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+++ b/zcat.c
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+/* zcat : stripped version based on gzip sources
+ Sven Rudolph <sr1@inf.tu-dresden.de>
+ */
+
+#include "internal.h"
+
+const char zcat_usage[] = "zcat\n"
+"\n"
+"\tuncompress gzipped data from stdin to stdout\n";
+
+
+
+/* gzip (GNU zip) -- compress files with zip algorithm and 'compress' interface
+ * Copyright (C) 1992-1993 Jean-loup Gailly
+ * The unzip code was written and put in the public domain by Mark Adler.
+ * Portions of the lzw code are derived from the public domain 'compress'
+ * written by Spencer Thomas, Joe Orost, James Woods, Jim McKie, Steve Davies,
+ * Ken Turkowski, Dave Mack and Peter Jannesen.
+ *
+ * See the license_msg below and the file COPYING for the software license.
+ * See the file algorithm.doc for the compression algorithms and file formats.
+ */
+
+#if 0
+static char *license_msg[] = {
+" Copyright (C) 1992-1993 Jean-loup Gailly",
+" This program is free software; you can redistribute it and/or modify",
+" it under the terms of the GNU General Public License as published by",
+" the Free Software Foundation; either version 2, or (at your option)",
+" any later version.",
+"",
+" This program is distributed in the hope that it will be useful,",
+" but WITHOUT ANY WARRANTY; without even the implied warranty of",
+" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the",
+" GNU General Public License for more details.",
+"",
+" You should have received a copy of the GNU General Public License",
+" along with this program; if not, write to the Free Software",
+" Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.",
+0};
+#endif
+
+/* Compress files with zip algorithm and 'compress' interface.
+ * See usage() and help() functions below for all options.
+ * Outputs:
+ * file.gz: compressed file with same mode, owner, and utimes
+ * or stdout with -c option or if stdin used as input.
+ * If the output file name had to be truncated, the original name is kept
+ * in the compressed file.
+ * On MSDOS, file.tmp -> file.tmz. On VMS, file.tmp -> file.tmp-gz.
+ *
+ * Using gz on MSDOS would create too many file name conflicts. For
+ * example, foo.txt -> foo.tgz (.tgz must be reserved as shorthand for
+ * tar.gz). Similarly, foo.dir and foo.doc would both be mapped to foo.dgz.
+ * I also considered 12345678.txt -> 12345txt.gz but this truncates the name
+ * too heavily. There is no ideal solution given the MSDOS 8+3 limitation.
+ *
+ * For the meaning of all compilation flags, see comments in Makefile.in.
+ */
+
+#ifdef RCSID
+static char rcsid[] = "$Id: zcat.c,v 1.1 1999/10/05 16:24:56 andersen Exp $";
+#endif
+
+#include <ctype.h>
+#include <sys/types.h>
+#include <signal.h>
+#include <sys/stat.h>
+#include <errno.h>
+
+/* #include "tailor.h" */
+
+/* tailor.h -- target dependent definitions
+ * Copyright (C) 1992-1993 Jean-loup Gailly.
+ * This is free software; you can redistribute it and/or modify it under the
+ * terms of the GNU General Public License, see the file COPYING.
+ */
+
+/* The target dependent definitions should be defined here only.
+ * The target dependent functions should be defined in tailor.c.
+ */
+
+/* $Id: zcat.c,v 1.1 1999/10/05 16:24:56 andersen Exp $ */
+
+#define RECORD_IO 0
+
+#define get_char() get_byte()
+#define put_char(c) put_byte(c)
+
+/* #include "gzip.h" */
+
+/* gzip.h -- common declarations for all gzip modules
+ * Copyright (C) 1992-1993 Jean-loup Gailly.
+ * This is free software; you can redistribute it and/or modify it under the
+ * terms of the GNU General Public License, see the file COPYING.
+ */
+
+#if defined(__STDC__) || defined(PROTO)
+# define OF(args) args
+#else
+# define OF(args) ()
+#endif
+
+#ifdef __STDC__
+ typedef void *voidp;
+#else
+ typedef char *voidp;
+#endif
+
+/* I don't like nested includes, but the string and io functions are used
+ * too often
+ */
+#include <stdio.h>
+#if !defined(NO_STRING_H) || defined(STDC_HEADERS)
+# include <string.h>
+# if !defined(STDC_HEADERS) && !defined(NO_MEMORY_H) && !defined(__GNUC__)
+# include <memory.h>
+# endif
+# define memzero(s, n) memset ((voidp)(s), 0, (n))
+#else
+# include <strings.h>
+# define strchr index
+# define strrchr rindex
+# define memcpy(d, s, n) bcopy((s), (d), (n))
+# define memcmp(s1, s2, n) bcmp((s1), (s2), (n))
+# define memzero(s, n) bzero((s), (n))
+#endif
+
+#ifndef RETSIGTYPE
+# define RETSIGTYPE void
+#endif
+
+#define local static
+
+typedef unsigned char uch;
+typedef unsigned short ush;
+typedef unsigned long ulg;
+
+/* Return codes from gzip */
+#define OK 0
+#define ERROR 1
+#define WARNING 2
+
+/* Compression methods (see algorithm.doc) */
+#define DEFLATED 8
+
+extern int method; /* compression method */
+
+/* To save memory for 16 bit systems, some arrays are overlaid between
+ * the various modules:
+ * deflate: prev+head window d_buf l_buf outbuf
+ * unlzw: tab_prefix tab_suffix stack inbuf outbuf
+ * inflate: window inbuf
+ * unpack: window inbuf prefix_len
+ * unlzh: left+right window c_table inbuf c_len
+ * For compression, input is done in window[]. For decompression, output
+ * is done in window except for unlzw.
+ */
+
+#ifndef INBUFSIZ
+# ifdef SMALL_MEM
+# define INBUFSIZ 0x2000 /* input buffer size */
+# else
+# define INBUFSIZ 0x8000 /* input buffer size */
+# endif
+#endif
+#define INBUF_EXTRA 64 /* required by unlzw() */
+
+#ifndef OUTBUFSIZ
+# ifdef SMALL_MEM
+# define OUTBUFSIZ 8192 /* output buffer size */
+# else
+# define OUTBUFSIZ 16384 /* output buffer size */
+# endif
+#endif
+#define OUTBUF_EXTRA 2048 /* required by unlzw() */
+
+#define SMALL_MEM
+
+#ifndef DIST_BUFSIZE
+# ifdef SMALL_MEM
+# define DIST_BUFSIZE 0x2000 /* buffer for distances, see trees.c */
+# else
+# define DIST_BUFSIZE 0x8000 /* buffer for distances, see trees.c */
+# endif
+#endif
+
+/*#define DYN_ALLOC*/
+
+#ifdef DYN_ALLOC
+# define EXTERN(type, array) extern type * array
+# define DECLARE(type, array, size) type * array
+# define ALLOC(type, array, size) { \
+ array = (type*)calloc((size_t)(((size)+1L)/2), 2*sizeof(type)); \
+ if (array == NULL) error("insufficient memory"); \
+ }
+# define FREE(array) {if (array != NULL) free(array), array=NULL;}
+#else
+# define EXTERN(type, array) extern type array[]
+# define DECLARE(type, array, size) type array[size]
+# define ALLOC(type, array, size)
+# define FREE(array)
+#endif
+
+EXTERN(uch, inbuf); /* input buffer */
+EXTERN(uch, outbuf); /* output buffer */
+EXTERN(ush, d_buf); /* buffer for distances, see trees.c */
+EXTERN(uch, window); /* Sliding window and suffix table (unlzw) */
+#define tab_suffix window
+#ifndef MAXSEG_64K
+# define tab_prefix prev /* hash link (see deflate.c) */
+# define head (prev+WSIZE) /* hash head (see deflate.c) */
+ EXTERN(ush, tab_prefix); /* prefix code (see unlzw.c) */
+#else
+# define tab_prefix0 prev
+# define head tab_prefix1
+ EXTERN(ush, tab_prefix0); /* prefix for even codes */
+ EXTERN(ush, tab_prefix1); /* prefix for odd codes */
+#endif
+
+extern unsigned insize; /* valid bytes in inbuf */
+extern unsigned inptr; /* index of next byte to be processed in inbuf */
+extern unsigned outcnt; /* bytes in output buffer */
+
+extern long bytes_in; /* number of input bytes */
+extern long bytes_out; /* number of output bytes */
+extern long header_bytes;/* number of bytes in gzip header */
+
+extern int ifd; /* input file descriptor */
+extern int ofd; /* output file descriptor */
+
+extern long ifile_size; /* input file size, -1 for devices (debug only) */
+
+typedef int file_t; /* Do not use stdio */
+#define NO_FILE (-1) /* in memory compression */
+
+
+#define GZIP_MAGIC "\037\213" /* Magic header for gzip files, 1F 8B */
+
+/* gzip flag byte */
+#define ASCII_FLAG 0x01 /* bit 0 set: file probably ascii text */
+#define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
+#define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
+#define ORIG_NAME 0x08 /* bit 3 set: original file name present */
+#define COMMENT 0x10 /* bit 4 set: file comment present */
+#define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */
+#define RESERVED 0xC0 /* bit 6,7: reserved */
+
+#ifndef WSIZE
+# define WSIZE 0x8000 /* window size--must be a power of two, and */
+#endif /* at least 32K for zip's deflate method */
+
+#define MIN_MATCH 3
+#define MAX_MATCH 258
+/* The minimum and maximum match lengths */
+
+#define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
+/* Minimum amount of lookahead, except at the end of the input file.
+ * See deflate.c for comments about the MIN_MATCH+1.
+ */
+
+#define MAX_DIST (WSIZE-MIN_LOOKAHEAD)
+/* In order to simplify the code, particularly on 16 bit machines, match
+ * distances are limited to MAX_DIST instead of WSIZE.
+ */
+
+extern int exit_code; /* program exit code */
+extern int verbose; /* be verbose (-v) */
+extern int level; /* compression level */
+extern int test; /* check .z file integrity */
+extern int to_stdout; /* output to stdout (-c) */
+extern int save_orig_name; /* set if original name must be saved */
+
+#define get_byte() (inptr < insize ? inbuf[inptr++] : fill_inbuf(0))
+#define try_byte() (inptr < insize ? inbuf[inptr++] : fill_inbuf(1))
+
+/* put_byte is used for the compressed output, put_ubyte for the
+ * uncompressed output. However unlzw() uses window for its
+ * suffix table instead of its output buffer, so it does not use put_ubyte
+ * (to be cleaned up).
+ */
+#define put_byte(c) {outbuf[outcnt++]=(uch)(c); if (outcnt==OUTBUFSIZ)\
+ flush_outbuf();}
+#define put_ubyte(c) {window[outcnt++]=(uch)(c); if (outcnt==WSIZE)\
+ flush_window();}
+
+/* Output a 16 bit value, lsb first */
+#define put_short(w) \
+{ if (outcnt < OUTBUFSIZ-2) { \
+ outbuf[outcnt++] = (uch) ((w) & 0xff); \
+ outbuf[outcnt++] = (uch) ((ush)(w) >> 8); \
+ } else { \
+ put_byte((uch)((w) & 0xff)); \
+ put_byte((uch)((ush)(w) >> 8)); \
+ } \
+}
+
+/* Output a 32 bit value to the bit stream, lsb first */
+#define put_long(n) { \
+ put_short((n) & 0xffff); \
+ put_short(((ulg)(n)) >> 16); \
+}
+
+#define seekable() 0 /* force sequential output */
+#define translate_eol 0 /* no option -a yet */
+
+#define tolow(c) (isupper(c) ? (c)-'A'+'a' : (c)) /* force to lower case */
+
+/* Macros for getting two-byte and four-byte header values */
+#define SH(p) ((ush)(uch)((p)[0]) | ((ush)(uch)((p)[1]) << 8))
+#define LG(p) ((ulg)(SH(p)) | ((ulg)(SH((p)+2)) << 16))
+
+/* Diagnostic functions */
+#ifdef DEBUG
+# define Assert(cond,msg) {if(!(cond)) error(msg);}
+# define Trace(x) fprintf x
+# define Tracev(x) {if (verbose) fprintf x ;}
+# define Tracevv(x) {if (verbose>1) fprintf x ;}
+# define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
+# define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
+#else
+# define Assert(cond,msg)
+# define Trace(x)
+# define Tracev(x)
+# define Tracevv(x)
+# define Tracec(c,x)
+# define Tracecv(c,x)
+#endif
+
+#define WARN(msg) {fprintf msg ; \
+ if (exit_code == OK) exit_code = WARNING;}
+
+ /* in unzip.c */
+extern int unzip OF((int in, int out));
+
+ /* in gzip.c */
+RETSIGTYPE abort_gzip OF((void));
+
+ /* in deflate.c */
+void lm_init OF((int pack_level, ush *flags));
+ulg deflate OF((void));
+
+ /* in trees.c */
+void ct_init OF((ush *attr, int *method));
+int ct_tally OF((int dist, int lc));
+ulg flush_block OF((char *buf, ulg stored_len, int eof));
+
+ /* in bits.c */
+void bi_init OF((file_t zipfile));
+void send_bits OF((int value, int length));
+unsigned bi_reverse OF((unsigned value, int length));
+void bi_windup OF((void));
+void copy_block OF((char *buf, unsigned len, int header));
+extern int (*read_buf) OF((char *buf, unsigned size));
+
+ /* in util.c: */
+extern int copy OF((int in, int out));
+extern ulg updcrc OF((uch *s, unsigned n));
+extern void clear_bufs OF((void));
+extern int fill_inbuf OF((int eof_ok));
+extern void flush_outbuf OF((void));
+extern void flush_window OF((void));
+extern void write_buf OF((int fd, voidp buf, unsigned cnt));
+#ifndef __linux__
+extern char *basename OF((char *fname));
+#endif /* not __linux__ */
+extern void error OF((char *m));
+extern void warn OF((char *a, char *b));
+extern void read_error OF((void));
+extern void write_error OF((void));
+extern voidp xmalloc OF((unsigned int size));
+
+ /* in inflate.c */
+extern int inflate OF((void));
+
+/* #include "lzw.h" */
+
+/* lzw.h -- define the lzw functions.
+ * Copyright (C) 1992-1993 Jean-loup Gailly.
+ * This is free software; you can redistribute it and/or modify it under the
+ * terms of the GNU General Public License, see the file COPYING.
+ */
+
+#if !defined(OF) && defined(lint)
+# include "gzip.h"
+#endif
+
+#ifndef BITS
+# define BITS 16
+#endif
+#define INIT_BITS 9 /* Initial number of bits per code */
+
+#define LZW_MAGIC "\037\235" /* Magic header for lzw files, 1F 9D */
+
+#define BIT_MASK 0x1f /* Mask for 'number of compression bits' */
+/* Mask 0x20 is reserved to mean a fourth header byte, and 0x40 is free.
+ * It's a pity that old uncompress does not check bit 0x20. That makes
+ * extension of the format actually undesirable because old compress
+ * would just crash on the new format instead of giving a meaningful
+ * error message. It does check the number of bits, but it's more
+ * helpful to say "unsupported format, get a new version" than
+ * "can only handle 16 bits".
+ */
+
+#define BLOCK_MODE 0x80
+/* Block compression: if table is full and compression rate is dropping,
+ * clear the dictionary.
+ */
+
+#define LZW_RESERVED 0x60 /* reserved bits */
+
+#define CLEAR 256 /* flush the dictionary */
+#define FIRST (CLEAR+1) /* first free entry */
+
+extern int maxbits; /* max bits per code for LZW */
+extern int block_mode; /* block compress mode -C compatible with 2.0 */
+
+extern int lzw OF((int in, int out));
+extern int unlzw OF((int in, int out));
+
+
+/* #include "revision.h" */
+
+/* revision.h -- define the version number
+ * Copyright (C) 1992-1993 Jean-loup Gailly.
+ * This is free software; you can redistribute it and/or modify it under the
+ * terms of the GNU General Public License, see the file COPYING.
+ */
+
+#define VERSION "1.2.4"
+#define PATCHLEVEL 0
+#define REVDATE "18 Aug 93"
+
+/* This version does not support compression into old compress format: */
+#ifdef LZW
+# undef LZW
+#endif
+
+/* $Id: zcat.c,v 1.1 1999/10/05 16:24:56 andersen Exp $ */
+
+/* #include "getopt.h" */
+
+/* Declarations for getopt.
+ Copyright (C) 1989, 1990, 1991, 1992, 1993 Free Software Foundation, Inc.
+
+ This program is free software; you can redistribute it and/or modify it
+ under the terms of the GNU General Public License as published by the
+ Free Software Foundation; either version 2, or (at your option) any
+ later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
+
+#ifndef _GETOPT_H
+#define _GETOPT_H 1
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* For communication from `getopt' to the caller.
+ When `getopt' finds an option that takes an argument,
+ the argument value is returned here.
+ Also, when `ordering' is RETURN_IN_ORDER,
+ each non-option ARGV-element is returned here. */
+
+extern char *optarg;
+
+/* Index in ARGV of the next element to be scanned.
+ This is used for communication to and from the caller
+ and for communication between successive calls to `getopt'.
+
+ On entry to `getopt', zero means this is the first call; initialize.
+
+ When `getopt' returns EOF, this is the index of the first of the
+ non-option elements that the caller should itself scan.
+
+ Otherwise, `optind' communicates from one call to the next
+ how much of ARGV has been scanned so far. */
+
+extern int optind;
+
+/* Callers store zero here to inhibit the error message `getopt' prints
+ for unrecognized options. */
+
+extern int opterr;
+
+/* Set to an option character which was unrecognized. */
+
+extern int optopt;
+
+/* Describe the long-named options requested by the application.
+ The LONG_OPTIONS argument to getopt_long or getopt_long_only is a vector
+ of `struct option' terminated by an element containing a name which is
+ zero.
+
+ The field `has_arg' is:
+ no_argument (or 0) if the option does not take an argument,
+ required_argument (or 1) if the option requires an argument,
+ optional_argument (or 2) if the option takes an optional argument.
+
+ If the field `flag' is not NULL, it points to a variable that is set
+ to the value given in the field `val' when the option is found, but
+ left unchanged if the option is not found.
+
+ To have a long-named option do something other than set an `int' to
+ a compiled-in constant, such as set a value from `optarg', set the
+ option's `flag' field to zero and its `val' field to a nonzero
+ value (the equivalent single-letter option character, if there is
+ one). For long options that have a zero `flag' field, `getopt'
+ returns the contents of the `val' field. */
+
+struct option
+{
+#if __STDC__
+ const char *name;
+#else
+ char *name;
+#endif
+ /* has_arg can't be an enum because some compilers complain about
+ type mismatches in all the code that assumes it is an int. */
+ int has_arg;
+ int *flag;
+ int val;
+};
+
+/* Names for the values of the `has_arg' field of `struct option'. */
+
+#define no_argument 0
+#define required_argument 1
+#define optional_argument 2
+
+#if __STDC__ || defined(PROTO)
+#if defined(__GNU_LIBRARY__)
+/* Many other libraries have conflicting prototypes for getopt, with
+ differences in the consts, in stdlib.h. To avoid compilation
+ errors, only prototype getopt for the GNU C library. */
+extern int getopt (int argc, char *const *argv, const char *shortopts);
+#endif /* not __GNU_LIBRARY__ */
+extern int getopt_long (int argc, char *const *argv, const char *shortopts,
+ const struct option *longopts, int *longind);
+extern int getopt_long_only (int argc, char *const *argv,
+ const char *shortopts,
+ const struct option *longopts, int *longind);
+
+/* Internal only. Users should not call this directly. */
+extern int _getopt_internal (int argc, char *const *argv,
+ const char *shortopts,
+ const struct option *longopts, int *longind,
+ int long_only);
+#else /* not __STDC__ */
+extern int getopt ();
+extern int getopt_long ();
+extern int getopt_long_only ();
+
+extern int _getopt_internal ();
+#endif /* not __STDC__ */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _GETOPT_H */
+
+
+#include <time.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include <stdlib.h>
+
+#if defined(DIRENT)
+# include <dirent.h>
+ typedef struct dirent dir_type;
+# define NLENGTH(dirent) ((int)strlen((dirent)->d_name))
+# define DIR_OPT "DIRENT"
+#else
+# define NLENGTH(dirent) ((dirent)->d_namlen)
+# ifdef SYSDIR
+# include <sys/dir.h>
+ typedef struct direct dir_type;
+# define DIR_OPT "SYSDIR"
+# else
+# ifdef SYSNDIR
+# include <sys/ndir.h>
+ typedef struct direct dir_type;
+# define DIR_OPT "SYSNDIR"
+# else
+# ifdef NDIR
+# include <ndir.h>
+ typedef struct direct dir_type;
+# define DIR_OPT "NDIR"
+# else
+# define NO_DIR
+# define DIR_OPT "NO_DIR"
+# endif
+# endif
+# endif
+#endif
+
+#if !defined(S_ISDIR) && defined(S_IFDIR)
+# define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
+#endif
+#if !defined(S_ISREG) && defined(S_IFREG)
+# define S_ISREG(m) (((m) & S_IFMT) == S_IFREG)
+#endif
+
+typedef RETSIGTYPE (*sig_type) OF((int));
+
+#ifndef O_BINARY
+# define O_BINARY 0 /* creation mode for open() */
+#endif
+
+#ifndef O_CREAT
+ /* Pure BSD system? */
+# include <sys/file.h>
+# ifndef O_CREAT
+# define O_CREAT FCREAT
+# endif
+# ifndef O_EXCL
+# define O_EXCL FEXCL
+# endif
+#endif
+
+#ifndef S_IRUSR
+# define S_IRUSR 0400
+#endif
+#ifndef S_IWUSR
+# define S_IWUSR 0200
+#endif
+#define RW_USER (S_IRUSR | S_IWUSR) /* creation mode for open() */
+
+#ifndef MAX_PATH_LEN
+# define MAX_PATH_LEN 1024 /* max pathname length */
+#endif
+
+#ifndef SEEK_END
+# define SEEK_END 2
+#endif
+
+#ifdef NO_OFF_T
+ typedef long off_t;
+ off_t lseek OF((int fd, off_t offset, int whence));
+#endif
+
+
+ /* global buffers */
+
+DECLARE(uch, inbuf, INBUFSIZ +INBUF_EXTRA);
+DECLARE(uch, outbuf, OUTBUFSIZ+OUTBUF_EXTRA);
+DECLARE(ush, d_buf, DIST_BUFSIZE);
+DECLARE(uch, window, 2L*WSIZE);
+#ifndef MAXSEG_64K
+ DECLARE(ush, tab_prefix, 1L<<BITS);
+#else
+ DECLARE(ush, tab_prefix0, 1L<<(BITS-1));
+ DECLARE(ush, tab_prefix1, 1L<<(BITS-1));
+#endif
+
+ /* local variables */
+
+int force = 0; /* don't ask questions, compress links (-f) */
+int foreground; /* set if program run in foreground */
+int maxbits = BITS; /* max bits per code for LZW */
+int method = DEFLATED;/* compression method */
+int exit_code = OK; /* program exit code */
+int last_member; /* set for .zip and .Z files */
+int part_nb; /* number of parts in .gz file */
+long ifile_size; /* input file size, -1 for devices (debug only) */
+
+long bytes_in; /* number of input bytes */
+long bytes_out; /* number of output bytes */
+long total_in = 0; /* input bytes for all files */
+long total_out = 0; /* output bytes for all files */
+struct stat istat; /* status for input file */
+int ifd; /* input file descriptor */
+int ofd; /* output file descriptor */
+unsigned insize; /* valid bytes in inbuf */
+unsigned inptr; /* index of next byte to be processed in inbuf */
+unsigned outcnt; /* bytes in output buffer */
+
+long header_bytes; /* number of bytes in gzip header */
+
+/* local functions */
+
+local void treat_stdin OF((void));
+local int get_method OF((int in));
+local void do_exit OF((int exitcode));
+ int main OF((int argc, char **argv));
+int (*work) OF((int infile, int outfile)) = unzip; /* function to call */
+
+#define strequ(s1, s2) (strcmp((s1),(s2)) == 0)
+
+/* ======================================================================== */
+int zcat_main (struct FileInfo * i, int argc, char * * argv)
+{
+ int file_count; /* number of files to precess */
+
+ foreground = signal(SIGINT, SIG_IGN) != SIG_IGN;
+ if (foreground) {
+ (void) signal (SIGINT, (sig_type)abort_gzip);
+ }
+#ifdef SIGTERM
+ if (signal(SIGTERM, SIG_IGN) != SIG_IGN) {
+ (void) signal(SIGTERM, (sig_type)abort_gzip);
+ }
+#endif
+#ifdef SIGHUP
+ if (signal(SIGHUP, SIG_IGN) != SIG_IGN) {
+ (void) signal(SIGHUP, (sig_type)abort_gzip);
+ }
+#endif
+
+ file_count = argc - optind;
+
+ /* Allocate all global buffers (for DYN_ALLOC option) */
+ ALLOC(uch, inbuf, INBUFSIZ +INBUF_EXTRA);
+ ALLOC(uch, outbuf, OUTBUFSIZ+OUTBUF_EXTRA);
+ ALLOC(ush, d_buf, DIST_BUFSIZE);
+ ALLOC(uch, window, 2L*WSIZE);
+#ifndef MAXSEG_64K
+ ALLOC(ush, tab_prefix, 1L<<BITS);
+#else
+ ALLOC(ush, tab_prefix0, 1L<<(BITS-1));
+ ALLOC(ush, tab_prefix1, 1L<<(BITS-1));
+#endif
+
+ /* And get to work */
+ treat_stdin();
+
+ do_exit(exit_code);
+ return exit_code; /* just to avoid lint warning */
+}
+
+/* ========================================================================
+ * Compress or decompress stdin
+ */
+local void treat_stdin()
+{
+ ifile_size = -1L; /* convention for unknown size */
+
+ clear_bufs(); /* clear input and output buffers */
+ part_nb = 0;
+
+ method = get_method(ifd);
+
+ if (method < 0) {
+ do_exit(exit_code); /* error message already emitted */
+ }
+
+ (*work)(fileno(stdin), fileno(stdout));
+
+}
+
+
+/* ========================================================================
+ * Check the magic number of the input file and update ofname if an
+ * original name was given and to_stdout is not set.
+ * Return the compression method, -1 for error, -2 for warning.
+ * Set inptr to the offset of the next byte to be processed.
+ * Updates time_stamp if there is one and --no-time is not used.
+ * This function may be called repeatedly for an input file consisting
+ * of several contiguous gzip'ed members.
+ * IN assertions: there is at least one remaining compressed member.
+ * If the member is a zip file, it must be the only one.
+ */
+local int get_method(in)
+ int in; /* input file descriptor */
+{
+ uch flags; /* compression flags */
+ char magic[2]; /* magic header */
+
+ /* If --force and --stdout, zcat == cat, so do not complain about
+ * premature end of file: use try_byte instead of get_byte.
+ */
+ if (force) {
+ magic[0] = (char)try_byte();
+ magic[1] = (char)try_byte();
+ /* If try_byte returned EOF, magic[1] == 0xff */
+ } else {
+ magic[0] = (char)get_byte();
+ magic[1] = (char)get_byte();
+ }
+ method = -1; /* unknown yet */
+ part_nb++; /* number of parts in gzip file */
+ header_bytes = 0;
+ last_member = RECORD_IO;
+ /* assume multiple members in gzip file except for record oriented I/O */
+
+ if (memcmp(magic, GZIP_MAGIC, 2) == 0) {
+
+ method = (int)get_byte();
+ if (method != DEFLATED) {
+ fprintf(stderr,
+ "unknown method %d -- get newer version of gzip\n",
+ method);
+ exit_code = ERROR;
+ return -1;
+ }
+ work = unzip;
+ flags = (uch)get_byte();
+
+ (ulg)get_byte(); /* Ignore time stamp */
+ (ulg)get_byte();
+ (ulg)get_byte();
+ (ulg)get_byte();
+
+ (void)get_byte(); /* Ignore extra flags for the moment */
+ (void)get_byte(); /* Ignore OS type for the moment */
+
+ if ((flags & EXTRA_FIELD) != 0) {
+ unsigned len = (unsigned)get_byte();
+ len |= ((unsigned)get_byte())<<8;
+
+ while (len--) (void)get_byte();
+ }
+
+ /* Discard original name if any */
+ if ((flags & ORIG_NAME) != 0) {
+ while (get_char() != 0) /* null */ ;
+ }
+
+ /* Discard file comment if any */
+ if ((flags & COMMENT) != 0) {
+ while (get_char() != 0) /* null */ ;
+ }
+ if (part_nb == 1) {
+ header_bytes = inptr + 2*sizeof(long); /* include crc and size */
+ }
+
+ }
+
+ if (method >= 0) return method;
+
+ if (part_nb == 1) {
+ fprintf(stderr, "\nnot in gzip format\n");
+ exit_code = ERROR;
+ return -1;
+ } else {
+ WARN((stderr, "\ndecompression OK, trailing garbage ignored\n"));
+ return -2;
+ }
+}
+
+
+/* ========================================================================
+ * Free all dynamically allocated variables and exit with the given code.
+ */
+local void do_exit(exitcode)
+ int exitcode;
+{
+ static int in_exit = 0;
+
+ if (in_exit) exit(exitcode);
+ in_exit = 1;
+ FREE(inbuf);
+ FREE(outbuf);
+ FREE(d_buf);
+ FREE(window);
+#ifndef MAXSEG_64K
+ FREE(tab_prefix);
+#else
+ FREE(tab_prefix0);
+ FREE(tab_prefix1);
+#endif
+ exit(exitcode);
+}
+
+/* ========================================================================
+ * Signal and error handler.
+ */
+RETSIGTYPE abort_gzip()
+{
+ do_exit(ERROR);
+}
+/* unzip.c -- decompress files in gzip or pkzip format.
+ * Copyright (C) 1992-1993 Jean-loup Gailly
+ * This is free software; you can redistribute it and/or modify it under the
+ * terms of the GNU General Public License, see the file COPYING.
+ *
+ * The code in this file is derived from the file funzip.c written
+ * and put in the public domain by Mark Adler.
+ */
+
+/*
+ This version can extract files in gzip or pkzip format.
+ For the latter, only the first entry is extracted, and it has to be
+ either deflated or stored.
+ */
+
+#ifdef RCSID
+static char rcsid[] = "$Id: zcat.c,v 1.1 1999/10/05 16:24:56 andersen Exp $";
+#endif
+
+/* #include "crypt.h" */
+
+/* crypt.h (dummy version) -- do not perform encryption
+ * Hardly worth copyrighting :-)
+ */
+
+#ifdef CRYPT
+# undef CRYPT /* dummy version */
+#endif
+
+#define RAND_HEAD_LEN 12 /* length of encryption random header */
+
+#define zencode
+#define zdecode
+
+/* PKZIP header definitions */
+#define LOCSIG 0x04034b50L /* four-byte lead-in (lsb first) */
+#define LOCFLG 6 /* offset of bit flag */
+#define CRPFLG 1 /* bit for encrypted entry */
+#define EXTFLG 8 /* bit for extended local header */
+#define LOCHOW 8 /* offset of compression method */
+#define LOCTIM 10 /* file mod time (for decryption) */
+#define LOCCRC 14 /* offset of crc */
+#define LOCSIZ 18 /* offset of compressed size */
+#define LOCLEN 22 /* offset of uncompressed length */
+#define LOCFIL 26 /* offset of file name field length */
+#define LOCEXT 28 /* offset of extra field length */
+#define LOCHDR 30 /* size of local header, including sig */
+#define EXTHDR 16 /* size of extended local header, inc sig */
+
+
+/* Globals */
+
+char *key; /* not used--needed to link crypt.c */
+int pkzip = 0; /* set for a pkzip file */
+int ext_header = 0; /* set if extended local header */
+
+/* ===========================================================================
+ * Unzip in to out. This routine works on both gzip and pkzip files.
+ *
+ * IN assertions: the buffer inbuf contains already the beginning of
+ * the compressed data, from offsets inptr to insize-1 included.
+ * The magic header has already been checked. The output buffer is cleared.
+ */
+int unzip(in, out)
+ int in, out; /* input and output file descriptors */
+{
+ ulg orig_crc = 0; /* original crc */
+ ulg orig_len = 0; /* original uncompressed length */
+ int n;
+ uch buf[EXTHDR]; /* extended local header */
+
+ ifd = in;
+ ofd = out;
+
+ updcrc(NULL, 0); /* initialize crc */
+
+ if (pkzip && !ext_header) { /* crc and length at the end otherwise */
+ orig_crc = LG(inbuf + LOCCRC);
+ orig_len = LG(inbuf + LOCLEN);
+ }
+
+ /* Decompress */
+ if (method == DEFLATED) {
+
+ int res = inflate();
+
+ if (res == 3) {
+ error("out of memory");
+ } else if (res != 0) {
+ error("invalid compressed data--format violated");
+ }
+
+ } else {
+ error("internal error, invalid method");
+ }
+
+ /* Get the crc and original length */
+ if (!pkzip) {
+ /* crc32 (see algorithm.doc)
+ * uncompressed input size modulo 2^32
+ */
+ for (n = 0; n < 8; n++) {
+ buf[n] = (uch)get_byte(); /* may cause an error if EOF */
+ }
+ orig_crc = LG(buf);
+ orig_len = LG(buf+4);
+
+ } else if (ext_header) { /* If extended header, check it */
+ /* signature - 4bytes: 0x50 0x4b 0x07 0x08
+ * CRC-32 value
+ * compressed size 4-bytes
+ * uncompressed size 4-bytes
+ */
+ for (n = 0; n < EXTHDR; n++) {
+ buf[n] = (uch)get_byte(); /* may cause an error if EOF */
+ }
+ orig_crc = LG(buf+4);
+ orig_len = LG(buf+12);
+ }
+
+ /* Validate decompression */
+ if (orig_crc != updcrc(outbuf, 0)) {
+ error("invalid compressed data--crc error");
+ }
+ if (orig_len != (ulg)bytes_out) {
+ error("invalid compressed data--length error");
+ }
+
+ /* Check if there are more entries in a pkzip file */
+ if (pkzip && inptr + 4 < insize && LG(inbuf+inptr) == LOCSIG) {
+ WARN((stderr,"has more than one entry--rest ignored\n"));
+ }
+ ext_header = pkzip = 0; /* for next file */
+ return OK;
+}
+/* util.c -- utility functions for gzip support
+ * Copyright (C) 1992-1993 Jean-loup Gailly
+ * This is free software; you can redistribute it and/or modify it under the
+ * terms of the GNU General Public License, see the file COPYING.
+ */
+
+#ifdef RCSID
+static char rcsid[] = "$Id: zcat.c,v 1.1 1999/10/05 16:24:56 andersen Exp $";
+#endif
+
+#include <ctype.h>
+#include <errno.h>
+#include <sys/types.h>
+
+#ifdef HAVE_UNISTD_H
+# include <unistd.h>
+#endif
+#ifndef NO_FCNTL_H
+# include <fcntl.h>
+#endif
+
+#if defined(STDC_HEADERS) || !defined(NO_STDLIB_H)
+# include <stdlib.h>
+#else
+ extern int errno;
+#endif
+
+extern ulg crc_32_tab[]; /* crc table, defined below */
+
+/* ===========================================================================
+ * Run a set of bytes through the crc shift register. If s is a NULL
+ * pointer, then initialize the crc shift register contents instead.
+ * Return the current crc in either case.
+ */
+ulg updcrc(s, n)
+ uch *s; /* pointer to bytes to pump through */
+ unsigned n; /* number of bytes in s[] */
+{
+ register ulg c; /* temporary variable */
+
+ static ulg crc = (ulg)0xffffffffL; /* shift register contents */
+
+ if (s == NULL) {
+ c = 0xffffffffL;
+ } else {
+ c = crc;
+ if (n) do {
+ c = crc_32_tab[((int)c ^ (*s++)) & 0xff] ^ (c >> 8);
+ } while (--n);
+ }
+ crc = c;
+ return c ^ 0xffffffffL; /* (instead of ~c for 64-bit machines) */
+}
+
+/* ===========================================================================
+ * Clear input and output buffers
+ */
+void clear_bufs()
+{
+ outcnt = 0;
+ insize = inptr = 0;
+ bytes_in = bytes_out = 0L;
+}
+
+/* ===========================================================================
+ * Fill the input buffer. This is called only when the buffer is empty.
+ */
+int fill_inbuf(eof_ok)
+ int eof_ok; /* set if EOF acceptable as a result */
+{
+ int len;
+
+ /* Read as much as possible */
+ insize = 0;
+ errno = 0;
+ do {
+ len = read(ifd, (char*)inbuf+insize, INBUFSIZ-insize);
+ if (len == 0 || len == EOF) break;
+ insize += len;
+ } while (insize < INBUFSIZ);
+
+ if (insize == 0) {
+ if (eof_ok) return EOF;
+ read_error();
+ }
+ bytes_in += (ulg)insize;
+ inptr = 1;
+ return inbuf[0];
+}
+
+/* ===========================================================================
+ * Write the output buffer outbuf[0..outcnt-1] and update bytes_out.
+ * (used for the compressed data only)
+ */
+void flush_outbuf()
+{
+ if (outcnt == 0) return;
+
+ write_buf(ofd, (char *)outbuf, outcnt);
+ bytes_out += (ulg)outcnt;
+ outcnt = 0;
+}
+
+/* ===========================================================================
+ * Write the output window window[0..outcnt-1] and update crc and bytes_out.
+ * (Used for the decompressed data only.)
+ */
+void flush_window()
+{
+ if (outcnt == 0) return;
+ updcrc(window, outcnt);
+
+ write_buf(ofd, (char *)window, outcnt);
+
+ bytes_out += (ulg)outcnt;
+ outcnt = 0;
+}
+
+/* ===========================================================================
+ * Does the same as write(), but also handles partial pipe writes and checks
+ * for error return.
+ */
+void write_buf(fd, buf, cnt)
+ int fd;
+ voidp buf;
+ unsigned cnt;
+{
+ unsigned n;
+
+ while ((n = write(fd, buf, cnt)) != cnt) {
+ if (n == (unsigned)(-1)) {
+ write_error();
+ }
+ cnt -= n;
+ buf = (voidp)((char*)buf+n);
+ }
+}
+
+#if defined(NO_STRING_H) && !defined(STDC_HEADERS)
+
+/* Provide missing strspn and strcspn functions. */
+
+# ifndef __STDC__
+# define const
+# endif
+
+int strspn OF((const char *s, const char *accept));
+int strcspn OF((const char *s, const char *reject));
+
+/* ========================================================================
+ * Return the length of the maximum initial segment
+ * of s which contains only characters in accept.
+ */
+int strspn(s, accept)
+ const char *s;
+ const char *accept;
+{
+ register const char *p;
+ register const char *a;
+ register int count = 0;
+
+ for (p = s; *p != '\0'; ++p) {
+ for (a = accept; *a != '\0'; ++a) {
+ if (*p == *a) break;
+ }
+ if (*a == '\0') return count;
+ ++count;
+ }
+ return count;
+}
+
+/* ========================================================================
+ * Return the length of the maximum inital segment of s
+ * which contains no characters from reject.
+ */
+int strcspn(s, reject)
+ const char *s;
+ const char *reject;
+{
+ register int count = 0;
+
+ while (*s != '\0') {
+ if (strchr(reject, *s++) != NULL) return count;
+ ++count;
+ }
+ return count;
+}
+
+#endif /* NO_STRING_H */
+
+
+/* ========================================================================
+ * Error handlers.
+ */
+void error(m)
+ char *m;
+{
+ fprintf(stderr, "\n%s\n", m);
+ abort_gzip();
+}
+
+void warn(a, b)
+ char *a, *b; /* message strings juxtaposed in output */
+{
+ WARN((stderr, "warning: %s%s\n", a, b));
+}
+
+void read_error()
+{
+ fprintf(stderr, "\n");
+ if (errno != 0) {
+ perror("");
+ } else {
+ fprintf(stderr, "unexpected end of file\n");
+ }
+ abort_gzip();
+}
+
+void write_error()
+{
+ fprintf(stderr, "\n");
+ perror("");
+ abort_gzip();
+}
+
+
+/* ========================================================================
+ * Semi-safe malloc -- never returns NULL.
+ */
+voidp xmalloc (size)
+ unsigned size;
+{
+ voidp cp = (voidp)malloc (size);
+
+ if (cp == NULL) error("out of memory");
+ return cp;
+}
+
+/* ========================================================================
+ * Table of CRC-32's of all single-byte values (made by makecrc.c)
+ */
+ulg crc_32_tab[] = {
+ 0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
+ 0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
+ 0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L,
+ 0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL,
+ 0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L,
+ 0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L,
+ 0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L,
+ 0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL,
+ 0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L,
+ 0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL,
+ 0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L,
+ 0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L,
+ 0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L,
+ 0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL,
+ 0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL,
+ 0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L,
+ 0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL,
+ 0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L,
+ 0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L,
+ 0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L,
+ 0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL,
+ 0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L,
+ 0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L,
+ 0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL,
+ 0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L,
+ 0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L,
+ 0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L,
+ 0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L,
+ 0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L,
+ 0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL,
+ 0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL,
+ 0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L,
+ 0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L,
+ 0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL,
+ 0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL,
+ 0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L,
+ 0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL,
+ 0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L,
+ 0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL,
+ 0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L,
+ 0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL,
+ 0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L,
+ 0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L,
+ 0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL,
+ 0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L,
+ 0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L,
+ 0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L,
+ 0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L,
+ 0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L,
+ 0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L,
+ 0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL,
+ 0x2d02ef8dL
+};
+/* inflate.c -- Not copyrighted 1992 by Mark Adler
+ version c10p1, 10 January 1993 */
+
+/* You can do whatever you like with this source file, though I would
+ prefer that if you modify it and redistribute it that you include
+ comments to that effect with your name and the date. Thank you.
+ [The history has been moved to the file ChangeLog.]
+ */
+
+/*
+ Inflate deflated (PKZIP's method 8 compressed) data. The compression
+ method searches for as much of the current string of bytes (up to a
+ length of 258) in the previous 32K bytes. If it doesn't find any
+ matches (of at least length 3), it codes the next byte. Otherwise, it
+ codes the length of the matched string and its distance backwards from
+ the current position. There is a single Huffman code that codes both
+ single bytes (called "literals") and match lengths. A second Huffman
+ code codes the distance information, which follows a length code. Each
+ length or distance code actually represents a base value and a number
+ of "extra" (sometimes zero) bits to get to add to the base value. At
+ the end of each deflated block is a special end-of-block (EOB) literal/
+ length code. The decoding process is basically: get a literal/length
+ code; if EOB then done; if a literal, emit the decoded byte; if a
+ length then get the distance and emit the referred-to bytes from the
+ sliding window of previously emitted data.
+
+ There are (currently) three kinds of inflate blocks: stored, fixed, and
+ dynamic. The compressor deals with some chunk of data at a time, and
+ decides which method to use on a chunk-by-chunk basis. A chunk might
+ typically be 32K or 64K. If the chunk is uncompressible, then the
+ "stored" method is used. In this case, the bytes are simply stored as
+ is, eight bits per byte, with none of the above coding. The bytes are
+ preceded by a count, since there is no longer an EOB code.
+
+ If the data is compressible, then either the fixed or dynamic methods
+ are used. In the dynamic method, the compressed data is preceded by
+ an encoding of the literal/length and distance Huffman codes that are
+ to be used to decode this block. The representation is itself Huffman
+ coded, and so is preceded by a description of that code. These code
+ descriptions take up a little space, and so for small blocks, there is
+ a predefined set of codes, called the fixed codes. The fixed method is
+ used if the block codes up smaller that way (usually for quite small
+ chunks), otherwise the dynamic method is used. In the latter case, the
+ codes are customized to the probabilities in the current block, and so
+ can code it much better than the pre-determined fixed codes.
+
+ The Huffman codes themselves are decoded using a mutli-level table
+ lookup, in order to maximize the speed of decoding plus the speed of
+ building the decoding tables. See the comments below that precede the
+ lbits and dbits tuning parameters.
+ */
+
+
+/*
+ Notes beyond the 1.93a appnote.txt:
+
+ 1. Distance pointers never point before the beginning of the output
+ stream.
+ 2. Distance pointers can point back across blocks, up to 32k away.
+ 3. There is an implied maximum of 7 bits for the bit length table and
+ 15 bits for the actual data.
+ 4. If only one code exists, then it is encoded using one bit. (Zero
+ would be more efficient, but perhaps a little confusing.) If two
+ codes exist, they are coded using one bit each (0 and 1).
+ 5. There is no way of sending zero distance codes--a dummy must be
+ sent if there are none. (History: a pre 2.0 version of PKZIP would
+ store blocks with no distance codes, but this was discovered to be
+ too harsh a criterion.) Valid only for 1.93a. 2.04c does allow
+ zero distance codes, which is sent as one code of zero bits in
+ length.
+ 6. There are up to 286 literal/length codes. Code 256 represents the
+ end-of-block. Note however that the static length tree defines
+ 288 codes just to fill out the Huffman codes. Codes 286 and 287
+ cannot be used though, since there is no length base or extra bits
+ defined for them. Similarly, there are up to 30 distance codes.
+ However, static trees define 32 codes (all 5 bits) to fill out the
+ Huffman codes, but the last two had better not show up in the data.
+ 7. Unzip can check dynamic Huffman blocks for complete code sets.
+ The exception is that a single code would not be complete (see #4).
+ 8. The five bits following the block type is really the number of
+ literal codes sent minus 257.
+ 9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits
+ (1+6+6). Therefore, to output three times the length, you output
+ three codes (1+1+1), whereas to output four times the same length,
+ you only need two codes (1+3). Hmm.
+ 10. In the tree reconstruction algorithm, Code = Code + Increment
+ only if BitLength(i) is not zero. (Pretty obvious.)
+ 11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19)
+ 12. Note: length code 284 can represent 227-258, but length code 285
+ really is 258. The last length deserves its own, short code
+ since it gets used a lot in very redundant files. The length
+ 258 is special since 258 - 3 (the min match length) is 255.
+ 13. The literal/length and distance code bit lengths are read as a
+ single stream of lengths. It is possible (and advantageous) for
+ a repeat code (16, 17, or 18) to go across the boundary between
+ the two sets of lengths.
+ */
+
+#ifdef RCSID
+static char rcsid[] = "$Id: zcat.c,v 1.1 1999/10/05 16:24:56 andersen Exp $";
+#endif
+
+#include <sys/types.h>
+
+#if defined(STDC_HEADERS) || !defined(NO_STDLIB_H)
+# include <stdlib.h>
+#endif
+
+
+#define slide window
+
+/* Huffman code lookup table entry--this entry is four bytes for machines
+ that have 16-bit pointers (e.g. PC's in the small or medium model).
+ Valid extra bits are 0..13. e == 15 is EOB (end of block), e == 16
+ means that v is a literal, 16 < e < 32 means that v is a pointer to
+ the next table, which codes e - 16 bits, and lastly e == 99 indicates
+ an unused code. If a code with e == 99 is looked up, this implies an
+ error in the data. */
+struct huft {
+ uch e; /* number of extra bits or operation */
+ uch b; /* number of bits in this code or subcode */
+ union {
+ ush n; /* literal, length base, or distance base */
+ struct huft *t; /* pointer to next level of table */
+ } v;
+};
+
+
+/* Function prototypes */
+int huft_build OF((unsigned *, unsigned, unsigned, ush *, ush *,
+ struct huft **, int *));
+int huft_free OF((struct huft *));
+int inflate_codes OF((struct huft *, struct huft *, int, int));
+int inflate_stored OF((void));
+int inflate_fixed OF((void));
+int inflate_dynamic OF((void));
+int inflate_block OF((int *));
+int inflate OF((void));
+
+
+/* The inflate algorithm uses a sliding 32K byte window on the uncompressed
+ stream to find repeated byte strings. This is implemented here as a
+ circular buffer. The index is updated simply by incrementing and then
+ and'ing with 0x7fff (32K-1). */
+/* It is left to other modules to supply the 32K area. It is assumed
+ to be usable as if it were declared "uch slide[32768];" or as just
+ "uch *slide;" and then malloc'ed in the latter case. The definition
+ must be in unzip.h, included above. */
+/* unsigned wp; current position in slide */
+#define wp outcnt
+#define flush_output(w) (wp=(w),flush_window())
+
+/* Tables for deflate from PKZIP's appnote.txt. */
+static unsigned border[] = { /* Order of the bit length code lengths */
+ 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
+static ush cplens[] = { /* Copy lengths for literal codes 257..285 */
+ 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
+ 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
+ /* note: see note #13 above about the 258 in this list. */
+static ush cplext[] = { /* Extra bits for literal codes 257..285 */
+ 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
+ 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 99, 99}; /* 99==invalid */
+static ush cpdist[] = { /* Copy offsets for distance codes 0..29 */
+ 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
+ 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
+ 8193, 12289, 16385, 24577};
+static ush cpdext[] = { /* Extra bits for distance codes */
+ 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
+ 7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
+ 12, 12, 13, 13};
+
+
+
+/* Macros for inflate() bit peeking and grabbing.
+ The usage is:
+
+ NEEDBITS(j)
+ x = b & mask_bits[j];
+ DUMPBITS(j)
+
+ where NEEDBITS makes sure that b has at least j bits in it, and
+ DUMPBITS removes the bits from b. The macros use the variable k
+ for the number of bits in b. Normally, b and k are register
+ variables for speed, and are initialized at the beginning of a
+ routine that uses these macros from a global bit buffer and count.
+
+ If we assume that EOB will be the longest code, then we will never
+ ask for bits with NEEDBITS that are beyond the end of the stream.
+ So, NEEDBITS should not read any more bytes than are needed to
+ meet the request. Then no bytes need to be "returned" to the buffer
+ at the end of the last block.
+
+ However, this assumption is not true for fixed blocks--the EOB code
+ is 7 bits, but the other literal/length codes can be 8 or 9 bits.
+ (The EOB code is shorter than other codes because fixed blocks are
+ generally short. So, while a block always has an EOB, many other
+ literal/length codes have a significantly lower probability of
+ showing up at all.) However, by making the first table have a
+ lookup of seven bits, the EOB code will be found in that first
+ lookup, and so will not require that too many bits be pulled from
+ the stream.
+ */
+
+ulg bb; /* bit buffer */
+unsigned bk; /* bits in bit buffer */
+
+ush mask_bits[] = {
+ 0x0000,
+ 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
+ 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
+};
+
+#ifdef CRYPT
+ uch cc;
+# define NEXTBYTE() (cc = get_byte(), zdecode(cc), cc)
+#else
+# define NEXTBYTE() (uch)get_byte()
+#endif
+#define NEEDBITS(n) {while(k<(n)){b|=((ulg)NEXTBYTE())<<k;k+=8;}}
+#define DUMPBITS(n) {b>>=(n);k-=(n);}
+
+
+/*
+ Huffman code decoding is performed using a multi-level table lookup.
+ The fastest way to decode is to simply build a lookup table whose
+ size is determined by the longest code. However, the time it takes
+ to build this table can also be a factor if the data being decoded
+ is not very long. The most common codes are necessarily the
+ shortest codes, so those codes dominate the decoding time, and hence
+ the speed. The idea is you can have a shorter table that decodes the
+ shorter, more probable codes, and then point to subsidiary tables for
+ the longer codes. The time it costs to decode the longer codes is
+ then traded against the time it takes to make longer tables.
+
+ This results of this trade are in the variables lbits and dbits
+ below. lbits is the number of bits the first level table for literal/
+ length codes can decode in one step, and dbits is the same thing for
+ the distance codes. Subsequent tables are also less than or equal to
+ those sizes. These values may be adjusted either when all of the
+ codes are shorter than that, in which case the longest code length in
+ bits is used, or when the shortest code is *longer* than the requested
+ table size, in which case the length of the shortest code in bits is
+ used.
+
+ There are two different values for the two tables, since they code a
+ different number of possibilities each. The literal/length table
+ codes 286 possible values, or in a flat code, a little over eight
+ bits. The distance table codes 30 possible values, or a little less
+ than five bits, flat. The optimum values for speed end up being
+ about one bit more than those, so lbits is 8+1 and dbits is 5+1.
+ The optimum values may differ though from machine to machine, and
+ possibly even between compilers. Your mileage may vary.
+ */
+
+
+int lbits = 9; /* bits in base literal/length lookup table */
+int dbits = 6; /* bits in base distance lookup table */
+
+
+/* If BMAX needs to be larger than 16, then h and x[] should be ulg. */
+#define BMAX 16 /* maximum bit length of any code (16 for explode) */
+#define N_MAX 288 /* maximum number of codes in any set */
+
+
+unsigned hufts; /* track memory usage */
+
+
+int huft_build(b, n, s, d, e, t, m)
+unsigned *b; /* code lengths in bits (all assumed <= BMAX) */
+unsigned n; /* number of codes (assumed <= N_MAX) */
+unsigned s; /* number of simple-valued codes (0..s-1) */
+ush *d; /* list of base values for non-simple codes */
+ush *e; /* list of extra bits for non-simple codes */
+struct huft **t; /* result: starting table */
+int *m; /* maximum lookup bits, returns actual */
+/* Given a list of code lengths and a maximum table size, make a set of
+ tables to decode that set of codes. Return zero on success, one if
+ the given code set is incomplete (the tables are still built in this
+ case), two if the input is invalid (all zero length codes or an
+ oversubscribed set of lengths), and three if not enough memory. */
+{
+ unsigned a; /* counter for codes of length k */
+ unsigned c[BMAX+1]; /* bit length count table */
+ unsigned f; /* i repeats in table every f entries */
+ int g; /* maximum code length */
+ int h; /* table level */
+ register unsigned i; /* counter, current code */
+ register unsigned j; /* counter */
+ register int k; /* number of bits in current code */
+ int l; /* bits per table (returned in m) */
+ register unsigned *p; /* pointer into c[], b[], or v[] */
+ register struct huft *q; /* points to current table */
+ struct huft r; /* table entry for structure assignment */
+ struct huft *u[BMAX]; /* table stack */
+ unsigned v[N_MAX]; /* values in order of bit length */
+ register int w; /* bits before this table == (l * h) */
+ unsigned x[BMAX+1]; /* bit offsets, then code stack */
+ unsigned *xp; /* pointer into x */
+ int y; /* number of dummy codes added */
+ unsigned z; /* number of entries in current table */
+
+
+ /* Generate counts for each bit length */
+ memzero(c, sizeof(c));
+ p = b; i = n;
+ do {
+ Tracecv(*p, (stderr, (n-i >= ' ' && n-i <= '~' ? "%c %d\n" : "0x%x %d\n"),
+ n-i, *p));
+ c[*p]++; /* assume all entries <= BMAX */
+ p++; /* Can't combine with above line (Solaris bug) */
+ } while (--i);
+ if (c[0] == n) /* null input--all zero length codes */
+ {
+ *t = (struct huft *)NULL;
+ *m = 0;
+ return 0;
+ }
+
+
+ /* Find minimum and maximum length, bound *m by those */
+ l = *m;
+ for (j = 1; j <= BMAX; j++)
+ if (c[j])
+ break;
+ k = j; /* minimum code length */
+ if ((unsigned)l < j)
+ l = j;
+ for (i = BMAX; i; i--)
+ if (c[i])
+ break;
+ g = i; /* maximum code length */
+ if ((unsigned)l > i)
+ l = i;
+ *m = l;
+
+
+ /* Adjust last length count to fill out codes, if needed */
+ for (y = 1 << j; j < i; j++, y <<= 1)
+ if ((y -= c[j]) < 0)
+ return 2; /* bad input: more codes than bits */
+ if ((y -= c[i]) < 0)
+ return 2;
+ c[i] += y;
+
+
+ /* Generate starting offsets into the value table for each length */
+ x[1] = j = 0;
+ p = c + 1; xp = x + 2;
+ while (--i) { /* note that i == g from above */
+ *xp++ = (j += *p++);
+ }
+
+
+ /* Make a table of values in order of bit lengths */
+ p = b; i = 0;
+ do {
+ if ((j = *p++) != 0)
+ v[x[j]++] = i;
+ } while (++i < n);
+
+
+ /* Generate the Huffman codes and for each, make the table entries */
+ x[0] = i = 0; /* first Huffman code is zero */
+ p = v; /* grab values in bit order */
+ h = -1; /* no tables yet--level -1 */
+ w = -l; /* bits decoded == (l * h) */
+ u[0] = (struct huft *)NULL; /* just to keep compilers happy */
+ q = (struct huft *)NULL; /* ditto */
+ z = 0; /* ditto */
+
+ /* go through the bit lengths (k already is bits in shortest code) */
+ for (; k <= g; k++)
+ {
+ a = c[k];
+ while (a--)
+ {
+ /* here i is the Huffman code of length k bits for value *p */
+ /* make tables up to required level */
+ while (k > w + l)
+ {
+ h++;
+ w += l; /* previous table always l bits */
+
+ /* compute minimum size table less than or equal to l bits */
+ z = (z = g - w) > (unsigned)l ? l : z; /* upper limit on table size */
+ if ((f = 1 << (j = k - w)) > a + 1) /* try a k-w bit table */
+ { /* too few codes for k-w bit table */
+ f -= a + 1; /* deduct codes from patterns left */
+ xp = c + k;
+ while (++j < z) /* try smaller tables up to z bits */
+ {
+ if ((f <<= 1) <= *++xp)
+ break; /* enough codes to use up j bits */
+ f -= *xp; /* else deduct codes from patterns */
+ }
+ }
+ z = 1 << j; /* table entries for j-bit table */
+
+ /* allocate and link in new table */
+ if ((q = (struct huft *)malloc((z + 1)*sizeof(struct huft))) ==
+ (struct huft *)NULL)
+ {
+ if (h)
+ huft_free(u[0]);
+ return 3; /* not enough memory */
+ }
+ hufts += z + 1; /* track memory usage */
+ *t = q + 1; /* link to list for huft_free() */
+ *(t = &(q->v.t)) = (struct huft *)NULL;
+ u[h] = ++q; /* table starts after link */
+
+ /* connect to last table, if there is one */
+ if (h)
+ {
+ x[h] = i; /* save pattern for backing up */
+ r.b = (uch)l; /* bits to dump before this table */
+ r.e = (uch)(16 + j); /* bits in this table */
+ r.v.t = q; /* pointer to this table */
+ j = i >> (w - l); /* (get around Turbo C bug) */
+ u[h-1][j] = r; /* connect to last table */
+ }
+ }
+
+ /* set up table entry in r */
+ r.b = (uch)(k - w);
+ if (p >= v + n)
+ r.e = 99; /* out of values--invalid code */
+ else if (*p < s)
+ {
+ r.e = (uch)(*p < 256 ? 16 : 15); /* 256 is end-of-block code */
+ r.v.n = (ush)(*p); /* simple code is just the value */
+ p++; /* one compiler does not like *p++ */
+ }
+ else
+ {
+ r.e = (uch)e[*p - s]; /* non-simple--look up in lists */
+ r.v.n = d[*p++ - s];
+ }
+
+ /* fill code-like entries with r */
+ f = 1 << (k - w);
+ for (j = i >> w; j < z; j += f)
+ q[j] = r;
+
+ /* backwards increment the k-bit code i */
+ for (j = 1 << (k - 1); i & j; j >>= 1)
+ i ^= j;
+ i ^= j;
+
+ /* backup over finished tables */
+ while ((i & ((1 << w) - 1)) != x[h])
+ {
+ h--; /* don't need to update q */
+ w -= l;
+ }
+ }
+ }
+
+
+ /* Return true (1) if we were given an incomplete table */
+ return y != 0 && g != 1;
+}
+
+
+
+int huft_free(t)
+struct huft *t; /* table to free */
+/* Free the malloc'ed tables built by huft_build(), which makes a linked
+ list of the tables it made, with the links in a dummy first entry of
+ each table. */
+{
+ register struct huft *p, *q;
+
+
+ /* Go through linked list, freeing from the malloced (t[-1]) address. */
+ p = t;
+ while (p != (struct huft *)NULL)
+ {
+ q = (--p)->v.t;
+ free((char*)p);
+ p = q;
+ }
+ return 0;
+}
+
+
+int inflate_codes(tl, td, bl, bd)
+struct huft *tl, *td; /* literal/length and distance decoder tables */
+int bl, bd; /* number of bits decoded by tl[] and td[] */
+/* inflate (decompress) the codes in a deflated (compressed) block.
+ Return an error code or zero if it all goes ok. */
+{
+ register unsigned e; /* table entry flag/number of extra bits */
+ unsigned n, d; /* length and index for copy */
+ unsigned w; /* current window position */
+ struct huft *t; /* pointer to table entry */
+ unsigned ml, md; /* masks for bl and bd bits */
+ register ulg b; /* bit buffer */
+ register unsigned k; /* number of bits in bit buffer */
+
+
+ /* make local copies of globals */
+ b = bb; /* initialize bit buffer */
+ k = bk;
+ w = wp; /* initialize window position */
+
+ /* inflate the coded data */
+ ml = mask_bits[bl]; /* precompute masks for speed */
+ md = mask_bits[bd];
+ for (;;) /* do until end of block */
+ {
+ NEEDBITS((unsigned)bl)
+ if ((e = (t = tl + ((unsigned)b & ml))->e) > 16)
+ do {
+ if (e == 99)
+ return 1;
+ DUMPBITS(t->b)
+ e -= 16;
+ NEEDBITS(e)
+ } while ((e = (t = t->v.t + ((unsigned)b & mask_bits[e]))->e) > 16);
+ DUMPBITS(t->b)
+ if (e == 16) /* then it's a literal */
+ {
+ slide[w++] = (uch)t->v.n;
+ Tracevv((stderr, "%c", slide[w-1]));
+ if (w == WSIZE)
+ {
+ flush_output(w);
+ w = 0;
+ }
+ }
+ else /* it's an EOB or a length */
+ {
+ /* exit if end of block */
+ if (e == 15)
+ break;
+
+ /* get length of block to copy */
+ NEEDBITS(e)
+ n = t->v.n + ((unsigned)b & mask_bits[e]);
+ DUMPBITS(e);
+
+ /* decode distance of block to copy */
+ NEEDBITS((unsigned)bd)
+ if ((e = (t = td + ((unsigned)b & md))->e) > 16)
+ do {
+ if (e == 99)
+ return 1;
+ DUMPBITS(t->b)
+ e -= 16;
+ NEEDBITS(e)
+ } while ((e = (t = t->v.t + ((unsigned)b & mask_bits[e]))->e) > 16);
+ DUMPBITS(t->b)
+ NEEDBITS(e)
+ d = w - t->v.n - ((unsigned)b & mask_bits[e]);
+ DUMPBITS(e)
+ Tracevv((stderr,"\\[%d,%d]", w-d, n));
+
+ /* do the copy */
+ do {
+ n -= (e = (e = WSIZE - ((d &= WSIZE-1) > w ? d : w)) > n ? n : e);
+#if !defined(NOMEMCPY) && !defined(DEBUG)
+ if (w - d >= e) /* (this test assumes unsigned comparison) */
+ {
+ memcpy(slide + w, slide + d, e);
+ w += e;
+ d += e;
+ }
+ else /* do it slow to avoid memcpy() overlap */
+#endif /* !NOMEMCPY */
+ do {
+ slide[w++] = slide[d++];
+ Tracevv((stderr, "%c", slide[w-1]));
+ } while (--e);
+ if (w == WSIZE)
+ {
+ flush_output(w);
+ w = 0;
+ }
+ } while (n);
+ }
+ }
+
+
+ /* restore the globals from the locals */
+ wp = w; /* restore global window pointer */
+ bb = b; /* restore global bit buffer */
+ bk = k;
+
+ /* done */
+ return 0;
+}
+
+
+
+int inflate_stored()
+/* "decompress" an inflated type 0 (stored) block. */
+{
+ unsigned n; /* number of bytes in block */
+ unsigned w; /* current window position */
+ register ulg b; /* bit buffer */
+ register unsigned k; /* number of bits in bit buffer */
+
+
+ /* make local copies of globals */
+ b = bb; /* initialize bit buffer */
+ k = bk;
+ w = wp; /* initialize window position */
+
+
+ /* go to byte boundary */
+ n = k & 7;
+ DUMPBITS(n);
+
+
+ /* get the length and its complement */
+ NEEDBITS(16)
+ n = ((unsigned)b & 0xffff);
+ DUMPBITS(16)
+ NEEDBITS(16)
+ if (n != (unsigned)((~b) & 0xffff))
+ return 1; /* error in compressed data */
+ DUMPBITS(16)
+
+
+ /* read and output the compressed data */
+ while (n--)
+ {
+ NEEDBITS(8)
+ slide[w++] = (uch)b;
+ if (w == WSIZE)
+ {
+ flush_output(w);
+ w = 0;
+ }
+ DUMPBITS(8)
+ }
+
+
+ /* restore the globals from the locals */
+ wp = w; /* restore global window pointer */
+ bb = b; /* restore global bit buffer */
+ bk = k;
+ return 0;
+}
+
+
+
+int inflate_fixed()
+/* decompress an inflated type 1 (fixed Huffman codes) block. We should
+ either replace this with a custom decoder, or at least precompute the
+ Huffman tables. */
+{
+ int i; /* temporary variable */
+ struct huft *tl; /* literal/length code table */
+ struct huft *td; /* distance code table */
+ int bl; /* lookup bits for tl */
+ int bd; /* lookup bits for td */
+ unsigned l[288]; /* length list for huft_build */
+
+
+ /* set up literal table */
+ for (i = 0; i < 144; i++)
+ l[i] = 8;
+ for (; i < 256; i++)
+ l[i] = 9;
+ for (; i < 280; i++)
+ l[i] = 7;
+ for (; i < 288; i++) /* make a complete, but wrong code set */
+ l[i] = 8;
+ bl = 7;
+ if ((i = huft_build(l, 288, 257, cplens, cplext, &tl, &bl)) != 0)
+ return i;
+
+
+ /* set up distance table */
+ for (i = 0; i < 30; i++) /* make an incomplete code set */
+ l[i] = 5;
+ bd = 5;
+ if ((i = huft_build(l, 30, 0, cpdist, cpdext, &td, &bd)) > 1)
+ {
+ huft_free(tl);
+ return i;
+ }
+
+
+ /* decompress until an end-of-block code */
+ if (inflate_codes(tl, td, bl, bd))
+ return 1;
+
+
+ /* free the decoding tables, return */
+ huft_free(tl);
+ huft_free(td);
+ return 0;
+}
+
+
+
+int inflate_dynamic()
+/* decompress an inflated type 2 (dynamic Huffman codes) block. */
+{
+ int i; /* temporary variables */
+ unsigned j;
+ unsigned l; /* last length */
+ unsigned m; /* mask for bit lengths table */
+ unsigned n; /* number of lengths to get */
+ struct huft *tl; /* literal/length code table */
+ struct huft *td; /* distance code table */
+ int bl; /* lookup bits for tl */
+ int bd; /* lookup bits for td */
+ unsigned nb; /* number of bit length codes */
+ unsigned nl; /* number of literal/length codes */
+ unsigned nd; /* number of distance codes */
+#ifdef PKZIP_BUG_WORKAROUND
+ unsigned ll[288+32]; /* literal/length and distance code lengths */
+#else
+ unsigned ll[286+30]; /* literal/length and distance code lengths */
+#endif
+ register ulg b; /* bit buffer */
+ register unsigned k; /* number of bits in bit buffer */
+
+
+ /* make local bit buffer */
+ b = bb;
+ k = bk;
+
+
+ /* read in table lengths */
+ NEEDBITS(5)
+ nl = 257 + ((unsigned)b & 0x1f); /* number of literal/length codes */
+ DUMPBITS(5)
+ NEEDBITS(5)
+ nd = 1 + ((unsigned)b & 0x1f); /* number of distance codes */
+ DUMPBITS(5)
+ NEEDBITS(4)
+ nb = 4 + ((unsigned)b & 0xf); /* number of bit length codes */
+ DUMPBITS(4)
+#ifdef PKZIP_BUG_WORKAROUND
+ if (nl > 288 || nd > 32)
+#else
+ if (nl > 286 || nd > 30)
+#endif
+ return 1; /* bad lengths */
+
+
+ /* read in bit-length-code lengths */
+ for (j = 0; j < nb; j++)
+ {
+ NEEDBITS(3)
+ ll[border[j]] = (unsigned)b & 7;
+ DUMPBITS(3)
+ }
+ for (; j < 19; j++)
+ ll[border[j]] = 0;
+
+
+ /* build decoding table for trees--single level, 7 bit lookup */
+ bl = 7;
+ if ((i = huft_build(ll, 19, 19, NULL, NULL, &tl, &bl)) != 0)
+ {
+ if (i == 1)
+ huft_free(tl);
+ return i; /* incomplete code set */
+ }
+
+
+ /* read in literal and distance code lengths */
+ n = nl + nd;
+ m = mask_bits[bl];
+ i = l = 0;
+ while ((unsigned)i < n)
+ {
+ NEEDBITS((unsigned)bl)
+ j = (td = tl + ((unsigned)b & m))->b;
+ DUMPBITS(j)
+ j = td->v.n;
+ if (j < 16) /* length of code in bits (0..15) */
+ ll[i++] = l = j; /* save last length in l */
+ else if (j == 16) /* repeat last length 3 to 6 times */
+ {
+ NEEDBITS(2)
+ j = 3 + ((unsigned)b & 3);
+ DUMPBITS(2)
+ if ((unsigned)i + j > n)
+ return 1;
+ while (j--)
+ ll[i++] = l;
+ }
+ else if (j == 17) /* 3 to 10 zero length codes */
+ {
+ NEEDBITS(3)
+ j = 3 + ((unsigned)b & 7);
+ DUMPBITS(3)
+ if ((unsigned)i + j > n)
+ return 1;
+ while (j--)
+ ll[i++] = 0;
+ l = 0;
+ }
+ else /* j == 18: 11 to 138 zero length codes */
+ {
+ NEEDBITS(7)
+ j = 11 + ((unsigned)b & 0x7f);
+ DUMPBITS(7)
+ if ((unsigned)i + j > n)
+ return 1;
+ while (j--)
+ ll[i++] = 0;
+ l = 0;
+ }
+ }
+
+
+ /* free decoding table for trees */
+ huft_free(tl);
+
+
+ /* restore the global bit buffer */
+ bb = b;
+ bk = k;
+
+
+ /* build the decoding tables for literal/length and distance codes */
+ bl = lbits;
+ if ((i = huft_build(ll, nl, 257, cplens, cplext, &tl, &bl)) != 0)
+ {
+ if (i == 1) {
+ fprintf(stderr, " incomplete literal tree\n");
+ huft_free(tl);
+ }
+ return i; /* incomplete code set */
+ }
+ bd = dbits;
+ if ((i = huft_build(ll + nl, nd, 0, cpdist, cpdext, &td, &bd)) != 0)
+ {
+ if (i == 1) {
+ fprintf(stderr, " incomplete distance tree\n");
+#ifdef PKZIP_BUG_WORKAROUND
+ i = 0;
+ }
+#else
+ huft_free(td);
+ }
+ huft_free(tl);
+ return i; /* incomplete code set */
+#endif
+ }
+
+
+ /* decompress until an end-of-block code */
+ if (inflate_codes(tl, td, bl, bd))
+ return 1;
+
+
+ /* free the decoding tables, return */
+ huft_free(tl);
+ huft_free(td);
+ return 0;
+}
+
+
+
+int inflate_block(e)
+int *e; /* last block flag */
+/* decompress an inflated block */
+{
+ unsigned t; /* block type */
+ register ulg b; /* bit buffer */
+ register unsigned k; /* number of bits in bit buffer */
+
+
+ /* make local bit buffer */
+ b = bb;
+ k = bk;
+
+
+ /* read in last block bit */
+ NEEDBITS(1)
+ *e = (int)b & 1;
+ DUMPBITS(1)
+
+
+ /* read in block type */
+ NEEDBITS(2)
+ t = (unsigned)b & 3;
+ DUMPBITS(2)
+
+
+ /* restore the global bit buffer */
+ bb = b;
+ bk = k;
+
+
+ /* inflate that block type */
+ if (t == 2)
+ return inflate_dynamic();
+ if (t == 0)
+ return inflate_stored();
+ if (t == 1)
+ return inflate_fixed();
+
+
+ /* bad block type */
+ return 2;
+}
+
+
+
+int inflate()
+/* decompress an inflated entry */
+{
+ int e; /* last block flag */
+ int r; /* result code */
+ unsigned h; /* maximum struct huft's malloc'ed */
+
+
+ /* initialize window, bit buffer */
+ wp = 0;
+ bk = 0;
+ bb = 0;
+
+
+ /* decompress until the last block */
+ h = 0;
+ do {
+ hufts = 0;
+ if ((r = inflate_block(&e)) != 0)
+ return r;
+ if (hufts > h)
+ h = hufts;
+ } while (!e);
+
+ /* Undo too much lookahead. The next read will be byte aligned so we
+ * can discard unused bits in the last meaningful byte.
+ */
+ while (bk >= 8) {
+ bk -= 8;
+ inptr--;
+ }
+
+ /* flush out slide */
+ flush_output(wp);
+
+
+ /* return success */
+#ifdef DEBUG
+ fprintf(stderr, "<%u> ", h);
+#endif /* DEBUG */
+ return 0;
+}