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diff --git a/busybox/archival/gzip.c b/busybox/archival/gzip.c
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+++ b/busybox/archival/gzip.c
@@ -0,0 +1,2548 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Gzip implementation for busybox
+ *
+ * Based on GNU gzip Copyright (C) 1992-1993 Jean-loup Gailly.
+ *
+ * Originally adjusted for busybox by Charles P. Wright <cpw@unix.asb.com>
+ *		"this is a stripped down version of gzip I put into busybox, it does
+ *		only standard in to standard out with -9 compression.  It also requires
+ *		the zcat module for some important functions."
+ *
+ * Adjusted further by Erik Andersen <andersen@codepoet.org> to support
+ * files as well as stdin/stdout, and to generally behave itself wrt
+ * command line handling.
+ *
+ * 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 of the License, 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+/* These defines are very important for BusyBox.  Without these,
+ * huge chunks of ram are pre-allocated making the BusyBox bss
+ * size Freaking Huge(tm), which is a bad thing.*/
+#define SMALL_MEM
+#define DYN_ALLOC
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <signal.h>
+#include <utime.h>
+#include <ctype.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <dirent.h>
+#include <fcntl.h>
+#include <time.h>
+#include "busybox.h"
+
+#define memzero(s, n)     memset ((void *)(s), 0, (n))
+
+#ifndef RETSIGTYPE
+#  define RETSIGTYPE void
+#endif
+
+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) */
+/* Only STORED and DEFLATED are supported by this BusyBox module */
+#define STORED      0
+/* methods 4 to 7 reserved */
+#define DEFLATED    8
+
+/* 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
+ * 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() */
+
+#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
+
+#ifdef DYN_ALLOC
+#  define DECLARE(type, array, size)  static type * array
+#  define ALLOC(type, array, size) { \
+      array = (type*)xcalloc((size_t)(((size)+1L)/2), 2*sizeof(type)); \
+   }
+#  define FREE(array) {free(array), array=NULL;}
+#else
+#  define DECLARE(type, array, size)  static type array[size]
+#  define ALLOC(type, array, size)
+#  define FREE(array)
+#endif
+
+#define tab_suffix window
+#define tab_prefix prev	/* hash link (see deflate.c) */
+#define head (prev+WSIZE)	/* hash head (see deflate.c) */
+
+static long bytes_in;	/* number of input bytes */
+
+#define isize bytes_in
+/* for compatibility with old zip sources (to be cleaned) */
+
+typedef int file_t;		/* Do not use stdio */
+
+#define NO_FILE  (-1)	/* in memory compression */
+
+
+#define	PACK_MAGIC     "\037\036"	/* Magic header for packed files */
+#define	GZIP_MAGIC     "\037\213"	/* Magic header for gzip files, 1F 8B */
+#define	OLD_GZIP_MAGIC "\037\236"	/* Magic header for gzip 0.5 = freeze 1.x */
+#define	LZH_MAGIC      "\037\240"	/* Magic header for SCO LZH Compress files */
+#define PKZIP_MAGIC    "\120\113\003\004"	/* Magic header for pkzip files */
+
+/* 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 RESERVED     0xC0	/* bit 6,7:   reserved */
+
+/* internal file attribute */
+#define UNKNOWN 0xffff
+#define BINARY  0
+#define ASCII   1
+
+#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.
+ */
+
+/* put_byte is used for the compressed output */
+#define put_byte(c) {outbuf[outcnt++]=(uch)(c); if (outcnt==OUTBUFSIZ)\
+   flush_outbuf();}
+
+
+/* Output a 32 bit value to the bit stream, lsb first */
+#if 0
+#define put_long(n) { \
+    put_short((n) & 0xffff); \
+    put_short(((ulg)(n)) >> 16); \
+}
+#endif
+
+#define seekable()    0	/* force sequential output */
+#define translate_eol 0	/* no option -a yet */
+
+/* Diagnostic functions */
+#ifdef DEBUG
+#  define Assert(cond,msg) {if(!(cond)) bb_error_msg(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) {if (!quiet) fprintf msg ; \
+		   if (exit_code == OK) exit_code = WARNING;}
+
+#ifndef MAX_PATH_LEN
+#  define MAX_PATH_LEN   1024	/* max pathname length */
+#endif
+
+
+	/* from zip.c: */
+static int zip(int in, int out);
+static int file_read(char *buf, unsigned size);
+
+	/* from gzip.c */
+static RETSIGTYPE abort_gzip(void);
+
+		/* from deflate.c */
+static void lm_init(ush * flags);
+static ulg deflate(void);
+
+		/* from trees.c */
+static void ct_init(ush * attr, int *methodp);
+static int ct_tally(int dist, int lc);
+static ulg flush_block(char *buf, ulg stored_len, int eof);
+
+		/* from bits.c */
+static void bi_init(file_t zipfile);
+static void send_bits(int value, int length);
+static unsigned bi_reverse(unsigned value, int length);
+static void bi_windup(void);
+static void copy_block(char *buf, unsigned len, int header);
+static int (*read_buf) (char *buf, unsigned size);
+
+	/* from util.c: */
+static void flush_outbuf(void);
+
+/* 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 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".
+ */
+
+/* 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.
+ */
+
+
+	/* Common defaults */
+
+#ifndef OS_CODE
+#  define OS_CODE  0x03	/* assume Unix */
+#endif
+
+#ifndef PATH_SEP
+#  define PATH_SEP '/'
+#endif
+
+#ifndef OPTIONS_VAR
+#  define OPTIONS_VAR "GZIP"
+#endif
+
+#ifndef Z_SUFFIX
+#  define Z_SUFFIX ".gz"
+#endif
+
+#ifdef MAX_EXT_CHARS
+#  define MAX_SUFFIX  MAX_EXT_CHARS
+#else
+#  define MAX_SUFFIX  30
+#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);
+DECLARE(ush, tab_prefix, 1L << BITS);
+
+static int foreground;	/* set if program run in foreground */
+static int method = DEFLATED;	/* compression method */
+static int exit_code = OK;	/* program exit code */
+static int part_nb;		/* number of parts in .gz file */
+static long time_stamp;	/* original time stamp (modification time) */
+static long ifile_size;	/* input file size, -1 for devices (debug only) */
+static char z_suffix[MAX_SUFFIX + 1];	/* default suffix (can be set with --suffix) */
+static int z_len;		/* strlen(z_suffix) */
+
+static int ifd;			/* input file descriptor */
+static int ofd;			/* output file descriptor */
+static unsigned insize;	/* valid bytes in inbuf */
+static unsigned outcnt;	/* bytes in output buffer */
+
+
+/* Output a 16 bit value, lsb first */
+static void put_short(ush 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));
+	}
+}
+
+/* ========================================================================
+ * Signal and error handler.
+ */
+static void abort_gzip()
+{
+	exit(ERROR);
+}
+
+/* ===========================================================================
+ * Clear input and output buffers
+ */
+static void clear_bufs(void)
+{
+	outcnt = 0;
+	insize = 0;
+	bytes_in = 0L;
+}
+
+static void write_bb_error_msg(void)
+{
+	fputc('\n', stderr);
+	bb_perror_nomsg();
+	abort_gzip();
+}
+
+/* ===========================================================================
+ * Does the same as write(), but also handles partial pipe writes and checks
+ * for error return.
+ */
+static void write_buf(int fd, void *buf, unsigned cnt)
+{
+	unsigned n;
+
+	while ((n = write(fd, buf, cnt)) != cnt) {
+		if (n == (unsigned) (-1)) {
+			write_bb_error_msg();
+		}
+		cnt -= n;
+		buf = (void *) ((char *) buf + n);
+	}
+}
+
+/* ===========================================================================
+ * 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.
+ */
+static ulg updcrc(uch * s, unsigned n)
+{
+	static ulg crc = (ulg) 0xffffffffL;	/* shift register contents */
+	register ulg c;		/* temporary variable */
+	static unsigned long crc_32_tab[256];
+
+	if (crc_32_tab[1] == 0x00000000L) {
+		unsigned long csr;	/* crc shift register */
+		const unsigned long e = 0xedb88320L;	/* polynomial exclusive-or pattern */
+		int i;			/* counter for all possible eight bit values */
+		int k;			/* byte being shifted into crc apparatus */
+
+		/* Compute table of CRC's. */
+		for (i = 1; i < 256; i++) {
+			csr = i;
+			/* The idea to initialize the register with the byte instead of
+			   * zero was stolen from Haruhiko Okumura's ar002
+			 */
+			for (k = 8; k; k--)
+				csr = csr & 1 ? (csr >> 1) ^ e : csr >> 1;
+			crc_32_tab[i] = csr;
+		}
+	}
+
+	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) */
+}
+
+/* bits.c -- output variable-length bit strings
+ * 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.
+ */
+
+
+/*
+ *  PURPOSE
+ *
+ *      Output variable-length bit strings. Compression can be done
+ *      to a file or to memory. (The latter is not supported in this version.)
+ *
+ *  DISCUSSION
+ *
+ *      The PKZIP "deflate" file format interprets compressed file data
+ *      as a sequence of bits.  Multi-bit strings in the file may cross
+ *      byte boundaries without restriction.
+ *
+ *      The first bit of each byte is the low-order bit.
+ *
+ *      The routines in this file allow a variable-length bit value to
+ *      be output right-to-left (useful for literal values). For
+ *      left-to-right output (useful for code strings from the tree routines),
+ *      the bits must have been reversed first with bi_reverse().
+ *
+ *      For in-memory compression, the compressed bit stream goes directly
+ *      into the requested output buffer. The input data is read in blocks
+ *      by the mem_read() function. The buffer is limited to 64K on 16 bit
+ *      machines.
+ *
+ *  INTERFACE
+ *
+ *      void bi_init (FILE *zipfile)
+ *          Initialize the bit string routines.
+ *
+ *      void send_bits (int value, int length)
+ *          Write out a bit string, taking the source bits right to
+ *          left.
+ *
+ *      int bi_reverse (int value, int length)
+ *          Reverse the bits of a bit string, taking the source bits left to
+ *          right and emitting them right to left.
+ *
+ *      void bi_windup (void)
+ *          Write out any remaining bits in an incomplete byte.
+ *
+ *      void copy_block(char *buf, unsigned len, int header)
+ *          Copy a stored block to the zip file, storing first the length and
+ *          its one's complement if requested.
+ *
+ */
+
+/* ===========================================================================
+ * Local data used by the "bit string" routines.
+ */
+
+static file_t zfile;	/* output gzip file */
+
+static unsigned short bi_buf;
+
+/* Output buffer. bits are inserted starting at the bottom (least significant
+ * bits).
+ */
+
+#define Buf_size (8 * 2*sizeof(char))
+/* Number of bits used within bi_buf. (bi_buf might be implemented on
+ * more than 16 bits on some systems.)
+ */
+
+static int bi_valid;
+
+/* Current input function. Set to mem_read for in-memory compression */
+
+#ifdef DEBUG
+ulg bits_sent;			/* bit length of the compressed data */
+#endif
+
+/* ===========================================================================
+ * Initialize the bit string routines.
+ */
+static void bi_init(file_t zipfile)
+{
+	zfile = zipfile;
+	bi_buf = 0;
+	bi_valid = 0;
+#ifdef DEBUG
+	bits_sent = 0L;
+#endif
+
+	/* Set the defaults for file compression. They are set by memcompress
+	 * for in-memory compression.
+	 */
+	if (zfile != NO_FILE) {
+		read_buf = file_read;
+	}
+}
+
+/* ===========================================================================
+ * Send a value on a given number of bits.
+ * IN assertion: length <= 16 and value fits in length bits.
+ */
+static void send_bits(int value, int length)
+{
+#ifdef DEBUG
+	Tracev((stderr, " l %2d v %4x ", length, value));
+	Assert(length > 0 && length <= 15, "invalid length");
+	bits_sent += (ulg) length;
+#endif
+	/* If not enough room in bi_buf, use (valid) bits from bi_buf and
+	 * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))
+	 * unused bits in value.
+	 */
+	if (bi_valid > (int) Buf_size - length) {
+		bi_buf |= (value << bi_valid);
+		put_short(bi_buf);
+		bi_buf = (ush) value >> (Buf_size - bi_valid);
+		bi_valid += length - Buf_size;
+	} else {
+		bi_buf |= value << bi_valid;
+		bi_valid += length;
+	}
+}
+
+/* ===========================================================================
+ * Reverse the first len bits of a code, using straightforward code (a faster
+ * method would use a table)
+ * IN assertion: 1 <= len <= 15
+ */
+static unsigned bi_reverse(unsigned code, int len)
+{
+	register unsigned res = 0;
+
+	do {
+		res |= code & 1;
+		code >>= 1, res <<= 1;
+	} while (--len > 0);
+	return res >> 1;
+}
+
+/* ===========================================================================
+ * Write out any remaining bits in an incomplete byte.
+ */
+static void bi_windup()
+{
+	if (bi_valid > 8) {
+		put_short(bi_buf);
+	} else if (bi_valid > 0) {
+		put_byte(bi_buf);
+	}
+	bi_buf = 0;
+	bi_valid = 0;
+#ifdef DEBUG
+	bits_sent = (bits_sent + 7) & ~7;
+#endif
+}
+
+/* ===========================================================================
+ * Copy a stored block to the zip file, storing first the length and its
+ * one's complement if requested.
+ */
+static void copy_block(char *buf, unsigned len, int header)
+{
+	bi_windup();		/* align on byte boundary */
+
+	if (header) {
+		put_short((ush) len);
+		put_short((ush) ~ len);
+#ifdef DEBUG
+		bits_sent += 2 * 16;
+#endif
+	}
+#ifdef DEBUG
+	bits_sent += (ulg) len << 3;
+#endif
+	while (len--) {
+		put_byte(*buf++);
+	}
+}
+
+/* deflate.c -- compress data using the deflation algorithm
+ * 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.
+ */
+
+/*
+ *  PURPOSE
+ *
+ *      Identify new text as repetitions of old text within a fixed-
+ *      length sliding window trailing behind the new text.
+ *
+ *  DISCUSSION
+ *
+ *      The "deflation" process depends on being able to identify portions
+ *      of the input text which are identical to earlier input (within a
+ *      sliding window trailing behind the input currently being processed).
+ *
+ *      The most straightforward technique turns out to be the fastest for
+ *      most input files: try all possible matches and select the longest.
+ *      The key feature of this algorithm is that insertions into the string
+ *      dictionary are very simple and thus fast, and deletions are avoided
+ *      completely. Insertions are performed at each input character, whereas
+ *      string matches are performed only when the previous match ends. So it
+ *      is preferable to spend more time in matches to allow very fast string
+ *      insertions and avoid deletions. The matching algorithm for small
+ *      strings is inspired from that of Rabin & Karp. A brute force approach
+ *      is used to find longer strings when a small match has been found.
+ *      A similar algorithm is used in comic (by Jan-Mark Wams) and freeze
+ *      (by Leonid Broukhis).
+ *         A previous version of this file used a more sophisticated algorithm
+ *      (by Fiala and Greene) which is guaranteed to run in linear amortized
+ *      time, but has a larger average cost, uses more memory and is patented.
+ *      However the F&G algorithm may be faster for some highly redundant
+ *      files if the parameter max_chain_length (described below) is too large.
+ *
+ *  ACKNOWLEDGMENTS
+ *
+ *      The idea of lazy evaluation of matches is due to Jan-Mark Wams, and
+ *      I found it in 'freeze' written by Leonid Broukhis.
+ *      Thanks to many info-zippers for bug reports and testing.
+ *
+ *  REFERENCES
+ *
+ *      APPNOTE.TXT documentation file in PKZIP 1.93a distribution.
+ *
+ *      A description of the Rabin and Karp algorithm is given in the book
+ *         "Algorithms" by R. Sedgewick, Addison-Wesley, p252.
+ *
+ *      Fiala,E.R., and Greene,D.H.
+ *         Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595
+ *
+ *  INTERFACE
+ *
+ *      void lm_init (int pack_level, ush *flags)
+ *          Initialize the "longest match" routines for a new file
+ *
+ *      ulg deflate (void)
+ *          Processes a new input file and return its compressed length. Sets
+ *          the compressed length, crc, deflate flags and internal file
+ *          attributes.
+ */
+
+
+/* ===========================================================================
+ * Configuration parameters
+ */
+
+/* Compile with MEDIUM_MEM to reduce the memory requirements or
+ * with SMALL_MEM to use as little memory as possible. Use BIG_MEM if the
+ * entire input file can be held in memory (not possible on 16 bit systems).
+ * Warning: defining these symbols affects HASH_BITS (see below) and thus
+ * affects the compression ratio. The compressed output
+ * is still correct, and might even be smaller in some cases.
+ */
+
+#ifdef SMALL_MEM
+#   define HASH_BITS  13	/* Number of bits used to hash strings */
+#endif
+#ifdef MEDIUM_MEM
+#   define HASH_BITS  14
+#endif
+#ifndef HASH_BITS
+#   define HASH_BITS  15
+   /* For portability to 16 bit machines, do not use values above 15. */
+#endif
+
+/* To save space (see unlzw.c), we overlay prev+head with tab_prefix and
+ * window with tab_suffix. Check that we can do this:
+ */
+#if (WSIZE<<1) > (1<<BITS)
+#  error cannot overlay window with tab_suffix and prev with tab_prefix0
+#endif
+#if HASH_BITS > BITS-1
+#  error cannot overlay head with tab_prefix1
+#endif
+#define HASH_SIZE (unsigned)(1<<HASH_BITS)
+#define HASH_MASK (HASH_SIZE-1)
+#define WMASK     (WSIZE-1)
+/* HASH_SIZE and WSIZE must be powers of two */
+#define NIL 0
+/* Tail of hash chains */
+#define FAST 4
+#define SLOW 2
+/* speed options for the general purpose bit flag */
+#ifndef TOO_FAR
+#  define TOO_FAR 4096
+#endif
+/* Matches of length 3 are discarded if their distance exceeds TOO_FAR */
+/* ===========================================================================
+ * Local data used by the "longest match" routines.
+ */
+typedef ush Pos;
+typedef unsigned IPos;
+
+/* A Pos is an index in the character window. We use short instead of int to
+ * save space in the various tables. IPos is used only for parameter passing.
+ */
+
+/* DECLARE(uch, window, 2L*WSIZE); */
+/* Sliding window. Input bytes are read into the second half of the window,
+ * and move to the first half later to keep a dictionary of at least WSIZE
+ * bytes. With this organization, matches are limited to a distance of
+ * WSIZE-MAX_MATCH bytes, but this ensures that IO is always
+ * performed with a length multiple of the block size. Also, it limits
+ * the window size to 64K, which is quite useful on MSDOS.
+ * To do: limit the window size to WSIZE+BSZ if SMALL_MEM (the code would
+ * be less efficient).
+ */
+
+/* DECLARE(Pos, prev, WSIZE); */
+/* Link to older string with same hash index. To limit the size of this
+ * array to 64K, this link is maintained only for the last 32K strings.
+ * An index in this array is thus a window index modulo 32K.
+ */
+
+/* DECLARE(Pos, head, 1<<HASH_BITS); */
+/* Heads of the hash chains or NIL. */
+
+static const ulg window_size = (ulg) 2 * WSIZE;
+
+/* window size, 2*WSIZE except for MMAP or BIG_MEM, where it is the
+ * input file length plus MIN_LOOKAHEAD.
+ */
+
+static long block_start;
+
+/* window position at the beginning of the current output block. Gets
+ * negative when the window is moved backwards.
+ */
+
+static unsigned ins_h;	/* hash index of string to be inserted */
+
+#define H_SHIFT  ((HASH_BITS+MIN_MATCH-1)/MIN_MATCH)
+/* Number of bits by which ins_h and del_h must be shifted at each
+ * input step. It must be such that after MIN_MATCH steps, the oldest
+ * byte no longer takes part in the hash key, that is:
+ *   H_SHIFT * MIN_MATCH >= HASH_BITS
+ */
+
+static unsigned int prev_length;
+
+/* Length of the best match at previous step. Matches not greater than this
+ * are discarded. This is used in the lazy match evaluation.
+ */
+
+static unsigned strstart;	/* start of string to insert */
+static unsigned match_start;	/* start of matching string */
+static int eofile;		/* flag set at end of input file */
+static unsigned lookahead;	/* number of valid bytes ahead in window */
+
+static const unsigned max_chain_length = 4096;
+
+/* To speed up deflation, hash chains are never searched beyond this length.
+ * A higher limit improves compression ratio but degrades the speed.
+ */
+
+static const unsigned int max_lazy_match = 258;
+
+/* Attempt to find a better match only when the current match is strictly
+ * smaller than this value. This mechanism is used only for compression
+ * levels >= 4.
+ */
+#define max_insert_length  max_lazy_match
+/* Insert new strings in the hash table only if the match length
+ * is not greater than this length. This saves time but degrades compression.
+ * max_insert_length is used only for compression levels <= 3.
+ */
+
+static const unsigned good_match = 32;
+
+/* Use a faster search when the previous match is longer than this */
+
+
+/* Values for max_lazy_match, good_match and max_chain_length, depending on
+ * the desired pack level (0..9). The values given below have been tuned to
+ * exclude worst case performance for pathological files. Better values may be
+ * found for specific files.
+ */
+
+static const int nice_match = 258;	/* Stop searching when current match exceeds this */
+
+/* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
+ * For deflate_fast() (levels <= 3) good is ignored and lazy has a different
+ * meaning.
+ */
+
+#define EQUAL 0
+/* result of memcmp for equal strings */
+
+/* ===========================================================================
+ *  Prototypes for local functions.
+ */
+static void fill_window(void);
+
+static int longest_match(IPos cur_match);
+
+#ifdef DEBUG
+static void check_match(IPos start, IPos match, int length);
+#endif
+
+/* ===========================================================================
+ * Update a hash value with the given input byte
+ * IN  assertion: all calls to to UPDATE_HASH are made with consecutive
+ *    input characters, so that a running hash key can be computed from the
+ *    previous key instead of complete recalculation each time.
+ */
+#define UPDATE_HASH(h,c) (h = (((h)<<H_SHIFT) ^ (c)) & HASH_MASK)
+
+/* ===========================================================================
+ * Insert string s in the dictionary and set match_head to the previous head
+ * of the hash chain (the most recent string with same hash key). Return
+ * the previous length of the hash chain.
+ * IN  assertion: all calls to to INSERT_STRING are made with consecutive
+ *    input characters and the first MIN_MATCH bytes of s are valid
+ *    (except for the last MIN_MATCH-1 bytes of the input file).
+ */
+#define INSERT_STRING(s, match_head) \
+   (UPDATE_HASH(ins_h, window[(s) + MIN_MATCH-1]), \
+    prev[(s) & WMASK] = match_head = head[ins_h], \
+    head[ins_h] = (s))
+
+/* ===========================================================================
+ * Initialize the "longest match" routines for a new file
+ */
+static void lm_init(ush * flags)
+{
+	register unsigned j;
+
+	/* Initialize the hash table. */
+	memzero((char *) head, HASH_SIZE * sizeof(*head));
+	/* prev will be initialized on the fly */
+
+	*flags |= SLOW;
+	/* ??? reduce max_chain_length for binary files */
+
+	strstart = 0;
+	block_start = 0L;
+
+	lookahead = read_buf((char *) window,
+						 sizeof(int) <= 2 ? (unsigned) WSIZE : 2 * WSIZE);
+
+	if (lookahead == 0 || lookahead == (unsigned) EOF) {
+		eofile = 1, lookahead = 0;
+		return;
+	}
+	eofile = 0;
+	/* Make sure that we always have enough lookahead. This is important
+	 * if input comes from a device such as a tty.
+	 */
+	while (lookahead < MIN_LOOKAHEAD && !eofile)
+		fill_window();
+
+	ins_h = 0;
+	for (j = 0; j < MIN_MATCH - 1; j++)
+		UPDATE_HASH(ins_h, window[j]);
+	/* If lookahead < MIN_MATCH, ins_h is garbage, but this is
+	 * not important since only literal bytes will be emitted.
+	 */
+}
+
+/* ===========================================================================
+ * Set match_start to the longest match starting at the given string and
+ * return its length. Matches shorter or equal to prev_length are discarded,
+ * in which case the result is equal to prev_length and match_start is
+ * garbage.
+ * IN assertions: cur_match is the head of the hash chain for the current
+ *   string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
+ */
+
+/* For MSDOS, OS/2 and 386 Unix, an optimized version is in match.asm or
+ * match.s. The code is functionally equivalent, so you can use the C version
+ * if desired.
+ */
+static int longest_match(IPos cur_match)
+{
+	unsigned chain_length = max_chain_length;	/* max hash chain length */
+	register uch *scan = window + strstart;	/* current string */
+	register uch *match;	/* matched string */
+	register int len;	/* length of current match */
+	int best_len = prev_length;	/* best match length so far */
+	IPos limit =
+		strstart > (IPos) MAX_DIST ? strstart - (IPos) MAX_DIST : NIL;
+	/* Stop when cur_match becomes <= limit. To simplify the code,
+	 * we prevent matches with the string of window index 0.
+	 */
+
+/* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
+ * It is easy to get rid of this optimization if necessary.
+ */
+#if HASH_BITS < 8 || MAX_MATCH != 258
+#  error Code too clever
+#endif
+	register uch *strend = window + strstart + MAX_MATCH;
+	register uch scan_end1 = scan[best_len - 1];
+	register uch scan_end = scan[best_len];
+
+	/* Do not waste too much time if we already have a good match: */
+	if (prev_length >= good_match) {
+		chain_length >>= 2;
+	}
+	Assert(strstart <= window_size - MIN_LOOKAHEAD, "insufficient lookahead");
+
+	do {
+		Assert(cur_match < strstart, "no future");
+		match = window + cur_match;
+
+		/* Skip to next match if the match length cannot increase
+		 * or if the match length is less than 2:
+		 */
+		if (match[best_len] != scan_end ||
+			match[best_len - 1] != scan_end1 ||
+			*match != *scan || *++match != scan[1])
+			continue;
+
+		/* The check at best_len-1 can be removed because it will be made
+		 * again later. (This heuristic is not always a win.)
+		 * It is not necessary to compare scan[2] and match[2] since they
+		 * are always equal when the other bytes match, given that
+		 * the hash keys are equal and that HASH_BITS >= 8.
+		 */
+		scan += 2, match++;
+
+		/* We check for insufficient lookahead only every 8th comparison;
+		 * the 256th check will be made at strstart+258.
+		 */
+		do {
+		} while (*++scan == *++match && *++scan == *++match &&
+				 *++scan == *++match && *++scan == *++match &&
+				 *++scan == *++match && *++scan == *++match &&
+				 *++scan == *++match && *++scan == *++match && scan < strend);
+
+		len = MAX_MATCH - (int) (strend - scan);
+		scan = strend - MAX_MATCH;
+
+		if (len > best_len) {
+			match_start = cur_match;
+			best_len = len;
+			if (len >= nice_match)
+				break;
+			scan_end1 = scan[best_len - 1];
+			scan_end = scan[best_len];
+		}
+	} while ((cur_match = prev[cur_match & WMASK]) > limit
+			 && --chain_length != 0);
+
+	return best_len;
+}
+
+#ifdef DEBUG
+/* ===========================================================================
+ * Check that the match at match_start is indeed a match.
+ */
+static void check_match(IPos start, IPos match, int length)
+{
+	/* check that the match is indeed a match */
+	if (memcmp((char *) window + match,
+			   (char *) window + start, length) != EQUAL) {
+		bb_error_msg(" start %d, match %d, length %d", start, match, length);
+		bb_error_msg("invalid match");
+	}
+	if (verbose > 1) {
+		bb_error_msg("\\[%d,%d]", start - match, length);
+		do {
+			putc(window[start++], stderr);
+		} while (--length != 0);
+	}
+}
+#else
+#  define check_match(start, match, length)
+#endif
+
+/* ===========================================================================
+ * Fill the window when the lookahead becomes insufficient.
+ * Updates strstart and lookahead, and sets eofile if end of input file.
+ * IN assertion: lookahead < MIN_LOOKAHEAD && strstart + lookahead > 0
+ * OUT assertions: at least one byte has been read, or eofile is set;
+ *    file reads are performed for at least two bytes (required for the
+ *    translate_eol option).
+ */
+static void fill_window()
+{
+	register unsigned n, m;
+	unsigned more =
+		(unsigned) (window_size - (ulg) lookahead - (ulg) strstart);
+	/* Amount of free space at the end of the window. */
+
+	/* If the window is almost full and there is insufficient lookahead,
+	 * move the upper half to the lower one to make room in the upper half.
+	 */
+	if (more == (unsigned) EOF) {
+		/* Very unlikely, but possible on 16 bit machine if strstart == 0
+		 * and lookahead == 1 (input done one byte at time)
+		 */
+		more--;
+	} else if (strstart >= WSIZE + MAX_DIST) {
+		/* By the IN assertion, the window is not empty so we can't confuse
+		 * more == 0 with more == 64K on a 16 bit machine.
+		 */
+		Assert(window_size == (ulg) 2 * WSIZE, "no sliding with BIG_MEM");
+
+		memcpy((char *) window, (char *) window + WSIZE, (unsigned) WSIZE);
+		match_start -= WSIZE;
+		strstart -= WSIZE;	/* we now have strstart >= MAX_DIST: */
+
+		block_start -= (long) WSIZE;
+
+		for (n = 0; n < HASH_SIZE; n++) {
+			m = head[n];
+			head[n] = (Pos) (m >= WSIZE ? m - WSIZE : NIL);
+		}
+		for (n = 0; n < WSIZE; n++) {
+			m = prev[n];
+			prev[n] = (Pos) (m >= WSIZE ? m - WSIZE : NIL);
+			/* If n is not on any hash chain, prev[n] is garbage but
+			 * its value will never be used.
+			 */
+		}
+		more += WSIZE;
+	}
+	/* At this point, more >= 2 */
+	if (!eofile) {
+		n = read_buf((char *) window + strstart + lookahead, more);
+		if (n == 0 || n == (unsigned) EOF) {
+			eofile = 1;
+		} else {
+			lookahead += n;
+		}
+	}
+}
+
+/* ===========================================================================
+ * Flush the current block, with given end-of-file flag.
+ * IN assertion: strstart is set to the end of the current match.
+ */
+#define FLUSH_BLOCK(eof) \
+   flush_block(block_start >= 0L ? (char*)&window[(unsigned)block_start] : \
+                (char*)NULL, (long)strstart - block_start, (eof))
+
+/* ===========================================================================
+ * Same as above, but achieves better compression. We use a lazy
+ * evaluation for matches: a match is finally adopted only if there is
+ * no better match at the next window position.
+ */
+static ulg deflate()
+{
+	IPos hash_head;		/* head of hash chain */
+	IPos prev_match;	/* previous match */
+	int flush;			/* set if current block must be flushed */
+	int match_available = 0;	/* set if previous match exists */
+	register unsigned match_length = MIN_MATCH - 1;	/* length of best match */
+
+	/* Process the input block. */
+	while (lookahead != 0) {
+		/* Insert the string window[strstart .. strstart+2] in the
+		 * dictionary, and set hash_head to the head of the hash chain:
+		 */
+		INSERT_STRING(strstart, hash_head);
+
+		/* Find the longest match, discarding those <= prev_length.
+		 */
+		prev_length = match_length, prev_match = match_start;
+		match_length = MIN_MATCH - 1;
+
+		if (hash_head != NIL && prev_length < max_lazy_match &&
+			strstart - hash_head <= MAX_DIST) {
+			/* To simplify the code, we prevent matches with the string
+			 * of window index 0 (in particular we have to avoid a match
+			 * of the string with itself at the start of the input file).
+			 */
+			match_length = longest_match(hash_head);
+			/* longest_match() sets match_start */
+			if (match_length > lookahead)
+				match_length = lookahead;
+
+			/* Ignore a length 3 match if it is too distant: */
+			if (match_length == MIN_MATCH && strstart - match_start > TOO_FAR) {
+				/* If prev_match is also MIN_MATCH, match_start is garbage
+				 * but we will ignore the current match anyway.
+				 */
+				match_length--;
+			}
+		}
+		/* If there was a match at the previous step and the current
+		 * match is not better, output the previous match:
+		 */
+		if (prev_length >= MIN_MATCH && match_length <= prev_length) {
+
+			check_match(strstart - 1, prev_match, prev_length);
+
+			flush =
+				ct_tally(strstart - 1 - prev_match, prev_length - MIN_MATCH);
+
+			/* Insert in hash table all strings up to the end of the match.
+			 * strstart-1 and strstart are already inserted.
+			 */
+			lookahead -= prev_length - 1;
+			prev_length -= 2;
+			do {
+				strstart++;
+				INSERT_STRING(strstart, hash_head);
+				/* strstart never exceeds WSIZE-MAX_MATCH, so there are
+				 * always MIN_MATCH bytes ahead. If lookahead < MIN_MATCH
+				 * these bytes are garbage, but it does not matter since the
+				 * next lookahead bytes will always be emitted as literals.
+				 */
+			} while (--prev_length != 0);
+			match_available = 0;
+			match_length = MIN_MATCH - 1;
+			strstart++;
+			if (flush)
+				FLUSH_BLOCK(0), block_start = strstart;
+
+		} else if (match_available) {
+			/* If there was no match at the previous position, output a
+			 * single literal. If there was a match but the current match
+			 * is longer, truncate the previous match to a single literal.
+			 */
+			Tracevv((stderr, "%c", window[strstart - 1]));
+			if (ct_tally(0, window[strstart - 1])) {
+				FLUSH_BLOCK(0), block_start = strstart;
+			}
+			strstart++;
+			lookahead--;
+		} else {
+			/* There is no previous match to compare with, wait for
+			 * the next step to decide.
+			 */
+			match_available = 1;
+			strstart++;
+			lookahead--;
+		}
+		Assert(strstart <= isize && lookahead <= isize, "a bit too far");
+
+		/* Make sure that we always have enough lookahead, except
+		 * at the end of the input file. We need MAX_MATCH bytes
+		 * for the next match, plus MIN_MATCH bytes to insert the
+		 * string following the next match.
+		 */
+		while (lookahead < MIN_LOOKAHEAD && !eofile)
+			fill_window();
+	}
+	if (match_available)
+		ct_tally(0, window[strstart - 1]);
+
+	return FLUSH_BLOCK(1);	/* eof */
+}
+
+/* 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.
+ */
+
+/* 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.
+ */
+
+		/* configuration */
+
+typedef struct dirent dir_type;
+
+typedef RETSIGTYPE(*sig_type) (int);
+
+/* ======================================================================== */
+int gzip_main(int argc, char **argv)
+{
+	int result;
+	int inFileNum;
+	int outFileNum;
+	struct stat statBuf;
+	char *delFileName;
+	int tostdout = 0;
+	int force = 0;
+	int opt;
+
+	while ((opt = getopt(argc, argv, "cf123456789dq")) != -1) {
+		switch (opt) {
+		case 'c':
+			tostdout = 1;
+			break;
+		case 'f':
+			force = 1;
+			break;
+			/* Ignore 1-9 (compression level) options */
+		case '1':
+		case '2':
+		case '3':
+		case '4':
+		case '5':
+		case '6':
+		case '7':
+		case '8':
+		case '9':
+			break;
+		case 'q':
+			break;
+#ifdef CONFIG_GUNZIP
+		case 'd':
+			optind = 1;
+			return gunzip_main(argc, argv);
+#endif
+		default:
+			bb_show_usage();
+		}
+	}
+
+	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
+
+	strncpy(z_suffix, Z_SUFFIX, sizeof(z_suffix) - 1);
+	z_len = strlen(z_suffix);
+
+	/* 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);
+	ALLOC(ush, tab_prefix, 1L << BITS);
+
+	clear_bufs();
+	part_nb = 0;
+
+	if (optind == argc) {
+		time_stamp = 0;
+		ifile_size = -1L;
+		zip(STDIN_FILENO, STDOUT_FILENO);
+	} else {
+		int i;
+
+		for (i = optind; i < argc; i++) {
+			char *path = NULL;
+
+			if (strcmp(argv[i], "-") == 0) {
+				time_stamp = 0;
+				ifile_size = -1L;
+				inFileNum = STDIN_FILENO;
+				outFileNum = STDOUT_FILENO;
+			} else {
+				inFileNum = open(argv[i], O_RDONLY);
+				if (inFileNum < 0 || fstat(inFileNum, &statBuf) < 0)
+					bb_perror_msg_and_die("%s", argv[i]);
+				time_stamp = statBuf.st_ctime;
+				ifile_size = statBuf.st_size;
+
+				if (!tostdout) {
+					path = xmalloc(strlen(argv[i]) + 4);
+					strcpy(path, argv[i]);
+					strcat(path, ".gz");
+
+					/* Open output file */
+#if (__GLIBC__ >= 2) && (__GLIBC_MINOR__ >= 1)
+					outFileNum =
+						open(path, O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW);
+#else
+					outFileNum = open(path, O_RDWR | O_CREAT | O_EXCL);
+#endif
+					if (outFileNum < 0) {
+						bb_perror_msg("%s", path);
+						free(path);
+						continue;
+					}
+
+					/* Set permissions on the file */
+					fchmod(outFileNum, statBuf.st_mode);
+				} else
+					outFileNum = STDOUT_FILENO;
+			}
+
+			if (path == NULL && isatty(outFileNum) && force == 0) {
+				bb_error_msg
+					("compressed data not written to a terminal. Use -f to force compression.");
+				free(path);
+				continue;
+			}
+
+			result = zip(inFileNum, outFileNum);
+
+			if (path != NULL) {
+				close(inFileNum);
+				close(outFileNum);
+
+				/* Delete the original file */
+				if (result == OK)
+					delFileName = argv[i];
+				else
+					delFileName = path;
+
+				if (unlink(delFileName) < 0)
+					bb_perror_msg("%s", delFileName);
+			}
+
+			free(path);
+		}
+	}
+
+	return (exit_code);
+}
+
+/* trees.c -- output deflated data using Huffman coding
+ * 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.
+ */
+
+/*
+ *  PURPOSE
+ *
+ *      Encode various sets of source values using variable-length
+ *      binary code trees.
+ *
+ *  DISCUSSION
+ *
+ *      The PKZIP "deflation" process uses several Huffman trees. The more
+ *      common source values are represented by shorter bit sequences.
+ *
+ *      Each code tree is stored in the ZIP file in a compressed form
+ *      which is itself a Huffman encoding of the lengths of
+ *      all the code strings (in ascending order by source values).
+ *      The actual code strings are reconstructed from the lengths in
+ *      the UNZIP process, as described in the "application note"
+ *      (APPNOTE.TXT) distributed as part of PKWARE's PKZIP program.
+ *
+ *  REFERENCES
+ *
+ *      Lynch, Thomas J.
+ *          Data Compression:  Techniques and Applications, pp. 53-55.
+ *          Lifetime Learning Publications, 1985.  ISBN 0-534-03418-7.
+ *
+ *      Storer, James A.
+ *          Data Compression:  Methods and Theory, pp. 49-50.
+ *          Computer Science Press, 1988.  ISBN 0-7167-8156-5.
+ *
+ *      Sedgewick, R.
+ *          Algorithms, p290.
+ *          Addison-Wesley, 1983. ISBN 0-201-06672-6.
+ *
+ *  INTERFACE
+ *
+ *      void ct_init (ush *attr, int *methodp)
+ *          Allocate the match buffer, initialize the various tables and save
+ *          the location of the internal file attribute (ascii/binary) and
+ *          method (DEFLATE/STORE)
+ *
+ *      void ct_tally (int dist, int lc);
+ *          Save the match info and tally the frequency counts.
+ *
+ *      long flush_block (char *buf, ulg stored_len, int eof)
+ *          Determine the best encoding for the current block: dynamic trees,
+ *          static trees or store, and output the encoded block to the zip
+ *          file. Returns the total compressed length for the file so far.
+ *
+ */
+
+/* ===========================================================================
+ * Constants
+ */
+
+#define MAX_BITS 15
+/* All codes must not exceed MAX_BITS bits */
+
+#define MAX_BL_BITS 7
+/* Bit length codes must not exceed MAX_BL_BITS bits */
+
+#define LENGTH_CODES 29
+/* number of length codes, not counting the special END_BLOCK code */
+
+#define LITERALS  256
+/* number of literal bytes 0..255 */
+
+#define END_BLOCK 256
+/* end of block literal code */
+
+#define L_CODES (LITERALS+1+LENGTH_CODES)
+/* number of Literal or Length codes, including the END_BLOCK code */
+
+#define D_CODES   30
+/* number of distance codes */
+
+#define BL_CODES  19
+/* number of codes used to transfer the bit lengths */
+
+typedef uch extra_bits_t;
+
+/* extra bits for each length code */
+static const extra_bits_t extra_lbits[LENGTH_CODES]
+	= { 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
+};
+
+/* extra bits for each distance code */
+static const extra_bits_t extra_dbits[D_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
+};
+
+/* extra bits for each bit length code */
+static const extra_bits_t extra_blbits[BL_CODES]
+= { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 3, 7 };
+
+#define STORED_BLOCK 0
+#define STATIC_TREES 1
+#define DYN_TREES    2
+/* The three kinds of block type */
+
+#ifndef LIT_BUFSIZE
+#  ifdef SMALL_MEM
+#    define LIT_BUFSIZE  0x2000
+#  else
+#  ifdef MEDIUM_MEM
+#    define LIT_BUFSIZE  0x4000
+#  else
+#    define LIT_BUFSIZE  0x8000
+#  endif
+#  endif
+#endif
+#ifndef DIST_BUFSIZE
+#  define DIST_BUFSIZE  LIT_BUFSIZE
+#endif
+/* Sizes of match buffers for literals/lengths and distances.  There are
+ * 4 reasons for limiting LIT_BUFSIZE to 64K:
+ *   - frequencies can be kept in 16 bit counters
+ *   - if compression is not successful for the first block, all input data is
+ *     still in the window so we can still emit a stored block even when input
+ *     comes from standard input.  (This can also be done for all blocks if
+ *     LIT_BUFSIZE is not greater than 32K.)
+ *   - if compression is not successful for a file smaller than 64K, we can
+ *     even emit a stored file instead of a stored block (saving 5 bytes).
+ *   - creating new Huffman trees less frequently may not provide fast
+ *     adaptation to changes in the input data statistics. (Take for
+ *     example a binary file with poorly compressible code followed by
+ *     a highly compressible string table.) Smaller buffer sizes give
+ *     fast adaptation but have of course the overhead of transmitting trees
+ *     more frequently.
+ *   - I can't count above 4
+ * The current code is general and allows DIST_BUFSIZE < LIT_BUFSIZE (to save
+ * memory at the expense of compression). Some optimizations would be possible
+ * if we rely on DIST_BUFSIZE == LIT_BUFSIZE.
+ */
+#if LIT_BUFSIZE > INBUFSIZ
+#error cannot overlay l_buf and inbuf
+#endif
+#define REP_3_6      16
+/* repeat previous bit length 3-6 times (2 bits of repeat count) */
+#define REPZ_3_10    17
+/* repeat a zero length 3-10 times  (3 bits of repeat count) */
+#define REPZ_11_138  18
+/* repeat a zero length 11-138 times  (7 bits of repeat count) */
+
+/* ===========================================================================
+ * Local data
+ */
+
+/* Data structure describing a single value and its code string. */
+typedef struct ct_data {
+	union {
+		ush freq;		/* frequency count */
+		ush code;		/* bit string */
+	} fc;
+	union {
+		ush dad;		/* father node in Huffman tree */
+		ush len;		/* length of bit string */
+	} dl;
+} ct_data;
+
+#define Freq fc.freq
+#define Code fc.code
+#define Dad  dl.dad
+#define Len  dl.len
+
+#define HEAP_SIZE (2*L_CODES+1)
+/* maximum heap size */
+
+static ct_data dyn_ltree[HEAP_SIZE];	/* literal and length tree */
+static ct_data dyn_dtree[2 * D_CODES + 1];	/* distance tree */
+
+static ct_data static_ltree[L_CODES + 2];
+
+/* The static literal tree. Since the bit lengths are imposed, there is no
+ * need for the L_CODES extra codes used during heap construction. However
+ * The codes 286 and 287 are needed to build a canonical tree (see ct_init
+ * below).
+ */
+
+static ct_data static_dtree[D_CODES];
+
+/* The static distance tree. (Actually a trivial tree since all codes use
+ * 5 bits.)
+ */
+
+static ct_data bl_tree[2 * BL_CODES + 1];
+
+/* Huffman tree for the bit lengths */
+
+typedef struct tree_desc {
+	ct_data *dyn_tree;	/* the dynamic tree */
+	ct_data *static_tree;	/* corresponding static tree or NULL */
+	const extra_bits_t *extra_bits;	/* extra bits for each code or NULL */
+	int extra_base;		/* base index for extra_bits */
+	int elems;			/* max number of elements in the tree */
+	int max_length;		/* max bit length for the codes */
+	int max_code;		/* largest code with non zero frequency */
+} tree_desc;
+
+static tree_desc l_desc =
+	{ dyn_ltree, static_ltree, extra_lbits, LITERALS + 1, L_CODES,
+	MAX_BITS, 0
+};
+
+static tree_desc d_desc =
+	{ dyn_dtree, static_dtree, extra_dbits, 0, D_CODES, MAX_BITS, 0 };
+
+static tree_desc bl_desc =
+	{ bl_tree, (ct_data *) 0, extra_blbits, 0, BL_CODES, MAX_BL_BITS,
+	0
+};
+
+
+static ush bl_count[MAX_BITS + 1];
+
+/* number of codes at each bit length for an optimal tree */
+
+static const uch bl_order[BL_CODES]
+= { 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15 };
+
+/* The lengths of the bit length codes are sent in order of decreasing
+ * probability, to avoid transmitting the lengths for unused bit length codes.
+ */
+
+static int heap[2 * L_CODES + 1];	/* heap used to build the Huffman trees */
+static int heap_len;	/* number of elements in the heap */
+static int heap_max;	/* element of largest frequency */
+
+/* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
+ * The same heap array is used to build all trees.
+ */
+
+static uch depth[2 * L_CODES + 1];
+
+/* Depth of each subtree used as tie breaker for trees of equal frequency */
+
+static uch length_code[MAX_MATCH - MIN_MATCH + 1];
+
+/* length code for each normalized match length (0 == MIN_MATCH) */
+
+static uch dist_code[512];
+
+/* distance codes. The first 256 values correspond to the distances
+ * 3 .. 258, the last 256 values correspond to the top 8 bits of
+ * the 15 bit distances.
+ */
+
+static int base_length[LENGTH_CODES];
+
+/* First normalized length for each code (0 = MIN_MATCH) */
+
+static int base_dist[D_CODES];
+
+/* First normalized distance for each code (0 = distance of 1) */
+
+#define l_buf inbuf
+/* DECLARE(uch, l_buf, LIT_BUFSIZE);  buffer for literals or lengths */
+
+/* DECLARE(ush, d_buf, DIST_BUFSIZE); buffer for distances */
+
+static uch flag_buf[(LIT_BUFSIZE / 8)];
+
+/* flag_buf is a bit array distinguishing literals from lengths in
+ * l_buf, thus indicating the presence or absence of a distance.
+ */
+
+static unsigned last_lit;	/* running index in l_buf */
+static unsigned last_dist;	/* running index in d_buf */
+static unsigned last_flags;	/* running index in flag_buf */
+static uch flags;		/* current flags not yet saved in flag_buf */
+static uch flag_bit;	/* current bit used in flags */
+
+/* bits are filled in flags starting at bit 0 (least significant).
+ * Note: these flags are overkill in the current code since we don't
+ * take advantage of DIST_BUFSIZE == LIT_BUFSIZE.
+ */
+
+static ulg opt_len;		/* bit length of current block with optimal trees */
+static ulg static_len;	/* bit length of current block with static trees */
+
+static ulg compressed_len;	/* total bit length of compressed file */
+
+
+static ush *file_type;	/* pointer to UNKNOWN, BINARY or ASCII */
+static int *file_method;	/* pointer to DEFLATE or STORE */
+
+/* ===========================================================================
+ * Local (static) routines in this file.
+ */
+
+static void init_block(void);
+static void pqdownheap(ct_data * tree, int k);
+static void gen_bitlen(tree_desc * desc);
+static void gen_codes(ct_data * tree, int max_code);
+static void build_tree(tree_desc * desc);
+static void scan_tree(ct_data * tree, int max_code);
+static void send_tree(ct_data * tree, int max_code);
+static int build_bl_tree(void);
+static void send_all_trees(int lcodes, int dcodes, int blcodes);
+static void compress_block(ct_data * ltree, ct_data * dtree);
+static void set_file_type(void);
+
+
+#ifndef DEBUG
+#  define send_code(c, tree) send_bits(tree[c].Code, tree[c].Len)
+   /* Send a code of the given tree. c and tree must not have side effects */
+
+#else							/* DEBUG */
+#  define send_code(c, tree) \
+     { if (verbose>1) bb_error_msg("\ncd %3d ",(c)); \
+       send_bits(tree[c].Code, tree[c].Len); }
+#endif
+
+#define d_code(dist) \
+   ((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)])
+/* Mapping from a distance to a distance code. dist is the distance - 1 and
+ * must not have side effects. dist_code[256] and dist_code[257] are never
+ * used.
+ */
+
+/* the arguments must not have side effects */
+
+/* ===========================================================================
+ * Allocate the match buffer, initialize the various tables and save the
+ * location of the internal file attribute (ascii/binary) and method
+ * (DEFLATE/STORE).
+ */
+static void ct_init(ush * attr, int *methodp)
+{
+	int n;				/* iterates over tree elements */
+	int bits;			/* bit counter */
+	int length;			/* length value */
+	int code;			/* code value */
+	int dist;			/* distance index */
+
+	file_type = attr;
+	file_method = methodp;
+	compressed_len = 0L;
+
+	if (static_dtree[0].Len != 0)
+		return;			/* ct_init already called */
+
+	/* Initialize the mapping length (0..255) -> length code (0..28) */
+	length = 0;
+	for (code = 0; code < LENGTH_CODES - 1; code++) {
+		base_length[code] = length;
+		for (n = 0; n < (1 << extra_lbits[code]); n++) {
+			length_code[length++] = (uch) code;
+		}
+	}
+	Assert(length == 256, "ct_init: length != 256");
+	/* Note that the length 255 (match length 258) can be represented
+	 * in two different ways: code 284 + 5 bits or code 285, so we
+	 * overwrite length_code[255] to use the best encoding:
+	 */
+	length_code[length - 1] = (uch) code;
+
+	/* Initialize the mapping dist (0..32K) -> dist code (0..29) */
+	dist = 0;
+	for (code = 0; code < 16; code++) {
+		base_dist[code] = dist;
+		for (n = 0; n < (1 << extra_dbits[code]); n++) {
+			dist_code[dist++] = (uch) code;
+		}
+	}
+	Assert(dist == 256, "ct_init: dist != 256");
+	dist >>= 7;			/* from now on, all distances are divided by 128 */
+	for (; code < D_CODES; code++) {
+		base_dist[code] = dist << 7;
+		for (n = 0; n < (1 << (extra_dbits[code] - 7)); n++) {
+			dist_code[256 + dist++] = (uch) code;
+		}
+	}
+	Assert(dist == 256, "ct_init: 256+dist != 512");
+
+	/* Construct the codes of the static literal tree */
+	for (bits = 0; bits <= MAX_BITS; bits++)
+		bl_count[bits] = 0;
+	n = 0;
+	while (n <= 143)
+		static_ltree[n++].Len = 8, bl_count[8]++;
+	while (n <= 255)
+		static_ltree[n++].Len = 9, bl_count[9]++;
+	while (n <= 279)
+		static_ltree[n++].Len = 7, bl_count[7]++;
+	while (n <= 287)
+		static_ltree[n++].Len = 8, bl_count[8]++;
+	/* Codes 286 and 287 do not exist, but we must include them in the
+	 * tree construction to get a canonical Huffman tree (longest code
+	 * all ones)
+	 */
+	gen_codes((ct_data *) static_ltree, L_CODES + 1);
+
+	/* The static distance tree is trivial: */
+	for (n = 0; n < D_CODES; n++) {
+		static_dtree[n].Len = 5;
+		static_dtree[n].Code = bi_reverse(n, 5);
+	}
+
+	/* Initialize the first block of the first file: */
+	init_block();
+}
+
+/* ===========================================================================
+ * Initialize a new block.
+ */
+static void init_block()
+{
+	int n;				/* iterates over tree elements */
+
+	/* Initialize the trees. */
+	for (n = 0; n < L_CODES; n++)
+		dyn_ltree[n].Freq = 0;
+	for (n = 0; n < D_CODES; n++)
+		dyn_dtree[n].Freq = 0;
+	for (n = 0; n < BL_CODES; n++)
+		bl_tree[n].Freq = 0;
+
+	dyn_ltree[END_BLOCK].Freq = 1;
+	opt_len = static_len = 0L;
+	last_lit = last_dist = last_flags = 0;
+	flags = 0;
+	flag_bit = 1;
+}
+
+#define SMALLEST 1
+/* Index within the heap array of least frequent node in the Huffman tree */
+
+
+/* ===========================================================================
+ * Remove the smallest element from the heap and recreate the heap with
+ * one less element. Updates heap and heap_len.
+ */
+#define pqremove(tree, top) \
+{\
+    top = heap[SMALLEST]; \
+    heap[SMALLEST] = heap[heap_len--]; \
+    pqdownheap(tree, SMALLEST); \
+}
+
+/* ===========================================================================
+ * Compares to subtrees, using the tree depth as tie breaker when
+ * the subtrees have equal frequency. This minimizes the worst case length.
+ */
+#define smaller(tree, n, m) \
+   (tree[n].Freq < tree[m].Freq || \
+   (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
+
+/* ===========================================================================
+ * Restore the heap property by moving down the tree starting at node k,
+ * exchanging a node with the smallest of its two sons if necessary, stopping
+ * when the heap property is re-established (each father smaller than its
+ * two sons).
+ */
+static void pqdownheap(ct_data * tree, int k)
+{
+	int v = heap[k];
+	int j = k << 1;		/* left son of k */
+
+	while (j <= heap_len) {
+		/* Set j to the smallest of the two sons: */
+		if (j < heap_len && smaller(tree, heap[j + 1], heap[j]))
+			j++;
+
+		/* Exit if v is smaller than both sons */
+		if (smaller(tree, v, heap[j]))
+			break;
+
+		/* Exchange v with the smallest son */
+		heap[k] = heap[j];
+		k = j;
+
+		/* And continue down the tree, setting j to the left son of k */
+		j <<= 1;
+	}
+	heap[k] = v;
+}
+
+/* ===========================================================================
+ * Compute the optimal bit lengths for a tree and update the total bit length
+ * for the current block.
+ * IN assertion: the fields freq and dad are set, heap[heap_max] and
+ *    above are the tree nodes sorted by increasing frequency.
+ * OUT assertions: the field len is set to the optimal bit length, the
+ *     array bl_count contains the frequencies for each bit length.
+ *     The length opt_len is updated; static_len is also updated if stree is
+ *     not null.
+ */
+static void gen_bitlen(tree_desc * desc)
+{
+	ct_data *tree = desc->dyn_tree;
+	const extra_bits_t *extra = desc->extra_bits;
+	int base = desc->extra_base;
+	int max_code = desc->max_code;
+	int max_length = desc->max_length;
+	ct_data *stree = desc->static_tree;
+	int h;				/* heap index */
+	int n, m;			/* iterate over the tree elements */
+	int bits;			/* bit length */
+	int xbits;			/* extra bits */
+	ush f;				/* frequency */
+	int overflow = 0;	/* number of elements with bit length too large */
+
+	for (bits = 0; bits <= MAX_BITS; bits++)
+		bl_count[bits] = 0;
+
+	/* In a first pass, compute the optimal bit lengths (which may
+	 * overflow in the case of the bit length tree).
+	 */
+	tree[heap[heap_max]].Len = 0;	/* root of the heap */
+
+	for (h = heap_max + 1; h < HEAP_SIZE; h++) {
+		n = heap[h];
+		bits = tree[tree[n].Dad].Len + 1;
+		if (bits > max_length)
+			bits = max_length, overflow++;
+		tree[n].Len = (ush) bits;
+		/* We overwrite tree[n].Dad which is no longer needed */
+
+		if (n > max_code)
+			continue;	/* not a leaf node */
+
+		bl_count[bits]++;
+		xbits = 0;
+		if (n >= base)
+			xbits = extra[n - base];
+		f = tree[n].Freq;
+		opt_len += (ulg) f *(bits + xbits);
+
+		if (stree)
+			static_len += (ulg) f *(stree[n].Len + xbits);
+	}
+	if (overflow == 0)
+		return;
+
+	Trace((stderr, "\nbit length overflow\n"));
+	/* This happens for example on obj2 and pic of the Calgary corpus */
+
+	/* Find the first bit length which could increase: */
+	do {
+		bits = max_length - 1;
+		while (bl_count[bits] == 0)
+			bits--;
+		bl_count[bits]--;	/* move one leaf down the tree */
+		bl_count[bits + 1] += 2;	/* move one overflow item as its brother */
+		bl_count[max_length]--;
+		/* The brother of the overflow item also moves one step up,
+		 * but this does not affect bl_count[max_length]
+		 */
+		overflow -= 2;
+	} while (overflow > 0);
+
+	/* Now recompute all bit lengths, scanning in increasing frequency.
+	 * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
+	 * lengths instead of fixing only the wrong ones. This idea is taken
+	 * from 'ar' written by Haruhiko Okumura.)
+	 */
+	for (bits = max_length; bits != 0; bits--) {
+		n = bl_count[bits];
+		while (n != 0) {
+			m = heap[--h];
+			if (m > max_code)
+				continue;
+			if (tree[m].Len != (unsigned) bits) {
+				Trace((stderr, "code %d bits %d->%d\n", m, tree[m].Len,
+					   bits));
+				opt_len +=
+					((long) bits - (long) tree[m].Len) * (long) tree[m].Freq;
+				tree[m].Len = (ush) bits;
+			}
+			n--;
+		}
+	}
+}
+
+/* ===========================================================================
+ * Generate the codes for a given tree and bit counts (which need not be
+ * optimal).
+ * IN assertion: the array bl_count contains the bit length statistics for
+ * the given tree and the field len is set for all tree elements.
+ * OUT assertion: the field code is set for all tree elements of non
+ *     zero code length.
+ */
+static void gen_codes(ct_data * tree, int max_code)
+{
+	ush next_code[MAX_BITS + 1];	/* next code value for each bit length */
+	ush code = 0;		/* running code value */
+	int bits;			/* bit index */
+	int n;				/* code index */
+
+	/* The distribution counts are first used to generate the code values
+	 * without bit reversal.
+	 */
+	for (bits = 1; bits <= MAX_BITS; bits++) {
+		next_code[bits] = code = (code + bl_count[bits - 1]) << 1;
+	}
+	/* Check that the bit counts in bl_count are consistent. The last code
+	 * must be all ones.
+	 */
+	Assert(code + bl_count[MAX_BITS] - 1 == (1 << MAX_BITS) - 1,
+		   "inconsistent bit counts");
+	Tracev((stderr, "\ngen_codes: max_code %d ", max_code));
+
+	for (n = 0; n <= max_code; n++) {
+		int len = tree[n].Len;
+
+		if (len == 0)
+			continue;
+		/* Now reverse the bits */
+		tree[n].Code = bi_reverse(next_code[len]++, len);
+
+		Tracec(tree != static_ltree,
+			   (stderr, "\nn %3d %c l %2d c %4x (%x) ", n,
+				(isgraph(n) ? n : ' '), len, tree[n].Code,
+				next_code[len] - 1));
+	}
+}
+
+/* ===========================================================================
+ * Construct one Huffman tree and assigns the code bit strings and lengths.
+ * Update the total bit length for the current block.
+ * IN assertion: the field freq is set for all tree elements.
+ * OUT assertions: the fields len and code are set to the optimal bit length
+ *     and corresponding code. The length opt_len is updated; static_len is
+ *     also updated if stree is not null. The field max_code is set.
+ */
+static void build_tree(tree_desc * desc)
+{
+	ct_data *tree = desc->dyn_tree;
+	ct_data *stree = desc->static_tree;
+	int elems = desc->elems;
+	int n, m;			/* iterate over heap elements */
+	int max_code = -1;	/* largest code with non zero frequency */
+	int node = elems;	/* next internal node of the tree */
+
+	/* Construct the initial heap, with least frequent element in
+	 * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
+	 * heap[0] is not used.
+	 */
+	heap_len = 0, heap_max = HEAP_SIZE;
+
+	for (n = 0; n < elems; n++) {
+		if (tree[n].Freq != 0) {
+			heap[++heap_len] = max_code = n;
+			depth[n] = 0;
+		} else {
+			tree[n].Len = 0;
+		}
+	}
+
+	/* The pkzip format requires that at least one distance code exists,
+	 * and that at least one bit should be sent even if there is only one
+	 * possible code. So to avoid special checks later on we force at least
+	 * two codes of non zero frequency.
+	 */
+	while (heap_len < 2) {
+		int new = heap[++heap_len] = (max_code < 2 ? ++max_code : 0);
+
+		tree[new].Freq = 1;
+		depth[new] = 0;
+		opt_len--;
+		if (stree)
+			static_len -= stree[new].Len;
+		/* new is 0 or 1 so it does not have extra bits */
+	}
+	desc->max_code = max_code;
+
+	/* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
+	 * establish sub-heaps of increasing lengths:
+	 */
+	for (n = heap_len / 2; n >= 1; n--)
+		pqdownheap(tree, n);
+
+	/* Construct the Huffman tree by repeatedly combining the least two
+	 * frequent nodes.
+	 */
+	do {
+		pqremove(tree, n);	/* n = node of least frequency */
+		m = heap[SMALLEST];	/* m = node of next least frequency */
+
+		heap[--heap_max] = n;	/* keep the nodes sorted by frequency */
+		heap[--heap_max] = m;
+
+		/* Create a new node father of n and m */
+		tree[node].Freq = tree[n].Freq + tree[m].Freq;
+		depth[node] = (uch) (MAX(depth[n], depth[m]) + 1);
+		tree[n].Dad = tree[m].Dad = (ush) node;
+#ifdef DUMP_BL_TREE
+		if (tree == bl_tree) {
+			bb_error_msg("\nnode %d(%d), sons %d(%d) %d(%d)",
+					node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq);
+		}
+#endif
+		/* and insert the new node in the heap */
+		heap[SMALLEST] = node++;
+		pqdownheap(tree, SMALLEST);
+
+	} while (heap_len >= 2);
+
+	heap[--heap_max] = heap[SMALLEST];
+
+	/* At this point, the fields freq and dad are set. We can now
+	 * generate the bit lengths.
+	 */
+	gen_bitlen((tree_desc *) desc);
+
+	/* The field len is now set, we can generate the bit codes */
+	gen_codes((ct_data *) tree, max_code);
+}
+
+/* ===========================================================================
+ * Scan a literal or distance tree to determine the frequencies of the codes
+ * in the bit length tree. Updates opt_len to take into account the repeat
+ * counts. (The contribution of the bit length codes will be added later
+ * during the construction of bl_tree.)
+ */
+static void scan_tree(ct_data * tree, int max_code)
+{
+	int n;				/* iterates over all tree elements */
+	int prevlen = -1;	/* last emitted length */
+	int curlen;			/* length of current code */
+	int nextlen = tree[0].Len;	/* length of next code */
+	int count = 0;		/* repeat count of the current code */
+	int max_count = 7;	/* max repeat count */
+	int min_count = 4;	/* min repeat count */
+
+	if (nextlen == 0)
+		max_count = 138, min_count = 3;
+	tree[max_code + 1].Len = (ush) 0xffff;	/* guard */
+
+	for (n = 0; n <= max_code; n++) {
+		curlen = nextlen;
+		nextlen = tree[n + 1].Len;
+		if (++count < max_count && curlen == nextlen) {
+			continue;
+		} else if (count < min_count) {
+			bl_tree[curlen].Freq += count;
+		} else if (curlen != 0) {
+			if (curlen != prevlen)
+				bl_tree[curlen].Freq++;
+			bl_tree[REP_3_6].Freq++;
+		} else if (count <= 10) {
+			bl_tree[REPZ_3_10].Freq++;
+		} else {
+			bl_tree[REPZ_11_138].Freq++;
+		}
+		count = 0;
+		prevlen = curlen;
+		if (nextlen == 0) {
+			max_count = 138, min_count = 3;
+		} else if (curlen == nextlen) {
+			max_count = 6, min_count = 3;
+		} else {
+			max_count = 7, min_count = 4;
+		}
+	}
+}
+
+/* ===========================================================================
+ * Send a literal or distance tree in compressed form, using the codes in
+ * bl_tree.
+ */
+static void send_tree(ct_data * tree, int max_code)
+{
+	int n;				/* iterates over all tree elements */
+	int prevlen = -1;	/* last emitted length */
+	int curlen;			/* length of current code */
+	int nextlen = tree[0].Len;	/* length of next code */
+	int count = 0;		/* repeat count of the current code */
+	int max_count = 7;	/* max repeat count */
+	int min_count = 4;	/* min repeat count */
+
+/* tree[max_code+1].Len = -1; *//* guard already set */
+	if (nextlen == 0)
+		max_count = 138, min_count = 3;
+
+	for (n = 0; n <= max_code; n++) {
+		curlen = nextlen;
+		nextlen = tree[n + 1].Len;
+		if (++count < max_count && curlen == nextlen) {
+			continue;
+		} else if (count < min_count) {
+			do {
+				send_code(curlen, bl_tree);
+			} while (--count != 0);
+
+		} else if (curlen != 0) {
+			if (curlen != prevlen) {
+				send_code(curlen, bl_tree);
+				count--;
+			}
+			Assert(count >= 3 && count <= 6, " 3_6?");
+			send_code(REP_3_6, bl_tree);
+			send_bits(count - 3, 2);
+
+		} else if (count <= 10) {
+			send_code(REPZ_3_10, bl_tree);
+			send_bits(count - 3, 3);
+
+		} else {
+			send_code(REPZ_11_138, bl_tree);
+			send_bits(count - 11, 7);
+		}
+		count = 0;
+		prevlen = curlen;
+		if (nextlen == 0) {
+			max_count = 138, min_count = 3;
+		} else if (curlen == nextlen) {
+			max_count = 6, min_count = 3;
+		} else {
+			max_count = 7, min_count = 4;
+		}
+	}
+}
+
+/* ===========================================================================
+ * Construct the Huffman tree for the bit lengths and return the index in
+ * bl_order of the last bit length code to send.
+ */
+static const int build_bl_tree()
+{
+	int max_blindex;	/* index of last bit length code of non zero freq */
+
+	/* Determine the bit length frequencies for literal and distance trees */
+	scan_tree((ct_data *) dyn_ltree, l_desc.max_code);
+	scan_tree((ct_data *) dyn_dtree, d_desc.max_code);
+
+	/* Build the bit length tree: */
+	build_tree((tree_desc *) (&bl_desc));
+	/* opt_len now includes the length of the tree representations, except
+	 * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
+	 */
+
+	/* Determine the number of bit length codes to send. The pkzip format
+	 * requires that at least 4 bit length codes be sent. (appnote.txt says
+	 * 3 but the actual value used is 4.)
+	 */
+	for (max_blindex = BL_CODES - 1; max_blindex >= 3; max_blindex--) {
+		if (bl_tree[bl_order[max_blindex]].Len != 0)
+			break;
+	}
+	/* Update opt_len to include the bit length tree and counts */
+	opt_len += 3 * (max_blindex + 1) + 5 + 5 + 4;
+	Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld", opt_len, static_len));
+
+	return max_blindex;
+}
+
+/* ===========================================================================
+ * Send the header for a block using dynamic Huffman trees: the counts, the
+ * lengths of the bit length codes, the literal tree and the distance tree.
+ * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
+ */
+static void send_all_trees(int lcodes, int dcodes, int blcodes)
+{
+	int rank;			/* index in bl_order */
+
+	Assert(lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");
+	Assert(lcodes <= L_CODES && dcodes <= D_CODES
+		   && blcodes <= BL_CODES, "too many codes");
+	Tracev((stderr, "\nbl counts: "));
+	send_bits(lcodes - 257, 5);	/* not +255 as stated in appnote.txt */
+	send_bits(dcodes - 1, 5);
+	send_bits(blcodes - 4, 4);	/* not -3 as stated in appnote.txt */
+	for (rank = 0; rank < blcodes; rank++) {
+		Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
+		send_bits(bl_tree[bl_order[rank]].Len, 3);
+	}
+	Tracev((stderr, "\nbl tree: sent %ld", bits_sent));
+
+	send_tree((ct_data *) dyn_ltree, lcodes - 1);	/* send the literal tree */
+	Tracev((stderr, "\nlit tree: sent %ld", bits_sent));
+
+	send_tree((ct_data *) dyn_dtree, dcodes - 1);	/* send the distance tree */
+	Tracev((stderr, "\ndist tree: sent %ld", bits_sent));
+}
+
+/* ===========================================================================
+ * Determine the best encoding for the current block: dynamic trees, static
+ * trees or store, and output the encoded block to the zip file. This function
+ * returns the total compressed length for the file so far.
+ */
+static ulg flush_block(char *buf, ulg stored_len, int eof)
+{
+	ulg opt_lenb, static_lenb;	/* opt_len and static_len in bytes */
+	int max_blindex;	/* index of last bit length code of non zero freq */
+
+	flag_buf[last_flags] = flags;	/* Save the flags for the last 8 items */
+
+	/* Check if the file is ascii or binary */
+	if (*file_type == (ush) UNKNOWN)
+		set_file_type();
+
+	/* Construct the literal and distance trees */
+	build_tree((tree_desc *) (&l_desc));
+	Tracev((stderr, "\nlit data: dyn %ld, stat %ld", opt_len, static_len));
+
+	build_tree((tree_desc *) (&d_desc));
+	Tracev((stderr, "\ndist data: dyn %ld, stat %ld", opt_len, static_len));
+	/* At this point, opt_len and static_len are the total bit lengths of
+	 * the compressed block data, excluding the tree representations.
+	 */
+
+	/* Build the bit length tree for the above two trees, and get the index
+	 * in bl_order of the last bit length code to send.
+	 */
+	max_blindex = build_bl_tree();
+
+	/* Determine the best encoding. Compute first the block length in bytes */
+	opt_lenb = (opt_len + 3 + 7) >> 3;
+	static_lenb = (static_len + 3 + 7) >> 3;
+
+	Trace((stderr,
+		   "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u dist %u ",
+		   opt_lenb, opt_len, static_lenb, static_len, stored_len,
+		   last_lit, last_dist));
+
+	if (static_lenb <= opt_lenb)
+		opt_lenb = static_lenb;
+
+	/* If compression failed and this is the first and last block,
+	 * and if the zip file can be seeked (to rewrite the local header),
+	 * the whole file is transformed into a stored file:
+	 */
+	if (stored_len <= opt_lenb && eof && compressed_len == 0L && seekable()) {
+		/* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */
+		if (buf == (char *) 0)
+			bb_error_msg("block vanished");
+
+		copy_block(buf, (unsigned) stored_len, 0);	/* without header */
+		compressed_len = stored_len << 3;
+		*file_method = STORED;
+
+	} else if (stored_len + 4 <= opt_lenb && buf != (char *) 0) {
+		/* 4: two words for the lengths */
+		/* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
+		 * Otherwise we can't have processed more than WSIZE input bytes since
+		 * the last block flush, because compression would have been
+		 * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
+		 * transform a block into a stored block.
+		 */
+		send_bits((STORED_BLOCK << 1) + eof, 3);	/* send block type */
+		compressed_len = (compressed_len + 3 + 7) & ~7L;
+		compressed_len += (stored_len + 4) << 3;
+
+		copy_block(buf, (unsigned) stored_len, 1);	/* with header */
+
+	} else if (static_lenb == opt_lenb) {
+		send_bits((STATIC_TREES << 1) + eof, 3);
+		compress_block((ct_data *) static_ltree, (ct_data *) static_dtree);
+		compressed_len += 3 + static_len;
+	} else {
+		send_bits((DYN_TREES << 1) + eof, 3);
+		send_all_trees(l_desc.max_code + 1, d_desc.max_code + 1,
+					   max_blindex + 1);
+		compress_block((ct_data *) dyn_ltree, (ct_data *) dyn_dtree);
+		compressed_len += 3 + opt_len;
+	}
+	Assert(compressed_len == bits_sent, "bad compressed size");
+	init_block();
+
+	if (eof) {
+		bi_windup();
+		compressed_len += 7;	/* align on byte boundary */
+	}
+	Tracev((stderr, "\ncomprlen %lu(%lu) ", compressed_len >> 3,
+			compressed_len - 7 * eof));
+
+	return compressed_len >> 3;
+}
+
+/* ===========================================================================
+ * Save the match info and tally the frequency counts. Return true if
+ * the current block must be flushed.
+ */
+static int ct_tally(int dist, int lc)
+{
+	l_buf[last_lit++] = (uch) lc;
+	if (dist == 0) {
+		/* lc is the unmatched char */
+		dyn_ltree[lc].Freq++;
+	} else {
+		/* Here, lc is the match length - MIN_MATCH */
+		dist--;			/* dist = match distance - 1 */
+		Assert((ush) dist < (ush) MAX_DIST &&
+			   (ush) lc <= (ush) (MAX_MATCH - MIN_MATCH) &&
+			   (ush) d_code(dist) < (ush) D_CODES, "ct_tally: bad match");
+
+		dyn_ltree[length_code[lc] + LITERALS + 1].Freq++;
+		dyn_dtree[d_code(dist)].Freq++;
+
+		d_buf[last_dist++] = (ush) dist;
+		flags |= flag_bit;
+	}
+	flag_bit <<= 1;
+
+	/* Output the flags if they fill a byte: */
+	if ((last_lit & 7) == 0) {
+		flag_buf[last_flags++] = flags;
+		flags = 0, flag_bit = 1;
+	}
+	/* Try to guess if it is profitable to stop the current block here */
+	if ((last_lit & 0xfff) == 0) {
+		/* Compute an upper bound for the compressed length */
+		ulg out_length = (ulg) last_lit * 8L;
+		ulg in_length = (ulg) strstart - block_start;
+		int dcode;
+
+		for (dcode = 0; dcode < D_CODES; dcode++) {
+			out_length +=
+				(ulg) dyn_dtree[dcode].Freq * (5L + extra_dbits[dcode]);
+		}
+		out_length >>= 3;
+		Trace((stderr,
+			   "\nlast_lit %u, last_dist %u, in %ld, out ~%ld(%ld%%) ",
+			   last_lit, last_dist, in_length, out_length,
+			   100L - out_length * 100L / in_length));
+		if (last_dist < last_lit / 2 && out_length < in_length / 2)
+			return 1;
+	}
+	return (last_lit == LIT_BUFSIZE - 1 || last_dist == DIST_BUFSIZE);
+	/* We avoid equality with LIT_BUFSIZE because of wraparound at 64K
+	 * on 16 bit machines and because stored blocks are restricted to
+	 * 64K-1 bytes.
+	 */
+}
+
+/* ===========================================================================
+ * Send the block data compressed using the given Huffman trees
+ */
+static void compress_block(ct_data * ltree, ct_data * dtree)
+{
+	unsigned dist;		/* distance of matched string */
+	int lc;				/* match length or unmatched char (if dist == 0) */
+	unsigned lx = 0;	/* running index in l_buf */
+	unsigned dx = 0;	/* running index in d_buf */
+	unsigned fx = 0;	/* running index in flag_buf */
+	uch flag = 0;		/* current flags */
+	unsigned code;		/* the code to send */
+	int extra;			/* number of extra bits to send */
+
+	if (last_lit != 0)
+		do {
+			if ((lx & 7) == 0)
+				flag = flag_buf[fx++];
+			lc = l_buf[lx++];
+			if ((flag & 1) == 0) {
+				send_code(lc, ltree);	/* send a literal byte */
+				Tracecv(isgraph(lc), (stderr, " '%c' ", lc));
+			} else {
+				/* Here, lc is the match length - MIN_MATCH */
+				code = length_code[lc];
+				send_code(code + LITERALS + 1, ltree);	/* send the length code */
+				extra = extra_lbits[code];
+				if (extra != 0) {
+					lc -= base_length[code];
+					send_bits(lc, extra);	/* send the extra length bits */
+				}
+				dist = d_buf[dx++];
+				/* Here, dist is the match distance - 1 */
+				code = d_code(dist);
+				Assert(code < D_CODES, "bad d_code");
+
+				send_code(code, dtree);	/* send the distance code */
+				extra = extra_dbits[code];
+				if (extra != 0) {
+					dist -= base_dist[code];
+					send_bits(dist, extra);	/* send the extra distance bits */
+				}
+			}			/* literal or match pair ? */
+			flag >>= 1;
+		} while (lx < last_lit);
+
+	send_code(END_BLOCK, ltree);
+}
+
+/* ===========================================================================
+ * Set the file type to ASCII or BINARY, using a crude approximation:
+ * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise.
+ * IN assertion: the fields freq of dyn_ltree are set and the total of all
+ * frequencies does not exceed 64K (to fit in an int on 16 bit machines).
+ */
+static void set_file_type()
+{
+	int n = 0;
+	unsigned ascii_freq = 0;
+	unsigned bin_freq = 0;
+
+	while (n < 7)
+		bin_freq += dyn_ltree[n++].Freq;
+	while (n < 128)
+		ascii_freq += dyn_ltree[n++].Freq;
+	while (n < LITERALS)
+		bin_freq += dyn_ltree[n++].Freq;
+	*file_type = bin_freq > (ascii_freq >> 2) ? BINARY : ASCII;
+	if (*file_type == BINARY && translate_eol) {
+		bb_error_msg("-l used on binary file");
+	}
+}
+
+/* zip.c -- compress files to the 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.
+ */
+
+
+static ulg crc;			/* crc on uncompressed file data */
+static long header_bytes;	/* number of bytes in gzip header */
+
+static void put_long(ulg n)
+{
+	put_short((n) & 0xffff);
+	put_short(((ulg) (n)) >> 16);
+}
+
+/* put_header_byte is used for the compressed output
+ * - for the initial 4 bytes that can't overflow the buffer.
+ */
+#define put_header_byte(c) {outbuf[outcnt++]=(uch)(c);}
+
+/* ===========================================================================
+ * Deflate in to out.
+ * IN assertions: the input and output buffers are cleared.
+ *   The variables time_stamp and save_orig_name are initialized.
+ */
+static int zip(int in, int out)
+{
+	uch my_flags = 0;	/* general purpose bit flags */
+	ush attr = 0;		/* ascii/binary flag */
+	ush deflate_flags = 0;	/* pkzip -es, -en or -ex equivalent */
+
+	ifd = in;
+	ofd = out;
+	outcnt = 0;
+
+	/* Write the header to the gzip file. See algorithm.doc for the format */
+
+
+	method = DEFLATED;
+	put_header_byte(GZIP_MAGIC[0]);	/* magic header */
+	put_header_byte(GZIP_MAGIC[1]);
+	put_header_byte(DEFLATED);	/* compression method */
+
+	put_header_byte(my_flags);	/* general flags */
+	put_long(time_stamp);
+
+	/* Write deflated file to zip file */
+	crc = updcrc(0, 0);
+
+	bi_init(out);
+	ct_init(&attr, &method);
+	lm_init(&deflate_flags);
+
+	put_byte((uch) deflate_flags);	/* extra flags */
+	put_byte(OS_CODE);	/* OS identifier */
+
+	header_bytes = (long) outcnt;
+
+	(void) deflate();
+
+	/* Write the crc and uncompressed size */
+	put_long(crc);
+	put_long(isize);
+	header_bytes += 2 * sizeof(long);
+
+	flush_outbuf();
+	return OK;
+}
+
+
+/* ===========================================================================
+ * Read a new buffer from the current input file, perform end-of-line
+ * translation, and update the crc and input file size.
+ * IN assertion: size >= 2 (for end-of-line translation)
+ */
+static int file_read(char *buf, unsigned size)
+{
+	unsigned len;
+
+	Assert(insize == 0, "inbuf not empty");
+
+	len = read(ifd, buf, size);
+	if (len == (unsigned) (-1) || len == 0)
+		return (int) len;
+
+	crc = updcrc((uch *) buf, len);
+	isize += (ulg) len;
+	return (int) len;
+}
+
+/* ===========================================================================
+ * Write the output buffer outbuf[0..outcnt-1] and update bytes_out.
+ * (used for the compressed data only)
+ */
+static void flush_outbuf()
+{
+	if (outcnt == 0)
+		return;
+
+	write_buf(ofd, (char *) outbuf, outcnt);
+	outcnt = 0;
+}