1 /* zcat : stripped version based on gzip sources
2 Sven Rudolph <sr1@inf.tu-dresden.de>
7 static const char zcat_usage[] = "zcat\n"
9 "\tuncompress gzipped data from stdin to stdout\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.
79 /* $Id: zcat.c,v 1.5 1999/10/23 07:09:58 andersen Exp $ */
83 #define get_char() get_byte()
84 #define put_char(c) put_byte(c)
86 /* #include "gzip.h" */
88 /* gzip.h -- common declarations for all gzip modules
89 * Copyright (C) 1992-1993 Jean-loup Gailly.
90 * This is free software; you can redistribute it and/or modify it under the
91 * terms of the GNU General Public License, see the file COPYING.
94 #if defined(__STDC__) || defined(PROTO)
95 # define OF(args) args
106 /* I don't like nested includes, but the string and io functions are used
110 #if !defined(NO_STRING_H) || defined(STDC_HEADERS)
112 # if !defined(STDC_HEADERS) && !defined(NO_MEMORY_H) && !defined(__GNUC__)
115 # define memzero(s, n) memset ((voidp)(s), 0, (n))
117 # include <strings.h>
118 # define strchr index
119 # define strrchr rindex
120 # define memcpy(d, s, n) bcopy((s), (d), (n))
121 # define memcmp(s1, s2, n) bcmp((s1), (s2), (n))
122 # define memzero(s, n) bzero((s), (n))
126 # define RETSIGTYPE void
131 typedef unsigned char uch;
132 typedef unsigned short ush;
133 typedef unsigned long ulg;
135 /* Return codes from gzip */
140 /* Compression methods (see algorithm.doc) */
143 extern int method; /* compression method */
145 /* To save memory for 16 bit systems, some arrays are overlaid between
146 * the various modules:
147 * deflate: prev+head window d_buf l_buf outbuf
148 * unlzw: tab_prefix tab_suffix stack inbuf outbuf
149 * inflate: window inbuf
150 * unpack: window inbuf prefix_len
151 * unlzh: left+right window c_table inbuf c_len
152 * For compression, input is done in window[]. For decompression, output
153 * is done in window except for unlzw.
158 # define INBUFSIZ 0x2000 /* input buffer size */
160 # define INBUFSIZ 0x8000 /* input buffer size */
163 #define INBUF_EXTRA 64 /* required by unlzw() */
167 # define OUTBUFSIZ 8192 /* output buffer size */
169 # define OUTBUFSIZ 16384 /* output buffer size */
172 #define OUTBUF_EXTRA 2048 /* required by unlzw() */
178 # define DIST_BUFSIZE 0x2000 /* buffer for distances, see trees.c */
180 # define DIST_BUFSIZE 0x8000 /* buffer for distances, see trees.c */
184 /*#define DYN_ALLOC*/
187 # define EXTERN(type, array) extern type * array
188 # define DECLARE(type, array, size) type * array
189 # define ALLOC(type, array, size) { \
190 array = (type*)calloc((size_t)(((size)+1L)/2), 2*sizeof(type)); \
191 if (array == NULL) error("insufficient memory"); \
193 # define FREE(array) {if (array != NULL) free(array), array=NULL;}
195 # define EXTERN(type, array) extern type array[]
196 # define DECLARE(type, array, size) type array[size]
197 # define ALLOC(type, array, size)
201 EXTERN(uch, inbuf); /* input buffer */
202 EXTERN(uch, outbuf); /* output buffer */
203 EXTERN(ush, d_buf); /* buffer for distances, see trees.c */
204 EXTERN(uch, window); /* Sliding window and suffix table (unlzw) */
205 #define tab_suffix window
207 # define tab_prefix prev /* hash link (see deflate.c) */
208 # define head (prev+WSIZE) /* hash head (see deflate.c) */
209 EXTERN(ush, tab_prefix); /* prefix code (see unlzw.c) */
211 # define tab_prefix0 prev
212 # define head tab_prefix1
213 EXTERN(ush, tab_prefix0); /* prefix for even codes */
214 EXTERN(ush, tab_prefix1); /* prefix for odd codes */
217 extern unsigned insize; /* valid bytes in inbuf */
218 extern unsigned inptr; /* index of next byte to be processed in inbuf */
219 extern unsigned outcnt; /* bytes in output buffer */
221 extern long bytes_in; /* number of input bytes */
222 extern long bytes_out; /* number of output bytes */
223 extern long header_bytes;/* number of bytes in gzip header */
225 extern int ifd; /* input file descriptor */
226 extern int ofd; /* output file descriptor */
228 extern long ifile_size; /* input file size, -1 for devices (debug only) */
230 typedef int file_t; /* Do not use stdio */
231 #define NO_FILE (-1) /* in memory compression */
234 #define GZIP_MAGIC "\037\213" /* Magic header for gzip files, 1F 8B */
237 #define ASCII_FLAG 0x01 /* bit 0 set: file probably ascii text */
238 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
239 #define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
240 #define ORIG_NAME 0x08 /* bit 3 set: original file name present */
241 #define COMMENT 0x10 /* bit 4 set: file comment present */
242 #define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */
243 #define RESERVED 0xC0 /* bit 6,7: reserved */
246 # define WSIZE 0x8000 /* window size--must be a power of two, and */
247 #endif /* at least 32K for zip's deflate method */
250 #define MAX_MATCH 258
251 /* The minimum and maximum match lengths */
253 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
254 /* Minimum amount of lookahead, except at the end of the input file.
255 * See deflate.c for comments about the MIN_MATCH+1.
258 #define MAX_DIST (WSIZE-MIN_LOOKAHEAD)
259 /* In order to simplify the code, particularly on 16 bit machines, match
260 * distances are limited to MAX_DIST instead of WSIZE.
263 extern int exit_code; /* program exit code */
264 extern int verbose; /* be verbose (-v) */
265 extern int level; /* compression level */
266 extern int test; /* check .z file integrity */
267 extern int to_stdout; /* output to stdout (-c) */
268 extern int save_orig_name; /* set if original name must be saved */
270 #define get_byte() (inptr < insize ? inbuf[inptr++] : fill_inbuf(0))
271 #define try_byte() (inptr < insize ? inbuf[inptr++] : fill_inbuf(1))
273 /* put_byte is used for the compressed output, put_ubyte for the
274 * uncompressed output. However unlzw() uses window for its
275 * suffix table instead of its output buffer, so it does not use put_ubyte
276 * (to be cleaned up).
278 #define put_byte(c) {outbuf[outcnt++]=(uch)(c); if (outcnt==OUTBUFSIZ)\
280 #define put_ubyte(c) {window[outcnt++]=(uch)(c); if (outcnt==WSIZE)\
283 /* Output a 16 bit value, lsb first */
284 #define put_short(w) \
285 { if (outcnt < OUTBUFSIZ-2) { \
286 outbuf[outcnt++] = (uch) ((w) & 0xff); \
287 outbuf[outcnt++] = (uch) ((ush)(w) >> 8); \
289 put_byte((uch)((w) & 0xff)); \
290 put_byte((uch)((ush)(w) >> 8)); \
294 /* Output a 32 bit value to the bit stream, lsb first */
295 #define put_long(n) { \
296 put_short((n) & 0xffff); \
297 put_short(((ulg)(n)) >> 16); \
300 #define seekable() 0 /* force sequential output */
301 #define translate_eol 0 /* no option -a yet */
303 #define tolow(c) (isupper(c) ? (c)-'A'+'a' : (c)) /* force to lower case */
305 /* Macros for getting two-byte and four-byte header values */
306 #define SH(p) ((ush)(uch)((p)[0]) | ((ush)(uch)((p)[1]) << 8))
307 #define LG(p) ((ulg)(SH(p)) | ((ulg)(SH((p)+2)) << 16))
309 /* Diagnostic functions */
311 # define Assert(cond,msg) {if(!(cond)) error(msg);}
312 # define Trace(x) fprintf x
313 # define Tracev(x) {if (verbose) fprintf x ;}
314 # define Tracevv(x) {if (verbose>1) fprintf x ;}
315 # define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
316 # define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
318 # define Assert(cond,msg)
323 # define Tracecv(c,x)
326 #define WARN(msg) {fprintf msg ; \
327 if (exit_code == OK) exit_code = WARNING;}
330 extern int unzip OF((int in, int out));
333 RETSIGTYPE abort_gzip OF((void));
336 void lm_init OF((int pack_level, ush *flags));
337 ulg deflate OF((void));
340 void ct_init OF((ush *attr, int *method));
341 int ct_tally OF((int dist, int lc));
342 ulg flush_block OF((char *buf, ulg stored_len, int eof));
345 void bi_init OF((file_t zipfile));
346 void send_bits OF((int value, int length));
347 unsigned bi_reverse OF((unsigned value, int length));
348 void bi_windup OF((void));
349 void copy_block OF((char *buf, unsigned len, int header));
350 extern int (*read_buf) OF((char *buf, unsigned size));
353 extern int copy OF((int in, int out));
354 extern ulg updcrc OF((uch *s, unsigned n));
355 extern void clear_bufs OF((void));
356 extern int fill_inbuf OF((int eof_ok));
357 extern void flush_outbuf OF((void));
358 extern void flush_window OF((void));
359 extern void write_buf OF((int fd, voidp buf, unsigned cnt));
361 extern char *basename OF((char *fname));
362 #endif /* not __linux__ */
363 extern void error OF((char *m));
364 extern void warn OF((char *a, char *b));
365 extern void read_error OF((void));
366 extern void write_error OF((void));
367 extern voidp xmalloc OF((unsigned int size));
370 extern int inflate OF((void));
372 /* #include "lzw.h" */
374 /* lzw.h -- define the lzw functions.
375 * Copyright (C) 1992-1993 Jean-loup Gailly.
376 * This is free software; you can redistribute it and/or modify it under the
377 * terms of the GNU General Public License, see the file COPYING.
380 #if !defined(OF) && defined(lint)
387 #define INIT_BITS 9 /* Initial number of bits per code */
389 #define LZW_MAGIC "\037\235" /* Magic header for lzw files, 1F 9D */
391 #define BIT_MASK 0x1f /* Mask for 'number of compression bits' */
392 /* Mask 0x20 is reserved to mean a fourth header byte, and 0x40 is free.
393 * It's a pity that old uncompress does not check bit 0x20. That makes
394 * extension of the format actually undesirable because old compress
395 * would just crash on the new format instead of giving a meaningful
396 * error message. It does check the number of bits, but it's more
397 * helpful to say "unsupported format, get a new version" than
398 * "can only handle 16 bits".
401 #define BLOCK_MODE 0x80
402 /* Block compression: if table is full and compression rate is dropping,
403 * clear the dictionary.
406 #define LZW_RESERVED 0x60 /* reserved bits */
408 #define CLEAR 256 /* flush the dictionary */
409 #define FIRST (CLEAR+1) /* first free entry */
411 extern int maxbits; /* max bits per code for LZW */
412 extern int block_mode; /* block compress mode -C compatible with 2.0 */
414 extern int lzw OF((int in, int out));
415 extern int unlzw OF((int in, int out));
418 /* #include "revision.h" */
420 /* revision.h -- define the version number
421 * Copyright (C) 1992-1993 Jean-loup Gailly.
422 * This is free software; you can redistribute it and/or modify it under the
423 * terms of the GNU General Public License, see the file COPYING.
426 #define VERSION "1.2.4"
428 #define REVDATE "18 Aug 93"
430 /* This version does not support compression into old compress format: */
435 /* $Id: zcat.c,v 1.5 1999/10/23 07:09:58 andersen Exp $ */
437 /* #include "getopt.h" */
439 /* Declarations for getopt.
440 Copyright (C) 1989, 1990, 1991, 1992, 1993 Free Software Foundation, Inc.
442 This program is free software; you can redistribute it and/or modify it
443 under the terms of the GNU General Public License as published by the
444 Free Software Foundation; either version 2, or (at your option) any
447 This program is distributed in the hope that it will be useful,
448 but WITHOUT ANY WARRANTY; without even the implied warranty of
449 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
450 GNU General Public License for more details.
452 You should have received a copy of the GNU General Public License
453 along with this program; if not, write to the Free Software
454 Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
463 /* For communication from `getopt' to the caller.
464 When `getopt' finds an option that takes an argument,
465 the argument value is returned here.
466 Also, when `ordering' is RETURN_IN_ORDER,
467 each non-option ARGV-element is returned here. */
471 /* Index in ARGV of the next element to be scanned.
472 This is used for communication to and from the caller
473 and for communication between successive calls to `getopt'.
475 On entry to `getopt', zero means this is the first call; initialize.
477 When `getopt' returns EOF, this is the index of the first of the
478 non-option elements that the caller should itself scan.
480 Otherwise, `optind' communicates from one call to the next
481 how much of ARGV has been scanned so far. */
485 /* Callers store zero here to inhibit the error message `getopt' prints
486 for unrecognized options. */
490 /* Set to an option character which was unrecognized. */
494 /* Describe the long-named options requested by the application.
495 The LONG_OPTIONS argument to getopt_long or getopt_long_only is a vector
496 of `struct option' terminated by an element containing a name which is
499 The field `has_arg' is:
500 no_argument (or 0) if the option does not take an argument,
501 required_argument (or 1) if the option requires an argument,
502 optional_argument (or 2) if the option takes an optional argument.
504 If the field `flag' is not NULL, it points to a variable that is set
505 to the value given in the field `val' when the option is found, but
506 left unchanged if the option is not found.
508 To have a long-named option do something other than set an `int' to
509 a compiled-in constant, such as set a value from `optarg', set the
510 option's `flag' field to zero and its `val' field to a nonzero
511 value (the equivalent single-letter option character, if there is
512 one). For long options that have a zero `flag' field, `getopt'
513 returns the contents of the `val' field. */
522 /* has_arg can't be an enum because some compilers complain about
523 type mismatches in all the code that assumes it is an int. */
529 /* Names for the values of the `has_arg' field of `struct option'. */
531 #define no_argument 0
532 #define required_argument 1
533 #define optional_argument 2
535 #if __STDC__ || defined(PROTO)
536 #if defined(__GNU_LIBRARY__)
537 /* Many other libraries have conflicting prototypes for getopt, with
538 differences in the consts, in stdlib.h. To avoid compilation
539 errors, only prototype getopt for the GNU C library. */
540 extern int getopt (int argc, char *const *argv, const char *shortopts);
541 #endif /* not __GNU_LIBRARY__ */
542 extern int getopt_long (int argc, char *const *argv, const char *shortopts,
543 const struct option *longopts, int *longind);
544 extern int getopt_long_only (int argc, char *const *argv,
545 const char *shortopts,
546 const struct option *longopts, int *longind);
548 /* Internal only. Users should not call this directly. */
549 extern int _getopt_internal (int argc, char *const *argv,
550 const char *shortopts,
551 const struct option *longopts, int *longind,
553 #else /* not __STDC__ */
554 extern int getopt ();
555 extern int getopt_long ();
556 extern int getopt_long_only ();
558 extern int _getopt_internal ();
559 #endif /* not __STDC__ */
565 #endif /* _GETOPT_H */
576 typedef struct dirent dir_type;
577 # define NLENGTH(dirent) ((int)strlen((dirent)->d_name))
578 # define DIR_OPT "DIRENT"
580 # define NLENGTH(dirent) ((dirent)->d_namlen)
582 # include <sys/dir.h>
583 typedef struct direct dir_type;
584 # define DIR_OPT "SYSDIR"
587 # include <sys/ndir.h>
588 typedef struct direct dir_type;
589 # define DIR_OPT "SYSNDIR"
593 typedef struct direct dir_type;
594 # define DIR_OPT "NDIR"
597 # define DIR_OPT "NO_DIR"
603 #if !defined(S_ISDIR) && defined(S_IFDIR)
604 # define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
606 #if !defined(S_ISREG) && defined(S_IFREG)
607 # define S_ISREG(m) (((m) & S_IFMT) == S_IFREG)
610 typedef RETSIGTYPE (*sig_type) OF((int));
613 # define O_BINARY 0 /* creation mode for open() */
617 /* Pure BSD system? */
618 # include <sys/file.h>
620 # define O_CREAT FCREAT
623 # define O_EXCL FEXCL
628 # define S_IRUSR 0400
631 # define S_IWUSR 0200
633 #define RW_USER (S_IRUSR | S_IWUSR) /* creation mode for open() */
636 # define MAX_PATH_LEN 1024 /* max pathname length */
645 off_t lseek OF((int fd, off_t offset, int whence));
651 DECLARE(uch, inbuf, INBUFSIZ +INBUF_EXTRA);
652 DECLARE(uch, outbuf, OUTBUFSIZ+OUTBUF_EXTRA);
653 DECLARE(ush, d_buf, DIST_BUFSIZE);
654 DECLARE(uch, window, 2L*WSIZE);
656 DECLARE(ush, tab_prefix, 1L<<BITS);
658 DECLARE(ush, tab_prefix0, 1L<<(BITS-1));
659 DECLARE(ush, tab_prefix1, 1L<<(BITS-1));
662 /* local variables */
664 int force = 0; /* don't ask questions, compress links (-f) */
665 int foreground; /* set if program run in foreground */
666 int maxbits = BITS; /* max bits per code for LZW */
667 int method = DEFLATED;/* compression method */
668 int exit_code = OK; /* program exit code */
669 int last_member; /* set for .zip and .Z files */
670 int part_nb; /* number of parts in .gz file */
671 long ifile_size; /* input file size, -1 for devices (debug only) */
673 long bytes_in; /* number of input bytes */
674 long bytes_out; /* number of output bytes */
675 long total_in = 0; /* input bytes for all files */
676 long total_out = 0; /* output bytes for all files */
677 struct stat istat; /* status for input file */
678 int ifd; /* input file descriptor */
679 int ofd; /* output file descriptor */
680 unsigned insize; /* valid bytes in inbuf */
681 unsigned inptr; /* index of next byte to be processed in inbuf */
682 unsigned outcnt; /* bytes in output buffer */
684 long header_bytes; /* number of bytes in gzip header */
686 /* local functions */
688 local void treat_stdin OF((void));
689 local int get_method OF((int in));
690 local void do_exit OF((int exitcode));
691 int main OF((int argc, char **argv));
692 int (*work) OF((int infile, int outfile)) = unzip; /* function to call */
694 #define strequ(s1, s2) (strcmp((s1),(s2)) == 0)
696 /* ======================================================================== */
697 int zcat_main (int argc, char * * argv)
699 int file_count; /* number of files to precess */
701 foreground = signal(SIGINT, SIG_IGN) != SIG_IGN;
703 (void) signal (SIGINT, (sig_type)abort_gzip);
706 if (signal(SIGTERM, SIG_IGN) != SIG_IGN) {
707 (void) signal(SIGTERM, (sig_type)abort_gzip);
711 if (signal(SIGHUP, SIG_IGN) != SIG_IGN) {
712 (void) signal(SIGHUP, (sig_type)abort_gzip);
716 file_count = argc - optind;
718 /* Allocate all global buffers (for DYN_ALLOC option) */
719 ALLOC(uch, inbuf, INBUFSIZ +INBUF_EXTRA);
720 ALLOC(uch, outbuf, OUTBUFSIZ+OUTBUF_EXTRA);
721 ALLOC(ush, d_buf, DIST_BUFSIZE);
722 ALLOC(uch, window, 2L*WSIZE);
724 ALLOC(ush, tab_prefix, 1L<<BITS);
726 ALLOC(ush, tab_prefix0, 1L<<(BITS-1));
727 ALLOC(ush, tab_prefix1, 1L<<(BITS-1));
730 /* And get to work */
734 return exit_code; /* just to avoid lint warning */
737 /* ========================================================================
738 * Compress or decompress stdin
740 local void treat_stdin()
742 ifile_size = -1L; /* convention for unknown size */
744 clear_bufs(); /* clear input and output buffers */
747 method = get_method(ifd);
750 do_exit(exit_code); /* error message already emitted */
753 (*work)(fileno(stdin), fileno(stdout));
758 /* ========================================================================
759 * Check the magic number of the input file and update ofname if an
760 * original name was given and to_stdout is not set.
761 * Return the compression method, -1 for error, -2 for warning.
762 * Set inptr to the offset of the next byte to be processed.
763 * Updates time_stamp if there is one and --no-time is not used.
764 * This function may be called repeatedly for an input file consisting
765 * of several contiguous gzip'ed members.
766 * IN assertions: there is at least one remaining compressed member.
767 * If the member is a zip file, it must be the only one.
769 local int get_method(in)
770 int in; /* input file descriptor */
772 uch flags; /* compression flags */
773 char magic[2]; /* magic header */
775 /* If --force and --stdout, zcat == cat, so do not complain about
776 * premature end of file: use try_byte instead of get_byte.
779 magic[0] = (char)try_byte();
780 magic[1] = (char)try_byte();
781 /* If try_byte returned EOF, magic[1] == 0xff */
783 magic[0] = (char)get_byte();
784 magic[1] = (char)get_byte();
786 method = -1; /* unknown yet */
787 part_nb++; /* number of parts in gzip file */
789 last_member = RECORD_IO;
790 /* assume multiple members in gzip file except for record oriented I/O */
792 if (memcmp(magic, GZIP_MAGIC, 2) == 0) {
794 method = (int)get_byte();
795 if (method != DEFLATED) {
797 "unknown method %d -- get newer version of gzip\n",
803 flags = (uch)get_byte();
805 (ulg)get_byte(); /* Ignore time stamp */
810 (void)get_byte(); /* Ignore extra flags for the moment */
811 (void)get_byte(); /* Ignore OS type for the moment */
813 if ((flags & EXTRA_FIELD) != 0) {
814 unsigned len = (unsigned)get_byte();
815 len |= ((unsigned)get_byte())<<8;
817 while (len--) (void)get_byte();
820 /* Discard original name if any */
821 if ((flags & ORIG_NAME) != 0) {
822 while (get_char() != 0) /* null */ ;
825 /* Discard file comment if any */
826 if ((flags & COMMENT) != 0) {
827 while (get_char() != 0) /* null */ ;
830 header_bytes = inptr + 2*sizeof(long); /* include crc and size */
835 if (method >= 0) return method;
838 fprintf(stderr, "\nnot in gzip format\n");
842 WARN((stderr, "\ndecompression OK, trailing garbage ignored\n"));
848 /* ========================================================================
849 * Free all dynamically allocated variables and exit with the given code.
851 local void do_exit(exitcode)
854 static int in_exit = 0;
856 if (in_exit) exit(exitcode);
871 /* ========================================================================
872 * Signal and error handler.
874 RETSIGTYPE abort_gzip()
878 /* unzip.c -- decompress files in gzip or pkzip format.
879 * Copyright (C) 1992-1993 Jean-loup Gailly
880 * This is free software; you can redistribute it and/or modify it under the
881 * terms of the GNU General Public License, see the file COPYING.
883 * The code in this file is derived from the file funzip.c written
884 * and put in the public domain by Mark Adler.
888 This version can extract files in gzip or pkzip format.
889 For the latter, only the first entry is extracted, and it has to be
890 either deflated or stored.
893 /* #include "crypt.h" */
895 /* crypt.h (dummy version) -- do not perform encryption
896 * Hardly worth copyrighting :-)
900 # undef CRYPT /* dummy version */
903 #define RAND_HEAD_LEN 12 /* length of encryption random header */
908 /* PKZIP header definitions */
909 #define LOCSIG 0x04034b50L /* four-byte lead-in (lsb first) */
910 #define LOCFLG 6 /* offset of bit flag */
911 #define CRPFLG 1 /* bit for encrypted entry */
912 #define EXTFLG 8 /* bit for extended local header */
913 #define LOCHOW 8 /* offset of compression method */
914 #define LOCTIM 10 /* file mod time (for decryption) */
915 #define LOCCRC 14 /* offset of crc */
916 #define LOCSIZ 18 /* offset of compressed size */
917 #define LOCLEN 22 /* offset of uncompressed length */
918 #define LOCFIL 26 /* offset of file name field length */
919 #define LOCEXT 28 /* offset of extra field length */
920 #define LOCHDR 30 /* size of local header, including sig */
921 #define EXTHDR 16 /* size of extended local header, inc sig */
926 char *key; /* not used--needed to link crypt.c */
927 int pkzip = 0; /* set for a pkzip file */
928 int ext_header = 0; /* set if extended local header */
930 /* ===========================================================================
931 * Unzip in to out. This routine works on both gzip and pkzip files.
933 * IN assertions: the buffer inbuf contains already the beginning of
934 * the compressed data, from offsets inptr to insize-1 included.
935 * The magic header has already been checked. The output buffer is cleared.
938 int in, out; /* input and output file descriptors */
940 ulg orig_crc = 0; /* original crc */
941 ulg orig_len = 0; /* original uncompressed length */
943 uch buf[EXTHDR]; /* extended local header */
948 updcrc(NULL, 0); /* initialize crc */
950 if (pkzip && !ext_header) { /* crc and length at the end otherwise */
951 orig_crc = LG(inbuf + LOCCRC);
952 orig_len = LG(inbuf + LOCLEN);
956 if (method == DEFLATED) {
961 error("out of memory");
962 } else if (res != 0) {
963 error("invalid compressed data--format violated");
967 error("internal error, invalid method");
970 /* Get the crc and original length */
972 /* crc32 (see algorithm.doc)
973 * uncompressed input size modulo 2^32
975 for (n = 0; n < 8; n++) {
976 buf[n] = (uch)get_byte(); /* may cause an error if EOF */
979 orig_len = LG(buf+4);
981 } else if (ext_header) { /* If extended header, check it */
982 /* signature - 4bytes: 0x50 0x4b 0x07 0x08
984 * compressed size 4-bytes
985 * uncompressed size 4-bytes
987 for (n = 0; n < EXTHDR; n++) {
988 buf[n] = (uch)get_byte(); /* may cause an error if EOF */
990 orig_crc = LG(buf+4);
991 orig_len = LG(buf+12);
994 /* Validate decompression */
995 if (orig_crc != updcrc(outbuf, 0)) {
996 error("invalid compressed data--crc error");
998 if (orig_len != (ulg)bytes_out) {
999 error("invalid compressed data--length error");
1002 /* Check if there are more entries in a pkzip file */
1003 if (pkzip && inptr + 4 < insize && LG(inbuf+inptr) == LOCSIG) {
1004 WARN((stderr,"has more than one entry--rest ignored\n"));
1006 ext_header = pkzip = 0; /* for next file */
1009 /* util.c -- utility functions for gzip support
1010 * Copyright (C) 1992-1993 Jean-loup Gailly
1011 * This is free software; you can redistribute it and/or modify it under the
1012 * terms of the GNU General Public License, see the file COPYING.
1017 #include <sys/types.h>
1019 #ifdef HAVE_UNISTD_H
1020 # include <unistd.h>
1026 #if defined(STDC_HEADERS) || !defined(NO_STDLIB_H)
1027 # include <stdlib.h>
1032 const ulg crc_32_tab[]; /* crc table, defined below */
1034 /* ===========================================================================
1035 * Run a set of bytes through the crc shift register. If s is a NULL
1036 * pointer, then initialize the crc shift register contents instead.
1037 * Return the current crc in either case.
1040 uch *s; /* pointer to bytes to pump through */
1041 unsigned n; /* number of bytes in s[] */
1043 register ulg c; /* temporary variable */
1045 static ulg crc = (ulg)0xffffffffL; /* shift register contents */
1052 c = crc_32_tab[((int)c ^ (*s++)) & 0xff] ^ (c >> 8);
1056 return c ^ 0xffffffffL; /* (instead of ~c for 64-bit machines) */
1059 /* ===========================================================================
1060 * Clear input and output buffers
1066 bytes_in = bytes_out = 0L;
1069 /* ===========================================================================
1070 * Fill the input buffer. This is called only when the buffer is empty.
1072 int fill_inbuf(eof_ok)
1073 int eof_ok; /* set if EOF acceptable as a result */
1077 /* Read as much as possible */
1081 len = read(ifd, (char*)inbuf+insize, INBUFSIZ-insize);
1082 if (len == 0 || len == EOF) break;
1084 } while (insize < INBUFSIZ);
1087 if (eof_ok) return EOF;
1090 bytes_in += (ulg)insize;
1095 /* ===========================================================================
1096 * Write the output buffer outbuf[0..outcnt-1] and update bytes_out.
1097 * (used for the compressed data only)
1101 if (outcnt == 0) return;
1103 write_buf(ofd, (char *)outbuf, outcnt);
1104 bytes_out += (ulg)outcnt;
1108 /* ===========================================================================
1109 * Write the output window window[0..outcnt-1] and update crc and bytes_out.
1110 * (Used for the decompressed data only.)
1114 if (outcnt == 0) return;
1115 updcrc(window, outcnt);
1117 write_buf(ofd, (char *)window, outcnt);
1119 bytes_out += (ulg)outcnt;
1123 /* ===========================================================================
1124 * Does the same as write(), but also handles partial pipe writes and checks
1127 void write_buf(fd, buf, cnt)
1134 while ((n = write(fd, buf, cnt)) != cnt) {
1135 if (n == (unsigned)(-1)) {
1139 buf = (voidp)((char*)buf+n);
1143 #if defined(NO_STRING_H) && !defined(STDC_HEADERS)
1145 /* Provide missing strspn and strcspn functions. */
1151 int strspn OF((const char *s, const char *accept));
1152 int strcspn OF((const char *s, const char *reject));
1154 /* ========================================================================
1155 * Return the length of the maximum initial segment
1156 * of s which contains only characters in accept.
1158 int strspn(s, accept)
1162 register const char *p;
1163 register const char *a;
1164 register int count = 0;
1166 for (p = s; *p != '\0'; ++p) {
1167 for (a = accept; *a != '\0'; ++a) {
1168 if (*p == *a) break;
1170 if (*a == '\0') return count;
1176 /* ========================================================================
1177 * Return the length of the maximum inital segment of s
1178 * which contains no characters from reject.
1180 int strcspn(s, reject)
1184 register int count = 0;
1186 while (*s != '\0') {
1187 if (strchr(reject, *s++) != NULL) return count;
1193 #endif /* NO_STRING_H */
1196 /* ========================================================================
1202 fprintf(stderr, "\n%s\n", m);
1207 char *a, *b; /* message strings juxtaposed in output */
1209 WARN((stderr, "warning: %s%s\n", a, b));
1214 fprintf(stderr, "\n");
1218 fprintf(stderr, "unexpected end of file\n");
1225 fprintf(stderr, "\n");
1231 /* ========================================================================
1232 * Semi-safe malloc -- never returns NULL.
1234 voidp xmalloc (size)
1237 voidp cp = (voidp)malloc (size);
1239 if (cp == NULL) error("out of memory");
1243 /* ========================================================================
1244 * Table of CRC-32's of all single-byte values (made by makecrc.c)
1246 const ulg crc_32_tab[] = {
1247 0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
1248 0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
1249 0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L,
1250 0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL,
1251 0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L,
1252 0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L,
1253 0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L,
1254 0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL,
1255 0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L,
1256 0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL,
1257 0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L,
1258 0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L,
1259 0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L,
1260 0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL,
1261 0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL,
1262 0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L,
1263 0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL,
1264 0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L,
1265 0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L,
1266 0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L,
1267 0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL,
1268 0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L,
1269 0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L,
1270 0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL,
1271 0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L,
1272 0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L,
1273 0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L,
1274 0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L,
1275 0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L,
1276 0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL,
1277 0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL,
1278 0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L,
1279 0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L,
1280 0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL,
1281 0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL,
1282 0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L,
1283 0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL,
1284 0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L,
1285 0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL,
1286 0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L,
1287 0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL,
1288 0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L,
1289 0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L,
1290 0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL,
1291 0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L,
1292 0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L,
1293 0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L,
1294 0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L,
1295 0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L,
1296 0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L,
1297 0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL,
1300 /* inflate.c -- Not copyrighted 1992 by Mark Adler
1301 version c10p1, 10 January 1993 */
1303 /* You can do whatever you like with this source file, though I would
1304 prefer that if you modify it and redistribute it that you include
1305 comments to that effect with your name and the date. Thank you.
1306 [The history has been moved to the file ChangeLog.]
1310 Inflate deflated (PKZIP's method 8 compressed) data. The compression
1311 method searches for as much of the current string of bytes (up to a
1312 length of 258) in the previous 32K bytes. If it doesn't find any
1313 matches (of at least length 3), it codes the next byte. Otherwise, it
1314 codes the length of the matched string and its distance backwards from
1315 the current position. There is a single Huffman code that codes both
1316 single bytes (called "literals") and match lengths. A second Huffman
1317 code codes the distance information, which follows a length code. Each
1318 length or distance code actually represents a base value and a number
1319 of "extra" (sometimes zero) bits to get to add to the base value. At
1320 the end of each deflated block is a special end-of-block (EOB) literal/
1321 length code. The decoding process is basically: get a literal/length
1322 code; if EOB then done; if a literal, emit the decoded byte; if a
1323 length then get the distance and emit the referred-to bytes from the
1324 sliding window of previously emitted data.
1326 There are (currently) three kinds of inflate blocks: stored, fixed, and
1327 dynamic. The compressor deals with some chunk of data at a time, and
1328 decides which method to use on a chunk-by-chunk basis. A chunk might
1329 typically be 32K or 64K. If the chunk is uncompressible, then the
1330 "stored" method is used. In this case, the bytes are simply stored as
1331 is, eight bits per byte, with none of the above coding. The bytes are
1332 preceded by a count, since there is no longer an EOB code.
1334 If the data is compressible, then either the fixed or dynamic methods
1335 are used. In the dynamic method, the compressed data is preceded by
1336 an encoding of the literal/length and distance Huffman codes that are
1337 to be used to decode this block. The representation is itself Huffman
1338 coded, and so is preceded by a description of that code. These code
1339 descriptions take up a little space, and so for small blocks, there is
1340 a predefined set of codes, called the fixed codes. The fixed method is
1341 used if the block codes up smaller that way (usually for quite small
1342 chunks), otherwise the dynamic method is used. In the latter case, the
1343 codes are customized to the probabilities in the current block, and so
1344 can code it much better than the pre-determined fixed codes.
1346 The Huffman codes themselves are decoded using a mutli-level table
1347 lookup, in order to maximize the speed of decoding plus the speed of
1348 building the decoding tables. See the comments below that precede the
1349 lbits and dbits tuning parameters.
1354 Notes beyond the 1.93a appnote.txt:
1356 1. Distance pointers never point before the beginning of the output
1358 2. Distance pointers can point back across blocks, up to 32k away.
1359 3. There is an implied maximum of 7 bits for the bit length table and
1360 15 bits for the actual data.
1361 4. If only one code exists, then it is encoded using one bit. (Zero
1362 would be more efficient, but perhaps a little confusing.) If two
1363 codes exist, they are coded using one bit each (0 and 1).
1364 5. There is no way of sending zero distance codes--a dummy must be
1365 sent if there are none. (History: a pre 2.0 version of PKZIP would
1366 store blocks with no distance codes, but this was discovered to be
1367 too harsh a criterion.) Valid only for 1.93a. 2.04c does allow
1368 zero distance codes, which is sent as one code of zero bits in
1370 6. There are up to 286 literal/length codes. Code 256 represents the
1371 end-of-block. Note however that the static length tree defines
1372 288 codes just to fill out the Huffman codes. Codes 286 and 287
1373 cannot be used though, since there is no length base or extra bits
1374 defined for them. Similarly, there are up to 30 distance codes.
1375 However, static trees define 32 codes (all 5 bits) to fill out the
1376 Huffman codes, but the last two had better not show up in the data.
1377 7. Unzip can check dynamic Huffman blocks for complete code sets.
1378 The exception is that a single code would not be complete (see #4).
1379 8. The five bits following the block type is really the number of
1380 literal codes sent minus 257.
1381 9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits
1382 (1+6+6). Therefore, to output three times the length, you output
1383 three codes (1+1+1), whereas to output four times the same length,
1384 you only need two codes (1+3). Hmm.
1385 10. In the tree reconstruction algorithm, Code = Code + Increment
1386 only if BitLength(i) is not zero. (Pretty obvious.)
1387 11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19)
1388 12. Note: length code 284 can represent 227-258, but length code 285
1389 really is 258. The last length deserves its own, short code
1390 since it gets used a lot in very redundant files. The length
1391 258 is special since 258 - 3 (the min match length) is 255.
1392 13. The literal/length and distance code bit lengths are read as a
1393 single stream of lengths. It is possible (and advantageous) for
1394 a repeat code (16, 17, or 18) to go across the boundary between
1395 the two sets of lengths.
1398 #include <sys/types.h>
1400 #if defined(STDC_HEADERS) || !defined(NO_STDLIB_H)
1401 # include <stdlib.h>
1405 #define slide window
1407 /* Huffman code lookup table entry--this entry is four bytes for machines
1408 that have 16-bit pointers (e.g. PC's in the small or medium model).
1409 Valid extra bits are 0..13. e == 15 is EOB (end of block), e == 16
1410 means that v is a literal, 16 < e < 32 means that v is a pointer to
1411 the next table, which codes e - 16 bits, and lastly e == 99 indicates
1412 an unused code. If a code with e == 99 is looked up, this implies an
1413 error in the data. */
1415 uch e; /* number of extra bits or operation */
1416 uch b; /* number of bits in this code or subcode */
1418 ush n; /* literal, length base, or distance base */
1419 struct huft *t; /* pointer to next level of table */
1424 /* Function prototypes */
1425 int huft_build OF((unsigned *, unsigned, unsigned, ush *, ush *,
1426 struct huft **, int *));
1427 int huft_free OF((struct huft *));
1428 int inflate_codes OF((struct huft *, struct huft *, int, int));
1429 int inflate_stored OF((void));
1430 int inflate_fixed OF((void));
1431 int inflate_dynamic OF((void));
1432 int inflate_block OF((int *));
1433 int inflate OF((void));
1436 /* The inflate algorithm uses a sliding 32K byte window on the uncompressed
1437 stream to find repeated byte strings. This is implemented here as a
1438 circular buffer. The index is updated simply by incrementing and then
1439 and'ing with 0x7fff (32K-1). */
1440 /* It is left to other modules to supply the 32K area. It is assumed
1441 to be usable as if it were declared "uch slide[32768];" or as just
1442 "uch *slide;" and then malloc'ed in the latter case. The definition
1443 must be in unzip.h, included above. */
1444 /* unsigned wp; current position in slide */
1446 #define flush_output(w) (wp=(w),flush_window())
1448 /* Tables for deflate from PKZIP's appnote.txt. */
1449 static unsigned border[] = { /* Order of the bit length code lengths */
1450 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
1451 static ush cplens[] = { /* Copy lengths for literal codes 257..285 */
1452 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
1453 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
1454 /* note: see note #13 above about the 258 in this list. */
1455 static ush cplext[] = { /* Extra bits for literal codes 257..285 */
1456 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
1457 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 99, 99}; /* 99==invalid */
1458 static ush cpdist[] = { /* Copy offsets for distance codes 0..29 */
1459 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
1460 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
1461 8193, 12289, 16385, 24577};
1462 static ush cpdext[] = { /* Extra bits for distance codes */
1463 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
1464 7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
1469 /* Macros for inflate() bit peeking and grabbing.
1473 x = b & mask_bits[j];
1476 where NEEDBITS makes sure that b has at least j bits in it, and
1477 DUMPBITS removes the bits from b. The macros use the variable k
1478 for the number of bits in b. Normally, b and k are register
1479 variables for speed, and are initialized at the beginning of a
1480 routine that uses these macros from a global bit buffer and count.
1482 If we assume that EOB will be the longest code, then we will never
1483 ask for bits with NEEDBITS that are beyond the end of the stream.
1484 So, NEEDBITS should not read any more bytes than are needed to
1485 meet the request. Then no bytes need to be "returned" to the buffer
1486 at the end of the last block.
1488 However, this assumption is not true for fixed blocks--the EOB code
1489 is 7 bits, but the other literal/length codes can be 8 or 9 bits.
1490 (The EOB code is shorter than other codes because fixed blocks are
1491 generally short. So, while a block always has an EOB, many other
1492 literal/length codes have a significantly lower probability of
1493 showing up at all.) However, by making the first table have a
1494 lookup of seven bits, the EOB code will be found in that first
1495 lookup, and so will not require that too many bits be pulled from
1499 ulg bb; /* bit buffer */
1500 unsigned bk; /* bits in bit buffer */
1504 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
1505 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
1510 # define NEXTBYTE() (cc = get_byte(), zdecode(cc), cc)
1512 # define NEXTBYTE() (uch)get_byte()
1514 #define NEEDBITS(n) {while(k<(n)){b|=((ulg)NEXTBYTE())<<k;k+=8;}}
1515 #define DUMPBITS(n) {b>>=(n);k-=(n);}
1519 Huffman code decoding is performed using a multi-level table lookup.
1520 The fastest way to decode is to simply build a lookup table whose
1521 size is determined by the longest code. However, the time it takes
1522 to build this table can also be a factor if the data being decoded
1523 is not very long. The most common codes are necessarily the
1524 shortest codes, so those codes dominate the decoding time, and hence
1525 the speed. The idea is you can have a shorter table that decodes the
1526 shorter, more probable codes, and then point to subsidiary tables for
1527 the longer codes. The time it costs to decode the longer codes is
1528 then traded against the time it takes to make longer tables.
1530 This results of this trade are in the variables lbits and dbits
1531 below. lbits is the number of bits the first level table for literal/
1532 length codes can decode in one step, and dbits is the same thing for
1533 the distance codes. Subsequent tables are also less than or equal to
1534 those sizes. These values may be adjusted either when all of the
1535 codes are shorter than that, in which case the longest code length in
1536 bits is used, or when the shortest code is *longer* than the requested
1537 table size, in which case the length of the shortest code in bits is
1540 There are two different values for the two tables, since they code a
1541 different number of possibilities each. The literal/length table
1542 codes 286 possible values, or in a flat code, a little over eight
1543 bits. The distance table codes 30 possible values, or a little less
1544 than five bits, flat. The optimum values for speed end up being
1545 about one bit more than those, so lbits is 8+1 and dbits is 5+1.
1546 The optimum values may differ though from machine to machine, and
1547 possibly even between compilers. Your mileage may vary.
1551 int lbits = 9; /* bits in base literal/length lookup table */
1552 int dbits = 6; /* bits in base distance lookup table */
1555 /* If BMAX needs to be larger than 16, then h and x[] should be ulg. */
1556 #define BMAX 16 /* maximum bit length of any code (16 for explode) */
1557 #define N_MAX 288 /* maximum number of codes in any set */
1560 unsigned hufts; /* track memory usage */
1563 int huft_build(b, n, s, d, e, t, m)
1564 unsigned *b; /* code lengths in bits (all assumed <= BMAX) */
1565 unsigned n; /* number of codes (assumed <= N_MAX) */
1566 unsigned s; /* number of simple-valued codes (0..s-1) */
1567 ush *d; /* list of base values for non-simple codes */
1568 ush *e; /* list of extra bits for non-simple codes */
1569 struct huft **t; /* result: starting table */
1570 int *m; /* maximum lookup bits, returns actual */
1571 /* Given a list of code lengths and a maximum table size, make a set of
1572 tables to decode that set of codes. Return zero on success, one if
1573 the given code set is incomplete (the tables are still built in this
1574 case), two if the input is invalid (all zero length codes or an
1575 oversubscribed set of lengths), and three if not enough memory. */
1577 unsigned a; /* counter for codes of length k */
1578 unsigned c[BMAX+1]; /* bit length count table */
1579 unsigned f; /* i repeats in table every f entries */
1580 int g; /* maximum code length */
1581 int h; /* table level */
1582 register unsigned i; /* counter, current code */
1583 register unsigned j; /* counter */
1584 register int k; /* number of bits in current code */
1585 int l; /* bits per table (returned in m) */
1586 register unsigned *p; /* pointer into c[], b[], or v[] */
1587 register struct huft *q; /* points to current table */
1588 struct huft r; /* table entry for structure assignment */
1589 struct huft *u[BMAX]; /* table stack */
1590 unsigned v[N_MAX]; /* values in order of bit length */
1591 register int w; /* bits before this table == (l * h) */
1592 unsigned x[BMAX+1]; /* bit offsets, then code stack */
1593 unsigned *xp; /* pointer into x */
1594 int y; /* number of dummy codes added */
1595 unsigned z; /* number of entries in current table */
1598 /* Generate counts for each bit length */
1599 memzero(c, sizeof(c));
1602 Tracecv(*p, (stderr, (n-i >= ' ' && n-i <= '~' ? "%c %d\n" : "0x%x %d\n"),
1604 c[*p]++; /* assume all entries <= BMAX */
1605 p++; /* Can't combine with above line (Solaris bug) */
1607 if (c[0] == n) /* null input--all zero length codes */
1609 *t = (struct huft *)NULL;
1615 /* Find minimum and maximum length, bound *m by those */
1617 for (j = 1; j <= BMAX; j++)
1620 k = j; /* minimum code length */
1621 if ((unsigned)l < j)
1623 for (i = BMAX; i; i--)
1626 g = i; /* maximum code length */
1627 if ((unsigned)l > i)
1632 /* Adjust last length count to fill out codes, if needed */
1633 for (y = 1 << j; j < i; j++, y <<= 1)
1634 if ((y -= c[j]) < 0)
1635 return 2; /* bad input: more codes than bits */
1636 if ((y -= c[i]) < 0)
1641 /* Generate starting offsets into the value table for each length */
1643 p = c + 1; xp = x + 2;
1644 while (--i) { /* note that i == g from above */
1645 *xp++ = (j += *p++);
1649 /* Make a table of values in order of bit lengths */
1652 if ((j = *p++) != 0)
1657 /* Generate the Huffman codes and for each, make the table entries */
1658 x[0] = i = 0; /* first Huffman code is zero */
1659 p = v; /* grab values in bit order */
1660 h = -1; /* no tables yet--level -1 */
1661 w = -l; /* bits decoded == (l * h) */
1662 u[0] = (struct huft *)NULL; /* just to keep compilers happy */
1663 q = (struct huft *)NULL; /* ditto */
1666 /* go through the bit lengths (k already is bits in shortest code) */
1672 /* here i is the Huffman code of length k bits for value *p */
1673 /* make tables up to required level */
1677 w += l; /* previous table always l bits */
1679 /* compute minimum size table less than or equal to l bits */
1680 z = (z = g - w) > (unsigned)l ? l : z; /* upper limit on table size */
1681 if ((f = 1 << (j = k - w)) > a + 1) /* try a k-w bit table */
1682 { /* too few codes for k-w bit table */
1683 f -= a + 1; /* deduct codes from patterns left */
1685 while (++j < z) /* try smaller tables up to z bits */
1687 if ((f <<= 1) <= *++xp)
1688 break; /* enough codes to use up j bits */
1689 f -= *xp; /* else deduct codes from patterns */
1692 z = 1 << j; /* table entries for j-bit table */
1694 /* allocate and link in new table */
1695 if ((q = (struct huft *)malloc((z + 1)*sizeof(struct huft))) ==
1696 (struct huft *)NULL)
1700 return 3; /* not enough memory */
1702 hufts += z + 1; /* track memory usage */
1703 *t = q + 1; /* link to list for huft_free() */
1704 *(t = &(q->v.t)) = (struct huft *)NULL;
1705 u[h] = ++q; /* table starts after link */
1707 /* connect to last table, if there is one */
1710 x[h] = i; /* save pattern for backing up */
1711 r.b = (uch)l; /* bits to dump before this table */
1712 r.e = (uch)(16 + j); /* bits in this table */
1713 r.v.t = q; /* pointer to this table */
1714 j = i >> (w - l); /* (get around Turbo C bug) */
1715 u[h-1][j] = r; /* connect to last table */
1719 /* set up table entry in r */
1722 r.e = 99; /* out of values--invalid code */
1725 r.e = (uch)(*p < 256 ? 16 : 15); /* 256 is end-of-block code */
1726 r.v.n = (ush)(*p); /* simple code is just the value */
1727 p++; /* one compiler does not like *p++ */
1731 r.e = (uch)e[*p - s]; /* non-simple--look up in lists */
1732 r.v.n = d[*p++ - s];
1735 /* fill code-like entries with r */
1737 for (j = i >> w; j < z; j += f)
1740 /* backwards increment the k-bit code i */
1741 for (j = 1 << (k - 1); i & j; j >>= 1)
1745 /* backup over finished tables */
1746 while ((i & ((1 << w) - 1)) != x[h])
1748 h--; /* don't need to update q */
1755 /* Return true (1) if we were given an incomplete table */
1756 return y != 0 && g != 1;
1762 struct huft *t; /* table to free */
1763 /* Free the malloc'ed tables built by huft_build(), which makes a linked
1764 list of the tables it made, with the links in a dummy first entry of
1767 register struct huft *p, *q;
1770 /* Go through linked list, freeing from the malloced (t[-1]) address. */
1772 while (p != (struct huft *)NULL)
1782 int inflate_codes(tl, td, bl, bd)
1783 struct huft *tl, *td; /* literal/length and distance decoder tables */
1784 int bl, bd; /* number of bits decoded by tl[] and td[] */
1785 /* inflate (decompress) the codes in a deflated (compressed) block.
1786 Return an error code or zero if it all goes ok. */
1788 register unsigned e; /* table entry flag/number of extra bits */
1789 unsigned n, d; /* length and index for copy */
1790 unsigned w; /* current window position */
1791 struct huft *t; /* pointer to table entry */
1792 unsigned ml, md; /* masks for bl and bd bits */
1793 register ulg b; /* bit buffer */
1794 register unsigned k; /* number of bits in bit buffer */
1797 /* make local copies of globals */
1798 b = bb; /* initialize bit buffer */
1800 w = wp; /* initialize window position */
1802 /* inflate the coded data */
1803 ml = mask_bits[bl]; /* precompute masks for speed */
1805 for (;;) /* do until end of block */
1807 NEEDBITS((unsigned)bl)
1808 if ((e = (t = tl + ((unsigned)b & ml))->e) > 16)
1815 } while ((e = (t = t->v.t + ((unsigned)b & mask_bits[e]))->e) > 16);
1817 if (e == 16) /* then it's a literal */
1819 slide[w++] = (uch)t->v.n;
1820 Tracevv((stderr, "%c", slide[w-1]));
1827 else /* it's an EOB or a length */
1829 /* exit if end of block */
1833 /* get length of block to copy */
1835 n = t->v.n + ((unsigned)b & mask_bits[e]);
1838 /* decode distance of block to copy */
1839 NEEDBITS((unsigned)bd)
1840 if ((e = (t = td + ((unsigned)b & md))->e) > 16)
1847 } while ((e = (t = t->v.t + ((unsigned)b & mask_bits[e]))->e) > 16);
1850 d = w - t->v.n - ((unsigned)b & mask_bits[e]);
1852 Tracevv((stderr,"\\[%d,%d]", w-d, n));
1856 n -= (e = (e = WSIZE - ((d &= WSIZE-1) > w ? d : w)) > n ? n : e);
1857 #if !defined(NOMEMCPY) && !defined(DEBUG)
1858 if (w - d >= e) /* (this test assumes unsigned comparison) */
1860 memcpy(slide + w, slide + d, e);
1864 else /* do it slow to avoid memcpy() overlap */
1865 #endif /* !NOMEMCPY */
1867 slide[w++] = slide[d++];
1868 Tracevv((stderr, "%c", slide[w-1]));
1880 /* restore the globals from the locals */
1881 wp = w; /* restore global window pointer */
1882 bb = b; /* restore global bit buffer */
1891 int inflate_stored()
1892 /* "decompress" an inflated type 0 (stored) block. */
1894 unsigned n; /* number of bytes in block */
1895 unsigned w; /* current window position */
1896 register ulg b; /* bit buffer */
1897 register unsigned k; /* number of bits in bit buffer */
1900 /* make local copies of globals */
1901 b = bb; /* initialize bit buffer */
1903 w = wp; /* initialize window position */
1906 /* go to byte boundary */
1911 /* get the length and its complement */
1913 n = ((unsigned)b & 0xffff);
1916 if (n != (unsigned)((~b) & 0xffff))
1917 return 1; /* error in compressed data */
1921 /* read and output the compressed data */
1925 slide[w++] = (uch)b;
1935 /* restore the globals from the locals */
1936 wp = w; /* restore global window pointer */
1937 bb = b; /* restore global bit buffer */
1945 /* decompress an inflated type 1 (fixed Huffman codes) block. We should
1946 either replace this with a custom decoder, or at least precompute the
1949 int i; /* temporary variable */
1950 struct huft *tl; /* literal/length code table */
1951 struct huft *td; /* distance code table */
1952 int bl; /* lookup bits for tl */
1953 int bd; /* lookup bits for td */
1954 unsigned l[288]; /* length list for huft_build */
1957 /* set up literal table */
1958 for (i = 0; i < 144; i++)
1960 for (; i < 256; i++)
1962 for (; i < 280; i++)
1964 for (; i < 288; i++) /* make a complete, but wrong code set */
1967 if ((i = huft_build(l, 288, 257, cplens, cplext, &tl, &bl)) != 0)
1971 /* set up distance table */
1972 for (i = 0; i < 30; i++) /* make an incomplete code set */
1975 if ((i = huft_build(l, 30, 0, cpdist, cpdext, &td, &bd)) > 1)
1982 /* decompress until an end-of-block code */
1983 if (inflate_codes(tl, td, bl, bd))
1987 /* free the decoding tables, return */
1995 int inflate_dynamic()
1996 /* decompress an inflated type 2 (dynamic Huffman codes) block. */
1998 int i; /* temporary variables */
2000 unsigned l; /* last length */
2001 unsigned m; /* mask for bit lengths table */
2002 unsigned n; /* number of lengths to get */
2003 struct huft *tl; /* literal/length code table */
2004 struct huft *td; /* distance code table */
2005 int bl; /* lookup bits for tl */
2006 int bd; /* lookup bits for td */
2007 unsigned nb; /* number of bit length codes */
2008 unsigned nl; /* number of literal/length codes */
2009 unsigned nd; /* number of distance codes */
2010 #ifdef PKZIP_BUG_WORKAROUND
2011 unsigned ll[288+32]; /* literal/length and distance code lengths */
2013 unsigned ll[286+30]; /* literal/length and distance code lengths */
2015 register ulg b; /* bit buffer */
2016 register unsigned k; /* number of bits in bit buffer */
2019 /* make local bit buffer */
2024 /* read in table lengths */
2026 nl = 257 + ((unsigned)b & 0x1f); /* number of literal/length codes */
2029 nd = 1 + ((unsigned)b & 0x1f); /* number of distance codes */
2032 nb = 4 + ((unsigned)b & 0xf); /* number of bit length codes */
2034 #ifdef PKZIP_BUG_WORKAROUND
2035 if (nl > 288 || nd > 32)
2037 if (nl > 286 || nd > 30)
2039 return 1; /* bad lengths */
2042 /* read in bit-length-code lengths */
2043 for (j = 0; j < nb; j++)
2046 ll[border[j]] = (unsigned)b & 7;
2053 /* build decoding table for trees--single level, 7 bit lookup */
2055 if ((i = huft_build(ll, 19, 19, NULL, NULL, &tl, &bl)) != 0)
2059 return i; /* incomplete code set */
2063 /* read in literal and distance code lengths */
2067 while ((unsigned)i < n)
2069 NEEDBITS((unsigned)bl)
2070 j = (td = tl + ((unsigned)b & m))->b;
2073 if (j < 16) /* length of code in bits (0..15) */
2074 ll[i++] = l = j; /* save last length in l */
2075 else if (j == 16) /* repeat last length 3 to 6 times */
2078 j = 3 + ((unsigned)b & 3);
2080 if ((unsigned)i + j > n)
2085 else if (j == 17) /* 3 to 10 zero length codes */
2088 j = 3 + ((unsigned)b & 7);
2090 if ((unsigned)i + j > n)
2096 else /* j == 18: 11 to 138 zero length codes */
2099 j = 11 + ((unsigned)b & 0x7f);
2101 if ((unsigned)i + j > n)
2110 /* free decoding table for trees */
2114 /* restore the global bit buffer */
2119 /* build the decoding tables for literal/length and distance codes */
2121 if ((i = huft_build(ll, nl, 257, cplens, cplext, &tl, &bl)) != 0)
2124 fprintf(stderr, " incomplete literal tree\n");
2127 return i; /* incomplete code set */
2130 if ((i = huft_build(ll + nl, nd, 0, cpdist, cpdext, &td, &bd)) != 0)
2133 fprintf(stderr, " incomplete distance tree\n");
2134 #ifdef PKZIP_BUG_WORKAROUND
2141 return i; /* incomplete code set */
2146 /* decompress until an end-of-block code */
2147 if (inflate_codes(tl, td, bl, bd))
2151 /* free the decoding tables, return */
2159 int inflate_block(e)
2160 int *e; /* last block flag */
2161 /* decompress an inflated block */
2163 unsigned t; /* block type */
2164 register ulg b; /* bit buffer */
2165 register unsigned k; /* number of bits in bit buffer */
2168 /* make local bit buffer */
2173 /* read in last block bit */
2179 /* read in block type */
2181 t = (unsigned)b & 3;
2185 /* restore the global bit buffer */
2190 /* inflate that block type */
2192 return inflate_dynamic();
2194 return inflate_stored();
2196 return inflate_fixed();
2199 /* bad block type */
2206 /* decompress an inflated entry */
2208 int e; /* last block flag */
2209 int r; /* result code */
2210 unsigned h; /* maximum struct huft's malloc'ed */
2213 /* initialize window, bit buffer */
2219 /* decompress until the last block */
2223 if ((r = inflate_block(&e)) != 0)
2229 /* Undo too much lookahead. The next read will be byte aligned so we
2230 * can discard unused bits in the last meaningful byte.
2237 /* flush out slide */
2241 /* return success */
2243 fprintf(stderr, "<%u> ", h);