst-case 371 sion. Bela Lubkin encouraged me to improve the worst-case
427 compression performance. Many people sent patches, helped 372 compression performance. Many people sent patches, helped
428 with portability problems, lent machines, gave advice and 373 with portability problems, lent machines, gave advice and
429 were generally helpful. 374 were generally helpful.
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