1 /* gzip.c -- this is a stripped down version of gzip I put into busybox, it does
2 * only standard in to standard out with -9 compression. It also requires the
3 * zcat module for some important functions.
5 * Charles P. Wright <cpw@unix.asb.com>
11 #error you need zcat to have gzip support!
14 static const char gzip_usage[] = "gzip\nignores all command line arguments\ncompress stdin to stdout with -9 compression\n";
16 /* gzip.h -- common declarations for all gzip modules
17 * Copyright (C) 1992-1993 Jean-loup Gailly.
18 * This is free software; you can redistribute it and/or modify it under the
19 * terms of the GNU General Public License, see the file COPYING.
22 #if defined(__STDC__) || defined(PROTO)
23 # define OF(args) args
34 /* I don't like nested includes, but the string and io functions are used
38 #if !defined(NO_STRING_H) || defined(STDC_HEADERS)
40 # if !defined(STDC_HEADERS) && !defined(NO_MEMORY_H) && !defined(__GNUC__)
43 # define memzero(s, n) memset ((voidp)(s), 0, (n))
47 # define strrchr rindex
48 # define memcpy(d, s, n) bcopy((s), (d), (n))
49 # define memcmp(s1, s2, n) bcmp((s1), (s2), (n))
50 # define memzero(s, n) bzero((s), (n))
54 # define RETSIGTYPE void
59 typedef unsigned char uch;
60 typedef unsigned short ush;
61 typedef unsigned long ulg;
63 /* Return codes from gzip */
68 /* Compression methods (see algorithm.doc) */
73 /* methods 4 to 7 reserved */
76 extern int method; /* compression method */
78 /* To save memory for 16 bit systems, some arrays are overlaid between
79 * the various modules:
80 * deflate: prev+head window d_buf l_buf outbuf
81 * unlzw: tab_prefix tab_suffix stack inbuf outbuf
82 * inflate: window inbuf
83 * unpack: window inbuf prefix_len
84 * unlzh: left+right window c_table inbuf c_len
85 * For compression, input is done in window[]. For decompression, output
86 * is done in window except for unlzw.
91 # define INBUFSIZ 0x2000 /* input buffer size */
93 # define INBUFSIZ 0x8000 /* input buffer size */
96 #define INBUF_EXTRA 64 /* required by unlzw() */
100 # define OUTBUFSIZ 8192 /* output buffer size */
102 # define OUTBUFSIZ 16384 /* output buffer size */
105 #define OUTBUF_EXTRA 2048 /* required by unlzw() */
109 # define DIST_BUFSIZE 0x2000 /* buffer for distances, see trees.c */
111 # define DIST_BUFSIZE 0x8000 /* buffer for distances, see trees.c */
116 # define EXTERN(type, array) extern type * near array
117 # define DECLARE(type, array, size) type * near array
118 # define ALLOC(type, array, size) { \
119 array = (type*)fcalloc((size_t)(((size)+1L)/2), 2*sizeof(type)); \
120 if (array == NULL) error("insufficient memory"); \
122 # define FREE(array) {if (array != NULL) fcfree(array), array=NULL;}
124 # define EXTERN(type, array) extern type array[]
125 # define DECLARE(type, array, size) type array[size]
126 # define ALLOC(type, array, size)
130 EXTERN(uch, inbuf); /* input buffer */
131 EXTERN(uch, outbuf); /* output buffer */
132 EXTERN(ush, d_buf); /* buffer for distances, see trees.c */
133 EXTERN(uch, window); /* Sliding window and suffix table (unlzw) */
134 #define tab_suffix window
136 # define tab_prefix prev /* hash link (see deflate.c) */
137 # define head (prev+WSIZE) /* hash head (see deflate.c) */
138 EXTERN(ush, tab_prefix); /* prefix code (see unlzw.c) */
140 # define tab_prefix0 prev
141 # define head tab_prefix1
142 EXTERN(ush, tab_prefix0); /* prefix for even codes */
143 EXTERN(ush, tab_prefix1); /* prefix for odd codes */
146 extern unsigned insize; /* valid bytes in inbuf */
147 extern unsigned inptr; /* index of next byte to be processed in inbuf */
148 extern unsigned outcnt; /* bytes in output buffer */
150 extern long bytes_in; /* number of input bytes */
151 extern long bytes_out; /* number of output bytes */
152 extern long header_bytes;/* number of bytes in gzip header */
154 #define isize bytes_in
155 /* for compatibility with old zip sources (to be cleaned) */
157 extern int ifd; /* input file descriptor */
158 extern int ofd; /* output file descriptor */
159 extern char ifname[]; /* input file name or "stdin" */
160 extern char ofname[]; /* output file name or "stdout" */
161 extern char *progname; /* program name */
163 extern long time_stamp; /* original time stamp (modification time) */
164 extern long ifile_size; /* input file size, -1 for devices (debug only) */
166 typedef int file_t; /* Do not use stdio */
167 #define NO_FILE (-1) /* in memory compression */
170 #define PACK_MAGIC "\037\036" /* Magic header for packed files */
171 #define GZIP_MAGIC "\037\213" /* Magic header for gzip files, 1F 8B */
172 #define OLD_GZIP_MAGIC "\037\236" /* Magic header for gzip 0.5 = freeze 1.x */
173 #define LZH_MAGIC "\037\240" /* Magic header for SCO LZH Compress files*/
174 #define PKZIP_MAGIC "\120\113\003\004" /* Magic header for pkzip files */
177 #define ASCII_FLAG 0x01 /* bit 0 set: file probably ascii text */
178 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
179 #define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
180 #define ORIG_NAME 0x08 /* bit 3 set: original file name present */
181 #define COMMENT 0x10 /* bit 4 set: file comment present */
182 #define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */
183 #define RESERVED 0xC0 /* bit 6,7: reserved */
185 /* internal file attribute */
186 #define UNKNOWN 0xffff
191 # define WSIZE 0x8000 /* window size--must be a power of two, and */
192 #endif /* at least 32K for zip's deflate method */
195 #define MAX_MATCH 258
196 /* The minimum and maximum match lengths */
198 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
199 /* Minimum amount of lookahead, except at the end of the input file.
200 * See deflate.c for comments about the MIN_MATCH+1.
203 #define MAX_DIST (WSIZE-MIN_LOOKAHEAD)
204 /* In order to simplify the code, particularly on 16 bit machines, match
205 * distances are limited to MAX_DIST instead of WSIZE.
208 extern int decrypt; /* flag to turn on decryption */
209 extern int exit_code; /* program exit code */
210 extern int verbose; /* be verbose (-v) */
211 extern int quiet; /* be quiet (-q) */
212 extern int test; /* check .z file integrity */
213 extern int to_stdout; /* output to stdout (-c) */
214 extern int save_orig_name; /* set if original name must be saved */
216 #define get_byte() (inptr < insize ? inbuf[inptr++] : fill_inbuf(0))
217 #define try_byte() (inptr < insize ? inbuf[inptr++] : fill_inbuf(1))
219 /* put_byte is used for the compressed output, put_ubyte for the
220 * uncompressed output. However unlzw() uses window for its
221 * suffix table instead of its output buffer, so it does not use put_ubyte
222 * (to be cleaned up).
224 #define put_byte(c) {outbuf[outcnt++]=(uch)(c); if (outcnt==OUTBUFSIZ)\
226 #define put_ubyte(c) {window[outcnt++]=(uch)(c); if (outcnt==WSIZE)\
229 /* Output a 16 bit value, lsb first */
230 #define put_short(w) \
231 { if (outcnt < OUTBUFSIZ-2) { \
232 outbuf[outcnt++] = (uch) ((w) & 0xff); \
233 outbuf[outcnt++] = (uch) ((ush)(w) >> 8); \
235 put_byte((uch)((w) & 0xff)); \
236 put_byte((uch)((ush)(w) >> 8)); \
240 /* Output a 32 bit value to the bit stream, lsb first */
241 #define put_long(n) { \
242 put_short((n) & 0xffff); \
243 put_short(((ulg)(n)) >> 16); \
246 #define seekable() 0 /* force sequential output */
247 #define translate_eol 0 /* no option -a yet */
249 #define tolow(c) (isupper(c) ? (c)-'A'+'a' : (c)) /* force to lower case */
251 /* Macros for getting two-byte and four-byte header values */
252 #define SH(p) ((ush)(uch)((p)[0]) | ((ush)(uch)((p)[1]) << 8))
253 #define LG(p) ((ulg)(SH(p)) | ((ulg)(SH((p)+2)) << 16))
255 /* Diagnostic functions */
257 # define Assert(cond,msg) {if(!(cond)) error(msg);}
258 # define Trace(x) fprintf x
259 # define Tracev(x) {if (verbose) fprintf x ;}
260 # define Tracevv(x) {if (verbose>1) fprintf x ;}
261 # define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
262 # define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
264 # define Assert(cond,msg)
269 # define Tracecv(c,x)
272 #define WARN(msg) {if (!quiet) fprintf msg ; \
273 if (exit_code == OK) exit_code = WARNING;}
275 local void do_exit(int exitcode);
278 extern int zip OF((int in, int out));
279 extern int file_read OF((char *buf, unsigned size));
282 extern int unzip OF((int in, int out));
283 extern int check_zipfile OF((int in));
286 extern int unpack OF((int in, int out));
289 extern int unlzh OF((int in, int out));
292 RETSIGTYPE abort_gzip OF((void));
295 void lm_init OF((ush *flags));
296 ulg deflate OF((void));
299 void ct_init OF((ush *attr, int *method));
300 int ct_tally OF((int dist, int lc));
301 ulg flush_block OF((char *buf, ulg stored_len, int eof));
304 void bi_init OF((file_t zipfile));
305 void send_bits OF((int value, int length));
306 unsigned bi_reverse OF((unsigned value, int length));
307 void bi_windup OF((void));
308 void copy_block OF((char *buf, unsigned len, int header));
309 extern int (*read_buf) OF((char *buf, unsigned size));
312 extern int copy OF((int in, int out));
313 extern ulg updcrc OF((uch *s, unsigned n));
314 extern void clear_bufs OF((void));
315 extern int fill_inbuf OF((int eof_ok));
316 extern void flush_outbuf OF((void));
317 extern void flush_window OF((void));
318 extern void write_buf OF((int fd, voidp buf, unsigned cnt));
319 extern char *strlwr OF((char *s));
320 extern char *add_envopt OF((int *argcp, char ***argvp, char *env));
321 extern void error OF((char *m));
322 extern void warn OF((char *a, char *b));
323 extern void read_error OF((void));
324 extern void write_error OF((void));
325 extern void display_ratio OF((long num, long den, FILE *file));
326 extern voidp xmalloc OF((unsigned int size));
329 extern int inflate OF((void));
330 /* lzw.h -- define the lzw functions.
331 * Copyright (C) 1992-1993 Jean-loup Gailly.
332 * This is free software; you can redistribute it and/or modify it under the
333 * terms of the GNU General Public License, see the file COPYING.
336 #if !defined(OF) && defined(lint)
343 #define INIT_BITS 9 /* Initial number of bits per code */
345 #define BIT_MASK 0x1f /* Mask for 'number of compression bits' */
346 /* Mask 0x20 is reserved to mean a fourth header byte, and 0x40 is free.
347 * It's a pity that old uncompress does not check bit 0x20. That makes
348 * extension of the format actually undesirable because old compress
349 * would just crash on the new format instead of giving a meaningful
350 * error message. It does check the number of bits, but it's more
351 * helpful to say "unsupported format, get a new version" than
352 * "can only handle 16 bits".
355 #define BLOCK_MODE 0x80
356 /* Block compression: if table is full and compression rate is dropping,
357 * clear the dictionary.
360 #define LZW_RESERVED 0x60 /* reserved bits */
362 #define CLEAR 256 /* flush the dictionary */
363 #define FIRST (CLEAR+1) /* first free entry */
365 extern int maxbits; /* max bits per code for LZW */
366 extern int block_mode; /* block compress mode -C compatible with 2.0 */
368 /* revision.h -- define the version number
369 * Copyright (C) 1992-1993 Jean-loup Gailly.
370 * This is free software; you can redistribute it and/or modify it under the
371 * terms of the GNU General Public License, see the file COPYING.
374 #define VERSION "1.2.4"
376 #define REVDATE "18 Aug 93"
378 /* This version does not support compression into old compress format: */
383 /* tailor.h -- target dependent definitions
384 * Copyright (C) 1992-1993 Jean-loup Gailly.
385 * This is free software; you can redistribute it and/or modify it under the
386 * terms of the GNU General Public License, see the file COPYING.
389 /* The target dependent definitions should be defined here only.
390 * The target dependent functions should be defined in tailor.c.
394 #if defined(__MSDOS__) && !defined(MSDOS)
398 #if defined(__OS2__) && !defined(OS2)
402 #if defined(OS2) && defined(MSDOS) /* MS C under OS/2 */
408 /* DJGPP version 1.09+ on MS-DOS.
409 * The DJGPP 1.09 stat() function must be upgraded before gzip will
411 * No need for DIRENT, since <unistd.h> defines POSIX_SOURCE which
425 # define HAVE_SYS_UTIME_H
429 # define PATH_SEP2 '\\'
430 # define PATH_SEP3 ':'
431 # define MAX_PATH_LEN 128
432 # define NO_MULTIPLE_DOTS
433 # define MAX_EXT_CHARS 3
434 # define Z_SUFFIX "z"
437 # define STDC_HEADERS
438 # define NO_SIZE_CHECK
439 # define casemap(c) tolow(c) /* Force file names to lower case */
441 # define OS_CODE 0x00
442 # define SET_BINARY_MODE(fd) setmode(fd, O_BINARY)
443 # if !defined(NO_ASM) && !defined(ASMV)
451 # define PATH_SEP2 '\\'
452 # define PATH_SEP3 ':'
453 # define MAX_PATH_LEN 260
455 # define NO_MULTIPLE_DOTS
456 # define MAX_EXT_CHARS 3
457 # define Z_SUFFIX "z"
458 # define casemap(c) tolow(c)
462 # define STDC_HEADERS
464 # define OS_CODE 0x06
465 # define SET_BINARY_MODE(fd) setmode(fd, O_BINARY)
467 # define HAVE_SYS_UTIME_H
474 # define HAVE_SYS_UTIME_H
477 # define EXPAND(argc,argv) \
478 {_response(&argc, &argv); _wildcard(&argc, &argv);}
487 # define EXPAND(argc,argv) \
488 {response_expand(&argc, &argv);}
492 #ifdef WIN32 /* Windows NT */
493 # define HAVE_SYS_UTIME_H
495 # define PATH_SEP2 '\\'
496 # define PATH_SEP3 ':'
497 # define MAX_PATH_LEN 260
500 # define STDC_HEADERS
501 # define SET_BINARY_MODE(fd) setmode(fd, O_BINARY)
505 # define NO_MULTIPLE_DOTS
506 # define MAX_EXT_CHARS 3
507 # define Z_SUFFIX "z"
508 # define casemap(c) tolow(c) /* Force file names to lower case */
510 # define OS_CODE 0x0b
517 /* Turbo C 2.0 does not accept static allocations of large arrays */
518 void * fcalloc (unsigned items, unsigned size);
519 void fcfree (void *ptr);
522 # define fcalloc(nitems,itemsize) halloc((long)(nitems),(itemsize))
523 # define fcfree(ptr) hfree(ptr)
527 # define fcalloc(items,size) calloc((items),(size))
529 # define fcalloc(items,size) malloc((size_t)(items)*(size_t)(size))
531 # define fcfree(ptr) free(ptr)
534 #if defined(VAXC) || defined(VMS)
535 # define PATH_SEP ']'
536 # define PATH_SEP2 ':'
537 # define SUFFIX_SEP ';'
538 # define NO_MULTIPLE_DOTS
539 # define Z_SUFFIX "-gz"
541 # define casemap(c) tolow(c)
542 # define OS_CODE 0x02
543 # define OPTIONS_VAR "GZIP_OPT"
544 # define STDC_HEADERS
546 # define EXPAND(argc,argv) vms_expand_args(&argc,&argv);
548 # define unlink delete
556 # define PATH_SEP2 ':'
557 # define STDC_HEADERS
558 # define OS_CODE 0x01
562 # define HAVE_UNISTD_H
564 # define NO_STDIN_FSTAT
569 # include <fcntl.h> /* for read() and write() */
570 # define direct dirent
571 extern void _expand_args(int *argc, char ***argv);
572 # define EXPAND(argc,argv) _expand_args(&argc,&argv);
573 # undef O_BINARY /* disable useless --ascii option */
577 #if defined(ATARI) || defined(atarist)
578 # ifndef STDC_HEADERS
579 # define STDC_HEADERS
580 # define HAVE_UNISTD_H
584 # define OS_CODE 0x05
586 # define PATH_SEP2 '\\'
587 # define PATH_SEP3 ':'
588 # define MAX_PATH_LEN 128
589 # define NO_MULTIPLE_DOTS
590 # define MAX_EXT_CHARS 3
591 # define Z_SUFFIX "z"
593 # define casemap(c) tolow(c) /* Force file names to lower case */
599 # define PATH_SEP ':'
602 # define NO_STDIN_FSTAT
605 # define chmod(file, mode) (0)
606 # define OPEN(name, flags, mode) open(name, flags)
607 # define OS_CODE 0x07
609 # define isatty(fd) ((fd) <= 2)
613 #ifdef __50SERIES /* Prime/PRIMOS */
614 # define PATH_SEP '>'
615 # define STDC_HEADERS
620 # define NO_STDIN_FSTAT
621 # define NO_SIZE_CHECK
624 # define casemap(c) tolow(c) /* Force file names to lower case */
625 # define put_char(c) put_byte((c) & 0x7F)
626 # define get_char(c) ascii2pascii(get_byte())
627 # define OS_CODE 0x0F /* temporary, subject to change */
629 # undef SIGTERM /* We don't want a signal handler for SIGTERM */
633 #if defined(pyr) && !defined(NOMEMCPY) /* Pyramid */
634 # define NOMEMCPY /* problem with overlapping copies */
638 # define OS_CODE 0x0a
642 # define NO_ST_INO /* don't rely on inode numbers */
646 /* Common defaults */
649 # define OS_CODE 0x03 /* assume Unix */
653 # define PATH_SEP '/'
657 # define casemap(c) (c)
661 # define OPTIONS_VAR "GZIP"
665 # define Z_SUFFIX ".gz"
669 # define MAX_SUFFIX MAX_EXT_CHARS
671 # define MAX_SUFFIX 30
674 #ifndef MAKE_LEGAL_NAME
675 # ifdef NO_MULTIPLE_DOTS
676 # define MAKE_LEGAL_NAME(name) make_simple_name(name)
678 # define MAKE_LEGAL_NAME(name)
684 /* keep at least MIN_PART chars between dots in a file name. */
688 # define EXPAND(argc,argv)
695 #ifndef SET_BINARY_MODE
696 # define SET_BINARY_MODE(fd)
700 # define OPEN(name, flags, mode) open(name, flags, mode)
704 # define get_char() get_byte()
708 # define put_char(c) put_byte(c)
710 /* bits.c -- output variable-length bit strings
711 * Copyright (C) 1992-1993 Jean-loup Gailly
712 * This is free software; you can redistribute it and/or modify it under the
713 * terms of the GNU General Public License, see the file COPYING.
720 * Output variable-length bit strings. Compression can be done
721 * to a file or to memory. (The latter is not supported in this version.)
725 * The PKZIP "deflate" file format interprets compressed file data
726 * as a sequence of bits. Multi-bit strings in the file may cross
727 * byte boundaries without restriction.
729 * The first bit of each byte is the low-order bit.
731 * The routines in this file allow a variable-length bit value to
732 * be output right-to-left (useful for literal values). For
733 * left-to-right output (useful for code strings from the tree routines),
734 * the bits must have been reversed first with bi_reverse().
736 * For in-memory compression, the compressed bit stream goes directly
737 * into the requested output buffer. The input data is read in blocks
738 * by the mem_read() function. The buffer is limited to 64K on 16 bit
743 * void bi_init (FILE *zipfile)
744 * Initialize the bit string routines.
746 * void send_bits (int value, int length)
747 * Write out a bit string, taking the source bits right to
750 * int bi_reverse (int value, int length)
751 * Reverse the bits of a bit string, taking the source bits left to
752 * right and emitting them right to left.
754 * void bi_windup (void)
755 * Write out any remaining bits in an incomplete byte.
757 * void copy_block(char *buf, unsigned len, int header)
758 * Copy a stored block to the zip file, storing first the length and
759 * its one's complement if requested.
767 /* ===========================================================================
768 * Local data used by the "bit string" routines.
771 local file_t zfile; /* output gzip file */
773 local unsigned short bi_buf;
774 /* Output buffer. bits are inserted starting at the bottom (least significant
778 #define Buf_size (8 * 2*sizeof(char))
779 /* Number of bits used within bi_buf. (bi_buf might be implemented on
780 * more than 16 bits on some systems.)
784 /* Number of valid bits in bi_buf. All bits above the last valid bit
788 int (*read_buf) OF((char *buf, unsigned size));
789 /* Current input function. Set to mem_read for in-memory compression */
792 ulg bits_sent; /* bit length of the compressed data */
795 /* ===========================================================================
796 * Initialize the bit string routines.
798 void bi_init (zipfile)
799 file_t zipfile; /* output zip file, NO_FILE for in-memory compression */
808 /* Set the defaults for file compression. They are set by memcompress
809 * for in-memory compression.
811 if (zfile != NO_FILE) {
812 read_buf = file_read;
816 /* ===========================================================================
817 * Send a value on a given number of bits.
818 * IN assertion: length <= 16 and value fits in length bits.
820 void send_bits(value, length)
821 int value; /* value to send */
822 int length; /* number of bits */
825 Tracev((stderr," l %2d v %4x ", length, value));
826 Assert(length > 0 && length <= 15, "invalid length");
827 bits_sent += (ulg)length;
829 /* If not enough room in bi_buf, use (valid) bits from bi_buf and
830 * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))
831 * unused bits in value.
833 if (bi_valid > (int)Buf_size - length) {
834 bi_buf |= (value << bi_valid);
836 bi_buf = (ush)value >> (Buf_size - bi_valid);
837 bi_valid += length - Buf_size;
839 bi_buf |= value << bi_valid;
844 /* ===========================================================================
845 * Reverse the first len bits of a code, using straightforward code (a faster
846 * method would use a table)
847 * IN assertion: 1 <= len <= 15
849 unsigned bi_reverse(code, len)
850 unsigned code; /* the value to invert */
851 int len; /* its bit length */
853 register unsigned res = 0;
856 code >>= 1, res <<= 1;
861 /* ===========================================================================
862 * Write out any remaining bits in an incomplete byte.
868 } else if (bi_valid > 0) {
874 bits_sent = (bits_sent+7) & ~7;
878 /* ===========================================================================
879 * Copy a stored block to the zip file, storing first the length and its
880 * one's complement if requested.
882 void copy_block(buf, len, header)
883 char *buf; /* the input data */
884 unsigned len; /* its length */
885 int header; /* true if block header must be written */
887 bi_windup(); /* align on byte boundary */
891 put_short((ush)~len);
897 bits_sent += (ulg)len<<3;
902 if (key) zencode(*buf, t);
907 /* deflate.c -- compress data using the deflation algorithm
908 * Copyright (C) 1992-1993 Jean-loup Gailly
909 * This is free software; you can redistribute it and/or modify it under the
910 * terms of the GNU General Public License, see the file COPYING.
916 * Identify new text as repetitions of old text within a fixed-
917 * length sliding window trailing behind the new text.
921 * The "deflation" process depends on being able to identify portions
922 * of the input text which are identical to earlier input (within a
923 * sliding window trailing behind the input currently being processed).
925 * The most straightforward technique turns out to be the fastest for
926 * most input files: try all possible matches and select the longest.
927 * The key feature of this algorithm is that insertions into the string
928 * dictionary are very simple and thus fast, and deletions are avoided
929 * completely. Insertions are performed at each input character, whereas
930 * string matches are performed only when the previous match ends. So it
931 * is preferable to spend more time in matches to allow very fast string
932 * insertions and avoid deletions. The matching algorithm for small
933 * strings is inspired from that of Rabin & Karp. A brute force approach
934 * is used to find longer strings when a small match has been found.
935 * A similar algorithm is used in comic (by Jan-Mark Wams) and freeze
936 * (by Leonid Broukhis).
937 * A previous version of this file used a more sophisticated algorithm
938 * (by Fiala and Greene) which is guaranteed to run in linear amortized
939 * time, but has a larger average cost, uses more memory and is patented.
940 * However the F&G algorithm may be faster for some highly redundant
941 * files if the parameter max_chain_length (described below) is too large.
945 * The idea of lazy evaluation of matches is due to Jan-Mark Wams, and
946 * I found it in 'freeze' written by Leonid Broukhis.
947 * Thanks to many info-zippers for bug reports and testing.
951 * APPNOTE.TXT documentation file in PKZIP 1.93a distribution.
953 * A description of the Rabin and Karp algorithm is given in the book
954 * "Algorithms" by R. Sedgewick, Addison-Wesley, p252.
956 * Fiala,E.R., and Greene,D.H.
957 * Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595
961 * void lm_init (int pack_level, ush *flags)
962 * Initialize the "longest match" routines for a new file
965 * Processes a new input file and return its compressed length. Sets
966 * the compressed length, crc, deflate flags and internal file
972 /* ===========================================================================
973 * Configuration parameters
976 /* Compile with MEDIUM_MEM to reduce the memory requirements or
977 * with SMALL_MEM to use as little memory as possible. Use BIG_MEM if the
978 * entire input file can be held in memory (not possible on 16 bit systems).
979 * Warning: defining these symbols affects HASH_BITS (see below) and thus
980 * affects the compression ratio. The compressed output
981 * is still correct, and might even be smaller in some cases.
985 # define HASH_BITS 13 /* Number of bits used to hash strings */
988 # define HASH_BITS 14
991 # define HASH_BITS 15
992 /* For portability to 16 bit machines, do not use values above 15. */
995 /* To save space (see unlzw.c), we overlay prev+head with tab_prefix and
996 * window with tab_suffix. Check that we can do this:
998 #if (WSIZE<<1) > (1<<BITS)
999 error: cannot overlay window with tab_suffix and prev with tab_prefix0
1001 #if HASH_BITS > BITS-1
1002 error: cannot overlay head with tab_prefix1
1005 #define HASH_SIZE (unsigned)(1<<HASH_BITS)
1006 #define HASH_MASK (HASH_SIZE-1)
1007 #define WMASK (WSIZE-1)
1008 /* HASH_SIZE and WSIZE must be powers of two */
1011 /* Tail of hash chains */
1015 /* speed options for the general purpose bit flag */
1018 # define TOO_FAR 4096
1020 /* Matches of length 3 are discarded if their distance exceeds TOO_FAR */
1022 /* ===========================================================================
1023 * Local data used by the "longest match" routines.
1027 typedef unsigned IPos;
1028 /* A Pos is an index in the character window. We use short instead of int to
1029 * save space in the various tables. IPos is used only for parameter passing.
1032 /* DECLARE(uch, window, 2L*WSIZE); */
1033 /* Sliding window. Input bytes are read into the second half of the window,
1034 * and move to the first half later to keep a dictionary of at least WSIZE
1035 * bytes. With this organization, matches are limited to a distance of
1036 * WSIZE-MAX_MATCH bytes, but this ensures that IO is always
1037 * performed with a length multiple of the block size. Also, it limits
1038 * the window size to 64K, which is quite useful on MSDOS.
1039 * To do: limit the window size to WSIZE+BSZ if SMALL_MEM (the code would
1040 * be less efficient).
1043 /* DECLARE(Pos, prev, WSIZE); */
1044 /* Link to older string with same hash index. To limit the size of this
1045 * array to 64K, this link is maintained only for the last 32K strings.
1046 * An index in this array is thus a window index modulo 32K.
1049 /* DECLARE(Pos, head, 1<<HASH_BITS); */
1050 /* Heads of the hash chains or NIL. */
1052 ulg window_size = (ulg)2*WSIZE;
1053 /* window size, 2*WSIZE except for MMAP or BIG_MEM, where it is the
1054 * input file length plus MIN_LOOKAHEAD.
1058 /* window position at the beginning of the current output block. Gets
1059 * negative when the window is moved backwards.
1062 local unsigned ins_h; /* hash index of string to be inserted */
1064 #define H_SHIFT ((HASH_BITS+MIN_MATCH-1)/MIN_MATCH)
1065 /* Number of bits by which ins_h and del_h must be shifted at each
1066 * input step. It must be such that after MIN_MATCH steps, the oldest
1067 * byte no longer takes part in the hash key, that is:
1068 * H_SHIFT * MIN_MATCH >= HASH_BITS
1071 unsigned int near prev_length;
1072 /* Length of the best match at previous step. Matches not greater than this
1073 * are discarded. This is used in the lazy match evaluation.
1076 unsigned near strstart; /* start of string to insert */
1077 unsigned near match_start; /* start of matching string */
1078 local int eofile; /* flag set at end of input file */
1079 local unsigned lookahead; /* number of valid bytes ahead in window */
1081 unsigned near max_chain_length;
1082 /* To speed up deflation, hash chains are never searched beyond this length.
1083 * A higher limit improves compression ratio but degrades the speed.
1086 local unsigned int max_lazy_match;
1087 /* Attempt to find a better match only when the current match is strictly
1088 * smaller than this value. This mechanism is used only for compression
1091 #define max_insert_length max_lazy_match
1092 /* Insert new strings in the hash table only if the match length
1093 * is not greater than this length. This saves time but degrades compression.
1094 * max_insert_length is used only for compression levels <= 3.
1097 unsigned near good_match;
1098 /* Use a faster search when the previous match is longer than this */
1101 /* Values for max_lazy_match, good_match and max_chain_length, depending on
1102 * the desired pack level (0..9). The values given below have been tuned to
1103 * exclude worst case performance for pathological files. Better values may be
1104 * found for specific files.
1107 typedef struct config {
1108 ush good_length; /* reduce lazy search above this match length */
1109 ush max_lazy; /* do not perform lazy search above this match length */
1110 ush nice_length; /* quit search above this match length */
1115 # define nice_match MAX_MATCH
1117 int near nice_match; /* Stop searching when current match exceeds this */
1120 local config configuration_table =
1121 /* 9 */ {32, 258, 258, 4096}; /* maximum compression */
1123 /* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
1124 * For deflate_fast() (levels <= 3) good is ignored and lazy has a different
1129 /* result of memcmp for equal strings */
1131 /* ===========================================================================
1132 * Prototypes for local functions.
1134 local void fill_window OF((void));
1136 int longest_match OF((IPos cur_match));
1138 void match_init OF((void)); /* asm code initialization */
1142 local void check_match OF((IPos start, IPos match, int length));
1145 /* ===========================================================================
1146 * Update a hash value with the given input byte
1147 * IN assertion: all calls to to UPDATE_HASH are made with consecutive
1148 * input characters, so that a running hash key can be computed from the
1149 * previous key instead of complete recalculation each time.
1151 #define UPDATE_HASH(h,c) (h = (((h)<<H_SHIFT) ^ (c)) & HASH_MASK)
1153 /* ===========================================================================
1154 * Insert string s in the dictionary and set match_head to the previous head
1155 * of the hash chain (the most recent string with same hash key). Return
1156 * the previous length of the hash chain.
1157 * IN assertion: all calls to to INSERT_STRING are made with consecutive
1158 * input characters and the first MIN_MATCH bytes of s are valid
1159 * (except for the last MIN_MATCH-1 bytes of the input file).
1161 #define INSERT_STRING(s, match_head) \
1162 (UPDATE_HASH(ins_h, window[(s) + MIN_MATCH-1]), \
1163 prev[(s) & WMASK] = match_head = head[ins_h], \
1166 /* ===========================================================================
1167 * Initialize the "longest match" routines for a new file
1169 void lm_init (flags)
1170 ush *flags; /* general purpose bit flag */
1172 register unsigned j;
1174 /* Initialize the hash table. */
1175 #if defined(MAXSEG_64K) && HASH_BITS == 15
1176 for (j = 0; j < HASH_SIZE; j++) head[j] = NIL;
1178 memzero((char*)head, HASH_SIZE*sizeof(*head));
1180 /* prev will be initialized on the fly */
1182 /* Set the default configuration parameters:
1184 max_lazy_match = configuration_table.max_lazy;
1185 good_match = configuration_table.good_length;
1187 nice_match = configuration_table.nice_length;
1189 max_chain_length = configuration_table.max_chain;
1191 /* ??? reduce max_chain_length for binary files */
1196 match_init(); /* initialize the asm code */
1199 lookahead = read_buf((char*)window,
1200 sizeof(int) <= 2 ? (unsigned)WSIZE : 2*WSIZE);
1202 if (lookahead == 0 || lookahead == (unsigned)EOF) {
1203 eofile = 1, lookahead = 0;
1207 /* Make sure that we always have enough lookahead. This is important
1208 * if input comes from a device such as a tty.
1210 while (lookahead < MIN_LOOKAHEAD && !eofile) fill_window();
1213 for (j=0; j<MIN_MATCH-1; j++) UPDATE_HASH(ins_h, window[j]);
1214 /* If lookahead < MIN_MATCH, ins_h is garbage, but this is
1215 * not important since only literal bytes will be emitted.
1219 /* ===========================================================================
1220 * Set match_start to the longest match starting at the given string and
1221 * return its length. Matches shorter or equal to prev_length are discarded,
1222 * in which case the result is equal to prev_length and match_start is
1224 * IN assertions: cur_match is the head of the hash chain for the current
1225 * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
1228 /* For MSDOS, OS/2 and 386 Unix, an optimized version is in match.asm or
1229 * match.s. The code is functionally equivalent, so you can use the C version
1232 int longest_match(cur_match)
1233 IPos cur_match; /* current match */
1235 unsigned chain_length = max_chain_length; /* max hash chain length */
1236 register uch *scan = window + strstart; /* current string */
1237 register uch *match; /* matched string */
1238 register int len; /* length of current match */
1239 int best_len = prev_length; /* best match length so far */
1240 IPos limit = strstart > (IPos)MAX_DIST ? strstart - (IPos)MAX_DIST : NIL;
1241 /* Stop when cur_match becomes <= limit. To simplify the code,
1242 * we prevent matches with the string of window index 0.
1245 /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
1246 * It is easy to get rid of this optimization if necessary.
1248 #if HASH_BITS < 8 || MAX_MATCH != 258
1249 error: Code too clever
1253 /* Compare two bytes at a time. Note: this is not always beneficial.
1254 * Try with and without -DUNALIGNED_OK to check.
1256 register uch *strend = window + strstart + MAX_MATCH - 1;
1257 register ush scan_start = *(ush*)scan;
1258 register ush scan_end = *(ush*)(scan+best_len-1);
1260 register uch *strend = window + strstart + MAX_MATCH;
1261 register uch scan_end1 = scan[best_len-1];
1262 register uch scan_end = scan[best_len];
1265 /* Do not waste too much time if we already have a good match: */
1266 if (prev_length >= good_match) {
1269 Assert(strstart <= window_size-MIN_LOOKAHEAD, "insufficient lookahead");
1272 Assert(cur_match < strstart, "no future");
1273 match = window + cur_match;
1275 /* Skip to next match if the match length cannot increase
1276 * or if the match length is less than 2:
1278 #if (defined(UNALIGNED_OK) && MAX_MATCH == 258)
1279 /* This code assumes sizeof(unsigned short) == 2. Do not use
1280 * UNALIGNED_OK if your compiler uses a different size.
1282 if (*(ush*)(match+best_len-1) != scan_end ||
1283 *(ush*)match != scan_start) continue;
1285 /* It is not necessary to compare scan[2] and match[2] since they are
1286 * always equal when the other bytes match, given that the hash keys
1287 * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at
1288 * strstart+3, +5, ... up to strstart+257. We check for insufficient
1289 * lookahead only every 4th comparison; the 128th check will be made
1290 * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is
1291 * necessary to put more guard bytes at the end of the window, or
1292 * to check more often for insufficient lookahead.
1296 } while (*(ush*)(scan+=2) == *(ush*)(match+=2) &&
1297 *(ush*)(scan+=2) == *(ush*)(match+=2) &&
1298 *(ush*)(scan+=2) == *(ush*)(match+=2) &&
1299 *(ush*)(scan+=2) == *(ush*)(match+=2) &&
1301 /* The funny "do {}" generates better code on most compilers */
1303 /* Here, scan <= window+strstart+257 */
1304 Assert(scan <= window+(unsigned)(window_size-1), "wild scan");
1305 if (*scan == *match) scan++;
1307 len = (MAX_MATCH - 1) - (int)(strend-scan);
1308 scan = strend - (MAX_MATCH-1);
1310 #else /* UNALIGNED_OK */
1312 if (match[best_len] != scan_end ||
1313 match[best_len-1] != scan_end1 ||
1315 *++match != scan[1]) continue;
1317 /* The check at best_len-1 can be removed because it will be made
1318 * again later. (This heuristic is not always a win.)
1319 * It is not necessary to compare scan[2] and match[2] since they
1320 * are always equal when the other bytes match, given that
1321 * the hash keys are equal and that HASH_BITS >= 8.
1325 /* We check for insufficient lookahead only every 8th comparison;
1326 * the 256th check will be made at strstart+258.
1329 } while (*++scan == *++match && *++scan == *++match &&
1330 *++scan == *++match && *++scan == *++match &&
1331 *++scan == *++match && *++scan == *++match &&
1332 *++scan == *++match && *++scan == *++match &&
1335 len = MAX_MATCH - (int)(strend - scan);
1336 scan = strend - MAX_MATCH;
1338 #endif /* UNALIGNED_OK */
1340 if (len > best_len) {
1341 match_start = cur_match;
1343 if (len >= nice_match) break;
1345 scan_end = *(ush*)(scan+best_len-1);
1347 scan_end1 = scan[best_len-1];
1348 scan_end = scan[best_len];
1351 } while ((cur_match = prev[cur_match & WMASK]) > limit
1352 && --chain_length != 0);
1359 /* ===========================================================================
1360 * Check that the match at match_start is indeed a match.
1362 local void check_match(start, match, length)
1366 /* check that the match is indeed a match */
1367 if (memcmp((char*)window + match,
1368 (char*)window + start, length) != EQUAL) {
1370 " start %d, match %d, length %d\n",
1371 start, match, length);
1372 error("invalid match");
1375 fprintf(stderr,"\\[%d,%d]", start-match, length);
1376 do { putc(window[start++], stderr); } while (--length != 0);
1380 # define check_match(start, match, length)
1383 /* ===========================================================================
1384 * Fill the window when the lookahead becomes insufficient.
1385 * Updates strstart and lookahead, and sets eofile if end of input file.
1386 * IN assertion: lookahead < MIN_LOOKAHEAD && strstart + lookahead > 0
1387 * OUT assertions: at least one byte has been read, or eofile is set;
1388 * file reads are performed for at least two bytes (required for the
1389 * translate_eol option).
1391 local void fill_window()
1393 register unsigned n, m;
1394 unsigned more = (unsigned)(window_size - (ulg)lookahead - (ulg)strstart);
1395 /* Amount of free space at the end of the window. */
1397 /* If the window is almost full and there is insufficient lookahead,
1398 * move the upper half to the lower one to make room in the upper half.
1400 if (more == (unsigned)EOF) {
1401 /* Very unlikely, but possible on 16 bit machine if strstart == 0
1402 * and lookahead == 1 (input done one byte at time)
1405 } else if (strstart >= WSIZE+MAX_DIST) {
1406 /* By the IN assertion, the window is not empty so we can't confuse
1407 * more == 0 with more == 64K on a 16 bit machine.
1409 Assert(window_size == (ulg)2*WSIZE, "no sliding with BIG_MEM");
1411 memcpy((char*)window, (char*)window+WSIZE, (unsigned)WSIZE);
1412 match_start -= WSIZE;
1413 strstart -= WSIZE; /* we now have strstart >= MAX_DIST: */
1415 block_start -= (long) WSIZE;
1417 for (n = 0; n < HASH_SIZE; n++) {
1419 head[n] = (Pos)(m >= WSIZE ? m-WSIZE : NIL);
1421 for (n = 0; n < WSIZE; n++) {
1423 prev[n] = (Pos)(m >= WSIZE ? m-WSIZE : NIL);
1424 /* If n is not on any hash chain, prev[n] is garbage but
1425 * its value will never be used.
1430 /* At this point, more >= 2 */
1432 n = read_buf((char*)window+strstart+lookahead, more);
1433 if (n == 0 || n == (unsigned)EOF) {
1441 /* ===========================================================================
1442 * Flush the current block, with given end-of-file flag.
1443 * IN assertion: strstart is set to the end of the current match.
1445 #define FLUSH_BLOCK(eof) \
1446 flush_block(block_start >= 0L ? (char*)&window[(unsigned)block_start] : \
1447 (char*)NULL, (long)strstart - block_start, (eof))
1449 /* ===========================================================================
1450 * Same as above, but achieves better compression. We use a lazy
1451 * evaluation for matches: a match is finally adopted only if there is
1452 * no better match at the next window position.
1456 IPos hash_head; /* head of hash chain */
1457 IPos prev_match; /* previous match */
1458 int flush; /* set if current block must be flushed */
1459 int match_available = 0; /* set if previous match exists */
1460 register unsigned match_length = MIN_MATCH-1; /* length of best match */
1462 extern long isize; /* byte length of input file, for debug only */
1465 /* Process the input block. */
1466 while (lookahead != 0) {
1467 /* Insert the string window[strstart .. strstart+2] in the
1468 * dictionary, and set hash_head to the head of the hash chain:
1470 INSERT_STRING(strstart, hash_head);
1472 /* Find the longest match, discarding those <= prev_length.
1474 prev_length = match_length, prev_match = match_start;
1475 match_length = MIN_MATCH-1;
1477 if (hash_head != NIL && prev_length < max_lazy_match &&
1478 strstart - hash_head <= MAX_DIST) {
1479 /* To simplify the code, we prevent matches with the string
1480 * of window index 0 (in particular we have to avoid a match
1481 * of the string with itself at the start of the input file).
1483 match_length = longest_match (hash_head);
1484 /* longest_match() sets match_start */
1485 if (match_length > lookahead) match_length = lookahead;
1487 /* Ignore a length 3 match if it is too distant: */
1488 if (match_length == MIN_MATCH && strstart-match_start > TOO_FAR){
1489 /* If prev_match is also MIN_MATCH, match_start is garbage
1490 * but we will ignore the current match anyway.
1495 /* If there was a match at the previous step and the current
1496 * match is not better, output the previous match:
1498 if (prev_length >= MIN_MATCH && match_length <= prev_length) {
1500 check_match(strstart-1, prev_match, prev_length);
1502 flush = ct_tally(strstart-1-prev_match, prev_length - MIN_MATCH);
1504 /* Insert in hash table all strings up to the end of the match.
1505 * strstart-1 and strstart are already inserted.
1507 lookahead -= prev_length-1;
1511 INSERT_STRING(strstart, hash_head);
1512 /* strstart never exceeds WSIZE-MAX_MATCH, so there are
1513 * always MIN_MATCH bytes ahead. If lookahead < MIN_MATCH
1514 * these bytes are garbage, but it does not matter since the
1515 * next lookahead bytes will always be emitted as literals.
1517 } while (--prev_length != 0);
1518 match_available = 0;
1519 match_length = MIN_MATCH-1;
1521 if (flush) FLUSH_BLOCK(0), block_start = strstart;
1523 } else if (match_available) {
1524 /* If there was no match at the previous position, output a
1525 * single literal. If there was a match but the current match
1526 * is longer, truncate the previous match to a single literal.
1528 Tracevv((stderr,"%c",window[strstart-1]));
1529 if (ct_tally (0, window[strstart-1])) {
1530 FLUSH_BLOCK(0), block_start = strstart;
1535 /* There is no previous match to compare with, wait for
1536 * the next step to decide.
1538 match_available = 1;
1542 Assert (strstart <= isize && lookahead <= isize, "a bit too far");
1544 /* Make sure that we always have enough lookahead, except
1545 * at the end of the input file. We need MAX_MATCH bytes
1546 * for the next match, plus MIN_MATCH bytes to insert the
1547 * string following the next match.
1549 while (lookahead < MIN_LOOKAHEAD && !eofile) fill_window();
1551 if (match_available) ct_tally (0, window[strstart-1]);
1553 return FLUSH_BLOCK(1); /* eof */
1555 /* gzip (GNU zip) -- compress files with zip algorithm and 'compress' interface
1556 * Copyright (C) 1992-1993 Jean-loup Gailly
1557 * The unzip code was written and put in the public domain by Mark Adler.
1558 * Portions of the lzw code are derived from the public domain 'compress'
1559 * written by Spencer Thomas, Joe Orost, James Woods, Jim McKie, Steve Davies,
1560 * Ken Turkowski, Dave Mack and Peter Jannesen.
1562 * See the license_msg below and the file COPYING for the software license.
1563 * See the file algorithm.doc for the compression algorithms and file formats.
1566 /* Compress files with zip algorithm and 'compress' interface.
1567 * See usage() and help() functions below for all options.
1569 * file.gz: compressed file with same mode, owner, and utimes
1570 * or stdout with -c option or if stdin used as input.
1571 * If the output file name had to be truncated, the original name is kept
1572 * in the compressed file.
1573 * On MSDOS, file.tmp -> file.tmz. On VMS, file.tmp -> file.tmp-gz.
1575 * Using gz on MSDOS would create too many file name conflicts. For
1576 * example, foo.txt -> foo.tgz (.tgz must be reserved as shorthand for
1577 * tar.gz). Similarly, foo.dir and foo.doc would both be mapped to foo.dgz.
1578 * I also considered 12345678.txt -> 12345txt.gz but this truncates the name
1579 * too heavily. There is no ideal solution given the MSDOS 8+3 limitation.
1581 * For the meaning of all compilation flags, see comments in Makefile.in.
1585 #include <sys/types.h>
1587 #include <sys/stat.h>
1593 # include <sys/time.h>
1602 #ifdef HAVE_UNISTD_H
1603 # include <unistd.h>
1606 #if defined(STDC_HEADERS) || !defined(NO_STDLIB_H)
1607 # include <stdlib.h>
1613 # include <dirent.h>
1614 typedef struct dirent dir_type;
1615 # define NLENGTH(dirent) ((int)strlen((dirent)->d_name))
1616 # define DIR_OPT "DIRENT"
1618 # define NLENGTH(dirent) ((dirent)->d_namlen)
1620 # include <sys/dir.h>
1621 typedef struct direct dir_type;
1622 # define DIR_OPT "SYSDIR"
1625 # include <sys/ndir.h>
1626 typedef struct direct dir_type;
1627 # define DIR_OPT "SYSNDIR"
1631 typedef struct direct dir_type;
1632 # define DIR_OPT "NDIR"
1635 # define DIR_OPT "NO_DIR"
1644 # define TIME_OPT "UTIME"
1646 # ifdef HAVE_SYS_UTIME_H
1647 # include <sys/utime.h>
1648 # define TIME_OPT "SYS_UTIME"
1654 # define TIME_OPT ""
1658 # define TIME_OPT "NO_UTIME"
1661 #if !defined(S_ISDIR) && defined(S_IFDIR)
1662 # define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
1664 #if !defined(S_ISREG) && defined(S_IFREG)
1665 # define S_ISREG(m) (((m) & S_IFMT) == S_IFREG)
1668 typedef RETSIGTYPE (*sig_type) OF((int));
1671 # define O_BINARY 0 /* creation mode for open() */
1675 /* Pure BSD system? */
1676 # include <sys/file.h>
1678 # define O_CREAT FCREAT
1681 # define O_EXCL FEXCL
1686 # define S_IRUSR 0400
1689 # define S_IWUSR 0200
1691 #define RW_USER (S_IRUSR | S_IWUSR) /* creation mode for open() */
1693 #ifndef MAX_PATH_LEN
1694 # define MAX_PATH_LEN 1024 /* max pathname length */
1703 off_t lseek OF((int fd, off_t offset, int whence));
1706 /* Separator for file name parts (see shorten_name()) */
1707 #ifdef NO_MULTIPLE_DOTS
1708 # define PART_SEP "-"
1710 # define PART_SEP "."
1713 /* global buffers */
1715 DECLARE(uch, inbuf, INBUFSIZ +INBUF_EXTRA);
1716 DECLARE(uch, outbuf, OUTBUFSIZ+OUTBUF_EXTRA);
1717 DECLARE(ush, d_buf, DIST_BUFSIZE);
1718 DECLARE(uch, window, 2L*WSIZE);
1720 DECLARE(ush, tab_prefix, 1L<<BITS);
1722 DECLARE(ush, tab_prefix0, 1L<<(BITS-1));
1723 DECLARE(ush, tab_prefix1, 1L<<(BITS-1));
1726 /* local variables */
1728 int ascii = 0; /* convert end-of-lines to local OS conventions */
1729 int to_stdout = 0; /* output to stdout (-c) */
1730 int decompress = 0; /* decompress (-d) */
1731 int no_name = -1; /* don't save or restore the original file name */
1732 int no_time = -1; /* don't save or restore the original file time */
1733 int foreground; /* set if program run in foreground */
1734 char *progname; /* program name */
1735 static int method = DEFLATED;/* compression method */
1736 static int exit_code = OK; /* program exit code */
1737 int save_orig_name; /* set if original name must be saved */
1738 int last_member; /* set for .zip and .Z files */
1739 int part_nb; /* number of parts in .gz file */
1740 long time_stamp; /* original time stamp (modification time) */
1741 long ifile_size; /* input file size, -1 for devices (debug only) */
1742 char *env; /* contents of GZIP env variable */
1743 char **args = NULL; /* argv pointer if GZIP env variable defined */
1744 char z_suffix[MAX_SUFFIX+1]; /* default suffix (can be set with --suffix) */
1745 int z_len; /* strlen(z_suffix) */
1747 long bytes_in; /* number of input bytes */
1748 long bytes_out; /* number of output bytes */
1749 char ifname[MAX_PATH_LEN]; /* input file name */
1750 char ofname[MAX_PATH_LEN]; /* output file name */
1751 int remove_ofname = 0; /* remove output file on error */
1752 struct stat istat; /* status for input file */
1753 int ifd; /* input file descriptor */
1754 int ofd; /* output file descriptor */
1755 unsigned insize; /* valid bytes in inbuf */
1756 unsigned inptr; /* index of next byte to be processed in inbuf */
1757 unsigned outcnt; /* bytes in output buffer */
1759 /* local functions */
1761 local void treat_stdin OF((void));
1762 static int (*work) OF((int infile, int outfile)) = zip; /* function to call */
1764 #define strequ(s1, s2) (strcmp((s1),(s2)) == 0)
1766 /* ======================================================================== */
1767 // int main (argc, argv)
1770 int gzip_main(int argc, char * * argv)
1772 foreground = signal(SIGINT, SIG_IGN) != SIG_IGN;
1774 (void) signal (SIGINT, (sig_type)abort_gzip);
1777 if (signal(SIGTERM, SIG_IGN) != SIG_IGN) {
1778 (void) signal(SIGTERM, (sig_type)abort_gzip);
1782 if (signal(SIGHUP, SIG_IGN) != SIG_IGN) {
1783 (void) signal(SIGHUP, (sig_type)abort_gzip);
1787 strncpy(z_suffix, Z_SUFFIX, sizeof(z_suffix)-1);
1788 z_len = strlen(z_suffix);
1792 /* Allocate all global buffers (for DYN_ALLOC option) */
1793 ALLOC(uch, inbuf, INBUFSIZ +INBUF_EXTRA);
1794 ALLOC(uch, outbuf, OUTBUFSIZ+OUTBUF_EXTRA);
1795 ALLOC(ush, d_buf, DIST_BUFSIZE);
1796 ALLOC(uch, window, 2L*WSIZE);
1798 ALLOC(ush, tab_prefix, 1L<<BITS);
1800 ALLOC(ush, tab_prefix0, 1L<<(BITS-1));
1801 ALLOC(ush, tab_prefix1, 1L<<(BITS-1));
1804 /* And get to work */
1807 return exit_code; /* just to avoid lint warning */
1810 /* ========================================================================
1811 * Compress or decompress stdin
1813 local void treat_stdin()
1815 SET_BINARY_MODE(fileno(stdout));
1816 strcpy(ifname, "stdin");
1817 strcpy(ofname, "stdout");
1819 /* Get the time stamp on the input file. */
1820 time_stamp = 0; /* time unknown by default */
1822 ifile_size = -1L; /* convention for unknown size */
1824 clear_bufs(); /* clear input and output buffers */
1828 /* Actually do the compression/decompression. Loop over zipped members.
1830 if ((*work)(fileno(stdin), fileno(stdout)) != OK) return;
1833 /* ========================================================================
1834 * Free all dynamically allocated variables and exit with the given code.
1836 local void do_exit(int exitcode)
1838 static int in_exit = 0;
1840 if (in_exit) exit(exitcode);
1842 if (env != NULL) free(env), env = NULL;
1843 if (args != NULL) free((char*)args), args = NULL;
1856 /* trees.c -- output deflated data using Huffman coding
1857 * Copyright (C) 1992-1993 Jean-loup Gailly
1858 * This is free software; you can redistribute it and/or modify it under the
1859 * terms of the GNU General Public License, see the file COPYING.
1865 * Encode various sets of source values using variable-length
1866 * binary code trees.
1870 * The PKZIP "deflation" process uses several Huffman trees. The more
1871 * common source values are represented by shorter bit sequences.
1873 * Each code tree is stored in the ZIP file in a compressed form
1874 * which is itself a Huffman encoding of the lengths of
1875 * all the code strings (in ascending order by source values).
1876 * The actual code strings are reconstructed from the lengths in
1877 * the UNZIP process, as described in the "application note"
1878 * (APPNOTE.TXT) distributed as part of PKWARE's PKZIP program.
1883 * Data Compression: Techniques and Applications, pp. 53-55.
1884 * Lifetime Learning Publications, 1985. ISBN 0-534-03418-7.
1887 * Data Compression: Methods and Theory, pp. 49-50.
1888 * Computer Science Press, 1988. ISBN 0-7167-8156-5.
1892 * Addison-Wesley, 1983. ISBN 0-201-06672-6.
1896 * void ct_init (ush *attr, int *methodp)
1897 * Allocate the match buffer, initialize the various tables and save
1898 * the location of the internal file attribute (ascii/binary) and
1899 * method (DEFLATE/STORE)
1901 * void ct_tally (int dist, int lc);
1902 * Save the match info and tally the frequency counts.
1904 * long flush_block (char *buf, ulg stored_len, int eof)
1905 * Determine the best encoding for the current block: dynamic trees,
1906 * static trees or store, and output the encoded block to the zip
1907 * file. Returns the total compressed length for the file so far.
1913 /* ===========================================================================
1918 /* All codes must not exceed MAX_BITS bits */
1920 #define MAX_BL_BITS 7
1921 /* Bit length codes must not exceed MAX_BL_BITS bits */
1923 #define LENGTH_CODES 29
1924 /* number of length codes, not counting the special END_BLOCK code */
1926 #define LITERALS 256
1927 /* number of literal bytes 0..255 */
1929 #define END_BLOCK 256
1930 /* end of block literal code */
1932 #define L_CODES (LITERALS+1+LENGTH_CODES)
1933 /* number of Literal or Length codes, including the END_BLOCK code */
1936 /* number of distance codes */
1939 /* number of codes used to transfer the bit lengths */
1942 local int near extra_lbits[LENGTH_CODES] /* extra bits for each length code */
1943 = {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};
1945 local int near extra_dbits[D_CODES] /* extra bits for each distance code */
1946 = {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};
1948 local int near extra_blbits[BL_CODES]/* extra bits for each bit length code */
1949 = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7};
1951 #define STORED_BLOCK 0
1952 #define STATIC_TREES 1
1954 /* The three kinds of block type */
1958 # define LIT_BUFSIZE 0x2000
1961 # define LIT_BUFSIZE 0x4000
1963 # define LIT_BUFSIZE 0x8000
1967 #ifndef DIST_BUFSIZE
1968 # define DIST_BUFSIZE LIT_BUFSIZE
1970 /* Sizes of match buffers for literals/lengths and distances. There are
1971 * 4 reasons for limiting LIT_BUFSIZE to 64K:
1972 * - frequencies can be kept in 16 bit counters
1973 * - if compression is not successful for the first block, all input data is
1974 * still in the window so we can still emit a stored block even when input
1975 * comes from standard input. (This can also be done for all blocks if
1976 * LIT_BUFSIZE is not greater than 32K.)
1977 * - if compression is not successful for a file smaller than 64K, we can
1978 * even emit a stored file instead of a stored block (saving 5 bytes).
1979 * - creating new Huffman trees less frequently may not provide fast
1980 * adaptation to changes in the input data statistics. (Take for
1981 * example a binary file with poorly compressible code followed by
1982 * a highly compressible string table.) Smaller buffer sizes give
1983 * fast adaptation but have of course the overhead of transmitting trees
1985 * - I can't count above 4
1986 * The current code is general and allows DIST_BUFSIZE < LIT_BUFSIZE (to save
1987 * memory at the expense of compression). Some optimizations would be possible
1988 * if we rely on DIST_BUFSIZE == LIT_BUFSIZE.
1990 #if LIT_BUFSIZE > INBUFSIZ
1991 error cannot overlay l_buf and inbuf
1995 /* repeat previous bit length 3-6 times (2 bits of repeat count) */
1997 #define REPZ_3_10 17
1998 /* repeat a zero length 3-10 times (3 bits of repeat count) */
2000 #define REPZ_11_138 18
2001 /* repeat a zero length 11-138 times (7 bits of repeat count) */
2003 /* ===========================================================================
2007 /* Data structure describing a single value and its code string. */
2008 typedef struct ct_data {
2010 ush freq; /* frequency count */
2011 ush code; /* bit string */
2014 ush dad; /* father node in Huffman tree */
2015 ush len; /* length of bit string */
2019 #define Freq fc.freq
2020 #define Code fc.code
2024 #define HEAP_SIZE (2*L_CODES+1)
2025 /* maximum heap size */
2027 local ct_data near dyn_ltree[HEAP_SIZE]; /* literal and length tree */
2028 local ct_data near dyn_dtree[2*D_CODES+1]; /* distance tree */
2030 local ct_data near static_ltree[L_CODES+2];
2031 /* The static literal tree. Since the bit lengths are imposed, there is no
2032 * need for the L_CODES extra codes used during heap construction. However
2033 * The codes 286 and 287 are needed to build a canonical tree (see ct_init
2037 local ct_data near static_dtree[D_CODES];
2038 /* The static distance tree. (Actually a trivial tree since all codes use
2042 local ct_data near bl_tree[2*BL_CODES+1];
2043 /* Huffman tree for the bit lengths */
2045 typedef struct tree_desc {
2046 ct_data near *dyn_tree; /* the dynamic tree */
2047 ct_data near *static_tree; /* corresponding static tree or NULL */
2048 int near *extra_bits; /* extra bits for each code or NULL */
2049 int extra_base; /* base index for extra_bits */
2050 int elems; /* max number of elements in the tree */
2051 int max_length; /* max bit length for the codes */
2052 int max_code; /* largest code with non zero frequency */
2055 local tree_desc near l_desc =
2056 {dyn_ltree, static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS, 0};
2058 local tree_desc near d_desc =
2059 {dyn_dtree, static_dtree, extra_dbits, 0, D_CODES, MAX_BITS, 0};
2061 local tree_desc near bl_desc =
2062 {bl_tree, (ct_data near *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS, 0};
2065 local ush near bl_count[MAX_BITS+1];
2066 /* number of codes at each bit length for an optimal tree */
2068 local uch near bl_order[BL_CODES]
2069 = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15};
2070 /* The lengths of the bit length codes are sent in order of decreasing
2071 * probability, to avoid transmitting the lengths for unused bit length codes.
2074 local int near heap[2*L_CODES+1]; /* heap used to build the Huffman trees */
2075 local int heap_len; /* number of elements in the heap */
2076 local int heap_max; /* element of largest frequency */
2077 /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
2078 * The same heap array is used to build all trees.
2081 local uch near depth[2*L_CODES+1];
2082 /* Depth of each subtree used as tie breaker for trees of equal frequency */
2084 local uch length_code[MAX_MATCH-MIN_MATCH+1];
2085 /* length code for each normalized match length (0 == MIN_MATCH) */
2087 local uch dist_code[512];
2088 /* distance codes. The first 256 values correspond to the distances
2089 * 3 .. 258, the last 256 values correspond to the top 8 bits of
2090 * the 15 bit distances.
2093 local int near base_length[LENGTH_CODES];
2094 /* First normalized length for each code (0 = MIN_MATCH) */
2096 local int near base_dist[D_CODES];
2097 /* First normalized distance for each code (0 = distance of 1) */
2100 /* DECLARE(uch, l_buf, LIT_BUFSIZE); buffer for literals or lengths */
2102 /* DECLARE(ush, d_buf, DIST_BUFSIZE); buffer for distances */
2104 local uch near flag_buf[(LIT_BUFSIZE/8)];
2105 /* flag_buf is a bit array distinguishing literals from lengths in
2106 * l_buf, thus indicating the presence or absence of a distance.
2109 local unsigned last_lit; /* running index in l_buf */
2110 local unsigned last_dist; /* running index in d_buf */
2111 local unsigned last_flags; /* running index in flag_buf */
2112 local uch flags; /* current flags not yet saved in flag_buf */
2113 local uch flag_bit; /* current bit used in flags */
2114 /* bits are filled in flags starting at bit 0 (least significant).
2115 * Note: these flags are overkill in the current code since we don't
2116 * take advantage of DIST_BUFSIZE == LIT_BUFSIZE.
2119 local ulg opt_len; /* bit length of current block with optimal trees */
2120 local ulg static_len; /* bit length of current block with static trees */
2122 local ulg compressed_len; /* total bit length of compressed file */
2124 local ulg input_len; /* total byte length of input file */
2125 /* input_len is for debugging only since we can get it by other means. */
2127 ush *file_type; /* pointer to UNKNOWN, BINARY or ASCII */
2128 int *file_method; /* pointer to DEFLATE or STORE */
2131 extern ulg bits_sent; /* bit length of the compressed data */
2132 extern long isize; /* byte length of input file */
2135 extern long block_start; /* window offset of current block */
2136 extern unsigned near strstart; /* window offset of current string */
2138 /* ===========================================================================
2139 * Local (static) routines in this file.
2142 local void init_block OF((void));
2143 local void pqdownheap OF((ct_data near *tree, int k));
2144 local void gen_bitlen OF((tree_desc near *desc));
2145 local void gen_codes OF((ct_data near *tree, int max_code));
2146 local void build_tree OF((tree_desc near *desc));
2147 local void scan_tree OF((ct_data near *tree, int max_code));
2148 local void send_tree OF((ct_data near *tree, int max_code));
2149 local int build_bl_tree OF((void));
2150 local void send_all_trees OF((int lcodes, int dcodes, int blcodes));
2151 local void compress_block OF((ct_data near *ltree, ct_data near *dtree));
2152 local void set_file_type OF((void));
2156 # define send_code(c, tree) send_bits(tree[c].Code, tree[c].Len)
2157 /* Send a code of the given tree. c and tree must not have side effects */
2160 # define send_code(c, tree) \
2161 { if (verbose>1) fprintf(stderr,"\ncd %3d ",(c)); \
2162 send_bits(tree[c].Code, tree[c].Len); }
2165 #define d_code(dist) \
2166 ((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)])
2167 /* Mapping from a distance to a distance code. dist is the distance - 1 and
2168 * must not have side effects. dist_code[256] and dist_code[257] are never
2172 #define MAX(a,b) (a >= b ? a : b)
2173 /* the arguments must not have side effects */
2175 /* ===========================================================================
2176 * Allocate the match buffer, initialize the various tables and save the
2177 * location of the internal file attribute (ascii/binary) and method
2180 void ct_init(attr, methodp)
2181 ush *attr; /* pointer to internal file attribute */
2182 int *methodp; /* pointer to compression method */
2184 int n; /* iterates over tree elements */
2185 int bits; /* bit counter */
2186 int length; /* length value */
2187 int code; /* code value */
2188 int dist; /* distance index */
2191 file_method = methodp;
2192 compressed_len = input_len = 0L;
2194 if (static_dtree[0].Len != 0) return; /* ct_init already called */
2196 /* Initialize the mapping length (0..255) -> length code (0..28) */
2198 for (code = 0; code < LENGTH_CODES-1; code++) {
2199 base_length[code] = length;
2200 for (n = 0; n < (1<<extra_lbits[code]); n++) {
2201 length_code[length++] = (uch)code;
2204 Assert (length == 256, "ct_init: length != 256");
2205 /* Note that the length 255 (match length 258) can be represented
2206 * in two different ways: code 284 + 5 bits or code 285, so we
2207 * overwrite length_code[255] to use the best encoding:
2209 length_code[length-1] = (uch)code;
2211 /* Initialize the mapping dist (0..32K) -> dist code (0..29) */
2213 for (code = 0 ; code < 16; code++) {
2214 base_dist[code] = dist;
2215 for (n = 0; n < (1<<extra_dbits[code]); n++) {
2216 dist_code[dist++] = (uch)code;
2219 Assert (dist == 256, "ct_init: dist != 256");
2220 dist >>= 7; /* from now on, all distances are divided by 128 */
2221 for ( ; code < D_CODES; code++) {
2222 base_dist[code] = dist << 7;
2223 for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) {
2224 dist_code[256 + dist++] = (uch)code;
2227 Assert (dist == 256, "ct_init: 256+dist != 512");
2229 /* Construct the codes of the static literal tree */
2230 for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0;
2232 while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++;
2233 while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++;
2234 while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++;
2235 while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++;
2236 /* Codes 286 and 287 do not exist, but we must include them in the
2237 * tree construction to get a canonical Huffman tree (longest code
2240 gen_codes((ct_data near *)static_ltree, L_CODES+1);
2242 /* The static distance tree is trivial: */
2243 for (n = 0; n < D_CODES; n++) {
2244 static_dtree[n].Len = 5;
2245 static_dtree[n].Code = bi_reverse(n, 5);
2248 /* Initialize the first block of the first file: */
2252 /* ===========================================================================
2253 * Initialize a new block.
2255 local void init_block()
2257 int n; /* iterates over tree elements */
2259 /* Initialize the trees. */
2260 for (n = 0; n < L_CODES; n++) dyn_ltree[n].Freq = 0;
2261 for (n = 0; n < D_CODES; n++) dyn_dtree[n].Freq = 0;
2262 for (n = 0; n < BL_CODES; n++) bl_tree[n].Freq = 0;
2264 dyn_ltree[END_BLOCK].Freq = 1;
2265 opt_len = static_len = 0L;
2266 last_lit = last_dist = last_flags = 0;
2267 flags = 0; flag_bit = 1;
2271 /* Index within the heap array of least frequent node in the Huffman tree */
2274 /* ===========================================================================
2275 * Remove the smallest element from the heap and recreate the heap with
2276 * one less element. Updates heap and heap_len.
2278 #define pqremove(tree, top) \
2280 top = heap[SMALLEST]; \
2281 heap[SMALLEST] = heap[heap_len--]; \
2282 pqdownheap(tree, SMALLEST); \
2285 /* ===========================================================================
2286 * Compares to subtrees, using the tree depth as tie breaker when
2287 * the subtrees have equal frequency. This minimizes the worst case length.
2289 #define smaller(tree, n, m) \
2290 (tree[n].Freq < tree[m].Freq || \
2291 (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
2293 /* ===========================================================================
2294 * Restore the heap property by moving down the tree starting at node k,
2295 * exchanging a node with the smallest of its two sons if necessary, stopping
2296 * when the heap property is re-established (each father smaller than its
2299 local void pqdownheap(tree, k)
2300 ct_data near *tree; /* the tree to restore */
2301 int k; /* node to move down */
2304 int j = k << 1; /* left son of k */
2305 while (j <= heap_len) {
2306 /* Set j to the smallest of the two sons: */
2307 if (j < heap_len && smaller(tree, heap[j+1], heap[j])) j++;
2309 /* Exit if v is smaller than both sons */
2310 if (smaller(tree, v, heap[j])) break;
2312 /* Exchange v with the smallest son */
2313 heap[k] = heap[j]; k = j;
2315 /* And continue down the tree, setting j to the left son of k */
2321 /* ===========================================================================
2322 * Compute the optimal bit lengths for a tree and update the total bit length
2323 * for the current block.
2324 * IN assertion: the fields freq and dad are set, heap[heap_max] and
2325 * above are the tree nodes sorted by increasing frequency.
2326 * OUT assertions: the field len is set to the optimal bit length, the
2327 * array bl_count contains the frequencies for each bit length.
2328 * The length opt_len is updated; static_len is also updated if stree is
2331 local void gen_bitlen(desc)
2332 tree_desc near *desc; /* the tree descriptor */
2334 ct_data near *tree = desc->dyn_tree;
2335 int near *extra = desc->extra_bits;
2336 int base = desc->extra_base;
2337 int max_code = desc->max_code;
2338 int max_length = desc->max_length;
2339 ct_data near *stree = desc->static_tree;
2340 int h; /* heap index */
2341 int n, m; /* iterate over the tree elements */
2342 int bits; /* bit length */
2343 int xbits; /* extra bits */
2344 ush f; /* frequency */
2345 int overflow = 0; /* number of elements with bit length too large */
2347 for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0;
2349 /* In a first pass, compute the optimal bit lengths (which may
2350 * overflow in the case of the bit length tree).
2352 tree[heap[heap_max]].Len = 0; /* root of the heap */
2354 for (h = heap_max+1; h < HEAP_SIZE; h++) {
2356 bits = tree[tree[n].Dad].Len + 1;
2357 if (bits > max_length) bits = max_length, overflow++;
2358 tree[n].Len = (ush)bits;
2359 /* We overwrite tree[n].Dad which is no longer needed */
2361 if (n > max_code) continue; /* not a leaf node */
2365 if (n >= base) xbits = extra[n-base];
2367 opt_len += (ulg)f * (bits + xbits);
2368 if (stree) static_len += (ulg)f * (stree[n].Len + xbits);
2370 if (overflow == 0) return;
2372 Trace((stderr,"\nbit length overflow\n"));
2373 /* This happens for example on obj2 and pic of the Calgary corpus */
2375 /* Find the first bit length which could increase: */
2377 bits = max_length-1;
2378 while (bl_count[bits] == 0) bits--;
2379 bl_count[bits]--; /* move one leaf down the tree */
2380 bl_count[bits+1] += 2; /* move one overflow item as its brother */
2381 bl_count[max_length]--;
2382 /* The brother of the overflow item also moves one step up,
2383 * but this does not affect bl_count[max_length]
2386 } while (overflow > 0);
2388 /* Now recompute all bit lengths, scanning in increasing frequency.
2389 * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
2390 * lengths instead of fixing only the wrong ones. This idea is taken
2391 * from 'ar' written by Haruhiko Okumura.)
2393 for (bits = max_length; bits != 0; bits--) {
2397 if (m > max_code) continue;
2398 if (tree[m].Len != (unsigned) bits) {
2399 Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
2400 opt_len += ((long)bits-(long)tree[m].Len)*(long)tree[m].Freq;
2401 tree[m].Len = (ush)bits;
2408 /* ===========================================================================
2409 * Generate the codes for a given tree and bit counts (which need not be
2411 * IN assertion: the array bl_count contains the bit length statistics for
2412 * the given tree and the field len is set for all tree elements.
2413 * OUT assertion: the field code is set for all tree elements of non
2416 local void gen_codes (tree, max_code)
2417 ct_data near *tree; /* the tree to decorate */
2418 int max_code; /* largest code with non zero frequency */
2420 ush next_code[MAX_BITS+1]; /* next code value for each bit length */
2421 ush code = 0; /* running code value */
2422 int bits; /* bit index */
2423 int n; /* code index */
2425 /* The distribution counts are first used to generate the code values
2426 * without bit reversal.
2428 for (bits = 1; bits <= MAX_BITS; bits++) {
2429 next_code[bits] = code = (code + bl_count[bits-1]) << 1;
2431 /* Check that the bit counts in bl_count are consistent. The last code
2434 Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,
2435 "inconsistent bit counts");
2436 Tracev((stderr,"\ngen_codes: max_code %d ", max_code));
2438 for (n = 0; n <= max_code; n++) {
2439 int len = tree[n].Len;
2440 if (len == 0) continue;
2441 /* Now reverse the bits */
2442 tree[n].Code = bi_reverse(next_code[len]++, len);
2444 Tracec(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ",
2445 n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1));
2449 /* ===========================================================================
2450 * Construct one Huffman tree and assigns the code bit strings and lengths.
2451 * Update the total bit length for the current block.
2452 * IN assertion: the field freq is set for all tree elements.
2453 * OUT assertions: the fields len and code are set to the optimal bit length
2454 * and corresponding code. The length opt_len is updated; static_len is
2455 * also updated if stree is not null. The field max_code is set.
2457 local void build_tree(desc)
2458 tree_desc near *desc; /* the tree descriptor */
2460 ct_data near *tree = desc->dyn_tree;
2461 ct_data near *stree = desc->static_tree;
2462 int elems = desc->elems;
2463 int n, m; /* iterate over heap elements */
2464 int max_code = -1; /* largest code with non zero frequency */
2465 int node = elems; /* next internal node of the tree */
2467 /* Construct the initial heap, with least frequent element in
2468 * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
2469 * heap[0] is not used.
2471 heap_len = 0, heap_max = HEAP_SIZE;
2473 for (n = 0; n < elems; n++) {
2474 if (tree[n].Freq != 0) {
2475 heap[++heap_len] = max_code = n;
2482 /* The pkzip format requires that at least one distance code exists,
2483 * and that at least one bit should be sent even if there is only one
2484 * possible code. So to avoid special checks later on we force at least
2485 * two codes of non zero frequency.
2487 while (heap_len < 2) {
2488 int new = heap[++heap_len] = (max_code < 2 ? ++max_code : 0);
2491 opt_len--; if (stree) static_len -= stree[new].Len;
2492 /* new is 0 or 1 so it does not have extra bits */
2494 desc->max_code = max_code;
2496 /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
2497 * establish sub-heaps of increasing lengths:
2499 for (n = heap_len/2; n >= 1; n--) pqdownheap(tree, n);
2501 /* Construct the Huffman tree by repeatedly combining the least two
2505 pqremove(tree, n); /* n = node of least frequency */
2506 m = heap[SMALLEST]; /* m = node of next least frequency */
2508 heap[--heap_max] = n; /* keep the nodes sorted by frequency */
2509 heap[--heap_max] = m;
2511 /* Create a new node father of n and m */
2512 tree[node].Freq = tree[n].Freq + tree[m].Freq;
2513 depth[node] = (uch) (MAX(depth[n], depth[m]) + 1);
2514 tree[n].Dad = tree[m].Dad = (ush)node;
2516 if (tree == bl_tree) {
2517 fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)",
2518 node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq);
2521 /* and insert the new node in the heap */
2522 heap[SMALLEST] = node++;
2523 pqdownheap(tree, SMALLEST);
2525 } while (heap_len >= 2);
2527 heap[--heap_max] = heap[SMALLEST];
2529 /* At this point, the fields freq and dad are set. We can now
2530 * generate the bit lengths.
2532 gen_bitlen((tree_desc near *)desc);
2534 /* The field len is now set, we can generate the bit codes */
2535 gen_codes ((ct_data near *)tree, max_code);
2538 /* ===========================================================================
2539 * Scan a literal or distance tree to determine the frequencies of the codes
2540 * in the bit length tree. Updates opt_len to take into account the repeat
2541 * counts. (The contribution of the bit length codes will be added later
2542 * during the construction of bl_tree.)
2544 local void scan_tree (tree, max_code)
2545 ct_data near *tree; /* the tree to be scanned */
2546 int max_code; /* and its largest code of non zero frequency */
2548 int n; /* iterates over all tree elements */
2549 int prevlen = -1; /* last emitted length */
2550 int curlen; /* length of current code */
2551 int nextlen = tree[0].Len; /* length of next code */
2552 int count = 0; /* repeat count of the current code */
2553 int max_count = 7; /* max repeat count */
2554 int min_count = 4; /* min repeat count */
2556 if (nextlen == 0) max_count = 138, min_count = 3;
2557 tree[max_code+1].Len = (ush)0xffff; /* guard */
2559 for (n = 0; n <= max_code; n++) {
2560 curlen = nextlen; nextlen = tree[n+1].Len;
2561 if (++count < max_count && curlen == nextlen) {
2563 } else if (count < min_count) {
2564 bl_tree[curlen].Freq += count;
2565 } else if (curlen != 0) {
2566 if (curlen != prevlen) bl_tree[curlen].Freq++;
2567 bl_tree[REP_3_6].Freq++;
2568 } else if (count <= 10) {
2569 bl_tree[REPZ_3_10].Freq++;
2571 bl_tree[REPZ_11_138].Freq++;
2573 count = 0; prevlen = curlen;
2575 max_count = 138, min_count = 3;
2576 } else if (curlen == nextlen) {
2577 max_count = 6, min_count = 3;
2579 max_count = 7, min_count = 4;
2584 /* ===========================================================================
2585 * Send a literal or distance tree in compressed form, using the codes in
2588 local void send_tree (tree, max_code)
2589 ct_data near *tree; /* the tree to be scanned */
2590 int max_code; /* and its largest code of non zero frequency */
2592 int n; /* iterates over all tree elements */
2593 int prevlen = -1; /* last emitted length */
2594 int curlen; /* length of current code */
2595 int nextlen = tree[0].Len; /* length of next code */
2596 int count = 0; /* repeat count of the current code */
2597 int max_count = 7; /* max repeat count */
2598 int min_count = 4; /* min repeat count */
2600 /* tree[max_code+1].Len = -1; */ /* guard already set */
2601 if (nextlen == 0) max_count = 138, min_count = 3;
2603 for (n = 0; n <= max_code; n++) {
2604 curlen = nextlen; nextlen = tree[n+1].Len;
2605 if (++count < max_count && curlen == nextlen) {
2607 } else if (count < min_count) {
2608 do { send_code(curlen, bl_tree); } while (--count != 0);
2610 } else if (curlen != 0) {
2611 if (curlen != prevlen) {
2612 send_code(curlen, bl_tree); count--;
2614 Assert(count >= 3 && count <= 6, " 3_6?");
2615 send_code(REP_3_6, bl_tree); send_bits(count-3, 2);
2617 } else if (count <= 10) {
2618 send_code(REPZ_3_10, bl_tree); send_bits(count-3, 3);
2621 send_code(REPZ_11_138, bl_tree); send_bits(count-11, 7);
2623 count = 0; prevlen = curlen;
2625 max_count = 138, min_count = 3;
2626 } else if (curlen == nextlen) {
2627 max_count = 6, min_count = 3;
2629 max_count = 7, min_count = 4;
2634 /* ===========================================================================
2635 * Construct the Huffman tree for the bit lengths and return the index in
2636 * bl_order of the last bit length code to send.
2638 local int build_bl_tree()
2640 int max_blindex; /* index of last bit length code of non zero freq */
2642 /* Determine the bit length frequencies for literal and distance trees */
2643 scan_tree((ct_data near *)dyn_ltree, l_desc.max_code);
2644 scan_tree((ct_data near *)dyn_dtree, d_desc.max_code);
2646 /* Build the bit length tree: */
2647 build_tree((tree_desc near *)(&bl_desc));
2648 /* opt_len now includes the length of the tree representations, except
2649 * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
2652 /* Determine the number of bit length codes to send. The pkzip format
2653 * requires that at least 4 bit length codes be sent. (appnote.txt says
2654 * 3 but the actual value used is 4.)
2656 for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) {
2657 if (bl_tree[bl_order[max_blindex]].Len != 0) break;
2659 /* Update opt_len to include the bit length tree and counts */
2660 opt_len += 3*(max_blindex+1) + 5+5+4;
2661 Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld", opt_len, static_len));
2666 /* ===========================================================================
2667 * Send the header for a block using dynamic Huffman trees: the counts, the
2668 * lengths of the bit length codes, the literal tree and the distance tree.
2669 * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
2671 local void send_all_trees(lcodes, dcodes, blcodes)
2672 int lcodes, dcodes, blcodes; /* number of codes for each tree */
2674 int rank; /* index in bl_order */
2676 Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");
2677 Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,
2679 Tracev((stderr, "\nbl counts: "));
2680 send_bits(lcodes-257, 5); /* not +255 as stated in appnote.txt */
2681 send_bits(dcodes-1, 5);
2682 send_bits(blcodes-4, 4); /* not -3 as stated in appnote.txt */
2683 for (rank = 0; rank < blcodes; rank++) {
2684 Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
2685 send_bits(bl_tree[bl_order[rank]].Len, 3);
2687 Tracev((stderr, "\nbl tree: sent %ld", bits_sent));
2689 send_tree((ct_data near *)dyn_ltree, lcodes-1); /* send the literal tree */
2690 Tracev((stderr, "\nlit tree: sent %ld", bits_sent));
2692 send_tree((ct_data near *)dyn_dtree, dcodes-1); /* send the distance tree */
2693 Tracev((stderr, "\ndist tree: sent %ld", bits_sent));
2696 /* ===========================================================================
2697 * Determine the best encoding for the current block: dynamic trees, static
2698 * trees or store, and output the encoded block to the zip file. This function
2699 * returns the total compressed length for the file so far.
2701 ulg flush_block(buf, stored_len, eof)
2702 char *buf; /* input block, or NULL if too old */
2703 ulg stored_len; /* length of input block */
2704 int eof; /* true if this is the last block for a file */
2706 ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
2707 int max_blindex; /* index of last bit length code of non zero freq */
2709 flag_buf[last_flags] = flags; /* Save the flags for the last 8 items */
2711 /* Check if the file is ascii or binary */
2712 if (*file_type == (ush)UNKNOWN) set_file_type();
2714 /* Construct the literal and distance trees */
2715 build_tree((tree_desc near *)(&l_desc));
2716 Tracev((stderr, "\nlit data: dyn %ld, stat %ld", opt_len, static_len));
2718 build_tree((tree_desc near *)(&d_desc));
2719 Tracev((stderr, "\ndist data: dyn %ld, stat %ld", opt_len, static_len));
2720 /* At this point, opt_len and static_len are the total bit lengths of
2721 * the compressed block data, excluding the tree representations.
2724 /* Build the bit length tree for the above two trees, and get the index
2725 * in bl_order of the last bit length code to send.
2727 max_blindex = build_bl_tree();
2729 /* Determine the best encoding. Compute first the block length in bytes */
2730 opt_lenb = (opt_len+3+7)>>3;
2731 static_lenb = (static_len+3+7)>>3;
2732 input_len += stored_len; /* for debugging only */
2734 Trace((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u dist %u ",
2735 opt_lenb, opt_len, static_lenb, static_len, stored_len,
2736 last_lit, last_dist));
2738 if (static_lenb <= opt_lenb) opt_lenb = static_lenb;
2740 /* If compression failed and this is the first and last block,
2741 * and if the zip file can be seeked (to rewrite the local header),
2742 * the whole file is transformed into a stored file:
2746 if (stored_len <= opt_lenb && eof && compressed_len == 0L && seekable()) {
2748 /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */
2749 if (buf == (char*)0) error ("block vanished");
2751 copy_block(buf, (unsigned)stored_len, 0); /* without header */
2752 compressed_len = stored_len << 3;
2753 *file_method = STORED;
2757 } else if (stored_len+4 <= opt_lenb && buf != (char*)0) {
2758 /* 4: two words for the lengths */
2760 /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
2761 * Otherwise we can't have processed more than WSIZE input bytes since
2762 * the last block flush, because compression would have been
2763 * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
2764 * transform a block into a stored block.
2766 send_bits((STORED_BLOCK<<1)+eof, 3); /* send block type */
2767 compressed_len = (compressed_len + 3 + 7) & ~7L;
2768 compressed_len += (stored_len + 4) << 3;
2770 copy_block(buf, (unsigned)stored_len, 1); /* with header */
2774 } else if (static_lenb == opt_lenb) {
2776 send_bits((STATIC_TREES<<1)+eof, 3);
2777 compress_block((ct_data near *)static_ltree, (ct_data near *)static_dtree);
2778 compressed_len += 3 + static_len;
2780 send_bits((DYN_TREES<<1)+eof, 3);
2781 send_all_trees(l_desc.max_code+1, d_desc.max_code+1, max_blindex+1);
2782 compress_block((ct_data near *)dyn_ltree, (ct_data near *)dyn_dtree);
2783 compressed_len += 3 + opt_len;
2785 Assert (compressed_len == bits_sent, "bad compressed size");
2789 Assert (input_len == isize, "bad input size");
2791 compressed_len += 7; /* align on byte boundary */
2793 Tracev((stderr,"\ncomprlen %lu(%lu) ", compressed_len>>3,
2794 compressed_len-7*eof));
2796 return compressed_len >> 3;
2799 /* ===========================================================================
2800 * Save the match info and tally the frequency counts. Return true if
2801 * the current block must be flushed.
2803 int ct_tally (dist, lc)
2804 int dist; /* distance of matched string */
2805 int lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */
2807 l_buf[last_lit++] = (uch)lc;
2809 /* lc is the unmatched char */
2810 dyn_ltree[lc].Freq++;
2812 /* Here, lc is the match length - MIN_MATCH */
2813 dist--; /* dist = match distance - 1 */
2814 Assert((ush)dist < (ush)MAX_DIST &&
2815 (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) &&
2816 (ush)d_code(dist) < (ush)D_CODES, "ct_tally: bad match");
2818 dyn_ltree[length_code[lc]+LITERALS+1].Freq++;
2819 dyn_dtree[d_code(dist)].Freq++;
2821 d_buf[last_dist++] = (ush)dist;
2826 /* Output the flags if they fill a byte: */
2827 if ((last_lit & 7) == 0) {
2828 flag_buf[last_flags++] = flags;
2829 flags = 0, flag_bit = 1;
2831 /* Try to guess if it is profitable to stop the current block here */
2832 if ((last_lit & 0xfff) == 0) {
2833 /* Compute an upper bound for the compressed length */
2834 ulg out_length = (ulg)last_lit*8L;
2835 ulg in_length = (ulg)strstart-block_start;
2837 for (dcode = 0; dcode < D_CODES; dcode++) {
2838 out_length += (ulg)dyn_dtree[dcode].Freq*(5L+extra_dbits[dcode]);
2841 Trace((stderr,"\nlast_lit %u, last_dist %u, in %ld, out ~%ld(%ld%%) ",
2842 last_lit, last_dist, in_length, out_length,
2843 100L - out_length*100L/in_length));
2844 if (last_dist < last_lit/2 && out_length < in_length/2) return 1;
2846 return (last_lit == LIT_BUFSIZE-1 || last_dist == DIST_BUFSIZE);
2847 /* We avoid equality with LIT_BUFSIZE because of wraparound at 64K
2848 * on 16 bit machines and because stored blocks are restricted to
2853 /* ===========================================================================
2854 * Send the block data compressed using the given Huffman trees
2856 local void compress_block(ltree, dtree)
2857 ct_data near *ltree; /* literal tree */
2858 ct_data near *dtree; /* distance tree */
2860 unsigned dist; /* distance of matched string */
2861 int lc; /* match length or unmatched char (if dist == 0) */
2862 unsigned lx = 0; /* running index in l_buf */
2863 unsigned dx = 0; /* running index in d_buf */
2864 unsigned fx = 0; /* running index in flag_buf */
2865 uch flag = 0; /* current flags */
2866 unsigned code; /* the code to send */
2867 int extra; /* number of extra bits to send */
2869 if (last_lit != 0) do {
2870 if ((lx & 7) == 0) flag = flag_buf[fx++];
2872 if ((flag & 1) == 0) {
2873 send_code(lc, ltree); /* send a literal byte */
2874 Tracecv(isgraph(lc), (stderr," '%c' ", lc));
2876 /* Here, lc is the match length - MIN_MATCH */
2877 code = length_code[lc];
2878 send_code(code+LITERALS+1, ltree); /* send the length code */
2879 extra = extra_lbits[code];
2881 lc -= base_length[code];
2882 send_bits(lc, extra); /* send the extra length bits */
2885 /* Here, dist is the match distance - 1 */
2886 code = d_code(dist);
2887 Assert (code < D_CODES, "bad d_code");
2889 send_code(code, dtree); /* send the distance code */
2890 extra = extra_dbits[code];
2892 dist -= base_dist[code];
2893 send_bits(dist, extra); /* send the extra distance bits */
2895 } /* literal or match pair ? */
2897 } while (lx < last_lit);
2899 send_code(END_BLOCK, ltree);
2902 /* ===========================================================================
2903 * Set the file type to ASCII or BINARY, using a crude approximation:
2904 * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise.
2905 * IN assertion: the fields freq of dyn_ltree are set and the total of all
2906 * frequencies does not exceed 64K (to fit in an int on 16 bit machines).
2908 local void set_file_type()
2911 unsigned ascii_freq = 0;
2912 unsigned bin_freq = 0;
2913 while (n < 7) bin_freq += dyn_ltree[n++].Freq;
2914 while (n < 128) ascii_freq += dyn_ltree[n++].Freq;
2915 while (n < LITERALS) bin_freq += dyn_ltree[n++].Freq;
2916 *file_type = bin_freq > (ascii_freq >> 2) ? BINARY : ASCII;
2917 if (*file_type == BINARY && translate_eol) {
2918 warn("-l used on binary file", "");
2921 /* util.c -- utility functions for gzip support
2922 * Copyright (C) 1992-1993 Jean-loup Gailly
2923 * This is free software; you can redistribute it and/or modify it under the
2924 * terms of the GNU General Public License, see the file COPYING.
2929 #include <sys/types.h>
2931 #ifdef HAVE_UNISTD_H
2932 # include <unistd.h>
2938 #if defined(STDC_HEADERS) || !defined(NO_STDLIB_H)
2939 # include <stdlib.h>
2944 extern ulg crc_32_tab[]; /* crc table, defined below */
2946 /* ===========================================================================
2947 * Copy input to output unchanged: zcat == cat with --force.
2948 * IN assertion: insize bytes have already been read in inbuf.
2951 int in, out; /* input and output file descriptors */
2954 while (insize != 0 && (int)insize != EOF) {
2955 write_buf(out, (char*)inbuf, insize);
2956 bytes_out += insize;
2957 insize = read(in, (char*)inbuf, INBUFSIZ);
2959 if ((int)insize == EOF && errno != 0) {
2962 bytes_in = bytes_out;
2966 /* ========================================================================
2967 * Put string s in lower case, return s.
2973 for (t = s; *t; t++) *t = tolow(*t);
2977 #if defined(NO_STRING_H) && !defined(STDC_HEADERS)
2979 /* Provide missing strspn and strcspn functions. */
2985 int strspn OF((const char *s, const char *accept));
2986 int strcspn OF((const char *s, const char *reject));
2988 /* ========================================================================
2989 * Return the length of the maximum initial segment
2990 * of s which contains only characters in accept.
2992 int strspn(s, accept)
2996 register const char *p;
2997 register const char *a;
2998 register int count = 0;
3000 for (p = s; *p != '\0'; ++p) {
3001 for (a = accept; *a != '\0'; ++a) {
3002 if (*p == *a) break;
3004 if (*a == '\0') return count;
3010 /* ========================================================================
3011 * Return the length of the maximum inital segment of s
3012 * which contains no characters from reject.
3014 int strcspn(s, reject)
3018 register int count = 0;
3020 while (*s != '\0') {
3021 if (strchr(reject, *s++) != NULL) return count;
3027 #endif /* NO_STRING_H */
3029 /* ========================================================================
3030 * Add an environment variable (if any) before argv, and update argc.
3031 * Return the expanded environment variable to be freed later, or NULL
3032 * if no options were added to argv.
3034 #define SEPARATOR " \t" /* separators in env variable */
3036 char *add_envopt(argcp, argvp, env)
3037 int *argcp; /* pointer to argc */
3038 char ***argvp; /* pointer to argv */
3039 char *env; /* name of environment variable */
3041 char *p; /* running pointer through env variable */
3042 char **oargv; /* runs through old argv array */
3043 char **nargv; /* runs through new argv array */
3044 int oargc = *argcp; /* old argc */
3045 int nargc = 0; /* number of arguments in env variable */
3047 env = (char*)getenv(env);
3048 if (env == NULL) return NULL;
3050 p = (char*)xmalloc(strlen(env)+1);
3051 env = strcpy(p, env); /* keep env variable intact */
3053 for (p = env; *p; nargc++ ) { /* move through env */
3054 p += strspn(p, SEPARATOR); /* skip leading separators */
3055 if (*p == '\0') break;
3057 p += strcspn(p, SEPARATOR); /* find end of word */
3058 if (*p) *p++ = '\0'; /* mark it */
3065 /* Allocate the new argv array, with an extra element just in case
3066 * the original arg list did not end with a NULL.
3068 nargv = (char**)calloc(*argcp+1, sizeof(char *));
3069 if (nargv == NULL) error("out of memory");
3073 /* Copy the program name first */
3074 if (oargc-- < 0) error("argc<=0");
3075 *(nargv++) = *(oargv++);
3077 /* Then copy the environment args */
3078 for (p = env; nargc > 0; nargc--) {
3079 p += strspn(p, SEPARATOR); /* skip separators */
3080 *(nargv++) = p; /* store start */
3081 while (*p++) ; /* skip over word */
3084 /* Finally copy the old args and add a NULL (usual convention) */
3085 while (oargc--) *(nargv++) = *(oargv++);
3089 /* ========================================================================
3090 * Display compression ratio on the given stream on 6 characters.
3092 void display_ratio(num, den, file)
3097 long ratio; /* 1000 times the compression ratio */
3100 ratio = 0; /* no compression */
3101 } else if (den < 2147483L) { /* (2**31 -1)/1000 */
3102 ratio = 1000L*num/den;
3104 ratio = num/(den/1000L);
3112 fprintf(file, "%2ld.%1ld%%", ratio / 10L, ratio % 10L);
3116 /* zip.c -- compress files to the gzip or pkzip format
3117 * Copyright (C) 1992-1993 Jean-loup Gailly
3118 * This is free software; you can redistribute it and/or modify it under the
3119 * terms of the GNU General Public License, see the file COPYING.
3123 #include <sys/types.h>
3125 #ifdef HAVE_UNISTD_H
3126 # include <unistd.h>
3132 local ulg crc; /* crc on uncompressed file data */
3133 long header_bytes; /* number of bytes in gzip header */
3135 /* ===========================================================================
3136 * Deflate in to out.
3137 * IN assertions: the input and output buffers are cleared.
3138 * The variables time_stamp and save_orig_name are initialized.
3141 int in, out; /* input and output file descriptors */
3143 uch flags = 0; /* general purpose bit flags */
3144 ush attr = 0; /* ascii/binary flag */
3145 ush deflate_flags = 0; /* pkzip -es, -en or -ex equivalent */
3151 /* Write the header to the gzip file. See algorithm.doc for the format */
3154 put_byte(GZIP_MAGIC[0]); /* magic header */
3155 put_byte(GZIP_MAGIC[1]);
3156 put_byte(DEFLATED); /* compression method */
3158 put_byte(flags); /* general flags */
3159 put_long(time_stamp);
3161 /* Write deflated file to zip file */
3165 ct_init(&attr, &method);
3166 lm_init(&deflate_flags);
3168 put_byte((uch)deflate_flags); /* extra flags */
3169 put_byte(OS_CODE); /* OS identifier */
3171 header_bytes = (long)outcnt;
3175 /* Write the crc and uncompressed size */
3178 header_bytes += 2*sizeof(long);
3185 /* ===========================================================================
3186 * Read a new buffer from the current input file, perform end-of-line
3187 * translation, and update the crc and input file size.
3188 * IN assertion: size >= 2 (for end-of-line translation)
3190 int file_read(buf, size)
3196 Assert(insize == 0, "inbuf not empty");
3198 len = read(ifd, buf, size);
3199 if (len == (unsigned)(-1) || len == 0) return (int)len;
3201 crc = updcrc((uch*)buf, len);