1
/* zcat : stripped version based on gzip sources
2
Sven Rudolph <sr1@inf.tu-dresden.de>
7
static const char gunzip_usage[] =
8
"gunzip [OPTION]... FILE\n\n"
9
"Uncompress FILE (or standard input if FILE is '-').\n\n"
11
"\t-c\tWrite output to standard output\n";
13
/* gzip (GNU zip) -- compress files with zip algorithm and 'compress' interface
14
* Copyright (C) 1992-1993 Jean-loup Gailly
15
* The unzip code was written and put in the public domain by Mark Adler.
16
* Portions of the lzw code are derived from the public domain 'compress'
17
* written by Spencer Thomas, Joe Orost, James Woods, Jim McKie, Steve Davies,
18
* Ken Turkowski, Dave Mack and Peter Jannesen.
20
* See the license_msg below and the file COPYING for the software license.
21
* See the file algorithm.doc for the compression algorithms and file formats.
25
static char *license_msg[] = {
26
" Copyright (C) 1992-1993 Jean-loup Gailly",
27
" This program is free software; you can redistribute it and/or modify",
28
" it under the terms of the GNU General Public License as published by",
29
" the Free Software Foundation; either version 2, or (at your option)",
30
" any later version.",
32
" This program is distributed in the hope that it will be useful,",
33
" but WITHOUT ANY WARRANTY; without even the implied warranty of",
34
" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the",
35
" GNU General Public License for more details.",
37
" You should have received a copy of the GNU General Public License",
38
" along with this program; if not, write to the Free Software",
39
" Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.",
43
/* Compress files with zip algorithm and 'compress' interface.
44
* See usage() and help() functions below for all options.
46
* file.gz: compressed file with same mode, owner, and utimes
47
* or stdout with -c option or if stdin used as input.
48
* If the output file name had to be truncated, the original name is kept
49
* in the compressed file.
50
* On MSDOS, file.tmp -> file.tmz. On VMS, file.tmp -> file.tmp-gz.
52
* Using gz on MSDOS would create too many file name conflicts. For
53
* example, foo.txt -> foo.tgz (.tgz must be reserved as shorthand for
54
* tar.gz). Similarly, foo.dir and foo.doc would both be mapped to foo.dgz.
55
* I also considered 12345678.txt -> 12345txt.gz but this truncates the name
56
* too heavily. There is no ideal solution given the MSDOS 8+3 limitation.
58
* For the meaning of all compilation flags, see comments in Makefile.in.
62
#include <sys/types.h>
67
/* #include "tailor.h" */
69
/* tailor.h -- target dependent definitions
70
* Copyright (C) 1992-1993 Jean-loup Gailly.
71
* This is free software; you can redistribute it and/or modify it under the
72
* terms of the GNU General Public License, see the file COPYING.
75
/* The target dependent definitions should be defined here only.
76
* The target dependent functions should be defined in tailor.c.
81
#define get_char() get_byte()
82
#define put_char(c) put_byte(c)
84
/* #include "gzip.h" */
86
/* gzip.h -- common declarations for all gzip modules
87
* Copyright (C) 1992-1993 Jean-loup Gailly.
88
* This is free software; you can redistribute it and/or modify it under the
89
* terms of the GNU General Public License, see the file COPYING.
92
#if defined(__STDC__) || defined(PROTO)
93
# define OF(args) args
104
/* I don't like nested includes, but the string and io functions are used
108
#if !defined(NO_STRING_H) || defined(STDC_HEADERS)
110
# if !defined(STDC_HEADERS) && !defined(NO_MEMORY_H) && !defined(__GNUC__)
113
# define memzero(s, n) memset ((voidp)(s), 0, (n))
115
# include <strings.h>
116
# define strchr index
117
# define strrchr rindex
118
# define memcpy(d, s, n) bcopy((s), (d), (n))
119
# define memcmp(s1, s2, n) bcmp((s1), (s2), (n))
120
# define memzero(s, n) bzero((s), (n))
124
# define RETSIGTYPE void
129
typedef unsigned char uch;
130
typedef unsigned short ush;
131
typedef unsigned long ulg;
133
/* Return codes from gzip */
138
/* Compression methods (see algorithm.doc) */
141
extern int method; /* compression method */
143
/* To save memory for 16 bit systems, some arrays are overlaid between
144
* the various modules:
145
* deflate: prev+head window d_buf l_buf outbuf
146
* unlzw: tab_prefix tab_suffix stack inbuf outbuf
147
* inflate: window inbuf
148
* unpack: window inbuf prefix_len
149
* unlzh: left+right window c_table inbuf c_len
150
* For compression, input is done in window[]. For decompression, output
151
* is done in window except for unlzw.
156
# define INBUFSIZ 0x2000 /* input buffer size */
158
# define INBUFSIZ 0x8000 /* input buffer size */
161
#define INBUF_EXTRA 64 /* required by unlzw() */
165
# define OUTBUFSIZ 8192 /* output buffer size */
167
# define OUTBUFSIZ 16384 /* output buffer size */
170
#define OUTBUF_EXTRA 2048 /* required by unlzw() */
176
# define DIST_BUFSIZE 0x2000 /* buffer for distances, see trees.c */
178
# define DIST_BUFSIZE 0x8000 /* buffer for distances, see trees.c */
182
/*#define DYN_ALLOC*/
185
# define EXTERN(type, array) extern type * array
186
# define DECLARE(type, array, size) type * array
187
# define ALLOC(type, array, size) { \
188
array = (type*)calloc((size_t)(((size)+1L)/2), 2*sizeof(type)); \
189
if (array == NULL) error("insufficient memory"); \
191
# define FREE(array) {if (array != NULL) free(array), array=NULL;}
193
# define EXTERN(type, array) extern type array[]
194
# define DECLARE(type, array, size) type array[size]
195
# define ALLOC(type, array, size)
199
EXTERN(uch, inbuf); /* input buffer */
200
EXTERN(uch, outbuf); /* output buffer */
201
EXTERN(ush, d_buf); /* buffer for distances, see trees.c */
202
EXTERN(uch, window); /* Sliding window and suffix table (unlzw) */
203
#define tab_suffix window
205
# define tab_prefix prev /* hash link (see deflate.c) */
206
# define head (prev+WSIZE) /* hash head (see deflate.c) */
207
EXTERN(ush, tab_prefix); /* prefix code (see unlzw.c) */
209
# define tab_prefix0 prev
210
# define head tab_prefix1
211
EXTERN(ush, tab_prefix0); /* prefix for even codes */
212
EXTERN(ush, tab_prefix1); /* prefix for odd codes */
215
extern unsigned insize; /* valid bytes in inbuf */
216
extern unsigned inptr; /* index of next byte to be processed in inbuf */
217
extern unsigned outcnt; /* bytes in output buffer */
219
extern long bytes_in; /* number of input bytes */
220
extern long bytes_out; /* number of output bytes */
221
extern long header_bytes;/* number of bytes in gzip header */
223
extern long ifile_size; /* input file size, -1 for devices (debug only) */
225
typedef int file_t; /* Do not use stdio */
226
#define NO_FILE (-1) /* in memory compression */
229
#define GZIP_MAGIC "\037\213" /* Magic header for gzip files, 1F 8B */
232
#define ASCII_FLAG 0x01 /* bit 0 set: file probably ascii text */
233
#define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
234
#define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
235
#define ORIG_NAME 0x08 /* bit 3 set: original file name present */
236
#define COMMENT 0x10 /* bit 4 set: file comment present */
237
#define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */
238
#define RESERVED 0xC0 /* bit 6,7: reserved */
241
# define WSIZE 0x8000 /* window size--must be a power of two, and */
242
#endif /* at least 32K for zip's deflate method */
245
#define MAX_MATCH 258
246
/* The minimum and maximum match lengths */
248
#define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
249
/* Minimum amount of lookahead, except at the end of the input file.
250
* See deflate.c for comments about the MIN_MATCH+1.
253
#define MAX_DIST (WSIZE-MIN_LOOKAHEAD)
254
/* In order to simplify the code, particularly on 16 bit machines, match
255
* distances are limited to MAX_DIST instead of WSIZE.
258
extern int exit_code; /* program exit code */
259
extern int verbose; /* be verbose (-v) */
260
extern int level; /* compression level */
261
extern int test; /* check .z file integrity */
262
extern int save_orig_name; /* set if original name must be saved */
264
#define get_byte() (inptr < insize ? inbuf[inptr++] : fill_inbuf(0))
265
#define try_byte() (inptr < insize ? inbuf[inptr++] : fill_inbuf(1))
267
/* put_byte is used for the compressed output, put_ubyte for the
268
* uncompressed output. However unlzw() uses window for its
269
* suffix table instead of its output buffer, so it does not use put_ubyte
270
* (to be cleaned up).
272
#define put_byte(c) {outbuf[outcnt++]=(uch)(c); if (outcnt==OUTBUFSIZ)\
274
#define put_ubyte(c) {window[outcnt++]=(uch)(c); if (outcnt==WSIZE)\
277
/* Output a 16 bit value, lsb first */
278
#define put_short(w) \
279
{ if (outcnt < OUTBUFSIZ-2) { \
280
outbuf[outcnt++] = (uch) ((w) & 0xff); \
281
outbuf[outcnt++] = (uch) ((ush)(w) >> 8); \
283
put_byte((uch)((w) & 0xff)); \
284
put_byte((uch)((ush)(w) >> 8)); \
288
/* Output a 32 bit value to the bit stream, lsb first */
289
#define put_long(n) { \
290
put_short((n) & 0xffff); \
291
put_short(((ulg)(n)) >> 16); \
294
#define seekable() 0 /* force sequential output */
295
#define translate_eol 0 /* no option -a yet */
297
#define tolow(c) (isupper(c) ? (c)-'A'+'a' : (c)) /* force to lower case */
299
/* Macros for getting two-byte and four-byte header values */
300
#define SH(p) ((ush)(uch)((p)[0]) | ((ush)(uch)((p)[1]) << 8))
301
#define LG(p) ((ulg)(SH(p)) | ((ulg)(SH((p)+2)) << 16))
303
/* Diagnostic functions */
305
# define Assert(cond,msg) {if(!(cond)) error(msg);}
306
# define Trace(x) fprintf x
307
# define Tracev(x) {if (verbose) fprintf x ;}
308
# define Tracevv(x) {if (verbose>1) fprintf x ;}
309
# define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
310
# define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
312
# define Assert(cond,msg)
317
# define Tracecv(c,x)
320
#define WARN(msg) {fprintf msg ; \
321
if (exit_code == OK) exit_code = WARNING;}
324
extern int unzip OF((int in, int out));
327
RETSIGTYPE abort_gzip OF((void));
330
void lm_init OF((int pack_level, ush *flags));
331
ulg deflate OF((void));
334
void ct_init OF((ush *attr, int *method));
335
int ct_tally OF((int dist, int lc));
336
ulg flush_block OF((char *buf, ulg stored_len, int eof));
339
void bi_init OF((file_t zipfile));
340
void send_bits OF((int value, int length));
341
unsigned bi_reverse OF((unsigned value, int length));
342
void bi_windup OF((void));
343
void copy_block OF((char *buf, unsigned len, int header));
344
extern int (*read_buf) OF((char *buf, unsigned size));
347
extern int copy OF((int in, int out));
348
extern ulg updcrc OF((uch *s, unsigned n));
349
extern void clear_bufs OF((void));
350
extern int fill_inbuf OF((int eof_ok));
351
extern void flush_outbuf OF((void));
352
extern void flush_window OF((void));
353
extern void write_buf OF((int fd, voidp buf, unsigned cnt));
355
extern char *basename OF((char *fname));
356
#endif /* not __linux__ */
357
extern void error OF((char *m));
358
extern void warn OF((char *a, char *b));
359
extern void read_error OF((void));
360
extern void write_error OF((void));
361
extern voidp xmalloc OF((unsigned int size));
364
extern int inflate OF((void));
366
/* #include "lzw.h" */
368
/* lzw.h -- define the lzw functions.
369
* Copyright (C) 1992-1993 Jean-loup Gailly.
370
* This is free software; you can redistribute it and/or modify it under the
371
* terms of the GNU General Public License, see the file COPYING.
374
#if !defined(OF) && defined(lint)
381
#define INIT_BITS 9 /* Initial number of bits per code */
383
#define LZW_MAGIC "\037\235" /* Magic header for lzw files, 1F 9D */
385
#define BIT_MASK 0x1f /* Mask for 'number of compression bits' */
386
/* Mask 0x20 is reserved to mean a fourth header byte, and 0x40 is free.
387
* It's a pity that old uncompress does not check bit 0x20. That makes
388
* extension of the format actually undesirable because old compress
389
* would just crash on the new format instead of giving a meaningful
390
* error message. It does check the number of bits, but it's more
391
* helpful to say "unsupported format, get a new version" than
392
* "can only handle 16 bits".
395
#define BLOCK_MODE 0x80
396
/* Block compression: if table is full and compression rate is dropping,
397
* clear the dictionary.
400
#define LZW_RESERVED 0x60 /* reserved bits */
402
#define CLEAR 256 /* flush the dictionary */
403
#define FIRST (CLEAR+1) /* first free entry */
405
extern int maxbits; /* max bits per code for LZW */
406
extern int block_mode; /* block compress mode -C compatible with 2.0 */
408
extern int lzw OF((int in, int out));
409
extern int unlzw OF((int in, int out));
412
/* #include "revision.h" */
414
/* revision.h -- define the version number
415
* Copyright (C) 1992-1993 Jean-loup Gailly.
416
* This is free software; you can redistribute it and/or modify it under the
417
* terms of the GNU General Public License, see the file COPYING.
420
#define VERSION "1.2.4"
422
#define REVDATE "18 Aug 93"
424
/* This version does not support compression into old compress format: */
429
/* #include "getopt.h" */
431
/* Declarations for getopt.
432
Copyright (C) 1989, 1990, 1991, 1992, 1993 Free Software Foundation, Inc.
434
This program is free software; you can redistribute it and/or modify it
435
under the terms of the GNU General Public License as published by the
436
Free Software Foundation; either version 2, or (at your option) any
439
This program is distributed in the hope that it will be useful,
440
but WITHOUT ANY WARRANTY; without even the implied warranty of
441
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
442
GNU General Public License for more details.
444
You should have received a copy of the GNU General Public License
445
along with this program; if not, write to the Free Software
446
Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
455
/* For communication from `getopt' to the caller.
456
When `getopt' finds an option that takes an argument,
457
the argument value is returned here.
458
Also, when `ordering' is RETURN_IN_ORDER,
459
each non-option ARGV-element is returned here. */
463
/* Index in ARGV of the next element to be scanned.
464
This is used for communication to and from the caller
465
and for communication between successive calls to `getopt'.
467
On entry to `getopt', zero means this is the first call; initialize.
469
When `getopt' returns EOF, this is the index of the first of the
470
non-option elements that the caller should itself scan.
472
Otherwise, `optind' communicates from one call to the next
473
how much of ARGV has been scanned so far. */
477
/* Callers store zero here to inhibit the error message `getopt' prints
478
for unrecognized options. */
482
/* Set to an option character which was unrecognized. */
486
/* Describe the long-named options requested by the application.
487
The LONG_OPTIONS argument to getopt_long or getopt_long_only is a vector
488
of `struct option' terminated by an element containing a name which is
491
The field `has_arg' is:
492
no_argument (or 0) if the option does not take an argument,
493
required_argument (or 1) if the option requires an argument,
494
optional_argument (or 2) if the option takes an optional argument.
496
If the field `flag' is not NULL, it points to a variable that is set
497
to the value given in the field `val' when the option is found, but
498
left unchanged if the option is not found.
500
To have a long-named option do something other than set an `int' to
501
a compiled-in constant, such as set a value from `optarg', set the
502
option's `flag' field to zero and its `val' field to a nonzero
503
value (the equivalent single-letter option character, if there is
504
one). For long options that have a zero `flag' field, `getopt'
505
returns the contents of the `val' field. */
514
/* has_arg can't be an enum because some compilers complain about
515
type mismatches in all the code that assumes it is an int. */
521
/* Names for the values of the `has_arg' field of `struct option'. */
523
#define no_argument 0
524
#define required_argument 1
525
#define optional_argument 2
527
#if __STDC__ || defined(PROTO)
528
#if defined(__GNU_LIBRARY__)
529
/* Many other libraries have conflicting prototypes for getopt, with
530
differences in the consts, in stdlib.h. To avoid compilation
531
errors, only prototype getopt for the GNU C library. */
532
extern int getopt (int argc, char *const *argv, const char *shortopts);
533
#endif /* not __GNU_LIBRARY__ */
534
extern int getopt_long (int argc, char *const *argv, const char *shortopts,
535
const struct option *longopts, int *longind);
536
extern int getopt_long_only (int argc, char *const *argv,
537
const char *shortopts,
538
const struct option *longopts, int *longind);
540
/* Internal only. Users should not call this directly. */
541
extern int _getopt_internal (int argc, char *const *argv,
542
const char *shortopts,
543
const struct option *longopts, int *longind,
545
#else /* not __STDC__ */
546
extern int getopt ();
547
extern int getopt_long ();
548
extern int getopt_long_only ();
550
extern int _getopt_internal ();
551
#endif /* not __STDC__ */
557
#endif /* _GETOPT_H */
568
typedef struct dirent dir_type;
569
# define NLENGTH(dirent) ((int)strlen((dirent)->d_name))
570
# define DIR_OPT "DIRENT"
572
# define NLENGTH(dirent) ((dirent)->d_namlen)
574
# include <sys/dir.h>
575
typedef struct direct dir_type;
576
# define DIR_OPT "SYSDIR"
579
# include <sys/ndir.h>
580
typedef struct direct dir_type;
581
# define DIR_OPT "SYSNDIR"
585
typedef struct direct dir_type;
586
# define DIR_OPT "NDIR"
589
# define DIR_OPT "NO_DIR"
595
#if !defined(S_ISDIR) && defined(S_IFDIR)
596
# define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
598
#if !defined(S_ISREG) && defined(S_IFREG)
599
# define S_ISREG(m) (((m) & S_IFMT) == S_IFREG)
602
typedef RETSIGTYPE (*sig_type) OF((int));
605
# define O_BINARY 0 /* creation mode for open() */
609
/* Pure BSD system? */
610
# include <sys/file.h>
612
# define O_CREAT FCREAT
615
# define O_EXCL FEXCL
620
# define S_IRUSR 0400
623
# define S_IWUSR 0200
625
#define RW_USER (S_IRUSR | S_IWUSR) /* creation mode for open() */
628
# define MAX_PATH_LEN 1024 /* max pathname length */
637
off_t lseek OF((int fd, off_t offset, int whence));
643
DECLARE(uch, inbuf, INBUFSIZ +INBUF_EXTRA);
644
DECLARE(uch, outbuf, OUTBUFSIZ+OUTBUF_EXTRA);
645
DECLARE(ush, d_buf, DIST_BUFSIZE);
646
DECLARE(uch, window, 2L*WSIZE);
648
DECLARE(ush, tab_prefix, 1L<<BITS);
650
DECLARE(ush, tab_prefix0, 1L<<(BITS-1));
651
DECLARE(ush, tab_prefix1, 1L<<(BITS-1));
654
/* local variables */
656
int force = 0; /* don't ask questions, compress links (-f) */
657
int foreground; /* set if program run in foreground */
658
int maxbits = BITS; /* max bits per code for LZW */
659
int method = DEFLATED;/* compression method */
660
int exit_code = OK; /* program exit code */
661
int last_member; /* set for .zip and .Z files */
662
int part_nb; /* number of parts in .gz file */
663
long ifile_size; /* input file size, -1 for devices (debug only) */
665
long bytes_in; /* number of input bytes */
666
long bytes_out; /* number of output bytes */
667
long total_in = 0; /* input bytes for all files */
668
long total_out = 0; /* output bytes for all files */
669
struct stat istat; /* status for input file */
670
int ifd; /* input file descriptor */
671
int ofd; /* output file descriptor */
672
unsigned insize; /* valid bytes in inbuf */
673
unsigned inptr; /* index of next byte to be processed in inbuf */
674
unsigned outcnt; /* bytes in output buffer */
676
long header_bytes; /* number of bytes in gzip header */
678
/* local functions */
680
local int get_method OF((int in));
681
local void do_exit(int exitcode) __attribute__ ((noreturn));
683
#define strequ(s1, s2) (strcmp((s1),(s2)) == 0)
685
/* ======================================================================== */
686
int gunzip_main (int argc, char** argv)
688
int file_count; /* number of files to precess */
697
char ifname[MAX_PATH_LEN]; /* input file name */
698
char ofname[MAX_PATH_LEN]; /* output file name */
703
if (strcmp(*argv, "zcat")==0)
706
/* Parse any options */
707
while (--argc > 0 && **(++argv) == '-') {
708
if (*((*argv)+1) == '\0') {
712
while (*(++(*argv))) {
723
foreground = signal(SIGINT, SIG_IGN) != SIG_IGN;
725
(void) signal (SIGINT, (sig_type)abort_gzip);
728
if (signal(SIGTERM, SIG_IGN) != SIG_IGN) {
729
(void) signal(SIGTERM, (sig_type)abort_gzip);
733
if (signal(SIGHUP, SIG_IGN) != SIG_IGN) {
734
(void) signal(SIGHUP, (sig_type)abort_gzip);
738
file_count = argc - optind;
740
/* Allocate all global buffers (for DYN_ALLOC option) */
741
ALLOC(uch, inbuf, INBUFSIZ +INBUF_EXTRA);
742
ALLOC(uch, outbuf, OUTBUFSIZ+OUTBUF_EXTRA);
743
ALLOC(ush, d_buf, DIST_BUFSIZE);
744
ALLOC(uch, window, 2L*WSIZE);
746
ALLOC(ush, tab_prefix, 1L<<BITS);
748
ALLOC(ush, tab_prefix0, 1L<<(BITS-1));
749
ALLOC(ush, tab_prefix1, 1L<<(BITS-1));
753
strcpy(ofname, "stdin");
755
inFileNum=fileno(stdin);
756
ifile_size = -1L; /* convention for unknown size */
758
/* Open up the input file */
761
strncpy(ifname, *argv, MAX_PATH_LEN);
763
/* Open input fille */
764
inFileNum=open( ifname, O_RDONLY);
769
/* Get the time stamp on the input file. */
770
result = stat(ifname, &statBuf);
775
ifile_size = statBuf.st_size;
779
/* And get to work */
780
strcpy(ofname, "stdout");
781
outFileNum=fileno(stdout);
783
clear_bufs(); /* clear input and output buffers */
786
/* Actually do the compression/decompression. */
787
unzip(inFileNum, outFileNum);
792
/* And get to work */
793
strncpy(ofname, ifname, MAX_PATH_LEN-4);
794
pos=strstr(ofname, ".gz");
799
pos=strstr(ofname, ".tgz");
802
strcat( pos, ".tar");
807
/* Open output fille */
808
outFileNum=open( ofname, O_RDWR|O_CREAT|O_EXCL|O_NOFOLLOW);
809
if (outFileNum < 0) {
813
/* Set permissions on the file */
814
fchmod(outFileNum, statBuf.st_mode);
816
clear_bufs(); /* clear input and output buffers */
819
/* Actually do the compression/decompression. */
820
result=unzip(inFileNum, outFileNum);
824
/* Delete the original file */
830
if (delInputFile == 1 && unlink (delFileName) < 0) {
831
perror (delFileName);
839
/* ========================================================================
840
* Check the magic number of the input file and update ofname if an
841
* original name was given and to_stdout is not set.
842
* Return the compression method, -1 for error, -2 for warning.
843
* Set inptr to the offset of the next byte to be processed.
844
* Updates time_stamp if there is one and --no-time is not used.
845
* This function may be called repeatedly for an input file consisting
846
* of several contiguous gzip'ed members.
847
* IN assertions: there is at least one remaining compressed member.
848
* If the member is a zip file, it must be the only one.
850
local int get_method(in)
851
int in; /* input file descriptor */
853
uch flags; /* compression flags */
854
char magic[2]; /* magic header */
856
/* If --force and --stdout, zcat == cat, so do not complain about
857
* premature end of file: use try_byte instead of get_byte.
860
magic[0] = (char)try_byte();
861
magic[1] = (char)try_byte();
862
/* If try_byte returned EOF, magic[1] == 0xff */
864
magic[0] = (char)get_byte();
865
magic[1] = (char)get_byte();
867
method = -1; /* unknown yet */
868
part_nb++; /* number of parts in gzip file */
870
last_member = RECORD_IO;
871
/* assume multiple members in gzip file except for record oriented I/O */
873
if (memcmp(magic, GZIP_MAGIC, 2) == 0) {
875
method = (int)get_byte();
876
if (method != DEFLATED) {
878
"unknown method %d -- get newer version of gzip\n",
883
flags = (uch)get_byte();
885
(ulg)get_byte(); /* Ignore time stamp */
890
(void)get_byte(); /* Ignore extra flags for the moment */
891
(void)get_byte(); /* Ignore OS type for the moment */
893
if ((flags & EXTRA_FIELD) != 0) {
894
unsigned len = (unsigned)get_byte();
895
len |= ((unsigned)get_byte())<<8;
897
while (len--) (void)get_byte();
900
/* Discard original name if any */
901
if ((flags & ORIG_NAME) != 0) {
902
while (get_char() != 0) /* null */ ;
905
/* Discard file comment if any */
906
if ((flags & COMMENT) != 0) {
907
while (get_char() != 0) /* null */ ;
910
header_bytes = inptr + 2*sizeof(long); /* include crc and size */
915
if (method >= 0) return method;
918
fprintf(stderr, "\nnot in gzip format\n");
922
WARN((stderr, "\ndecompression OK, trailing garbage ignored\n"));
928
/* ========================================================================
929
* Free all dynamically allocated variables and exit with the given code.
931
local void do_exit(exitcode)
934
static int in_exit = 0;
936
if (in_exit) exit(exitcode);
951
/* ========================================================================
952
* Signal and error handler.
954
RETSIGTYPE abort_gzip()
958
/* unzip.c -- decompress files in gzip or pkzip format.
959
* Copyright (C) 1992-1993 Jean-loup Gailly
960
* This is free software; you can redistribute it and/or modify it under the
961
* terms of the GNU General Public License, see the file COPYING.
963
* The code in this file is derived from the file funzip.c written
964
* and put in the public domain by Mark Adler.
968
This version can extract files in gzip or pkzip format.
969
For the latter, only the first entry is extracted, and it has to be
970
either deflated or stored.
973
/* #include "crypt.h" */
975
/* crypt.h (dummy version) -- do not perform encryption
976
* Hardly worth copyrighting :-)
980
# undef CRYPT /* dummy version */
983
#define RAND_HEAD_LEN 12 /* length of encryption random header */
988
/* PKZIP header definitions */
989
#define LOCSIG 0x04034b50L /* four-byte lead-in (lsb first) */
990
#define LOCFLG 6 /* offset of bit flag */
991
#define CRPFLG 1 /* bit for encrypted entry */
992
#define EXTFLG 8 /* bit for extended local header */
993
#define LOCHOW 8 /* offset of compression method */
994
#define LOCTIM 10 /* file mod time (for decryption) */
995
#define LOCCRC 14 /* offset of crc */
996
#define LOCSIZ 18 /* offset of compressed size */
997
#define LOCLEN 22 /* offset of uncompressed length */
998
#define LOCFIL 26 /* offset of file name field length */
999
#define LOCEXT 28 /* offset of extra field length */
1000
#define LOCHDR 30 /* size of local header, including sig */
1001
#define EXTHDR 16 /* size of extended local header, inc sig */
1006
char *key; /* not used--needed to link crypt.c */
1007
int pkzip = 0; /* set for a pkzip file */
1008
int ext_header = 0; /* set if extended local header */
1010
/* ===========================================================================
1011
* Unzip in to out. This routine works on both gzip and pkzip files.
1013
* IN assertions: the buffer inbuf contains already the beginning of
1014
* the compressed data, from offsets inptr to insize-1 included.
1015
* The magic header has already been checked. The output buffer is cleared.
1018
int in, out; /* input and output file descriptors */
1020
ulg orig_crc = 0; /* original crc */
1021
ulg orig_len = 0; /* original uncompressed length */
1023
uch buf[EXTHDR]; /* extended local header */
1027
method = get_method(ifd);
1029
do_exit(exit_code); /* error message already emitted */
1032
updcrc(NULL, 0); /* initialize crc */
1034
if (pkzip && !ext_header) { /* crc and length at the end otherwise */
1035
orig_crc = LG(inbuf + LOCCRC);
1036
orig_len = LG(inbuf + LOCLEN);
1040
if (method == DEFLATED) {
1042
int res = inflate();
1045
error("out of memory");
1046
} else if (res != 0) {
1047
error("invalid compressed data--format violated");
1051
error("internal error, invalid method");
1054
/* Get the crc and original length */
1056
/* crc32 (see algorithm.doc)
1057
* uncompressed input size modulo 2^32
1059
for (n = 0; n < 8; n++) {
1060
buf[n] = (uch)get_byte(); /* may cause an error if EOF */
1063
orig_len = LG(buf+4);
1065
} else if (ext_header) { /* If extended header, check it */
1066
/* signature - 4bytes: 0x50 0x4b 0x07 0x08
1068
* compressed size 4-bytes
1069
* uncompressed size 4-bytes
1071
for (n = 0; n < EXTHDR; n++) {
1072
buf[n] = (uch)get_byte(); /* may cause an error if EOF */
1074
orig_crc = LG(buf+4);
1075
orig_len = LG(buf+12);
1078
/* Validate decompression */
1079
if (orig_crc != updcrc(outbuf, 0)) {
1080
error("invalid compressed data--crc error");
1082
if (orig_len != (ulg)bytes_out) {
1083
error("invalid compressed data--length error");
1086
/* Check if there are more entries in a pkzip file */
1087
if (pkzip && inptr + 4 < insize && LG(inbuf+inptr) == LOCSIG) {
1088
WARN((stderr,"has more than one entry--rest ignored\n"));
1090
ext_header = pkzip = 0; /* for next file */
1093
/* util.c -- utility functions for gzip support
1094
* Copyright (C) 1992-1993 Jean-loup Gailly
1095
* This is free software; you can redistribute it and/or modify it under the
1096
* terms of the GNU General Public License, see the file COPYING.
1101
#include <sys/types.h>
1103
#ifdef HAVE_UNISTD_H
1104
# include <unistd.h>
1110
#if defined(STDC_HEADERS) || !defined(NO_STDLIB_H)
1111
# include <stdlib.h>
1116
static const ulg crc_32_tab[]; /* crc table, defined below */
1118
/* ===========================================================================
1119
* Run a set of bytes through the crc shift register. If s is a NULL
1120
* pointer, then initialize the crc shift register contents instead.
1121
* Return the current crc in either case.
1124
uch *s; /* pointer to bytes to pump through */
1125
unsigned n; /* number of bytes in s[] */
1127
register ulg c; /* temporary variable */
1129
static ulg crc = (ulg)0xffffffffL; /* shift register contents */
1136
c = crc_32_tab[((int)c ^ (*s++)) & 0xff] ^ (c >> 8);
1140
return c ^ 0xffffffffL; /* (instead of ~c for 64-bit machines) */
1143
/* ===========================================================================
1144
* Clear input and output buffers
1150
bytes_in = bytes_out = 0L;
1153
/* ===========================================================================
1154
* Fill the input buffer. This is called only when the buffer is empty.
1156
int fill_inbuf(eof_ok)
1157
int eof_ok; /* set if EOF acceptable as a result */
1161
/* Read as much as possible */
1165
len = read(ifd, (char*)inbuf+insize, INBUFSIZ-insize);
1166
if (len == 0 || len == EOF) break;
1168
} while (insize < INBUFSIZ);
1171
if (eof_ok) return EOF;
1174
bytes_in += (ulg)insize;
1179
/* ===========================================================================
1180
* Write the output buffer outbuf[0..outcnt-1] and update bytes_out.
1181
* (used for the compressed data only)
1185
if (outcnt == 0) return;
1187
write_buf(ofd, (char *)outbuf, outcnt);
1188
bytes_out += (ulg)outcnt;
1192
/* ===========================================================================
1193
* Write the output window window[0..outcnt-1] and update crc and bytes_out.
1194
* (Used for the decompressed data only.)
1198
if (outcnt == 0) return;
1199
updcrc(window, outcnt);
1201
write_buf(ofd, (char *)window, outcnt);
1203
bytes_out += (ulg)outcnt;
1207
/* ===========================================================================
1208
* Does the same as write(), but also handles partial pipe writes and checks
1211
void write_buf(fd, buf, cnt)
1218
while ((n = write(fd, buf, cnt)) != cnt) {
1219
if (n == (unsigned)(-1)) {
1223
buf = (voidp)((char*)buf+n);
1227
#if defined(NO_STRING_H) && !defined(STDC_HEADERS)
1229
/* Provide missing strspn and strcspn functions. */
1235
int strspn OF((const char *s, const char *accept));
1236
int strcspn OF((const char *s, const char *reject));
1238
/* ========================================================================
1239
* Return the length of the maximum initial segment
1240
* of s which contains only characters in accept.
1242
int strspn(s, accept)
1246
register const char *p;
1247
register const char *a;
1248
register int count = 0;
1250
for (p = s; *p != '\0'; ++p) {
1251
for (a = accept; *a != '\0'; ++a) {
1252
if (*p == *a) break;
1254
if (*a == '\0') return count;
1260
/* ========================================================================
1261
* Return the length of the maximum inital segment of s
1262
* which contains no characters from reject.
1264
int strcspn(s, reject)
1268
register int count = 0;
1270
while (*s != '\0') {
1271
if (strchr(reject, *s++) != NULL) return count;
1277
#endif /* NO_STRING_H */
1280
/* ========================================================================
1286
fprintf(stderr, "\n%s\n", m);
1291
char *a, *b; /* message strings juxtaposed in output */
1293
WARN((stderr, "warning: %s%s\n", a, b));
1298
fprintf(stderr, "\n");
1302
fprintf(stderr, "unexpected end of file\n");
1309
fprintf(stderr, "\n");
1315
/* ========================================================================
1316
* Semi-safe malloc -- never returns NULL.
1318
voidp xmalloc (size)
1321
voidp cp = (voidp)malloc (size);
1323
if (cp == NULL) error("out of memory");
1327
/* ========================================================================
1328
* Table of CRC-32's of all single-byte values (made by makecrc.c)
1330
static const ulg crc_32_tab[] = {
1331
0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
1332
0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
1333
0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L,
1334
0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL,
1335
0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L,
1336
0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L,
1337
0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L,
1338
0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL,
1339
0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L,
1340
0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL,
1341
0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L,
1342
0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L,
1343
0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L,
1344
0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL,
1345
0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL,
1346
0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L,
1347
0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL,
1348
0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L,
1349
0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L,
1350
0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L,
1351
0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL,
1352
0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L,
1353
0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L,
1354
0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL,
1355
0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L,
1356
0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L,
1357
0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L,
1358
0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L,
1359
0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L,
1360
0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL,
1361
0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL,
1362
0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L,
1363
0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L,
1364
0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL,
1365
0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL,
1366
0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L,
1367
0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL,
1368
0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L,
1369
0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL,
1370
0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L,
1371
0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL,
1372
0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L,
1373
0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L,
1374
0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL,
1375
0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L,
1376
0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L,
1377
0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L,
1378
0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L,
1379
0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L,
1380
0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L,
1381
0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL,
1384
/* inflate.c -- Not copyrighted 1992 by Mark Adler
1385
version c10p1, 10 January 1993 */
1387
/* You can do whatever you like with this source file, though I would
1388
prefer that if you modify it and redistribute it that you include
1389
comments to that effect with your name and the date. Thank you.
1390
[The history has been moved to the file ChangeLog.]
1394
Inflate deflated (PKZIP's method 8 compressed) data. The compression
1395
method searches for as much of the current string of bytes (up to a
1396
length of 258) in the previous 32K bytes. If it doesn't find any
1397
matches (of at least length 3), it codes the next byte. Otherwise, it
1398
codes the length of the matched string and its distance backwards from
1399
the current position. There is a single Huffman code that codes both
1400
single bytes (called "literals") and match lengths. A second Huffman
1401
code codes the distance information, which follows a length code. Each
1402
length or distance code actually represents a base value and a number
1403
of "extra" (sometimes zero) bits to get to add to the base value. At
1404
the end of each deflated block is a special end-of-block (EOB) literal/
1405
length code. The decoding process is basically: get a literal/length
1406
code; if EOB then done; if a literal, emit the decoded byte; if a
1407
length then get the distance and emit the referred-to bytes from the
1408
sliding window of previously emitted data.
1410
There are (currently) three kinds of inflate blocks: stored, fixed, and
1411
dynamic. The compressor deals with some chunk of data at a time, and
1412
decides which method to use on a chunk-by-chunk basis. A chunk might
1413
typically be 32K or 64K. If the chunk is uncompressible, then the
1414
"stored" method is used. In this case, the bytes are simply stored as
1415
is, eight bits per byte, with none of the above coding. The bytes are
1416
preceded by a count, since there is no longer an EOB code.
1418
If the data is compressible, then either the fixed or dynamic methods
1419
are used. In the dynamic method, the compressed data is preceded by
1420
an encoding of the literal/length and distance Huffman codes that are
1421
to be used to decode this block. The representation is itself Huffman
1422
coded, and so is preceded by a description of that code. These code
1423
descriptions take up a little space, and so for small blocks, there is
1424
a predefined set of codes, called the fixed codes. The fixed method is
1425
used if the block codes up smaller that way (usually for quite small
1426
chunks), otherwise the dynamic method is used. In the latter case, the
1427
codes are customized to the probabilities in the current block, and so
1428
can code it much better than the pre-determined fixed codes.
1430
The Huffman codes themselves are decoded using a mutli-level table
1431
lookup, in order to maximize the speed of decoding plus the speed of
1432
building the decoding tables. See the comments below that precede the
1433
lbits and dbits tuning parameters.
1438
Notes beyond the 1.93a appnote.txt:
1440
1. Distance pointers never point before the beginning of the output
1442
2. Distance pointers can point back across blocks, up to 32k away.
1443
3. There is an implied maximum of 7 bits for the bit length table and
1444
15 bits for the actual data.
1445
4. If only one code exists, then it is encoded using one bit. (Zero
1446
would be more efficient, but perhaps a little confusing.) If two
1447
codes exist, they are coded using one bit each (0 and 1).
1448
5. There is no way of sending zero distance codes--a dummy must be
1449
sent if there are none. (History: a pre 2.0 version of PKZIP would
1450
store blocks with no distance codes, but this was discovered to be
1451
too harsh a criterion.) Valid only for 1.93a. 2.04c does allow
1452
zero distance codes, which is sent as one code of zero bits in
1454
6. There are up to 286 literal/length codes. Code 256 represents the
1455
end-of-block. Note however that the static length tree defines
1456
288 codes just to fill out the Huffman codes. Codes 286 and 287
1457
cannot be used though, since there is no length base or extra bits
1458
defined for them. Similarly, there are up to 30 distance codes.
1459
However, static trees define 32 codes (all 5 bits) to fill out the
1460
Huffman codes, but the last two had better not show up in the data.
1461
7. Unzip can check dynamic Huffman blocks for complete code sets.
1462
The exception is that a single code would not be complete (see #4).
1463
8. The five bits following the block type is really the number of
1464
literal codes sent minus 257.
1465
9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits
1466
(1+6+6). Therefore, to output three times the length, you output
1467
three codes (1+1+1), whereas to output four times the same length,
1468
you only need two codes (1+3). Hmm.
1469
10. In the tree reconstruction algorithm, Code = Code + Increment
1470
only if BitLength(i) is not zero. (Pretty obvious.)
1471
11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19)
1472
12. Note: length code 284 can represent 227-258, but length code 285
1473
really is 258. The last length deserves its own, short code
1474
since it gets used a lot in very redundant files. The length
1475
258 is special since 258 - 3 (the min match length) is 255.
1476
13. The literal/length and distance code bit lengths are read as a
1477
single stream of lengths. It is possible (and advantageous) for
1478
a repeat code (16, 17, or 18) to go across the boundary between
1479
the two sets of lengths.
1482
#include <sys/types.h>
1484
#if defined(STDC_HEADERS) || !defined(NO_STDLIB_H)
1485
# include <stdlib.h>
1489
#define slide window
1491
/* Huffman code lookup table entry--this entry is four bytes for machines
1492
that have 16-bit pointers (e.g. PC's in the small or medium model).
1493
Valid extra bits are 0..13. e == 15 is EOB (end of block), e == 16
1494
means that v is a literal, 16 < e < 32 means that v is a pointer to
1495
the next table, which codes e - 16 bits, and lastly e == 99 indicates
1496
an unused code. If a code with e == 99 is looked up, this implies an
1497
error in the data. */
1499
uch e; /* number of extra bits or operation */
1500
uch b; /* number of bits in this code or subcode */
1502
ush n; /* literal, length base, or distance base */
1503
struct huft *t; /* pointer to next level of table */
1508
/* Function prototypes */
1509
int huft_build OF((unsigned *, unsigned, unsigned, ush *, ush *,
1510
struct huft **, int *));
1511
int huft_free OF((struct huft *));
1512
int inflate_codes OF((struct huft *, struct huft *, int, int));
1513
int inflate_stored OF((void));
1514
int inflate_fixed OF((void));
1515
int inflate_dynamic OF((void));
1516
int inflate_block OF((int *));
1517
int inflate OF((void));
1520
/* The inflate algorithm uses a sliding 32K byte window on the uncompressed
1521
stream to find repeated byte strings. This is implemented here as a
1522
circular buffer. The index is updated simply by incrementing and then
1523
and'ing with 0x7fff (32K-1). */
1524
/* It is left to other modules to supply the 32K area. It is assumed
1525
to be usable as if it were declared "uch slide[32768];" or as just
1526
"uch *slide;" and then malloc'ed in the latter case. The definition
1527
must be in unzip.h, included above. */
1528
/* unsigned wp; current position in slide */
1530
#define flush_output(w) (wp=(w),flush_window())
1532
/* Tables for deflate from PKZIP's appnote.txt. */
1533
static unsigned border[] = { /* Order of the bit length code lengths */
1534
16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
1535
static ush cplens[] = { /* Copy lengths for literal codes 257..285 */
1536
3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
1537
35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
1538
/* note: see note #13 above about the 258 in this list. */
1539
static ush cplext[] = { /* Extra bits for literal codes 257..285 */
1540
0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
1541
3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 99, 99}; /* 99==invalid */
1542
static ush cpdist[] = { /* Copy offsets for distance codes 0..29 */
1543
1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
1544
257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
1545
8193, 12289, 16385, 24577};
1546
static ush cpdext[] = { /* Extra bits for distance codes */
1547
0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
1548
7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
1553
/* Macros for inflate() bit peeking and grabbing.
1557
x = b & mask_bits[j];
1560
where NEEDBITS makes sure that b has at least j bits in it, and
1561
DUMPBITS removes the bits from b. The macros use the variable k
1562
for the number of bits in b. Normally, b and k are register
1563
variables for speed, and are initialized at the beginning of a
1564
routine that uses these macros from a global bit buffer and count.
1566
If we assume that EOB will be the longest code, then we will never
1567
ask for bits with NEEDBITS that are beyond the end of the stream.
1568
So, NEEDBITS should not read any more bytes than are needed to
1569
meet the request. Then no bytes need to be "returned" to the buffer
1570
at the end of the last block.
1572
However, this assumption is not true for fixed blocks--the EOB code
1573
is 7 bits, but the other literal/length codes can be 8 or 9 bits.
1574
(The EOB code is shorter than other codes because fixed blocks are
1575
generally short. So, while a block always has an EOB, many other
1576
literal/length codes have a significantly lower probability of
1577
showing up at all.) However, by making the first table have a
1578
lookup of seven bits, the EOB code will be found in that first
1579
lookup, and so will not require that too many bits be pulled from
1583
ulg bb; /* bit buffer */
1584
unsigned bk; /* bits in bit buffer */
1588
0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
1589
0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
1594
# define NEXTBYTE() (cc = get_byte(), zdecode(cc), cc)
1596
# define NEXTBYTE() (uch)get_byte()
1598
#define NEEDBITS(n) {while(k<(n)){b|=((ulg)NEXTBYTE())<<k;k+=8;}}
1599
#define DUMPBITS(n) {b>>=(n);k-=(n);}
1603
Huffman code decoding is performed using a multi-level table lookup.
1604
The fastest way to decode is to simply build a lookup table whose
1605
size is determined by the longest code. However, the time it takes
1606
to build this table can also be a factor if the data being decoded
1607
is not very long. The most common codes are necessarily the
1608
shortest codes, so those codes dominate the decoding time, and hence
1609
the speed. The idea is you can have a shorter table that decodes the
1610
shorter, more probable codes, and then point to subsidiary tables for
1611
the longer codes. The time it costs to decode the longer codes is
1612
then traded against the time it takes to make longer tables.
1614
This results of this trade are in the variables lbits and dbits
1615
below. lbits is the number of bits the first level table for literal/
1616
length codes can decode in one step, and dbits is the same thing for
1617
the distance codes. Subsequent tables are also less than or equal to
1618
those sizes. These values may be adjusted either when all of the
1619
codes are shorter than that, in which case the longest code length in
1620
bits is used, or when the shortest code is *longer* than the requested
1621
table size, in which case the length of the shortest code in bits is
1624
There are two different values for the two tables, since they code a
1625
different number of possibilities each. The literal/length table
1626
codes 286 possible values, or in a flat code, a little over eight
1627
bits. The distance table codes 30 possible values, or a little less
1628
than five bits, flat. The optimum values for speed end up being
1629
about one bit more than those, so lbits is 8+1 and dbits is 5+1.
1630
The optimum values may differ though from machine to machine, and
1631
possibly even between compilers. Your mileage may vary.
1635
int lbits = 9; /* bits in base literal/length lookup table */
1636
int dbits = 6; /* bits in base distance lookup table */
1639
/* If BMAX needs to be larger than 16, then h and x[] should be ulg. */
1640
#define BMAX 16 /* maximum bit length of any code (16 for explode) */
1641
#define N_MAX 288 /* maximum number of codes in any set */
1644
unsigned hufts; /* track memory usage */
1647
int huft_build(b, n, s, d, e, t, m)
1648
unsigned *b; /* code lengths in bits (all assumed <= BMAX) */
1649
unsigned n; /* number of codes (assumed <= N_MAX) */
1650
unsigned s; /* number of simple-valued codes (0..s-1) */
1651
ush *d; /* list of base values for non-simple codes */
1652
ush *e; /* list of extra bits for non-simple codes */
1653
struct huft **t; /* result: starting table */
1654
int *m; /* maximum lookup bits, returns actual */
1655
/* Given a list of code lengths and a maximum table size, make a set of
1656
tables to decode that set of codes. Return zero on success, one if
1657
the given code set is incomplete (the tables are still built in this
1658
case), two if the input is invalid (all zero length codes or an
1659
oversubscribed set of lengths), and three if not enough memory. */
1661
unsigned a; /* counter for codes of length k */
1662
unsigned c[BMAX+1]; /* bit length count table */
1663
unsigned f; /* i repeats in table every f entries */
1664
int g; /* maximum code length */
1665
int h; /* table level */
1666
register unsigned i; /* counter, current code */
1667
register unsigned j; /* counter */
1668
register int k; /* number of bits in current code */
1669
int l; /* bits per table (returned in m) */
1670
register unsigned *p; /* pointer into c[], b[], or v[] */
1671
register struct huft *q; /* points to current table */
1672
struct huft r; /* table entry for structure assignment */
1673
struct huft *u[BMAX]; /* table stack */
1674
unsigned v[N_MAX]; /* values in order of bit length */
1675
register int w; /* bits before this table == (l * h) */
1676
unsigned x[BMAX+1]; /* bit offsets, then code stack */
1677
unsigned *xp; /* pointer into x */
1678
int y; /* number of dummy codes added */
1679
unsigned z; /* number of entries in current table */
1682
/* Generate counts for each bit length */
1683
memzero(c, sizeof(c));
1686
Tracecv(*p, (stderr, (n-i >= ' ' && n-i <= '~' ? "%c %d\n" : "0x%x %d\n"),
1688
c[*p]++; /* assume all entries <= BMAX */
1689
p++; /* Can't combine with above line (Solaris bug) */
1691
if (c[0] == n) /* null input--all zero length codes */
1693
*t = (struct huft *)NULL;
1699
/* Find minimum and maximum length, bound *m by those */
1701
for (j = 1; j <= BMAX; j++)
1704
k = j; /* minimum code length */
1705
if ((unsigned)l < j)
1707
for (i = BMAX; i; i--)
1710
g = i; /* maximum code length */
1711
if ((unsigned)l > i)
1716
/* Adjust last length count to fill out codes, if needed */
1717
for (y = 1 << j; j < i; j++, y <<= 1)
1718
if ((y -= c[j]) < 0)
1719
return 2; /* bad input: more codes than bits */
1720
if ((y -= c[i]) < 0)
1725
/* Generate starting offsets into the value table for each length */
1727
p = c + 1; xp = x + 2;
1728
while (--i) { /* note that i == g from above */
1729
*xp++ = (j += *p++);
1733
/* Make a table of values in order of bit lengths */
1736
if ((j = *p++) != 0)
1741
/* Generate the Huffman codes and for each, make the table entries */
1742
x[0] = i = 0; /* first Huffman code is zero */
1743
p = v; /* grab values in bit order */
1744
h = -1; /* no tables yet--level -1 */
1745
w = -l; /* bits decoded == (l * h) */
1746
u[0] = (struct huft *)NULL; /* just to keep compilers happy */
1747
q = (struct huft *)NULL; /* ditto */
1750
/* go through the bit lengths (k already is bits in shortest code) */
1756
/* here i is the Huffman code of length k bits for value *p */
1757
/* make tables up to required level */
1761
w += l; /* previous table always l bits */
1763
/* compute minimum size table less than or equal to l bits */
1764
z = (z = g - w) > (unsigned)l ? l : z; /* upper limit on table size */
1765
if ((f = 1 << (j = k - w)) > a + 1) /* try a k-w bit table */
1766
{ /* too few codes for k-w bit table */
1767
f -= a + 1; /* deduct codes from patterns left */
1769
while (++j < z) /* try smaller tables up to z bits */
1771
if ((f <<= 1) <= *++xp)
1772
break; /* enough codes to use up j bits */
1773
f -= *xp; /* else deduct codes from patterns */
1776
z = 1 << j; /* table entries for j-bit table */
1778
/* allocate and link in new table */
1779
if ((q = (struct huft *)malloc((z + 1)*sizeof(struct huft))) ==
1780
(struct huft *)NULL)
1784
return 3; /* not enough memory */
1786
hufts += z + 1; /* track memory usage */
1787
*t = q + 1; /* link to list for huft_free() */
1788
*(t = &(q->v.t)) = (struct huft *)NULL;
1789
u[h] = ++q; /* table starts after link */
1791
/* connect to last table, if there is one */
1794
x[h] = i; /* save pattern for backing up */
1795
r.b = (uch)l; /* bits to dump before this table */
1796
r.e = (uch)(16 + j); /* bits in this table */
1797
r.v.t = q; /* pointer to this table */
1798
j = i >> (w - l); /* (get around Turbo C bug) */
1799
u[h-1][j] = r; /* connect to last table */
1803
/* set up table entry in r */
1806
r.e = 99; /* out of values--invalid code */
1809
r.e = (uch)(*p < 256 ? 16 : 15); /* 256 is end-of-block code */
1810
r.v.n = (ush)(*p); /* simple code is just the value */
1811
p++; /* one compiler does not like *p++ */
1815
r.e = (uch)e[*p - s]; /* non-simple--look up in lists */
1816
r.v.n = d[*p++ - s];
1819
/* fill code-like entries with r */
1821
for (j = i >> w; j < z; j += f)
1824
/* backwards increment the k-bit code i */
1825
for (j = 1 << (k - 1); i & j; j >>= 1)
1829
/* backup over finished tables */
1830
while ((i & ((1 << w) - 1)) != x[h])
1832
h--; /* don't need to update q */
1839
/* Return true (1) if we were given an incomplete table */
1840
return y != 0 && g != 1;
1846
struct huft *t; /* table to free */
1847
/* Free the malloc'ed tables built by huft_build(), which makes a linked
1848
list of the tables it made, with the links in a dummy first entry of
1851
register struct huft *p, *q;
1854
/* Go through linked list, freeing from the malloced (t[-1]) address. */
1856
while (p != (struct huft *)NULL)
1866
int inflate_codes(tl, td, bl, bd)
1867
struct huft *tl, *td; /* literal/length and distance decoder tables */
1868
int bl, bd; /* number of bits decoded by tl[] and td[] */
1869
/* inflate (decompress) the codes in a deflated (compressed) block.
1870
Return an error code or zero if it all goes ok. */
1872
register unsigned e; /* table entry flag/number of extra bits */
1873
unsigned n, d; /* length and index for copy */
1874
unsigned w; /* current window position */
1875
struct huft *t; /* pointer to table entry */
1876
unsigned ml, md; /* masks for bl and bd bits */
1877
register ulg b; /* bit buffer */
1878
register unsigned k; /* number of bits in bit buffer */
1881
/* make local copies of globals */
1882
b = bb; /* initialize bit buffer */
1884
w = wp; /* initialize window position */
1886
/* inflate the coded data */
1887
ml = mask_bits[bl]; /* precompute masks for speed */
1889
for (;;) /* do until end of block */
1891
NEEDBITS((unsigned)bl)
1892
if ((e = (t = tl + ((unsigned)b & ml))->e) > 16)
1899
} while ((e = (t = t->v.t + ((unsigned)b & mask_bits[e]))->e) > 16);
1901
if (e == 16) /* then it's a literal */
1903
slide[w++] = (uch)t->v.n;
1904
Tracevv((stderr, "%c", slide[w-1]));
1911
else /* it's an EOB or a length */
1913
/* exit if end of block */
1917
/* get length of block to copy */
1919
n = t->v.n + ((unsigned)b & mask_bits[e]);
1922
/* decode distance of block to copy */
1923
NEEDBITS((unsigned)bd)
1924
if ((e = (t = td + ((unsigned)b & md))->e) > 16)
1931
} while ((e = (t = t->v.t + ((unsigned)b & mask_bits[e]))->e) > 16);
1934
d = w - t->v.n - ((unsigned)b & mask_bits[e]);
1936
Tracevv((stderr,"\\[%d,%d]", w-d, n));
1940
n -= (e = (e = WSIZE - ((d &= WSIZE-1) > w ? d : w)) > n ? n : e);
1941
#if !defined(NOMEMCPY) && !defined(DEBUG)
1942
if (w - d >= e) /* (this test assumes unsigned comparison) */
1944
memcpy(slide + w, slide + d, e);
1948
else /* do it slow to avoid memcpy() overlap */
1949
#endif /* !NOMEMCPY */
1951
slide[w++] = slide[d++];
1952
Tracevv((stderr, "%c", slide[w-1]));
1964
/* restore the globals from the locals */
1965
wp = w; /* restore global window pointer */
1966
bb = b; /* restore global bit buffer */
1975
int inflate_stored()
1976
/* "decompress" an inflated type 0 (stored) block. */
1978
unsigned n; /* number of bytes in block */
1979
unsigned w; /* current window position */
1980
register ulg b; /* bit buffer */
1981
register unsigned k; /* number of bits in bit buffer */
1984
/* make local copies of globals */
1985
b = bb; /* initialize bit buffer */
1987
w = wp; /* initialize window position */
1990
/* go to byte boundary */
1995
/* get the length and its complement */
1997
n = ((unsigned)b & 0xffff);
2000
if (n != (unsigned)((~b) & 0xffff))
2001
return 1; /* error in compressed data */
2005
/* read and output the compressed data */
2009
slide[w++] = (uch)b;
2019
/* restore the globals from the locals */
2020
wp = w; /* restore global window pointer */
2021
bb = b; /* restore global bit buffer */
2029
/* decompress an inflated type 1 (fixed Huffman codes) block. We should
2030
either replace this with a custom decoder, or at least precompute the
2033
int i; /* temporary variable */
2034
struct huft *tl; /* literal/length code table */
2035
struct huft *td; /* distance code table */
2036
int bl; /* lookup bits for tl */
2037
int bd; /* lookup bits for td */
2038
unsigned l[288]; /* length list for huft_build */
2041
/* set up literal table */
2042
for (i = 0; i < 144; i++)
2044
for (; i < 256; i++)
2046
for (; i < 280; i++)
2048
for (; i < 288; i++) /* make a complete, but wrong code set */
2051
if ((i = huft_build(l, 288, 257, cplens, cplext, &tl, &bl)) != 0)
2055
/* set up distance table */
2056
for (i = 0; i < 30; i++) /* make an incomplete code set */
2059
if ((i = huft_build(l, 30, 0, cpdist, cpdext, &td, &bd)) > 1)
2066
/* decompress until an end-of-block code */
2067
if (inflate_codes(tl, td, bl, bd))
2071
/* free the decoding tables, return */
2079
int inflate_dynamic()
2080
/* decompress an inflated type 2 (dynamic Huffman codes) block. */
2082
int i; /* temporary variables */
2084
unsigned l; /* last length */
2085
unsigned m; /* mask for bit lengths table */
2086
unsigned n; /* number of lengths to get */
2087
struct huft *tl; /* literal/length code table */
2088
struct huft *td; /* distance code table */
2089
int bl; /* lookup bits for tl */
2090
int bd; /* lookup bits for td */
2091
unsigned nb; /* number of bit length codes */
2092
unsigned nl; /* number of literal/length codes */
2093
unsigned nd; /* number of distance codes */
2094
#ifdef PKZIP_BUG_WORKAROUND
2095
unsigned ll[288+32]; /* literal/length and distance code lengths */
2097
unsigned ll[286+30]; /* literal/length and distance code lengths */
2099
register ulg b; /* bit buffer */
2100
register unsigned k; /* number of bits in bit buffer */
2103
/* make local bit buffer */
2108
/* read in table lengths */
2110
nl = 257 + ((unsigned)b & 0x1f); /* number of literal/length codes */
2113
nd = 1 + ((unsigned)b & 0x1f); /* number of distance codes */
2116
nb = 4 + ((unsigned)b & 0xf); /* number of bit length codes */
2118
#ifdef PKZIP_BUG_WORKAROUND
2119
if (nl > 288 || nd > 32)
2121
if (nl > 286 || nd > 30)
2123
return 1; /* bad lengths */
2126
/* read in bit-length-code lengths */
2127
for (j = 0; j < nb; j++)
2130
ll[border[j]] = (unsigned)b & 7;
2137
/* build decoding table for trees--single level, 7 bit lookup */
2139
if ((i = huft_build(ll, 19, 19, NULL, NULL, &tl, &bl)) != 0)
2143
return i; /* incomplete code set */
2147
/* read in literal and distance code lengths */
2151
while ((unsigned)i < n)
2153
NEEDBITS((unsigned)bl)
2154
j = (td = tl + ((unsigned)b & m))->b;
2157
if (j < 16) /* length of code in bits (0..15) */
2158
ll[i++] = l = j; /* save last length in l */
2159
else if (j == 16) /* repeat last length 3 to 6 times */
2162
j = 3 + ((unsigned)b & 3);
2164
if ((unsigned)i + j > n)
2169
else if (j == 17) /* 3 to 10 zero length codes */
2172
j = 3 + ((unsigned)b & 7);
2174
if ((unsigned)i + j > n)
2180
else /* j == 18: 11 to 138 zero length codes */
2183
j = 11 + ((unsigned)b & 0x7f);
2185
if ((unsigned)i + j > n)
2194
/* free decoding table for trees */
2198
/* restore the global bit buffer */
2203
/* build the decoding tables for literal/length and distance codes */
2205
if ((i = huft_build(ll, nl, 257, cplens, cplext, &tl, &bl)) != 0)
2208
fprintf(stderr, " incomplete literal tree\n");
2211
return i; /* incomplete code set */
2214
if ((i = huft_build(ll + nl, nd, 0, cpdist, cpdext, &td, &bd)) != 0)
2217
fprintf(stderr, " incomplete distance tree\n");
2218
#ifdef PKZIP_BUG_WORKAROUND
2225
return i; /* incomplete code set */
2230
/* decompress until an end-of-block code */
2231
if (inflate_codes(tl, td, bl, bd))
2235
/* free the decoding tables, return */
2243
int inflate_block(e)
2244
int *e; /* last block flag */
2245
/* decompress an inflated block */
2247
unsigned t; /* block type */
2248
register ulg b; /* bit buffer */
2249
register unsigned k; /* number of bits in bit buffer */
2252
/* make local bit buffer */
2257
/* read in last block bit */
2263
/* read in block type */
2265
t = (unsigned)b & 3;
2269
/* restore the global bit buffer */
2274
/* inflate that block type */
2276
return inflate_dynamic();
2278
return inflate_stored();
2280
return inflate_fixed();
2283
/* bad block type */
2290
/* decompress an inflated entry */
2292
int e; /* last block flag */
2293
int r; /* result code */
2294
unsigned h; /* maximum struct huft's malloc'ed */
2297
/* initialize window, bit buffer */
2303
/* decompress until the last block */
2307
if ((r = inflate_block(&e)) != 0)
2313
/* Undo too much lookahead. The next read will be byte aligned so we
2314
* can discard unused bits in the last meaningful byte.
2321
/* flush out slide */
2325
/* return success */
2327
fprintf(stderr, "<%u> ", h);
added
removed
gunzip.c
