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