1 /* vi: set sw=4 ts=4: */
3 * Gzip implementation for busybox
5 * Based on GNU gzip v1.2.4 Copyright (C) 1992-1993 Jean-loup Gailly.
7 * Originally adjusted for busybox by Sven Rudolph <sr1@inf.tu-dresden.de>
8 * based on gzip sources
10 * Adjusted further by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>
11 * to support files as well as stdin/stdout, and to generally behave itself wrt
12 * command line handling.
14 * General cleanup to better adhere to the style guide and make use of standard
15 * busybox functions by Glenn McGrath <bug1@optushome.com.au>
17 * This program is free software; you can redistribute it and/or modify
18 * it under the terms of the GNU General Public License as published by
19 * the Free Software Foundation; either version 2 of the License, or
20 * (at your option) any later version.
22 * This program is distributed in the hope that it will be useful,
23 * but WITHOUT ANY WARRANTY; without even the implied warranty of
24 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
25 * General Public License for more details.
27 * You should have received a copy of the GNU General Public License
28 * along with this program; if not, write to the Free Software
29 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
32 * gzip (GNU zip) -- compress files with zip algorithm and 'compress' interface
33 * Copyright (C) 1992-1993 Jean-loup Gailly
34 * The unzip code was written and put in the public domain by Mark Adler.
35 * Portions of the lzw code are derived from the public domain 'compress'
36 * written by Spencer Thomas, Joe Orost, James Woods, Jim McKie, Steve Davies,
37 * Ken Turkowski, Dave Mack and Peter Jannesen.
39 * See the license_msg below and the file COPYING for the software license.
40 * See the file algorithm.doc for the compression algorithms and file formats.
44 static char *license_msg[] = {
45 " Copyright (C) 1992-1993 Jean-loup Gailly",
46 " This program is free software; you can redistribute it and/or modify",
47 " it under the terms of the GNU General Public License as published by",
48 " the Free Software Foundation; either version 2, or (at your option)",
49 " any later version.",
51 " This program is distributed in the hope that it will be useful,",
52 " but WITHOUT ANY WARRANTY; without even the implied warranty of",
53 " MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the",
54 " GNU General Public License for more details.",
56 " You should have received a copy of the GNU General Public License",
57 " along with this program; if not, write to the Free Software",
58 " Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.",
65 #include <sys/types.h>
78 #define BB_DECLARE_EXTERN
79 #define bb_need_memory_exhausted
80 #define bb_need_name_too_long
83 FILE *in_file, *out_file;
85 static unsigned long *crc_table;
86 static unsigned long crc = 0xffffffffL; /* shift register contents */
88 /* Return codes from gzip */
89 static const int ERROR = 1;
92 * window size--must be a power of two, and
93 * at least 32K for zip's deflate method
95 static const int WSIZE = 0x8000;
97 /* If BMAX needs to be larger than 16, then h and x[] should be ulg. */
98 static const int BMAX = 16; /* maximum bit length of any code (16 for explode) */
99 static const int N_MAX = 288; /* maximum number of codes in any set */
101 static unsigned char *window;
103 static long bytes_out; /* number of output bytes */
104 static unsigned long outcnt; /* bytes in output buffer */
106 unsigned hufts; /* track memory usage */
107 unsigned long bb; /* bit buffer */
108 unsigned bk; /* bits in bit buffer */
110 typedef struct huft_s {
111 unsigned char e; /* number of extra bits or operation */
112 unsigned char b; /* number of bits in this code or subcode */
114 unsigned short n; /* literal, length base, or distance base */
115 struct huft_s *t; /* pointer to next level of table */
119 unsigned short mask_bits[] = {
121 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
122 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
125 //static int error_number = 0;
126 /* ========================================================================
127 * Signal and error handler.
130 static void abort_gzip()
132 error_msg("gzip aborted\n");
136 static void make_crc_table()
138 unsigned long table_entry; /* crc shift register */
139 unsigned long poly = 0; /* polynomial exclusive-or pattern */
140 int i; /* counter for all possible eight bit values */
141 int k; /* byte being shifted into crc apparatus */
143 /* terms of polynomial defining this crc (except x^32): */
144 static int p[] = {0,1,2,4,5,7,8,10,11,12,16,22,23,26};
146 crc_table = (unsigned long *) malloc(256 * sizeof(unsigned long));
148 /* Make exclusive-or pattern from polynomial (0xedb88320) */
149 for (i = 0; i < sizeof(p)/sizeof(int); i++)
150 poly |= 1L << (31 - p[i]);
152 /* Compute and print table of CRC's, five per line */
153 for (i = 0; i < 256; i++) {
155 /* The idea to initialize the register with the byte instead of
156 * zero was stolen from Haruhiko Okumura's ar002
158 for (k = 8; k; k--) {
159 table_entry = table_entry & 1 ? (table_entry >> 1) ^ poly : table_entry >> 1;
161 crc_table[i]=table_entry;
165 /* ===========================================================================
166 * Write the output window window[0..outcnt-1] and update crc and bytes_out.
167 * (Used for the decompressed data only.)
176 for (n = 0; n < outcnt; n++) {
177 crc = crc_table[((int) crc ^ (window[n])) & 0xff] ^ (crc >> 8);
180 if (fwrite(window, 1, outcnt, out_file) != outcnt) {
181 error_msg_and_die("Couldnt write");
183 bytes_out += (unsigned long) outcnt;
188 * Free the malloc'ed tables built by huft_build(), which makes a linked
189 * list of the tables it made, with the links in a dummy first entry of
193 static int huft_free(huft_t *t)
197 /* Go through linked list, freeing from the malloced (t[-1]) address. */
199 while (p != (huft_t *) NULL) {
207 /* Given a list of code lengths and a maximum table size, make a set of
208 * tables to decode that set of codes. Return zero on success, one if
209 * the given code set is incomplete (the tables are still built in this
210 * case), two if the input is invalid (all zero length codes or an
211 * oversubscribed set of lengths), and three if not enough memory.
213 * b: code lengths in bits (all assumed <= BMAX)
214 * n: number of codes (assumed <= N_MAX)
215 * s: number of simple-valued codes (0..s-1)
216 * d: list of base values for non-simple codes
217 * e: list of extra bits for non-simple codes
218 * t: result: starting table
219 * m: maximum lookup bits, returns actual
221 static int huft_build(unsigned int *b, const unsigned int n, const unsigned int s,
222 const unsigned short *d, const unsigned short *e, huft_t **t, int *m)
224 unsigned a; /* counter for codes of length k */
225 unsigned c[BMAX + 1]; /* bit length count table */
226 unsigned f; /* i repeats in table every f entries */
227 int g; /* maximum code length */
228 int h; /* table level */
229 register unsigned i; /* counter, current code */
230 register unsigned j; /* counter */
231 register int k; /* number of bits in current code */
232 int l; /* bits per table (returned in m) */
233 register unsigned *p; /* pointer into c[], b[], or v[] */
234 register huft_t *q; /* points to current table */
235 huft_t r; /* table entry for structure assignment */
236 huft_t *u[BMAX]; /* table stack */
237 unsigned v[N_MAX]; /* values in order of bit length */
238 register int w; /* bits before this table == (l * h) */
239 unsigned x[BMAX + 1]; /* bit offsets, then code stack */
240 unsigned *xp; /* pointer into x */
241 int y; /* number of dummy codes added */
242 unsigned z; /* number of entries in current table */
244 /* Generate counts for each bit length */
245 memset ((void *)(c), 0, sizeof(c));
249 c[*p]++; /* assume all entries <= BMAX */
250 p++; /* Can't combine with above line (Solaris bug) */
252 if (c[0] == n) { /* null input--all zero length codes */
253 *t = (huft_t *) NULL;
258 /* Find minimum and maximum length, bound *m by those */
260 for (j = 1; j <= BMAX; j++)
263 k = j; /* minimum code length */
264 if ((unsigned) l < j)
266 for (i = BMAX; i; i--)
269 g = i; /* maximum code length */
270 if ((unsigned) l > i)
274 /* Adjust last length count to fill out codes, if needed */
275 for (y = 1 << j; j < i; j++, y <<= 1)
277 return 2; /* bad input: more codes than bits */
282 /* Generate starting offsets into the value table for each length */
286 while (--i) { /* note that i == g from above */
290 /* Make a table of values in order of bit lengths */
298 /* Generate the Huffman codes and for each, make the table entries */
299 x[0] = i = 0; /* first Huffman code is zero */
300 p = v; /* grab values in bit order */
301 h = -1; /* no tables yet--level -1 */
302 w = -l; /* bits decoded == (l * h) */
303 u[0] = (huft_t *) NULL; /* just to keep compilers happy */
304 q = (huft_t *) NULL; /* ditto */
307 /* go through the bit lengths (k already is bits in shortest code) */
308 for (; k <= g; k++) {
311 /* here i is the Huffman code of length k bits for value *p */
312 /* make tables up to required level */
315 w += l; /* previous table always l bits */
317 /* compute minimum size table less than or equal to l bits */
318 z = (z = g - w) > (unsigned) l ? l : z; /* upper limit on table size */
319 if ((f = 1 << (j = k - w)) > a + 1) { /* try a k-w bit table *//* too few codes for k-w bit table */
320 f -= a + 1; /* deduct codes from patterns left */
322 while (++j < z) { /* try smaller tables up to z bits */
323 if ((f <<= 1) <= *++xp)
324 break; /* enough codes to use up j bits */
325 f -= *xp; /* else deduct codes from patterns */
328 z = 1 << j; /* table entries for j-bit table */
330 /* allocate and link in new table */
331 if ((q = (huft_t *) xmalloc((z + 1) * sizeof(huft_t))) == NULL) {
335 return 3; /* not enough memory */
337 hufts += z + 1; /* track memory usage */
338 *t = q + 1; /* link to list for huft_free() */
339 *(t = &(q->v.t)) = NULL;
340 u[h] = ++q; /* table starts after link */
342 /* connect to last table, if there is one */
344 x[h] = i; /* save pattern for backing up */
345 r.b = (unsigned char) l; /* bits to dump before this table */
346 r.e = (unsigned char) (16 + j); /* bits in this table */
347 r.v.t = q; /* pointer to this table */
348 j = i >> (w - l); /* (get around Turbo C bug) */
349 u[h - 1][j] = r; /* connect to last table */
353 /* set up table entry in r */
354 r.b = (unsigned char) (k - w);
356 r.e = 99; /* out of values--invalid code */
358 r.e = (unsigned char) (*p < 256 ? 16 : 15); /* 256 is end-of-block code */
359 r.v.n = (unsigned short) (*p); /* simple code is just the value */
360 p++; /* one compiler does not like *p++ */
362 r.e = (unsigned char) e[*p - s]; /* non-simple--look up in lists */
366 /* fill code-like entries with r */
368 for (j = i >> w; j < z; j += f)
371 /* backwards increment the k-bit code i */
372 for (j = 1 << (k - 1); i & j; j >>= 1)
376 /* backup over finished tables */
377 while ((i & ((1 << w) - 1)) != x[h]) {
378 h--; /* don't need to update q */
383 /* Return true (1) if we were given an incomplete table */
384 return y != 0 && g != 1;
388 * inflate (decompress) the codes in a deflated (compressed) block.
389 * Return an error code or zero if it all goes ok.
391 * tl, td: literal/length and distance decoder tables
392 * bl, bd: number of bits decoded by tl[] and td[]
394 static int inflate_codes(huft_t *tl, huft_t *td, int bl, int bd)
396 register unsigned long e; /* table entry flag/number of extra bits */
397 unsigned long n, d; /* length and index for copy */
398 unsigned long w; /* current window position */
399 huft_t *t; /* pointer to table entry */
400 unsigned ml, md; /* masks for bl and bd bits */
401 register unsigned long b; /* bit buffer */
402 register unsigned k; /* number of bits in bit buffer */
404 /* make local copies of globals */
405 b = bb; /* initialize bit buffer */
407 w = outcnt; /* initialize window position */
409 /* inflate the coded data */
410 ml = mask_bits[bl]; /* precompute masks for speed */
412 for (;;) { /* do until end of block */
413 while (k < (unsigned) bl) {
414 b |= ((unsigned long)fgetc(in_file)) << k;
417 if ((e = (t = tl + ((unsigned) b & ml))->e) > 16)
426 b |= ((unsigned long)fgetc(in_file)) << k;
429 } while ((e = (t = t->v.t + ((unsigned) b & mask_bits[e]))->e) > 16);
432 if (e == 16) { /* then it's a literal */
433 window[w++] = (unsigned char) t->v.n;
439 } else { /* it's an EOB or a length */
441 /* exit if end of block */
446 /* get length of block to copy */
448 b |= ((unsigned long)fgetc(in_file)) << k;
451 n = t->v.n + ((unsigned) b & mask_bits[e]);
455 /* decode distance of block to copy */
456 while (k < (unsigned) bd) {
457 b |= ((unsigned long)fgetc(in_file)) << k;
461 if ((e = (t = td + ((unsigned) b & md))->e) > 16)
469 b |= ((unsigned long)fgetc(in_file)) << k;
472 } while ((e = (t = t->v.t + ((unsigned) b & mask_bits[e]))->e) > 16);
476 b |= ((unsigned long)fgetc(in_file)) << k;
479 d = w - t->v.n - ((unsigned) b & mask_bits[e]);
485 n -= (e = (e = WSIZE - ((d &= WSIZE - 1) > w ? d : w)) > n ? n : e);
486 #if !defined(NOMEMCPY) && !defined(DEBUG)
487 if (w - d >= e) { /* (this test assumes unsigned comparison) */
488 memcpy(window + w, window + d, e);
491 } else /* do it slow to avoid memcpy() overlap */
492 #endif /* !NOMEMCPY */
494 window[w++] = window[d++];
505 /* restore the globals from the locals */
506 outcnt = w; /* restore global window pointer */
507 bb = b; /* restore global bit buffer */
515 * decompress an inflated block
518 * GLOBAL VARIABLES: bb, kk,
520 static int inflate_block(int *e)
522 unsigned t; /* block type */
523 register unsigned long b; /* bit buffer */
524 register unsigned k; /* number of bits in bit buffer */
525 static unsigned short cplens[] = { /* Copy lengths for literal codes 257..285 */
526 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
527 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0
529 /* note: see note #13 above about the 258 in this list. */
530 static unsigned short cplext[] = { /* Extra bits for literal codes 257..285 */
531 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
532 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 99, 99
534 static unsigned short cpdist[] = { /* Copy offsets for distance codes 0..29 */
535 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
536 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
537 8193, 12289, 16385, 24577
539 static unsigned short cpdext[] = { /* Extra bits for distance codes */
540 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
541 7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
545 /* make local bit buffer */
549 /* read in last block bit */
551 b |= ((unsigned long)fgetc(in_file)) << k;
558 /* read in block type */
560 b |= ((unsigned long)fgetc(in_file)) << k;
563 t = (unsigned) b & 3;
567 /* restore the global bit buffer */
571 /* inflate that block type */
573 case 0: /* Inflate stored */
575 unsigned long n; /* number of bytes in block */
576 unsigned long w; /* current window position */
577 register unsigned long b_stored; /* bit buffer */
578 register unsigned long k_stored; /* number of bits in bit buffer */
580 /* make local copies of globals */
581 b_stored = bb; /* initialize bit buffer */
583 w = outcnt; /* initialize window position */
585 /* go to byte boundary */
590 /* get the length and its complement */
591 while (k_stored < 16) {
592 b_stored |= ((unsigned long)fgetc(in_file)) << k_stored;
595 n = ((unsigned) b_stored & 0xffff);
598 while (k_stored < 16) {
599 b_stored |= ((unsigned long)fgetc(in_file)) << k_stored;
602 if (n != (unsigned) ((~b_stored) & 0xffff)) {
603 return 1; /* error in compressed data */
608 /* read and output the compressed data */
610 while (k_stored < 8) {
611 b_stored |= ((unsigned long)fgetc(in_file)) << k_stored;
614 window[w++] = (unsigned char) b_stored;
615 if (w == (unsigned long)WSIZE) {
624 /* restore the globals from the locals */
625 outcnt = w; /* restore global window pointer */
626 bb = b_stored; /* restore global bit buffer */
630 case 1: /* Inflate fixed
631 * decompress an inflated type 1 (fixed Huffman codes) block. We should
632 * either replace this with a custom decoder, or at least precompute the
636 int i; /* temporary variable */
637 huft_t *tl; /* literal/length code table */
638 huft_t *td; /* distance code table */
639 int bl; /* lookup bits for tl */
640 int bd; /* lookup bits for td */
641 unsigned int l[288]; /* length list for huft_build */
643 /* set up literal table */
644 for (i = 0; i < 144; i++) {
647 for (; i < 256; i++) {
650 for (; i < 280; i++) {
653 for (; i < 288; i++) { /* make a complete, but wrong code set */
657 if ((i = huft_build(l, 288, 257, cplens, cplext, &tl, &bl)) != 0) {
661 /* set up distance table */
662 for (i = 0; i < 30; i++) { /* make an incomplete code set */
666 if ((i = huft_build(l, 30, 0, cpdist, cpdext, &td, &bd)) > 1) {
671 /* decompress until an end-of-block code */
672 if (inflate_codes(tl, td, bl, bd))
675 /* free the decoding tables, return */
680 case 2: /* Inflate dynamic */
682 /* Tables for deflate from PKZIP's appnote.txt. */
683 static unsigned border[] = { /* Order of the bit length code lengths */
684 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15
686 int dbits = 6; /* bits in base distance lookup table */
687 int lbits = 9; /* bits in base literal/length lookup table */
689 int i; /* temporary variables */
691 unsigned l; /* last length */
692 unsigned m; /* mask for bit lengths table */
693 unsigned n; /* number of lengths to get */
694 huft_t *tl; /* literal/length code table */
695 huft_t *td; /* distance code table */
696 int bl; /* lookup bits for tl */
697 int bd; /* lookup bits for td */
698 unsigned nb; /* number of bit length codes */
699 unsigned nl; /* number of literal/length codes */
700 unsigned nd; /* number of distance codes */
702 unsigned ll[286 + 30]; /* literal/length and distance code lengths */
703 register unsigned long b_dynamic; /* bit buffer */
704 register unsigned k_dynamic; /* number of bits in bit buffer */
706 /* make local bit buffer */
710 /* read in table lengths */
711 while (k_dynamic < 5) {
712 b_dynamic |= ((unsigned long)fgetc(in_file)) << k_dynamic;
715 nl = 257 + ((unsigned) b_dynamic & 0x1f); /* number of literal/length codes */
718 while (k_dynamic < 5) {
719 b_dynamic |= ((unsigned long)fgetc(in_file)) << k_dynamic;
722 nd = 1 + ((unsigned) b_dynamic & 0x1f); /* number of distance codes */
725 while (k_dynamic < 4) {
726 b_dynamic |= ((unsigned long)fgetc(in_file)) << k_dynamic;
729 nb = 4 + ((unsigned) b_dynamic & 0xf); /* number of bit length codes */
732 if (nl > 286 || nd > 30) {
733 return 1; /* bad lengths */
736 /* read in bit-length-code lengths */
737 for (j = 0; j < nb; j++) {
738 while (k_dynamic < 3) {
739 b_dynamic |= ((unsigned long)fgetc(in_file)) << k_dynamic;
742 ll[border[j]] = (unsigned) b_dynamic & 7;
746 for (; j < 19; j++) {
750 /* build decoding table for trees--single level, 7 bit lookup */
752 if ((i = huft_build(ll, 19, 19, NULL, NULL, &tl, &bl)) != 0) {
756 return i; /* incomplete code set */
759 /* read in literal and distance code lengths */
763 while ((unsigned) i < n) {
764 while (k_dynamic < (unsigned) bl) {
765 b_dynamic |= ((unsigned long)fgetc(in_file)) << k_dynamic;
768 j = (td = tl + ((unsigned) b_dynamic & m))->b;
772 if (j < 16) { /* length of code in bits (0..15) */
773 ll[i++] = l = j; /* save last length in l */
775 else if (j == 16) { /* repeat last length 3 to 6 times */
776 while (k_dynamic < 2) {
777 b_dynamic |= ((unsigned long)fgetc(in_file)) << k_dynamic;
780 j = 3 + ((unsigned) b_dynamic & 3);
783 if ((unsigned) i + j > n) {
789 } else if (j == 17) { /* 3 to 10 zero length codes */
790 while (k_dynamic < 3) {
791 b_dynamic |= ((unsigned long)fgetc(in_file)) << k_dynamic;
794 j = 3 + ((unsigned) b_dynamic & 7);
797 if ((unsigned) i + j > n) {
804 } else { /* j == 18: 11 to 138 zero length codes */
805 while (k_dynamic < 7) {
806 b_dynamic |= ((unsigned long)fgetc(in_file)) << k_dynamic;
809 j = 11 + ((unsigned) b_dynamic & 0x7f);
812 if ((unsigned) i + j > n) {
822 /* free decoding table for trees */
825 /* restore the global bit buffer */
829 /* build the decoding tables for literal/length and distance codes */
831 if ((i = huft_build(ll, nl, 257, cplens, cplext, &tl, &bl)) != 0) {
833 error_msg("Incomplete literal tree");
836 return i; /* incomplete code set */
839 if ((i = huft_build(ll + nl, nd, 0, cpdist, cpdext, &td, &bd)) != 0) {
841 error_msg("incomplete distance tree");
845 return i; /* incomplete code set */
848 /* decompress until an end-of-block code */
849 if (inflate_codes(tl, td, bl, bd))
852 /* free the decoding tables, return */
864 * decompress an inflated entry
866 * GLOBAL VARIABLES: outcnt, bk, bb, hufts, inptr
870 int e; /* last block flag */
871 int r; /* result code */
872 unsigned h = 0; /* maximum struct huft's malloc'ed */
874 /* initialize window, bit buffer */
879 /* decompress until the last block */
882 if ((r = inflate_block(&e)) != 0) {
890 /* flush out window */
897 /* ===========================================================================
898 * Unzip in to out. This routine works on both gzip and pkzip files.
900 * IN assertions: the buffer inbuf contains already the beginning of
901 * the compressed data, from offsets inptr to insize-1 included.
902 * The magic header has already been checked. The output buffer is cleared.
903 * in, out: input and output file descriptors
905 extern int unzip(FILE *l_in_file, FILE *l_out_file)
907 const int extra_field = 0x04; /* bit 2 set: extra field present */
908 const int orig_name = 0x08; /* bit 3 set: original file name present */
909 const int comment = 0x10; /* bit 4 set: file comment present */
910 unsigned char buf[8]; /* extended local header */
911 unsigned char flags; /* compression flags */
912 char magic[2]; /* magic header */
914 typedef void (*sig_type) (int);
915 int exit_code=0; /* program exit code */
918 out_file = l_out_file;
920 if (signal(SIGINT, SIG_IGN) != SIG_IGN) {
921 (void) signal(SIGINT, (sig_type) abort_gzip);
924 if (signal(SIGTERM, SIG_IGN) != SIG_IGN) {
925 (void) signal(SIGTERM, (sig_type) abort_gzip);
929 if (signal(SIGHUP, SIG_IGN) != SIG_IGN) {
930 (void) signal(SIGHUP, (sig_type) abort_gzip);
934 /* Allocate all global buffers (for DYN_ALLOC option) */
935 window = xmalloc((size_t)(((2L*WSIZE)+1L)*sizeof(unsigned char)));
939 /* set the buffer size */
940 setvbuf(in_file, NULL, _IOFBF, 0x8000);
942 magic[0] = fgetc(in_file);
943 magic[1] = fgetc(in_file);
945 /* Magic header for gzip files, 1F 8B = \037\213 */
946 if (memcmp(magic, "\037\213", 2) != 0) {
947 error_msg("Invalid gzip magic");
951 method = (int) fgetc(in_file);
953 error_msg("unknown method %d -- get newer version of gzip", method);
958 flags = (unsigned char) fgetc(in_file);
960 /* Ignore time stamp(4), extra flags(1), OS type(1) */
961 fseek(in_file, 6, SEEK_CUR);
963 if ((flags & extra_field) != 0) {
964 fseek(in_file, (size_t) fgetc(in_file) + ((size_t)fgetc(in_file) << 8), SEEK_CUR);
967 /* Discard original name if any */
968 if ((flags & orig_name) != 0) {
969 while (fgetc(in_file) != 0); /* null */
972 /* Discard file comment if any */
973 if ((flags & comment) != 0) {
974 while (fgetc(in_file) != 0); /* null */
978 printf("it failed\n");
979 return(exit_code); /* error message already emitted */
990 error_msg(memory_exhausted);
991 } else if (res != 0) {
992 error_msg("invalid compressed data--format violated");
996 error_msg("internal error, invalid method");
999 /* Get the crc and original length
1000 * crc32 (see algorithm.doc)
1001 * uncompressed input size modulo 2^32
1003 fread(buf, 1, 8, in_file);
1005 /* Validate decompression - crc */
1006 if (((buf[0] | (buf[1] << 8)) |((buf[2] | (buf[3] << 8)) << 16)) != (crc ^ 0xffffffffL)) {
1007 error_msg("invalid compressed data--crc error");
1009 /* Validate decompression - size */
1010 if (((buf[4] | (buf[5] << 8)) |((buf[6] | (buf[7] << 8)) << 16)) != (unsigned long) bytes_out) {
1011 error_msg("invalid compressed data--length error");
1020 extern int gz_open(FILE *compressed_file, int *pid)
1024 if (pipe(unzip_pipe)!=0) {
1025 error_msg("pipe error");
1026 return(EXIT_FAILURE);
1028 if ((*pid = fork()) == -1) {
1029 error_msg("fork failured");
1030 return(EXIT_FAILURE);
1034 close(unzip_pipe[0]);
1035 unzip(compressed_file, fdopen(unzip_pipe[1], "w"));
1036 printf("finished unzipping\n");
1038 fclose(compressed_file);
1039 close(unzip_pipe[1]);
1043 close(unzip_pipe[1]);
1044 return(unzip_pipe[0]);
1047 extern void gz_close(int gunzip_pid)
1049 if (kill(gunzip_pid, SIGTERM) == -1) {
1050 error_msg_and_die("*** Couldnt kill old gunzip process *** aborting");
1053 if (waitpid(gunzip_pid, NULL, 0) == -1) {
1054 printf("Couldnt wait ?");
1060 extern int gunzip_main(int argc, char **argv)
1062 struct stat stat_buf;
1064 char *if_name = NULL;
1065 char *of_name = NULL;
1066 char *delete_file_name = NULL;
1068 const int gunzip_to_stdout = 1;
1069 const int gunzip_from_stdin = 2;
1070 const int gunzip_force = 4;
1071 const int gunzip_test = 8;
1075 int delete_old_file = FALSE;
1077 /* if called as zcat */
1078 if (strcmp(applet_name, "zcat") == 0) {
1083 flags |= (gunzip_force | gunzip_to_stdout);
1085 /* workout flags as regular gunzip */
1086 /* set default flags */
1088 flags |= (gunzip_from_stdin | gunzip_to_stdout);
1090 /* Parse any options */
1091 while ((opt = getopt(argc, argv, "ctfh")) != -1) {
1094 flags |= gunzip_to_stdout;
1097 flags |= gunzip_force;
1100 flags |= gunzip_test;
1104 show_usage(); /* exit's inside usage */
1110 /* Set input filename and number */
1111 if (flags & gunzip_from_stdin) {
1113 if ((flags & gunzip_force) == 0) {
1114 error_msg_and_die("data not written to terminal. Use -f to force it.");
1117 if_name = strdup(argv[optind]);
1118 /* Open input file */
1119 in_file = xfopen(if_name, "r");
1121 /* Get the time stamp on the input file. */
1122 if (stat(if_name, &stat_buf) < 0) {
1123 error_msg_and_die("Couldnt stat file %s",if_name);
1127 /* Set output filename and number */
1128 if (flags & gunzip_to_stdout) {
1130 /* whats the best way to do this with streams ? */
1131 if (isatty(fileno(out_file)) && ((flags & gunzip_force) == 0)) {
1132 error_msg_and_die("data not written to terminal. Use -f to force it.");
1134 } else if (flags & gunzip_test) {
1135 out_file = xfopen("/dev/null", "w"); /* why does test use filenum 2 ? */
1138 int length = strlen(if_name);
1140 delete_old_file = TRUE;
1141 extension = strrchr(if_name, '.');
1142 if (strcmp(extension, ".gz") == 0) {
1144 } else if (strcmp(extension, ".tgz") == 0) {
1147 error_msg_and_die("Invalid extension");
1149 of_name = (char *) xcalloc(sizeof(char), length + 1);
1150 strncpy(of_name, if_name, length);
1152 /* Open output file */
1153 out_file = xfopen(of_name, "w");
1155 /* Set permissions on the file */
1156 chmod(of_name, stat_buf.st_mode);
1159 /* do the decompression, and cleanup */
1160 if (unzip(in_file, out_file) == 0) {
1161 /* Success, remove .gz file */
1162 delete_file_name = if_name;
1164 /* remove failed attempt */
1165 delete_file_name = of_name;
1171 if (delete_old_file == TRUE) {
1172 if (unlink(delete_file_name) < 0) {
1173 error_msg_and_die("Couldnt remove %s", delete_file_name);
1179 return(EXIT_SUCCESS);