[1096] | 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 concantenated. 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 orignal 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 = (char *)"unknown lzw flags set";
|
---|
| 231 | return Z_DATA_ERROR;
|
---|
| 232 | }
|
---|
| 233 | max = flags & 0x1f;
|
---|
| 234 | if (max < 9 || max > 16) {
|
---|
| 235 | strm->msg = (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 = (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 = (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 = (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 = (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 = (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 = (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 = (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 | }
|
---|