|
1
|
/* gun.c -- simple gunzip to give an example of the use of inflateBack() |
|
2
|
* Copyright (C) 2003, 2005, 2008, 2010, 2012 Mark Adler |
|
3
|
* For conditions of distribution and use, see copyright notice in zlib.h |
|
4
|
Version 1.7 12 August 2012 Mark Adler */ |
|
5
|
|
|
6
|
/* Version history: |
|
7
|
1.0 16 Feb 2003 First version for testing of inflateBack() |
|
8
|
1.1 21 Feb 2005 Decompress concatenated gzip streams |
|
9
|
Remove use of "this" variable (C++ keyword) |
|
10
|
Fix return value for in() |
|
11
|
Improve allocation failure checking |
|
12
|
Add typecasting for void * structures |
|
13
|
Add -h option for command version and usage |
|
14
|
Add a bunch of comments |
|
15
|
1.2 20 Mar 2005 Add Unix compress (LZW) decompression |
|
16
|
Copy file attributes from input file to output file |
|
17
|
1.3 12 Jun 2005 Add casts for error messages [Oberhumer] |
|
18
|
1.4 8 Dec 2006 LZW decompression speed improvements |
|
19
|
1.5 9 Feb 2008 Avoid warning in latest version of gcc |
|
20
|
1.6 17 Jan 2010 Avoid signed/unsigned comparison warnings |
|
21
|
1.7 12 Aug 2012 Update for z_const usage in zlib 1.2.8 |
|
22
|
*/ |
|
23
|
|
|
24
|
/* |
|
25
|
gun [ -t ] [ name ... ] |
|
26
|
|
|
27
|
decompresses the data in the named gzip files. If no arguments are given, |
|
28
|
gun will decompress from stdin to stdout. The names must end in .gz, -gz, |
|
29
|
.z, -z, _z, or .Z. The uncompressed data will be written to a file name |
|
30
|
with the suffix stripped. On success, the original file is deleted. On |
|
31
|
failure, the output file is deleted. For most failures, the command will |
|
32
|
continue to process the remaining names on the command line. A memory |
|
33
|
allocation failure will abort the command. If -t is specified, then the |
|
34
|
listed files or stdin will be tested as gzip files for integrity (without |
|
35
|
checking for a proper suffix), no output will be written, and no files |
|
36
|
will be deleted. |
|
37
|
|
|
38
|
Like gzip, gun allows concatenated gzip streams and will decompress them, |
|
39
|
writing all of the uncompressed data to the output. Unlike gzip, gun allows |
|
40
|
an empty file on input, and will produce no error writing an empty output |
|
41
|
file. |
|
42
|
|
|
43
|
gun will also decompress files made by Unix compress, which uses LZW |
|
44
|
compression. These files are automatically detected by virtue of their |
|
45
|
magic header bytes. Since the end of Unix compress stream is marked by the |
|
46
|
end-of-file, they cannot be concatenated. If a Unix compress stream is |
|
47
|
encountered in an input file, it is the last stream in that file. |
|
48
|
|
|
49
|
Like gunzip and uncompress, the file attributes of the original compressed |
|
50
|
file are maintained in the final uncompressed file, to the extent that the |
|
51
|
user permissions allow it. |
|
52
|
|
|
53
|
On my Mac OS X PowerPC G4, gun is almost twice as fast as gunzip (version |
|
54
|
1.2.4) is on the same file, when gun is linked with zlib 1.2.2. Also the |
|
55
|
LZW decompression provided by gun is about twice as fast as the standard |
|
56
|
Unix uncompress command. |
|
57
|
*/ |
|
58
|
|
|
59
|
/* external functions and related types and constants */ |
|
60
|
#include <stdio.h> /* fprintf() */ |
|
61
|
#include <stdlib.h> /* malloc(), free() */ |
|
62
|
#include <string.h> /* strerror(), strcmp(), strlen(), memcpy() */ |
|
63
|
#include <errno.h> /* errno */ |
|
64
|
#include <fcntl.h> /* open() */ |
|
65
|
#include <unistd.h> /* read(), write(), close(), chown(), unlink() */ |
|
66
|
#include <sys/types.h> |
|
67
|
#include <sys/stat.h> /* stat(), chmod() */ |
|
68
|
#include <utime.h> /* utime() */ |
|
69
|
#include "zlib.h" /* inflateBackInit(), inflateBack(), */ |
|
70
|
/* inflateBackEnd(), crc32() */ |
|
71
|
|
|
72
|
/* function declaration */ |
|
73
|
#define local static |
|
74
|
|
|
75
|
/* buffer constants */ |
|
76
|
#define SIZE 32768U /* input and output buffer sizes */ |
|
77
|
#define PIECE 16384 /* limits i/o chunks for 16-bit int case */ |
|
78
|
|
|
79
|
/* structure for infback() to pass to input function in() -- it maintains the |
|
80
|
input file and a buffer of size SIZE */ |
|
81
|
struct ind { |
|
82
|
int infile; |
|
83
|
unsigned char *inbuf; |
|
84
|
}; |
|
85
|
|
|
86
|
/* Load input buffer, assumed to be empty, and return bytes loaded and a |
|
87
|
pointer to them. read() is called until the buffer is full, or until it |
|
88
|
returns end-of-file or error. Return 0 on error. */ |
|
89
|
local unsigned in(void *in_desc, z_const unsigned char **buf) |
|
90
|
{ |
|
91
|
int ret; |
|
92
|
unsigned len; |
|
93
|
unsigned char *next; |
|
94
|
struct ind *me = (struct ind *)in_desc; |
|
95
|
|
|
96
|
next = me->inbuf; |
|
97
|
*buf = next; |
|
98
|
len = 0; |
|
99
|
do { |
|
100
|
ret = PIECE; |
|
101
|
if ((unsigned)ret > SIZE - len) |
|
102
|
ret = (int)(SIZE - len); |
|
103
|
ret = (int)read(me->infile, next, ret); |
|
104
|
if (ret == -1) { |
|
105
|
len = 0; |
|
106
|
break; |
|
107
|
} |
|
108
|
next += ret; |
|
109
|
len += ret; |
|
110
|
} while (ret != 0 && len < SIZE); |
|
111
|
return len; |
|
112
|
} |
|
113
|
|
|
114
|
/* structure for infback() to pass to output function out() -- it maintains the |
|
115
|
output file, a running CRC-32 check on the output and the total number of |
|
116
|
bytes output, both for checking against the gzip trailer. (The length in |
|
117
|
the gzip trailer is stored modulo 2^32, so it's ok if a long is 32 bits and |
|
118
|
the output is greater than 4 GB.) */ |
|
119
|
struct outd { |
|
120
|
int outfile; |
|
121
|
int check; /* true if checking crc and total */ |
|
122
|
unsigned long crc; |
|
123
|
unsigned long total; |
|
124
|
}; |
|
125
|
|
|
126
|
/* Write output buffer and update the CRC-32 and total bytes written. write() |
|
127
|
is called until all of the output is written or an error is encountered. |
|
128
|
On success out() returns 0. For a write failure, out() returns 1. If the |
|
129
|
output file descriptor is -1, then nothing is written. |
|
130
|
*/ |
|
131
|
local int out(void *out_desc, unsigned char *buf, unsigned len) |
|
132
|
{ |
|
133
|
int ret; |
|
134
|
struct outd *me = (struct outd *)out_desc; |
|
135
|
|
|
136
|
if (me->check) { |
|
137
|
me->crc = crc32(me->crc, buf, len); |
|
138
|
me->total += len; |
|
139
|
} |
|
140
|
if (me->outfile != -1) |
|
141
|
do { |
|
142
|
ret = PIECE; |
|
143
|
if ((unsigned)ret > len) |
|
144
|
ret = (int)len; |
|
145
|
ret = (int)write(me->outfile, buf, ret); |
|
146
|
if (ret == -1) |
|
147
|
return 1; |
|
148
|
buf += ret; |
|
149
|
len -= ret; |
|
150
|
} while (len != 0); |
|
151
|
return 0; |
|
152
|
} |
|
153
|
|
|
154
|
/* next input byte macro for use inside lunpipe() and gunpipe() */ |
|
155
|
#define NEXT() (have ? 0 : (have = in(indp, &next)), \ |
|
156
|
last = have ? (have--, (int)(*next++)) : -1) |
|
157
|
|
|
158
|
/* memory for gunpipe() and lunpipe() -- |
|
159
|
the first 256 entries of prefix[] and suffix[] are never used, could |
|
160
|
have offset the index, but it's faster to waste the memory */ |
|
161
|
unsigned char inbuf[SIZE]; /* input buffer */ |
|
162
|
unsigned char outbuf[SIZE]; /* output buffer */ |
|
163
|
unsigned short prefix[65536]; /* index to LZW prefix string */ |
|
164
|
unsigned char suffix[65536]; /* one-character LZW suffix */ |
|
165
|
unsigned char match[65280 + 2]; /* buffer for reversed match or gzip |
|
166
|
32K sliding window */ |
|
167
|
|
|
168
|
/* throw out what's left in the current bits byte buffer (this is a vestigial |
|
169
|
aspect of the compressed data format derived from an implementation that |
|
170
|
made use of a special VAX machine instruction!) */ |
|
171
|
#define FLUSHCODE() \ |
|
172
|
do { \ |
|
173
|
left = 0; \ |
|
174
|
rem = 0; \ |
|
175
|
if (chunk > have) { \ |
|
176
|
chunk -= have; \ |
|
177
|
have = 0; \ |
|
178
|
if (NEXT() == -1) \ |
|
179
|
break; \ |
|
180
|
chunk--; \ |
|
181
|
if (chunk > have) { \ |
|
182
|
chunk = have = 0; \ |
|
183
|
break; \ |
|
184
|
} \ |
|
185
|
} \ |
|
186
|
have -= chunk; \ |
|
187
|
next += chunk; \ |
|
188
|
chunk = 0; \ |
|
189
|
} while (0) |
|
190
|
|
|
191
|
/* Decompress a compress (LZW) file from indp to outfile. The compress magic |
|
192
|
header (two bytes) has already been read and verified. There are have bytes |
|
193
|
of buffered input at next. strm is used for passing error information back |
|
194
|
to gunpipe(). |
|
195
|
|
|
196
|
lunpipe() will return Z_OK on success, Z_BUF_ERROR for an unexpected end of |
|
197
|
file, read error, or write error (a write error indicated by strm->next_in |
|
198
|
not equal to Z_NULL), or Z_DATA_ERROR for invalid input. |
|
199
|
*/ |
|
200
|
local int lunpipe(unsigned have, z_const unsigned char *next, struct ind *indp, |
|
201
|
int outfile, z_stream *strm) |
|
202
|
{ |
|
203
|
int last; /* last byte read by NEXT(), or -1 if EOF */ |
|
204
|
unsigned chunk; /* bytes left in current chunk */ |
|
205
|
int left; /* bits left in rem */ |
|
206
|
unsigned rem; /* unused bits from input */ |
|
207
|
int bits; /* current bits per code */ |
|
208
|
unsigned code; /* code, table traversal index */ |
|
209
|
unsigned mask; /* mask for current bits codes */ |
|
210
|
int max; /* maximum bits per code for this stream */ |
|
211
|
unsigned flags; /* compress flags, then block compress flag */ |
|
212
|
unsigned end; /* last valid entry in prefix/suffix tables */ |
|
213
|
unsigned temp; /* current code */ |
|
214
|
unsigned prev; /* previous code */ |
|
215
|
unsigned final; /* last character written for previous code */ |
|
216
|
unsigned stack; /* next position for reversed string */ |
|
217
|
unsigned outcnt; /* bytes in output buffer */ |
|
218
|
struct outd outd; /* output structure */ |
|
219
|
unsigned char *p; |
|
220
|
|
|
221
|
/* set up output */ |
|
222
|
outd.outfile = outfile; |
|
223
|
outd.check = 0; |
|
224
|
|
|
225
|
/* process remainder of compress header -- a flags byte */ |
|
226
|
flags = NEXT(); |
|
227
|
if (last == -1) |
|
228
|
return Z_BUF_ERROR; |
|
229
|
if (flags & 0x60) { |
|
230
|
strm->msg = (z_const char *)"unknown lzw flags set"; |
|
231
|
return Z_DATA_ERROR; |
|
232
|
} |
|
233
|
max = flags & 0x1f; |
|
234
|
if (max < 9 || max > 16) { |
|
235
|
strm->msg = (z_const char *)"lzw bits out of range"; |
|
236
|
return Z_DATA_ERROR; |
|
237
|
} |
|
238
|
if (max == 9) /* 9 doesn't really mean 9 */ |
|
239
|
max = 10; |
|
240
|
flags &= 0x80; /* true if block compress */ |
|
241
|
|
|
242
|
/* clear table */ |
|
243
|
bits = 9; |
|
244
|
mask = 0x1ff; |
|
245
|
end = flags ? 256 : 255; |
|
246
|
|
|
247
|
/* set up: get first 9-bit code, which is the first decompressed byte, but |
|
248
|
don't create a table entry until the next code */ |
|
249
|
if (NEXT() == -1) /* no compressed data is ok */ |
|
250
|
return Z_OK; |
|
251
|
final = prev = (unsigned)last; /* low 8 bits of code */ |
|
252
|
if (NEXT() == -1) /* missing a bit */ |
|
253
|
return Z_BUF_ERROR; |
|
254
|
if (last & 1) { /* code must be < 256 */ |
|
255
|
strm->msg = (z_const char *)"invalid lzw code"; |
|
256
|
return Z_DATA_ERROR; |
|
257
|
} |
|
258
|
rem = (unsigned)last >> 1; /* remaining 7 bits */ |
|
259
|
left = 7; |
|
260
|
chunk = bits - 2; /* 7 bytes left in this chunk */ |
|
261
|
outbuf[0] = (unsigned char)final; /* write first decompressed byte */ |
|
262
|
outcnt = 1; |
|
263
|
|
|
264
|
/* decode codes */ |
|
265
|
stack = 0; |
|
266
|
for (;;) { |
|
267
|
/* if the table will be full after this, increment the code size */ |
|
268
|
if (end >= mask && bits < max) { |
|
269
|
FLUSHCODE(); |
|
270
|
bits++; |
|
271
|
mask <<= 1; |
|
272
|
mask++; |
|
273
|
} |
|
274
|
|
|
275
|
/* get a code of length bits */ |
|
276
|
if (chunk == 0) /* decrement chunk modulo bits */ |
|
277
|
chunk = bits; |
|
278
|
code = rem; /* low bits of code */ |
|
279
|
if (NEXT() == -1) { /* EOF is end of compressed data */ |
|
280
|
/* write remaining buffered output */ |
|
281
|
if (outcnt && out(&outd, outbuf, outcnt)) { |
|
282
|
strm->next_in = outbuf; /* signal write error */ |
|
283
|
return Z_BUF_ERROR; |
|
284
|
} |
|
285
|
return Z_OK; |
|
286
|
} |
|
287
|
code += (unsigned)last << left; /* middle (or high) bits of code */ |
|
288
|
left += 8; |
|
289
|
chunk--; |
|
290
|
if (bits > left) { /* need more bits */ |
|
291
|
if (NEXT() == -1) /* can't end in middle of code */ |
|
292
|
return Z_BUF_ERROR; |
|
293
|
code += (unsigned)last << left; /* high bits of code */ |
|
294
|
left += 8; |
|
295
|
chunk--; |
|
296
|
} |
|
297
|
code &= mask; /* mask to current code length */ |
|
298
|
left -= bits; /* number of unused bits */ |
|
299
|
rem = (unsigned)last >> (8 - left); /* unused bits from last byte */ |
|
300
|
|
|
301
|
/* process clear code (256) */ |
|
302
|
if (code == 256 && flags) { |
|
303
|
FLUSHCODE(); |
|
304
|
bits = 9; /* initialize bits and mask */ |
|
305
|
mask = 0x1ff; |
|
306
|
end = 255; /* empty table */ |
|
307
|
continue; /* get next code */ |
|
308
|
} |
|
309
|
|
|
310
|
/* special code to reuse last match */ |
|
311
|
temp = code; /* save the current code */ |
|
312
|
if (code > end) { |
|
313
|
/* Be picky on the allowed code here, and make sure that the code |
|
314
|
we drop through (prev) will be a valid index so that random |
|
315
|
input does not cause an exception. The code != end + 1 check is |
|
316
|
empirically derived, and not checked in the original uncompress |
|
317
|
code. If this ever causes a problem, that check could be safely |
|
318
|
removed. Leaving this check in greatly improves gun's ability |
|
319
|
to detect random or corrupted input after a compress header. |
|
320
|
In any case, the prev > end check must be retained. */ |
|
321
|
if (code != end + 1 || prev > end) { |
|
322
|
strm->msg = (z_const char *)"invalid lzw code"; |
|
323
|
return Z_DATA_ERROR; |
|
324
|
} |
|
325
|
match[stack++] = (unsigned char)final; |
|
326
|
code = prev; |
|
327
|
} |
|
328
|
|
|
329
|
/* walk through linked list to generate output in reverse order */ |
|
330
|
p = match + stack; |
|
331
|
while (code >= 256) { |
|
332
|
*p++ = suffix[code]; |
|
333
|
code = prefix[code]; |
|
334
|
} |
|
335
|
stack = p - match; |
|
336
|
match[stack++] = (unsigned char)code; |
|
337
|
final = code; |
|
338
|
|
|
339
|
/* link new table entry */ |
|
340
|
if (end < mask) { |
|
341
|
end++; |
|
342
|
prefix[end] = (unsigned short)prev; |
|
343
|
suffix[end] = (unsigned char)final; |
|
344
|
} |
|
345
|
|
|
346
|
/* set previous code for next iteration */ |
|
347
|
prev = temp; |
|
348
|
|
|
349
|
/* write output in forward order */ |
|
350
|
while (stack > SIZE - outcnt) { |
|
351
|
while (outcnt < SIZE) |
|
352
|
outbuf[outcnt++] = match[--stack]; |
|
353
|
if (out(&outd, outbuf, outcnt)) { |
|
354
|
strm->next_in = outbuf; /* signal write error */ |
|
355
|
return Z_BUF_ERROR; |
|
356
|
} |
|
357
|
outcnt = 0; |
|
358
|
} |
|
359
|
p = match + stack; |
|
360
|
do { |
|
361
|
outbuf[outcnt++] = *--p; |
|
362
|
} while (p > match); |
|
363
|
stack = 0; |
|
364
|
|
|
365
|
/* loop for next code with final and prev as the last match, rem and |
|
366
|
left provide the first 0..7 bits of the next code, end is the last |
|
367
|
valid table entry */ |
|
368
|
} |
|
369
|
} |
|
370
|
|
|
371
|
/* Decompress a gzip file from infile to outfile. strm is assumed to have been |
|
372
|
successfully initialized with inflateBackInit(). The input file may consist |
|
373
|
of a series of gzip streams, in which case all of them will be decompressed |
|
374
|
to the output file. If outfile is -1, then the gzip stream(s) integrity is |
|
375
|
checked and nothing is written. |
|
376
|
|
|
377
|
The return value is a zlib error code: Z_MEM_ERROR if out of memory, |
|
378
|
Z_DATA_ERROR if the header or the compressed data is invalid, or if the |
|
379
|
trailer CRC-32 check or length doesn't match, Z_BUF_ERROR if the input ends |
|
380
|
prematurely or a write error occurs, or Z_ERRNO if junk (not a another gzip |
|
381
|
stream) follows a valid gzip stream. |
|
382
|
*/ |
|
383
|
local int gunpipe(z_stream *strm, int infile, int outfile) |
|
384
|
{ |
|
385
|
int ret, first, last; |
|
386
|
unsigned have, flags, len; |
|
387
|
z_const unsigned char *next = NULL; |
|
388
|
struct ind ind, *indp; |
|
389
|
struct outd outd; |
|
390
|
|
|
391
|
/* setup input buffer */ |
|
392
|
ind.infile = infile; |
|
393
|
ind.inbuf = inbuf; |
|
394
|
indp = &ind; |
|
395
|
|
|
396
|
/* decompress concatenated gzip streams */ |
|
397
|
have = 0; /* no input data read in yet */ |
|
398
|
first = 1; /* looking for first gzip header */ |
|
399
|
strm->next_in = Z_NULL; /* so Z_BUF_ERROR means EOF */ |
|
400
|
for (;;) { |
|
401
|
/* look for the two magic header bytes for a gzip stream */ |
|
402
|
if (NEXT() == -1) { |
|
403
|
ret = Z_OK; |
|
404
|
break; /* empty gzip stream is ok */ |
|
405
|
} |
|
406
|
if (last != 31 || (NEXT() != 139 && last != 157)) { |
|
407
|
strm->msg = (z_const char *)"incorrect header check"; |
|
408
|
ret = first ? Z_DATA_ERROR : Z_ERRNO; |
|
409
|
break; /* not a gzip or compress header */ |
|
410
|
} |
|
411
|
first = 0; /* next non-header is junk */ |
|
412
|
|
|
413
|
/* process a compress (LZW) file -- can't be concatenated after this */ |
|
414
|
if (last == 157) { |
|
415
|
ret = lunpipe(have, next, indp, outfile, strm); |
|
416
|
break; |
|
417
|
} |
|
418
|
|
|
419
|
/* process remainder of gzip header */ |
|
420
|
ret = Z_BUF_ERROR; |
|
421
|
if (NEXT() != 8) { /* only deflate method allowed */ |
|
422
|
if (last == -1) break; |
|
423
|
strm->msg = (z_const char *)"unknown compression method"; |
|
424
|
ret = Z_DATA_ERROR; |
|
425
|
break; |
|
426
|
} |
|
427
|
flags = NEXT(); /* header flags */ |
|
428
|
NEXT(); /* discard mod time, xflgs, os */ |
|
429
|
NEXT(); |
|
430
|
NEXT(); |
|
431
|
NEXT(); |
|
432
|
NEXT(); |
|
433
|
NEXT(); |
|
434
|
if (last == -1) break; |
|
435
|
if (flags & 0xe0) { |
|
436
|
strm->msg = (z_const char *)"unknown header flags set"; |
|
437
|
ret = Z_DATA_ERROR; |
|
438
|
break; |
|
439
|
} |
|
440
|
if (flags & 4) { /* extra field */ |
|
441
|
len = NEXT(); |
|
442
|
len += (unsigned)(NEXT()) << 8; |
|
443
|
if (last == -1) break; |
|
444
|
while (len > have) { |
|
445
|
len -= have; |
|
446
|
have = 0; |
|
447
|
if (NEXT() == -1) break; |
|
448
|
len--; |
|
449
|
} |
|
450
|
if (last == -1) break; |
|
451
|
have -= len; |
|
452
|
next += len; |
|
453
|
} |
|
454
|
if (flags & 8) /* file name */ |
|
455
|
while (NEXT() != 0 && last != -1) |
|
456
|
; |
|
457
|
if (flags & 16) /* comment */ |
|
458
|
while (NEXT() != 0 && last != -1) |
|
459
|
; |
|
460
|
if (flags & 2) { /* header crc */ |
|
461
|
NEXT(); |
|
462
|
NEXT(); |
|
463
|
} |
|
464
|
if (last == -1) break; |
|
465
|
|
|
466
|
/* set up output */ |
|
467
|
outd.outfile = outfile; |
|
468
|
outd.check = 1; |
|
469
|
outd.crc = crc32(0L, Z_NULL, 0); |
|
470
|
outd.total = 0; |
|
471
|
|
|
472
|
/* decompress data to output */ |
|
473
|
strm->next_in = next; |
|
474
|
strm->avail_in = have; |
|
475
|
ret = inflateBack(strm, in, indp, out, &outd); |
|
476
|
if (ret != Z_STREAM_END) break; |
|
477
|
next = strm->next_in; |
|
478
|
have = strm->avail_in; |
|
479
|
strm->next_in = Z_NULL; /* so Z_BUF_ERROR means EOF */ |
|
480
|
|
|
481
|
/* check trailer */ |
|
482
|
ret = Z_BUF_ERROR; |
|
483
|
if (NEXT() != (int)(outd.crc & 0xff) || |
|
484
|
NEXT() != (int)((outd.crc >> 8) & 0xff) || |
|
485
|
NEXT() != (int)((outd.crc >> 16) & 0xff) || |
|
486
|
NEXT() != (int)((outd.crc >> 24) & 0xff)) { |
|
487
|
/* crc error */ |
|
488
|
if (last != -1) { |
|
489
|
strm->msg = (z_const char *)"incorrect data check"; |
|
490
|
ret = Z_DATA_ERROR; |
|
491
|
} |
|
492
|
break; |
|
493
|
} |
|
494
|
if (NEXT() != (int)(outd.total & 0xff) || |
|
495
|
NEXT() != (int)((outd.total >> 8) & 0xff) || |
|
496
|
NEXT() != (int)((outd.total >> 16) & 0xff) || |
|
497
|
NEXT() != (int)((outd.total >> 24) & 0xff)) { |
|
498
|
/* length error */ |
|
499
|
if (last != -1) { |
|
500
|
strm->msg = (z_const char *)"incorrect length check"; |
|
501
|
ret = Z_DATA_ERROR; |
|
502
|
} |
|
503
|
break; |
|
504
|
} |
|
505
|
|
|
506
|
/* go back and look for another gzip stream */ |
|
507
|
} |
|
508
|
|
|
509
|
/* clean up and return */ |
|
510
|
return ret; |
|
511
|
} |
|
512
|
|
|
513
|
/* Copy file attributes, from -> to, as best we can. This is best effort, so |
|
514
|
no errors are reported. The mode bits, including suid, sgid, and the sticky |
|
515
|
bit are copied (if allowed), the owner's user id and group id are copied |
|
516
|
(again if allowed), and the access and modify times are copied. */ |
|
517
|
local void copymeta(char *from, char *to) |
|
518
|
{ |
|
519
|
struct stat was; |
|
520
|
struct utimbuf when; |
|
521
|
|
|
522
|
/* get all of from's Unix meta data, return if not a regular file */ |
|
523
|
if (stat(from, &was) != 0 || (was.st_mode & S_IFMT) != S_IFREG) |
|
524
|
return; |
|
525
|
|
|
526
|
/* set to's mode bits, ignore errors */ |
|
527
|
(void)chmod(to, was.st_mode & 07777); |
|
528
|
|
|
529
|
/* copy owner's user and group, ignore errors */ |
|
530
|
(void)chown(to, was.st_uid, was.st_gid); |
|
531
|
|
|
532
|
/* copy access and modify times, ignore errors */ |
|
533
|
when.actime = was.st_atime; |
|
534
|
when.modtime = was.st_mtime; |
|
535
|
(void)utime(to, &when); |
|
536
|
} |
|
537
|
|
|
538
|
/* Decompress the file inname to the file outnname, of if test is true, just |
|
539
|
decompress without writing and check the gzip trailer for integrity. If |
|
540
|
inname is NULL or an empty string, read from stdin. If outname is NULL or |
|
541
|
an empty string, write to stdout. strm is a pre-initialized inflateBack |
|
542
|
structure. When appropriate, copy the file attributes from inname to |
|
543
|
outname. |
|
544
|
|
|
545
|
gunzip() returns 1 if there is an out-of-memory error or an unexpected |
|
546
|
return code from gunpipe(). Otherwise it returns 0. |
|
547
|
*/ |
|
548
|
local int gunzip(z_stream *strm, char *inname, char *outname, int test) |
|
549
|
{ |
|
550
|
int ret; |
|
551
|
int infile, outfile; |
|
552
|
|
|
553
|
/* open files */ |
|
554
|
if (inname == NULL || *inname == 0) { |
|
555
|
inname = "-"; |
|
556
|
infile = 0; /* stdin */ |
|
557
|
} |
|
558
|
else { |
|
559
|
infile = open(inname, O_RDONLY, 0); |
|
560
|
if (infile == -1) { |
|
561
|
fprintf(stderr, "gun cannot open %s\n", inname); |
|
562
|
return 0; |
|
563
|
} |
|
564
|
} |
|
565
|
if (test) |
|
566
|
outfile = -1; |
|
567
|
else if (outname == NULL || *outname == 0) { |
|
568
|
outname = "-"; |
|
569
|
outfile = 1; /* stdout */ |
|
570
|
} |
|
571
|
else { |
|
572
|
outfile = open(outname, O_CREAT | O_TRUNC | O_WRONLY, 0666); |
|
573
|
if (outfile == -1) { |
|
574
|
close(infile); |
|
575
|
fprintf(stderr, "gun cannot create %s\n", outname); |
|
576
|
return 0; |
|
577
|
} |
|
578
|
} |
|
579
|
errno = 0; |
|
580
|
|
|
581
|
/* decompress */ |
|
582
|
ret = gunpipe(strm, infile, outfile); |
|
583
|
if (outfile > 2) close(outfile); |
|
584
|
if (infile > 2) close(infile); |
|
585
|
|
|
586
|
/* interpret result */ |
|
587
|
switch (ret) { |
|
588
|
case Z_OK: |
|
589
|
case Z_ERRNO: |
|
590
|
if (infile > 2 && outfile > 2) { |
|
591
|
copymeta(inname, outname); /* copy attributes */ |
|
592
|
unlink(inname); |
|
593
|
} |
|
594
|
if (ret == Z_ERRNO) |
|
595
|
fprintf(stderr, "gun warning: trailing garbage ignored in %s\n", |
|
596
|
inname); |
|
597
|
break; |
|
598
|
case Z_DATA_ERROR: |
|
599
|
if (outfile > 2) unlink(outname); |
|
600
|
fprintf(stderr, "gun data error on %s: %s\n", inname, strm->msg); |
|
601
|
break; |
|
602
|
case Z_MEM_ERROR: |
|
603
|
if (outfile > 2) unlink(outname); |
|
604
|
fprintf(stderr, "gun out of memory error--aborting\n"); |
|
605
|
return 1; |
|
606
|
case Z_BUF_ERROR: |
|
607
|
if (outfile > 2) unlink(outname); |
|
608
|
if (strm->next_in != Z_NULL) { |
|
609
|
fprintf(stderr, "gun write error on %s: %s\n", |
|
610
|
outname, strerror(errno)); |
|
611
|
} |
|
612
|
else if (errno) { |
|
613
|
fprintf(stderr, "gun read error on %s: %s\n", |
|
614
|
inname, strerror(errno)); |
|
615
|
} |
|
616
|
else { |
|
617
|
fprintf(stderr, "gun unexpected end of file on %s\n", |
|
618
|
inname); |
|
619
|
} |
|
620
|
break; |
|
621
|
default: |
|
622
|
if (outfile > 2) unlink(outname); |
|
623
|
fprintf(stderr, "gun internal error--aborting\n"); |
|
624
|
return 1; |
|
625
|
} |
|
626
|
return 0; |
|
627
|
} |
|
628
|
|
|
629
|
/* Process the gun command line arguments. See the command syntax near the |
|
630
|
beginning of this source file. */ |
|
631
|
int main(int argc, char **argv) |
|
632
|
{ |
|
633
|
int ret, len, test; |
|
634
|
char *outname; |
|
635
|
unsigned char *window; |
|
636
|
z_stream strm; |
|
637
|
|
|
638
|
/* initialize inflateBack state for repeated use */ |
|
639
|
window = match; /* reuse LZW match buffer */ |
|
640
|
strm.zalloc = Z_NULL; |
|
641
|
strm.zfree = Z_NULL; |
|
642
|
strm.opaque = Z_NULL; |
|
643
|
ret = inflateBackInit(&strm, 15, window); |
|
644
|
if (ret != Z_OK) { |
|
645
|
fprintf(stderr, "gun out of memory error--aborting\n"); |
|
646
|
return 1; |
|
647
|
} |
|
648
|
|
|
649
|
/* decompress each file to the same name with the suffix removed */ |
|
650
|
argc--; |
|
651
|
argv++; |
|
652
|
test = 0; |
|
653
|
if (argc && strcmp(*argv, "-h") == 0) { |
|
654
|
fprintf(stderr, "gun 1.6 (17 Jan 2010)\n"); |
|
655
|
fprintf(stderr, "Copyright (C) 2003-2010 Mark Adler\n"); |
|
656
|
fprintf(stderr, "usage: gun [-t] [file1.gz [file2.Z ...]]\n"); |
|
657
|
return 0; |
|
658
|
} |
|
659
|
if (argc && strcmp(*argv, "-t") == 0) { |
|
660
|
test = 1; |
|
661
|
argc--; |
|
662
|
argv++; |
|
663
|
} |
|
664
|
if (argc) |
|
665
|
do { |
|
666
|
if (test) |
|
667
|
outname = NULL; |
|
668
|
else { |
|
669
|
len = (int)strlen(*argv); |
|
670
|
if (strcmp(*argv + len - 3, ".gz") == 0 || |
|
671
|
strcmp(*argv + len - 3, "-gz") == 0) |
|
672
|
len -= 3; |
|
673
|
else if (strcmp(*argv + len - 2, ".z") == 0 || |
|
674
|
strcmp(*argv + len - 2, "-z") == 0 || |
|
675
|
strcmp(*argv + len - 2, "_z") == 0 || |
|
676
|
strcmp(*argv + len - 2, ".Z") == 0) |
|
677
|
len -= 2; |
|
678
|
else { |
|
679
|
fprintf(stderr, "gun error: no gz type on %s--skipping\n", |
|
680
|
*argv); |
|
681
|
continue; |
|
682
|
} |
|
683
|
outname = malloc(len + 1); |
|
684
|
if (outname == NULL) { |
|
685
|
fprintf(stderr, "gun out of memory error--aborting\n"); |
|
686
|
ret = 1; |
|
687
|
break; |
|
688
|
} |
|
689
|
memcpy(outname, *argv, len); |
|
690
|
outname[len] = 0; |
|
691
|
} |
|
692
|
ret = gunzip(&strm, *argv, outname, test); |
|
693
|
if (outname != NULL) free(outname); |
|
694
|
if (ret) break; |
|
695
|
} while (argv++, --argc); |
|
696
|
else |
|
697
|
ret = gunzip(&strm, NULL, NULL, test); |
|
698
|
|
|
699
|
/* clean up */ |
|
700
|
inflateBackEnd(&strm); |
|
701
|
return ret; |
|
702
|
} |
|
703
|
|