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[] =
15 "gzip [OPTION]... FILE\n\n"
16 "Compress FILE with maximum compression.\n"
17 "When FILE is -, reads standard input. Implies -c.\n\n"
19 "\t-c\tWrite output to standard output instead of FILE.gz\n";
22 /* gzip.h -- common declarations for all gzip modules
23 * Copyright (C) 1992-1993 Jean-loup Gailly.
24 * This is free software; you can redistribute it and/or modify it under the
25 * terms of the GNU General Public License, see the file COPYING.
28 #if defined(__STDC__) || defined(PROTO)
29 # define OF(args) args
40 /* I don't like nested includes, but the string and io functions are used
44 #if !defined(NO_STRING_H) || defined(STDC_HEADERS)
46 # if !defined(STDC_HEADERS) && !defined(NO_MEMORY_H) && !defined(__GNUC__)
49 # define memzero(s, n) memset ((voidp)(s), 0, (n))
53 # define strrchr rindex
54 # define memcpy(d, s, n) bcopy((s), (d), (n))
55 # define memcmp(s1, s2, n) bcmp((s1), (s2), (n))
56 # define memzero(s, n) bzero((s), (n))
60 # define RETSIGTYPE void
65 typedef unsigned char uch;
66 typedef unsigned short ush;
67 typedef unsigned long ulg;
69 /* Return codes from gzip */
74 /* Compression methods (see algorithm.doc) */
79 /* methods 4 to 7 reserved */
82 extern int method; /* compression method */
84 /* To save memory for 16 bit systems, some arrays are overlaid between
85 * the various modules:
86 * deflate: prev+head window d_buf l_buf outbuf
87 * unlzw: tab_prefix tab_suffix stack inbuf outbuf
88 * inflate: window inbuf
89 * unpack: window inbuf prefix_len
90 * unlzh: left+right window c_table inbuf c_len
91 * For compression, input is done in window[]. For decompression, output
92 * is done in window except for unlzw.
97 # define INBUFSIZ 0x2000 /* input buffer size */
99 # define INBUFSIZ 0x8000 /* input buffer size */
102 #define INBUF_EXTRA 64 /* required by unlzw() */
106 # define OUTBUFSIZ 8192 /* output buffer size */
108 # define OUTBUFSIZ 16384 /* output buffer size */
111 #define OUTBUF_EXTRA 2048 /* required by unlzw() */
115 # define DIST_BUFSIZE 0x2000 /* buffer for distances, see trees.c */
117 # define DIST_BUFSIZE 0x8000 /* buffer for distances, see trees.c */
122 # define EXTERN(type, array) extern type * near array
123 # define DECLARE(type, array, size) type * near array
124 # define ALLOC(type, array, size) { \
125 array = (type*)fcalloc((size_t)(((size)+1L)/2), 2*sizeof(type)); \
126 if (array == NULL) error("insufficient memory"); \
128 # define FREE(array) {if (array != NULL) fcfree(array), array=NULL;}
130 # define EXTERN(type, array) extern type array[]
131 # define DECLARE(type, array, size) type array[size]
132 # define ALLOC(type, array, size)
136 EXTERN(uch, inbuf); /* input buffer */
137 EXTERN(uch, outbuf); /* output buffer */
138 EXTERN(ush, d_buf); /* buffer for distances, see trees.c */
139 EXTERN(uch, window); /* Sliding window and suffix table (unlzw) */
140 #define tab_suffix window
142 # define tab_prefix prev /* hash link (see deflate.c) */
143 # define head (prev+WSIZE) /* hash head (see deflate.c) */
144 EXTERN(ush, tab_prefix); /* prefix code (see unlzw.c) */
146 # define tab_prefix0 prev
147 # define head tab_prefix1
148 EXTERN(ush, tab_prefix0); /* prefix for even codes */
149 EXTERN(ush, tab_prefix1); /* prefix for odd codes */
152 extern unsigned insize; /* valid bytes in inbuf */
153 extern unsigned inptr; /* index of next byte to be processed in inbuf */
154 extern unsigned outcnt; /* bytes in output buffer */
156 extern long bytes_in; /* number of input bytes */
157 extern long bytes_out; /* number of output bytes */
158 extern long header_bytes;/* number of bytes in gzip header */
160 #define isize bytes_in
161 /* for compatibility with old zip sources (to be cleaned) */
163 extern int ifd; /* input file descriptor */
164 extern int ofd; /* output file descriptor */
165 extern char ifname[]; /* input file name or "stdin" */
166 extern char ofname[]; /* output file name or "stdout" */
167 extern char *progname; /* program name */
169 extern long time_stamp; /* original time stamp (modification time) */
170 extern long ifile_size; /* input file size, -1 for devices (debug only) */
172 typedef int file_t; /* Do not use stdio */
173 #define NO_FILE (-1) /* in memory compression */
176 #define PACK_MAGIC "\037\036" /* Magic header for packed files */
177 #define GZIP_MAGIC "\037\213" /* Magic header for gzip files, 1F 8B */
178 #define OLD_GZIP_MAGIC "\037\236" /* Magic header for gzip 0.5 = freeze 1.x */
179 #define LZH_MAGIC "\037\240" /* Magic header for SCO LZH Compress files*/
180 #define PKZIP_MAGIC "\120\113\003\004" /* Magic header for pkzip files */
183 #define ASCII_FLAG 0x01 /* bit 0 set: file probably ascii text */
184 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
185 #define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
186 #define ORIG_NAME 0x08 /* bit 3 set: original file name present */
187 #define COMMENT 0x10 /* bit 4 set: file comment present */
188 #define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */
189 #define RESERVED 0xC0 /* bit 6,7: reserved */
191 /* internal file attribute */
192 #define UNKNOWN 0xffff
197 # define WSIZE 0x8000 /* window size--must be a power of two, and */
198 #endif /* at least 32K for zip's deflate method */
201 #define MAX_MATCH 258
202 /* The minimum and maximum match lengths */
204 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
205 /* Minimum amount of lookahead, except at the end of the input file.
206 * See deflate.c for comments about the MIN_MATCH+1.
209 #define MAX_DIST (WSIZE-MIN_LOOKAHEAD)
210 /* In order to simplify the code, particularly on 16 bit machines, match
211 * distances are limited to MAX_DIST instead of WSIZE.
214 extern int decrypt; /* flag to turn on decryption */
215 extern int exit_code; /* program exit code */
216 extern int verbose; /* be verbose (-v) */
217 extern int quiet; /* be quiet (-q) */
218 extern int test; /* check .z file integrity */
219 extern int save_orig_name; /* set if original name must be saved */
221 #define get_byte() (inptr < insize ? inbuf[inptr++] : fill_inbuf(0))
222 #define try_byte() (inptr < insize ? inbuf[inptr++] : fill_inbuf(1))
224 /* put_byte is used for the compressed output, put_ubyte for the
225 * uncompressed output. However unlzw() uses window for its
226 * suffix table instead of its output buffer, so it does not use put_ubyte
227 * (to be cleaned up).
229 #define put_byte(c) {outbuf[outcnt++]=(uch)(c); if (outcnt==OUTBUFSIZ)\
231 #define put_ubyte(c) {window[outcnt++]=(uch)(c); if (outcnt==WSIZE)\
234 /* Output a 16 bit value, lsb first */
235 #define put_short(w) \
236 { if (outcnt < OUTBUFSIZ-2) { \
237 outbuf[outcnt++] = (uch) ((w) & 0xff); \
238 outbuf[outcnt++] = (uch) ((ush)(w) >> 8); \
240 put_byte((uch)((w) & 0xff)); \
241 put_byte((uch)((ush)(w) >> 8)); \
245 /* Output a 32 bit value to the bit stream, lsb first */
246 #define put_long(n) { \
247 put_short((n) & 0xffff); \
248 put_short(((ulg)(n)) >> 16); \
251 #define seekable() 0 /* force sequential output */
252 #define translate_eol 0 /* no option -a yet */
254 #define tolow(c) (isupper(c) ? (c)-'A'+'a' : (c)) /* force to lower case */
256 /* Macros for getting two-byte and four-byte header values */
257 #define SH(p) ((ush)(uch)((p)[0]) | ((ush)(uch)((p)[1]) << 8))
258 #define LG(p) ((ulg)(SH(p)) | ((ulg)(SH((p)+2)) << 16))
260 /* Diagnostic functions */
262 # define Assert(cond,msg) {if(!(cond)) error(msg);}
263 # define Trace(x) fprintf x
264 # define Tracev(x) {if (verbose) fprintf x ;}
265 # define Tracevv(x) {if (verbose>1) fprintf x ;}
266 # define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
267 # define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
269 # define Assert(cond,msg)
274 # define Tracecv(c,x)
277 #define WARN(msg) {if (!quiet) fprintf msg ; \
278 if (exit_code == OK) exit_code = WARNING;}
280 local void do_exit(int exitcode) __attribute__ ((noreturn));
283 extern int zip OF((int in, int out));
284 extern int file_read OF((char *buf, unsigned size));
287 extern int unzip OF((int in, int out));
288 extern int check_zipfile OF((int in));
291 extern int unpack OF((int in, int out));
294 extern int unlzh OF((int in, int out));
297 RETSIGTYPE abort_gzip OF((void));
300 void lm_init OF((ush *flags));
301 ulg deflate OF((void));
304 void ct_init OF((ush *attr, int *method));
305 int ct_tally OF((int dist, int lc));
306 ulg flush_block OF((char *buf, ulg stored_len, int eof));
309 void bi_init OF((file_t zipfile));
310 void send_bits OF((int value, int length));
311 unsigned bi_reverse OF((unsigned value, int length));
312 void bi_windup OF((void));
313 void copy_block OF((char *buf, unsigned len, int header));
314 extern int (*read_buf) OF((char *buf, unsigned size));
317 extern int copy OF((int in, int out));
318 extern ulg updcrc OF((uch *s, unsigned n));
319 extern void clear_bufs OF((void));
320 extern int fill_inbuf OF((int eof_ok));
321 extern void flush_outbuf OF((void));
322 extern void flush_window OF((void));
323 extern void write_buf OF((int fd, voidp buf, unsigned cnt));
324 extern char *strlwr OF((char *s));
325 extern char *add_envopt OF((int *argcp, char ***argvp, char *env));
326 extern void error OF((char *m));
327 extern void warn OF((char *a, char *b));
328 extern void read_error OF((void));
329 extern void write_error OF((void));
330 extern void display_ratio OF((long num, long den, FILE *file));
331 extern voidp xmalloc OF((unsigned int size));
334 extern int inflate OF((void));
335 /* lzw.h -- define the lzw functions.
336 * Copyright (C) 1992-1993 Jean-loup Gailly.
337 * This is free software; you can redistribute it and/or modify it under the
338 * terms of the GNU General Public License, see the file COPYING.
341 #if !defined(OF) && defined(lint)
348 #define INIT_BITS 9 /* Initial number of bits per code */
350 #define BIT_MASK 0x1f /* Mask for 'number of compression bits' */
351 /* Mask 0x20 is reserved to mean a fourth header byte, and 0x40 is free.
352 * It's a pity that old uncompress does not check bit 0x20. That makes
353 * extension of the format actually undesirable because old compress
354 * would just crash on the new format instead of giving a meaningful
355 * error message. It does check the number of bits, but it's more
356 * helpful to say "unsupported format, get a new version" than
357 * "can only handle 16 bits".
360 #define BLOCK_MODE 0x80
361 /* Block compression: if table is full and compression rate is dropping,
362 * clear the dictionary.
365 #define LZW_RESERVED 0x60 /* reserved bits */
367 #define CLEAR 256 /* flush the dictionary */
368 #define FIRST (CLEAR+1) /* first free entry */
370 extern int maxbits; /* max bits per code for LZW */
371 extern int block_mode; /* block compress mode -C compatible with 2.0 */
373 /* revision.h -- define the version number
374 * Copyright (C) 1992-1993 Jean-loup Gailly.
375 * This is free software; you can redistribute it and/or modify it under the
376 * terms of the GNU General Public License, see the file COPYING.
379 #define VERSION "1.2.4"
381 #define REVDATE "18 Aug 93"
383 /* This version does not support compression into old compress format: */
388 /* tailor.h -- target dependent definitions
389 * Copyright (C) 1992-1993 Jean-loup Gailly.
390 * This is free software; you can redistribute it and/or modify it under the
391 * terms of the GNU General Public License, see the file COPYING.
394 /* The target dependent definitions should be defined here only.
395 * The target dependent functions should be defined in tailor.c.
399 #if defined(__MSDOS__) && !defined(MSDOS)
403 #if defined(__OS2__) && !defined(OS2)
407 #if defined(OS2) && defined(MSDOS) /* MS C under OS/2 */
413 /* DJGPP version 1.09+ on MS-DOS.
414 * The DJGPP 1.09 stat() function must be upgraded before gzip will
416 * No need for DIRENT, since <unistd.h> defines POSIX_SOURCE which
430 # define HAVE_SYS_UTIME_H
434 # define PATH_SEP2 '\\'
435 # define PATH_SEP3 ':'
436 # define MAX_PATH_LEN 128
437 # define NO_MULTIPLE_DOTS
438 # define MAX_EXT_CHARS 3
439 # define Z_SUFFIX "z"
442 # define STDC_HEADERS
443 # define NO_SIZE_CHECK
444 # define casemap(c) tolow(c) /* Force file names to lower case */
446 # define OS_CODE 0x00
447 # define SET_BINARY_MODE(fd) setmode(fd, O_BINARY)
448 # if !defined(NO_ASM) && !defined(ASMV)
456 # define PATH_SEP2 '\\'
457 # define PATH_SEP3 ':'
458 # define MAX_PATH_LEN 260
460 # define NO_MULTIPLE_DOTS
461 # define MAX_EXT_CHARS 3
462 # define Z_SUFFIX "z"
463 # define casemap(c) tolow(c)
467 # define STDC_HEADERS
469 # define OS_CODE 0x06
470 # define SET_BINARY_MODE(fd) setmode(fd, O_BINARY)
472 # define HAVE_SYS_UTIME_H
479 # define HAVE_SYS_UTIME_H
482 # define EXPAND(argc,argv) \
483 {_response(&argc, &argv); _wildcard(&argc, &argv);}
492 # define EXPAND(argc,argv) \
493 {response_expand(&argc, &argv);}
497 #ifdef WIN32 /* Windows NT */
498 # define HAVE_SYS_UTIME_H
500 # define PATH_SEP2 '\\'
501 # define PATH_SEP3 ':'
502 # define MAX_PATH_LEN 260
505 # define STDC_HEADERS
506 # define SET_BINARY_MODE(fd) setmode(fd, O_BINARY)
510 # define NO_MULTIPLE_DOTS
511 # define MAX_EXT_CHARS 3
512 # define Z_SUFFIX "z"
513 # define casemap(c) tolow(c) /* Force file names to lower case */
515 # define OS_CODE 0x0b
522 /* Turbo C 2.0 does not accept static allocations of large arrays */
523 void * fcalloc (unsigned items, unsigned size);
524 void fcfree (void *ptr);
527 # define fcalloc(nitems,itemsize) halloc((long)(nitems),(itemsize))
528 # define fcfree(ptr) hfree(ptr)
532 # define fcalloc(items,size) calloc((items),(size))
534 # define fcalloc(items,size) malloc((size_t)(items)*(size_t)(size))
536 # define fcfree(ptr) free(ptr)
539 #if defined(VAXC) || defined(VMS)
540 # define PATH_SEP ']'
541 # define PATH_SEP2 ':'
542 # define SUFFIX_SEP ';'
543 # define NO_MULTIPLE_DOTS
544 # define Z_SUFFIX "-gz"
546 # define casemap(c) tolow(c)
547 # define OS_CODE 0x02
548 # define OPTIONS_VAR "GZIP_OPT"
549 # define STDC_HEADERS
551 # define EXPAND(argc,argv) vms_expand_args(&argc,&argv);
553 # define unlink delete
561 # define PATH_SEP2 ':'
562 # define STDC_HEADERS
563 # define OS_CODE 0x01
567 # define HAVE_UNISTD_H
569 # define NO_STDIN_FSTAT
574 # include <fcntl.h> /* for read() and write() */
575 # define direct dirent
576 extern void _expand_args(int *argc, char ***argv);
577 # define EXPAND(argc,argv) _expand_args(&argc,&argv);
578 # undef O_BINARY /* disable useless --ascii option */
582 #if defined(ATARI) || defined(atarist)
583 # ifndef STDC_HEADERS
584 # define STDC_HEADERS
585 # define HAVE_UNISTD_H
589 # define OS_CODE 0x05
591 # define PATH_SEP2 '\\'
592 # define PATH_SEP3 ':'
593 # define MAX_PATH_LEN 128
594 # define NO_MULTIPLE_DOTS
595 # define MAX_EXT_CHARS 3
596 # define Z_SUFFIX "z"
598 # define casemap(c) tolow(c) /* Force file names to lower case */
604 # define PATH_SEP ':'
607 # define NO_STDIN_FSTAT
610 # define chmod(file, mode) (0)
611 # define OPEN(name, flags, mode) open(name, flags)
612 # define OS_CODE 0x07
614 # define isatty(fd) ((fd) <= 2)
618 #ifdef __50SERIES /* Prime/PRIMOS */
619 # define PATH_SEP '>'
620 # define STDC_HEADERS
625 # define NO_STDIN_FSTAT
626 # define NO_SIZE_CHECK
629 # define casemap(c) tolow(c) /* Force file names to lower case */
630 # define put_char(c) put_byte((c) & 0x7F)
631 # define get_char(c) ascii2pascii(get_byte())
632 # define OS_CODE 0x0F /* temporary, subject to change */
634 # undef SIGTERM /* We don't want a signal handler for SIGTERM */
638 #if defined(pyr) && !defined(NOMEMCPY) /* Pyramid */
639 # define NOMEMCPY /* problem with overlapping copies */
643 # define OS_CODE 0x0a
647 # define NO_ST_INO /* don't rely on inode numbers */
651 /* Common defaults */
654 # define OS_CODE 0x03 /* assume Unix */
658 # define PATH_SEP '/'
662 # define casemap(c) (c)
666 # define OPTIONS_VAR "GZIP"
670 # define Z_SUFFIX ".gz"
674 # define MAX_SUFFIX MAX_EXT_CHARS
676 # define MAX_SUFFIX 30
679 #ifndef MAKE_LEGAL_NAME
680 # ifdef NO_MULTIPLE_DOTS
681 # define MAKE_LEGAL_NAME(name) make_simple_name(name)
683 # define MAKE_LEGAL_NAME(name)
689 /* keep at least MIN_PART chars between dots in a file name. */
693 # define EXPAND(argc,argv)
700 #ifndef SET_BINARY_MODE
701 # define SET_BINARY_MODE(fd)
705 # define OPEN(name, flags, mode) open(name, flags, mode)
709 # define get_char() get_byte()
713 # define put_char(c) put_byte(c)
715 /* bits.c -- output variable-length bit strings
716 * Copyright (C) 1992-1993 Jean-loup Gailly
717 * This is free software; you can redistribute it and/or modify it under the
718 * terms of the GNU General Public License, see the file COPYING.
725 * Output variable-length bit strings. Compression can be done
726 * to a file or to memory. (The latter is not supported in this version.)
730 * The PKZIP "deflate" file format interprets compressed file data
731 * as a sequence of bits. Multi-bit strings in the file may cross
732 * byte boundaries without restriction.
734 * The first bit of each byte is the low-order bit.
736 * The routines in this file allow a variable-length bit value to
737 * be output right-to-left (useful for literal values). For
738 * left-to-right output (useful for code strings from the tree routines),
739 * the bits must have been reversed first with bi_reverse().
741 * For in-memory compression, the compressed bit stream goes directly
742 * into the requested output buffer. The input data is read in blocks
743 * by the mem_read() function. The buffer is limited to 64K on 16 bit
748 * void bi_init (FILE *zipfile)
749 * Initialize the bit string routines.
751 * void send_bits (int value, int length)
752 * Write out a bit string, taking the source bits right to
755 * int bi_reverse (int value, int length)
756 * Reverse the bits of a bit string, taking the source bits left to
757 * right and emitting them right to left.
759 * void bi_windup (void)
760 * Write out any remaining bits in an incomplete byte.
762 * void copy_block(char *buf, unsigned len, int header)
763 * Copy a stored block to the zip file, storing first the length and
764 * its one's complement if requested.
772 /* ===========================================================================
773 * Local data used by the "bit string" routines.
776 local file_t zfile; /* output gzip file */
778 local unsigned short bi_buf;
779 /* Output buffer. bits are inserted starting at the bottom (least significant
783 #define Buf_size (8 * 2*sizeof(char))
784 /* Number of bits used within bi_buf. (bi_buf might be implemented on
785 * more than 16 bits on some systems.)
789 /* Number of valid bits in bi_buf. All bits above the last valid bit
793 int (*read_buf) OF((char *buf, unsigned size));
794 /* Current input function. Set to mem_read for in-memory compression */
797 ulg bits_sent; /* bit length of the compressed data */
800 /* ===========================================================================
801 * Initialize the bit string routines.
803 void bi_init (zipfile)
804 file_t zipfile; /* output zip file, NO_FILE for in-memory compression */
813 /* Set the defaults for file compression. They are set by memcompress
814 * for in-memory compression.
816 if (zfile != NO_FILE) {
817 read_buf = file_read;
821 /* ===========================================================================
822 * Send a value on a given number of bits.
823 * IN assertion: length <= 16 and value fits in length bits.
825 void send_bits(value, length)
826 int value; /* value to send */
827 int length; /* number of bits */
830 Tracev((stderr," l %2d v %4x ", length, value));
831 Assert(length > 0 && length <= 15, "invalid length");
832 bits_sent += (ulg)length;
834 /* If not enough room in bi_buf, use (valid) bits from bi_buf and
835 * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))
836 * unused bits in value.
838 if (bi_valid > (int)Buf_size - length) {
839 bi_buf |= (value << bi_valid);
841 bi_buf = (ush)value >> (Buf_size - bi_valid);
842 bi_valid += length - Buf_size;
844 bi_buf |= value << bi_valid;
849 /* ===========================================================================
850 * Reverse the first len bits of a code, using straightforward code (a faster
851 * method would use a table)
852 * IN assertion: 1 <= len <= 15
854 unsigned bi_reverse(code, len)
855 unsigned code; /* the value to invert */
856 int len; /* its bit length */
858 register unsigned res = 0;
861 code >>= 1, res <<= 1;
866 /* ===========================================================================
867 * Write out any remaining bits in an incomplete byte.
873 } else if (bi_valid > 0) {
879 bits_sent = (bits_sent+7) & ~7;
883 /* ===========================================================================
884 * Copy a stored block to the zip file, storing first the length and its
885 * one's complement if requested.
887 void copy_block(buf, len, header)
888 char *buf; /* the input data */
889 unsigned len; /* its length */
890 int header; /* true if block header must be written */
892 bi_windup(); /* align on byte boundary */
896 put_short((ush)~len);
902 bits_sent += (ulg)len<<3;
907 if (key) zencode(*buf, t);
912 /* deflate.c -- compress data using the deflation algorithm
913 * Copyright (C) 1992-1993 Jean-loup Gailly
914 * This is free software; you can redistribute it and/or modify it under the
915 * terms of the GNU General Public License, see the file COPYING.
921 * Identify new text as repetitions of old text within a fixed-
922 * length sliding window trailing behind the new text.
926 * The "deflation" process depends on being able to identify portions
927 * of the input text which are identical to earlier input (within a
928 * sliding window trailing behind the input currently being processed).
930 * The most straightforward technique turns out to be the fastest for
931 * most input files: try all possible matches and select the longest.
932 * The key feature of this algorithm is that insertions into the string
933 * dictionary are very simple and thus fast, and deletions are avoided
934 * completely. Insertions are performed at each input character, whereas
935 * string matches are performed only when the previous match ends. So it
936 * is preferable to spend more time in matches to allow very fast string
937 * insertions and avoid deletions. The matching algorithm for small
938 * strings is inspired from that of Rabin & Karp. A brute force approach
939 * is used to find longer strings when a small match has been found.
940 * A similar algorithm is used in comic (by Jan-Mark Wams) and freeze
941 * (by Leonid Broukhis).
942 * A previous version of this file used a more sophisticated algorithm
943 * (by Fiala and Greene) which is guaranteed to run in linear amortized
944 * time, but has a larger average cost, uses more memory and is patented.
945 * However the F&G algorithm may be faster for some highly redundant
946 * files if the parameter max_chain_length (described below) is too large.
950 * The idea of lazy evaluation of matches is due to Jan-Mark Wams, and
951 * I found it in 'freeze' written by Leonid Broukhis.
952 * Thanks to many info-zippers for bug reports and testing.
956 * APPNOTE.TXT documentation file in PKZIP 1.93a distribution.
958 * A description of the Rabin and Karp algorithm is given in the book
959 * "Algorithms" by R. Sedgewick, Addison-Wesley, p252.
961 * Fiala,E.R., and Greene,D.H.
962 * Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595
966 * void lm_init (int pack_level, ush *flags)
967 * Initialize the "longest match" routines for a new file
970 * Processes a new input file and return its compressed length. Sets
971 * the compressed length, crc, deflate flags and internal file
977 /* ===========================================================================
978 * Configuration parameters
981 /* Compile with MEDIUM_MEM to reduce the memory requirements or
982 * with SMALL_MEM to use as little memory as possible. Use BIG_MEM if the
983 * entire input file can be held in memory (not possible on 16 bit systems).
984 * Warning: defining these symbols affects HASH_BITS (see below) and thus
985 * affects the compression ratio. The compressed output
986 * is still correct, and might even be smaller in some cases.
990 # define HASH_BITS 13 /* Number of bits used to hash strings */
993 # define HASH_BITS 14
996 # define HASH_BITS 15
997 /* For portability to 16 bit machines, do not use values above 15. */
1000 /* To save space (see unlzw.c), we overlay prev+head with tab_prefix and
1001 * window with tab_suffix. Check that we can do this:
1003 #if (WSIZE<<1) > (1<<BITS)
1004 error: cannot overlay window with tab_suffix and prev with tab_prefix0
1006 #if HASH_BITS > BITS-1
1007 error: cannot overlay head with tab_prefix1
1010 #define HASH_SIZE (unsigned)(1<<HASH_BITS)
1011 #define HASH_MASK (HASH_SIZE-1)
1012 #define WMASK (WSIZE-1)
1013 /* HASH_SIZE and WSIZE must be powers of two */
1016 /* Tail of hash chains */
1020 /* speed options for the general purpose bit flag */
1023 # define TOO_FAR 4096
1025 /* Matches of length 3 are discarded if their distance exceeds TOO_FAR */
1027 /* ===========================================================================
1028 * Local data used by the "longest match" routines.
1032 typedef unsigned IPos;
1033 /* A Pos is an index in the character window. We use short instead of int to
1034 * save space in the various tables. IPos is used only for parameter passing.
1037 /* DECLARE(uch, window, 2L*WSIZE); */
1038 /* Sliding window. Input bytes are read into the second half of the window,
1039 * and move to the first half later to keep a dictionary of at least WSIZE
1040 * bytes. With this organization, matches are limited to a distance of
1041 * WSIZE-MAX_MATCH bytes, but this ensures that IO is always
1042 * performed with a length multiple of the block size. Also, it limits
1043 * the window size to 64K, which is quite useful on MSDOS.
1044 * To do: limit the window size to WSIZE+BSZ if SMALL_MEM (the code would
1045 * be less efficient).
1048 /* DECLARE(Pos, prev, WSIZE); */
1049 /* Link to older string with same hash index. To limit the size of this
1050 * array to 64K, this link is maintained only for the last 32K strings.
1051 * An index in this array is thus a window index modulo 32K.
1054 /* DECLARE(Pos, head, 1<<HASH_BITS); */
1055 /* Heads of the hash chains or NIL. */
1057 ulg window_size = (ulg)2*WSIZE;
1058 /* window size, 2*WSIZE except for MMAP or BIG_MEM, where it is the
1059 * input file length plus MIN_LOOKAHEAD.
1063 /* window position at the beginning of the current output block. Gets
1064 * negative when the window is moved backwards.
1067 local unsigned ins_h; /* hash index of string to be inserted */
1069 #define H_SHIFT ((HASH_BITS+MIN_MATCH-1)/MIN_MATCH)
1070 /* Number of bits by which ins_h and del_h must be shifted at each
1071 * input step. It must be such that after MIN_MATCH steps, the oldest
1072 * byte no longer takes part in the hash key, that is:
1073 * H_SHIFT * MIN_MATCH >= HASH_BITS
1076 unsigned int near prev_length;
1077 /* Length of the best match at previous step. Matches not greater than this
1078 * are discarded. This is used in the lazy match evaluation.
1081 unsigned near strstart; /* start of string to insert */
1082 unsigned near match_start; /* start of matching string */
1083 local int eofile; /* flag set at end of input file */
1084 local unsigned lookahead; /* number of valid bytes ahead in window */
1086 unsigned near max_chain_length;
1087 /* To speed up deflation, hash chains are never searched beyond this length.
1088 * A higher limit improves compression ratio but degrades the speed.
1091 local unsigned int max_lazy_match;
1092 /* Attempt to find a better match only when the current match is strictly
1093 * smaller than this value. This mechanism is used only for compression
1096 #define max_insert_length max_lazy_match
1097 /* Insert new strings in the hash table only if the match length
1098 * is not greater than this length. This saves time but degrades compression.
1099 * max_insert_length is used only for compression levels <= 3.
1102 unsigned near good_match;
1103 /* Use a faster search when the previous match is longer than this */
1106 /* Values for max_lazy_match, good_match and max_chain_length, depending on
1107 * the desired pack level (0..9). The values given below have been tuned to
1108 * exclude worst case performance for pathological files. Better values may be
1109 * found for specific files.
1112 typedef struct config {
1113 ush good_length; /* reduce lazy search above this match length */
1114 ush max_lazy; /* do not perform lazy search above this match length */
1115 ush nice_length; /* quit search above this match length */
1120 # define nice_match MAX_MATCH
1122 int near nice_match; /* Stop searching when current match exceeds this */
1125 local config configuration_table =
1126 /* 9 */ {32, 258, 258, 4096}; /* maximum compression */
1128 /* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
1129 * For deflate_fast() (levels <= 3) good is ignored and lazy has a different
1134 /* result of memcmp for equal strings */
1136 /* ===========================================================================
1137 * Prototypes for local functions.
1139 local void fill_window OF((void));
1141 int longest_match OF((IPos cur_match));
1143 void match_init OF((void)); /* asm code initialization */
1147 local void check_match OF((IPos start, IPos match, int length));
1150 /* ===========================================================================
1151 * Update a hash value with the given input byte
1152 * IN assertion: all calls to to UPDATE_HASH are made with consecutive
1153 * input characters, so that a running hash key can be computed from the
1154 * previous key instead of complete recalculation each time.
1156 #define UPDATE_HASH(h,c) (h = (((h)<<H_SHIFT) ^ (c)) & HASH_MASK)
1158 /* ===========================================================================
1159 * Insert string s in the dictionary and set match_head to the previous head
1160 * of the hash chain (the most recent string with same hash key). Return
1161 * the previous length of the hash chain.
1162 * IN assertion: all calls to to INSERT_STRING are made with consecutive
1163 * input characters and the first MIN_MATCH bytes of s are valid
1164 * (except for the last MIN_MATCH-1 bytes of the input file).
1166 #define INSERT_STRING(s, match_head) \
1167 (UPDATE_HASH(ins_h, window[(s) + MIN_MATCH-1]), \
1168 prev[(s) & WMASK] = match_head = head[ins_h], \
1171 /* ===========================================================================
1172 * Initialize the "longest match" routines for a new file
1174 void lm_init (flags)
1175 ush *flags; /* general purpose bit flag */
1177 register unsigned j;
1179 /* Initialize the hash table. */
1180 #if defined(MAXSEG_64K) && HASH_BITS == 15
1181 for (j = 0; j < HASH_SIZE; j++) head[j] = NIL;
1183 memzero((char*)head, HASH_SIZE*sizeof(*head));
1185 /* prev will be initialized on the fly */
1187 /* Set the default configuration parameters:
1189 max_lazy_match = configuration_table.max_lazy;
1190 good_match = configuration_table.good_length;
1192 nice_match = configuration_table.nice_length;
1194 max_chain_length = configuration_table.max_chain;
1196 /* ??? reduce max_chain_length for binary files */
1201 match_init(); /* initialize the asm code */
1204 lookahead = read_buf((char*)window,
1205 sizeof(int) <= 2 ? (unsigned)WSIZE : 2*WSIZE);
1207 if (lookahead == 0 || lookahead == (unsigned)EOF) {
1208 eofile = 1, lookahead = 0;
1212 /* Make sure that we always have enough lookahead. This is important
1213 * if input comes from a device such as a tty.
1215 while (lookahead < MIN_LOOKAHEAD && !eofile) fill_window();
1218 for (j=0; j<MIN_MATCH-1; j++) UPDATE_HASH(ins_h, window[j]);
1219 /* If lookahead < MIN_MATCH, ins_h is garbage, but this is
1220 * not important since only literal bytes will be emitted.
1224 /* ===========================================================================
1225 * Set match_start to the longest match starting at the given string and
1226 * return its length. Matches shorter or equal to prev_length are discarded,
1227 * in which case the result is equal to prev_length and match_start is
1229 * IN assertions: cur_match is the head of the hash chain for the current
1230 * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
1233 /* For MSDOS, OS/2 and 386 Unix, an optimized version is in match.asm or
1234 * match.s. The code is functionally equivalent, so you can use the C version
1237 int longest_match(cur_match)
1238 IPos cur_match; /* current match */
1240 unsigned chain_length = max_chain_length; /* max hash chain length */
1241 register uch *scan = window + strstart; /* current string */
1242 register uch *match; /* matched string */
1243 register int len; /* length of current match */
1244 int best_len = prev_length; /* best match length so far */
1245 IPos limit = strstart > (IPos)MAX_DIST ? strstart - (IPos)MAX_DIST : NIL;
1246 /* Stop when cur_match becomes <= limit. To simplify the code,
1247 * we prevent matches with the string of window index 0.
1250 /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
1251 * It is easy to get rid of this optimization if necessary.
1253 #if HASH_BITS < 8 || MAX_MATCH != 258
1254 error: Code too clever
1258 /* Compare two bytes at a time. Note: this is not always beneficial.
1259 * Try with and without -DUNALIGNED_OK to check.
1261 register uch *strend = window + strstart + MAX_MATCH - 1;
1262 register ush scan_start = *(ush*)scan;
1263 register ush scan_end = *(ush*)(scan+best_len-1);
1265 register uch *strend = window + strstart + MAX_MATCH;
1266 register uch scan_end1 = scan[best_len-1];
1267 register uch scan_end = scan[best_len];
1270 /* Do not waste too much time if we already have a good match: */
1271 if (prev_length >= good_match) {
1274 Assert(strstart <= window_size-MIN_LOOKAHEAD, "insufficient lookahead");
1277 Assert(cur_match < strstart, "no future");
1278 match = window + cur_match;
1280 /* Skip to next match if the match length cannot increase
1281 * or if the match length is less than 2:
1283 #if (defined(UNALIGNED_OK) && MAX_MATCH == 258)
1284 /* This code assumes sizeof(unsigned short) == 2. Do not use
1285 * UNALIGNED_OK if your compiler uses a different size.
1287 if (*(ush*)(match+best_len-1) != scan_end ||
1288 *(ush*)match != scan_start) continue;
1290 /* It is not necessary to compare scan[2] and match[2] since they are
1291 * always equal when the other bytes match, given that the hash keys
1292 * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at
1293 * strstart+3, +5, ... up to strstart+257. We check for insufficient
1294 * lookahead only every 4th comparison; the 128th check will be made
1295 * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is
1296 * necessary to put more guard bytes at the end of the window, or
1297 * to check more often for insufficient lookahead.
1301 } while (*(ush*)(scan+=2) == *(ush*)(match+=2) &&
1302 *(ush*)(scan+=2) == *(ush*)(match+=2) &&
1303 *(ush*)(scan+=2) == *(ush*)(match+=2) &&
1304 *(ush*)(scan+=2) == *(ush*)(match+=2) &&
1306 /* The funny "do {}" generates better code on most compilers */
1308 /* Here, scan <= window+strstart+257 */
1309 Assert(scan <= window+(unsigned)(window_size-1), "wild scan");
1310 if (*scan == *match) scan++;
1312 len = (MAX_MATCH - 1) - (int)(strend-scan);
1313 scan = strend - (MAX_MATCH-1);
1315 #else /* UNALIGNED_OK */
1317 if (match[best_len] != scan_end ||
1318 match[best_len-1] != scan_end1 ||
1320 *++match != scan[1]) continue;
1322 /* The check at best_len-1 can be removed because it will be made
1323 * again later. (This heuristic is not always a win.)
1324 * It is not necessary to compare scan[2] and match[2] since they
1325 * are always equal when the other bytes match, given that
1326 * the hash keys are equal and that HASH_BITS >= 8.
1330 /* We check for insufficient lookahead only every 8th comparison;
1331 * the 256th check will be made at strstart+258.
1334 } while (*++scan == *++match && *++scan == *++match &&
1335 *++scan == *++match && *++scan == *++match &&
1336 *++scan == *++match && *++scan == *++match &&
1337 *++scan == *++match && *++scan == *++match &&
1340 len = MAX_MATCH - (int)(strend - scan);
1341 scan = strend - MAX_MATCH;
1343 #endif /* UNALIGNED_OK */
1345 if (len > best_len) {
1346 match_start = cur_match;
1348 if (len >= nice_match) break;
1350 scan_end = *(ush*)(scan+best_len-1);
1352 scan_end1 = scan[best_len-1];
1353 scan_end = scan[best_len];
1356 } while ((cur_match = prev[cur_match & WMASK]) > limit
1357 && --chain_length != 0);
1364 /* ===========================================================================
1365 * Check that the match at match_start is indeed a match.
1367 local void check_match(start, match, length)
1371 /* check that the match is indeed a match */
1372 if (memcmp((char*)window + match,
1373 (char*)window + start, length) != EQUAL) {
1375 " start %d, match %d, length %d\n",
1376 start, match, length);
1377 error("invalid match");
1380 fprintf(stderr,"\\[%d,%d]", start-match, length);
1381 do { putc(window[start++], stderr); } while (--length != 0);
1385 # define check_match(start, match, length)
1388 /* ===========================================================================
1389 * Fill the window when the lookahead becomes insufficient.
1390 * Updates strstart and lookahead, and sets eofile if end of input file.
1391 * IN assertion: lookahead < MIN_LOOKAHEAD && strstart + lookahead > 0
1392 * OUT assertions: at least one byte has been read, or eofile is set;
1393 * file reads are performed for at least two bytes (required for the
1394 * translate_eol option).
1396 local void fill_window()
1398 register unsigned n, m;
1399 unsigned more = (unsigned)(window_size - (ulg)lookahead - (ulg)strstart);
1400 /* Amount of free space at the end of the window. */
1402 /* If the window is almost full and there is insufficient lookahead,
1403 * move the upper half to the lower one to make room in the upper half.
1405 if (more == (unsigned)EOF) {
1406 /* Very unlikely, but possible on 16 bit machine if strstart == 0
1407 * and lookahead == 1 (input done one byte at time)
1410 } else if (strstart >= WSIZE+MAX_DIST) {
1411 /* By the IN assertion, the window is not empty so we can't confuse
1412 * more == 0 with more == 64K on a 16 bit machine.
1414 Assert(window_size == (ulg)2*WSIZE, "no sliding with BIG_MEM");
1416 memcpy((char*)window, (char*)window+WSIZE, (unsigned)WSIZE);
1417 match_start -= WSIZE;
1418 strstart -= WSIZE; /* we now have strstart >= MAX_DIST: */
1420 block_start -= (long) WSIZE;
1422 for (n = 0; n < HASH_SIZE; n++) {
1424 head[n] = (Pos)(m >= WSIZE ? m-WSIZE : NIL);
1426 for (n = 0; n < WSIZE; n++) {
1428 prev[n] = (Pos)(m >= WSIZE ? m-WSIZE : NIL);
1429 /* If n is not on any hash chain, prev[n] is garbage but
1430 * its value will never be used.
1435 /* At this point, more >= 2 */
1437 n = read_buf((char*)window+strstart+lookahead, more);
1438 if (n == 0 || n == (unsigned)EOF) {
1446 /* ===========================================================================
1447 * Flush the current block, with given end-of-file flag.
1448 * IN assertion: strstart is set to the end of the current match.
1450 #define FLUSH_BLOCK(eof) \
1451 flush_block(block_start >= 0L ? (char*)&window[(unsigned)block_start] : \
1452 (char*)NULL, (long)strstart - block_start, (eof))
1454 /* ===========================================================================
1455 * Same as above, but achieves better compression. We use a lazy
1456 * evaluation for matches: a match is finally adopted only if there is
1457 * no better match at the next window position.
1461 IPos hash_head; /* head of hash chain */
1462 IPos prev_match; /* previous match */
1463 int flush; /* set if current block must be flushed */
1464 int match_available = 0; /* set if previous match exists */
1465 register unsigned match_length = MIN_MATCH-1; /* length of best match */
1467 extern long isize; /* byte length of input file, for debug only */
1470 /* Process the input block. */
1471 while (lookahead != 0) {
1472 /* Insert the string window[strstart .. strstart+2] in the
1473 * dictionary, and set hash_head to the head of the hash chain:
1475 INSERT_STRING(strstart, hash_head);
1477 /* Find the longest match, discarding those <= prev_length.
1479 prev_length = match_length, prev_match = match_start;
1480 match_length = MIN_MATCH-1;
1482 if (hash_head != NIL && prev_length < max_lazy_match &&
1483 strstart - hash_head <= MAX_DIST) {
1484 /* To simplify the code, we prevent matches with the string
1485 * of window index 0 (in particular we have to avoid a match
1486 * of the string with itself at the start of the input file).
1488 match_length = longest_match (hash_head);
1489 /* longest_match() sets match_start */
1490 if (match_length > lookahead) match_length = lookahead;
1492 /* Ignore a length 3 match if it is too distant: */
1493 if (match_length == MIN_MATCH && strstart-match_start > TOO_FAR){
1494 /* If prev_match is also MIN_MATCH, match_start is garbage
1495 * but we will ignore the current match anyway.
1500 /* If there was a match at the previous step and the current
1501 * match is not better, output the previous match:
1503 if (prev_length >= MIN_MATCH && match_length <= prev_length) {
1505 check_match(strstart-1, prev_match, prev_length);
1507 flush = ct_tally(strstart-1-prev_match, prev_length - MIN_MATCH);
1509 /* Insert in hash table all strings up to the end of the match.
1510 * strstart-1 and strstart are already inserted.
1512 lookahead -= prev_length-1;
1516 INSERT_STRING(strstart, hash_head);
1517 /* strstart never exceeds WSIZE-MAX_MATCH, so there are
1518 * always MIN_MATCH bytes ahead. If lookahead < MIN_MATCH
1519 * these bytes are garbage, but it does not matter since the
1520 * next lookahead bytes will always be emitted as literals.
1522 } while (--prev_length != 0);
1523 match_available = 0;
1524 match_length = MIN_MATCH-1;
1526 if (flush) FLUSH_BLOCK(0), block_start = strstart;
1528 } else if (match_available) {
1529 /* If there was no match at the previous position, output a
1530 * single literal. If there was a match but the current match
1531 * is longer, truncate the previous match to a single literal.
1533 Tracevv((stderr,"%c",window[strstart-1]));
1534 if (ct_tally (0, window[strstart-1])) {
1535 FLUSH_BLOCK(0), block_start = strstart;
1540 /* There is no previous match to compare with, wait for
1541 * the next step to decide.
1543 match_available = 1;
1547 Assert (strstart <= isize && lookahead <= isize, "a bit too far");
1549 /* Make sure that we always have enough lookahead, except
1550 * at the end of the input file. We need MAX_MATCH bytes
1551 * for the next match, plus MIN_MATCH bytes to insert the
1552 * string following the next match.
1554 while (lookahead < MIN_LOOKAHEAD && !eofile) fill_window();
1556 if (match_available) ct_tally (0, window[strstart-1]);
1558 return FLUSH_BLOCK(1); /* eof */
1560 /* gzip (GNU zip) -- compress files with zip algorithm and 'compress' interface
1561 * Copyright (C) 1992-1993 Jean-loup Gailly
1562 * The unzip code was written and put in the public domain by Mark Adler.
1563 * Portions of the lzw code are derived from the public domain 'compress'
1564 * written by Spencer Thomas, Joe Orost, James Woods, Jim McKie, Steve Davies,
1565 * Ken Turkowski, Dave Mack and Peter Jannesen.
1567 * See the license_msg below and the file COPYING for the software license.
1568 * See the file algorithm.doc for the compression algorithms and file formats.
1571 /* Compress files with zip algorithm and 'compress' interface.
1572 * See usage() and help() functions below for all options.
1574 * file.gz: compressed file with same mode, owner, and utimes
1575 * or stdout with -c option or if stdin used as input.
1576 * If the output file name had to be truncated, the original name is kept
1577 * in the compressed file.
1578 * On MSDOS, file.tmp -> file.tmz. On VMS, file.tmp -> file.tmp-gz.
1580 * Using gz on MSDOS would create too many file name conflicts. For
1581 * example, foo.txt -> foo.tgz (.tgz must be reserved as shorthand for
1582 * tar.gz). Similarly, foo.dir and foo.doc would both be mapped to foo.dgz.
1583 * I also considered 12345678.txt -> 12345txt.gz but this truncates the name
1584 * too heavily. There is no ideal solution given the MSDOS 8+3 limitation.
1586 * For the meaning of all compilation flags, see comments in Makefile.in.
1590 #include <sys/types.h>
1592 #include <sys/stat.h>
1598 # include <sys/time.h>
1607 #ifdef HAVE_UNISTD_H
1608 # include <unistd.h>
1611 #if defined(STDC_HEADERS) || !defined(NO_STDLIB_H)
1612 # include <stdlib.h>
1618 # include <dirent.h>
1619 typedef struct dirent dir_type;
1620 # define NLENGTH(dirent) ((int)strlen((dirent)->d_name))
1621 # define DIR_OPT "DIRENT"
1623 # define NLENGTH(dirent) ((dirent)->d_namlen)
1625 # include <sys/dir.h>
1626 typedef struct direct dir_type;
1627 # define DIR_OPT "SYSDIR"
1630 # include <sys/ndir.h>
1631 typedef struct direct dir_type;
1632 # define DIR_OPT "SYSNDIR"
1636 typedef struct direct dir_type;
1637 # define DIR_OPT "NDIR"
1640 # define DIR_OPT "NO_DIR"
1649 # define TIME_OPT "UTIME"
1651 # ifdef HAVE_SYS_UTIME_H
1652 # include <sys/utime.h>
1653 # define TIME_OPT "SYS_UTIME"
1659 # define TIME_OPT ""
1663 # define TIME_OPT "NO_UTIME"
1666 #if !defined(S_ISDIR) && defined(S_IFDIR)
1667 # define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
1669 #if !defined(S_ISREG) && defined(S_IFREG)
1670 # define S_ISREG(m) (((m) & S_IFMT) == S_IFREG)
1673 typedef RETSIGTYPE (*sig_type) OF((int));
1676 # define O_BINARY 0 /* creation mode for open() */
1680 /* Pure BSD system? */
1681 # include <sys/file.h>
1683 # define O_CREAT FCREAT
1686 # define O_EXCL FEXCL
1691 # define S_IRUSR 0400
1694 # define S_IWUSR 0200
1696 #define RW_USER (S_IRUSR | S_IWUSR) /* creation mode for open() */
1698 #ifndef MAX_PATH_LEN
1699 # define MAX_PATH_LEN 1024 /* max pathname length */
1708 off_t lseek OF((int fd, off_t offset, int whence));
1711 /* Separator for file name parts (see shorten_name()) */
1712 #ifdef NO_MULTIPLE_DOTS
1713 # define PART_SEP "-"
1715 # define PART_SEP "."
1718 /* global buffers */
1720 DECLARE(uch, inbuf, INBUFSIZ +INBUF_EXTRA);
1721 DECLARE(uch, outbuf, OUTBUFSIZ+OUTBUF_EXTRA);
1722 DECLARE(ush, d_buf, DIST_BUFSIZE);
1723 DECLARE(uch, window, 2L*WSIZE);
1725 DECLARE(ush, tab_prefix, 1L<<BITS);
1727 DECLARE(ush, tab_prefix0, 1L<<(BITS-1));
1728 DECLARE(ush, tab_prefix1, 1L<<(BITS-1));
1731 /* local variables */
1733 int ascii = 0; /* convert end-of-lines to local OS conventions */
1734 int decompress = 0; /* decompress (-d) */
1735 int no_name = -1; /* don't save or restore the original file name */
1736 int no_time = -1; /* don't save or restore the original file time */
1737 int foreground; /* set if program run in foreground */
1738 char *progname; /* program name */
1739 static int method = DEFLATED;/* compression method */
1740 static int exit_code = OK; /* program exit code */
1741 int save_orig_name; /* set if original name must be saved */
1742 int last_member; /* set for .zip and .Z files */
1743 int part_nb; /* number of parts in .gz file */
1744 long time_stamp; /* original time stamp (modification time) */
1745 long ifile_size; /* input file size, -1 for devices (debug only) */
1746 char *env; /* contents of GZIP env variable */
1747 char **args = NULL; /* argv pointer if GZIP env variable defined */
1748 char z_suffix[MAX_SUFFIX+1]; /* default suffix (can be set with --suffix) */
1749 int z_len; /* strlen(z_suffix) */
1751 long bytes_in; /* number of input bytes */
1752 long bytes_out; /* number of output bytes */
1753 char ifname[MAX_PATH_LEN]; /* input file name */
1754 char ofname[MAX_PATH_LEN]; /* output file name */
1755 int remove_ofname = 0; /* remove output file on error */
1756 struct stat istat; /* status for input file */
1757 int ifd; /* input file descriptor */
1758 int ofd; /* output file descriptor */
1759 unsigned insize; /* valid bytes in inbuf */
1760 unsigned inptr; /* index of next byte to be processed in inbuf */
1761 unsigned outcnt; /* bytes in output buffer */
1763 /* local functions */
1765 #define strequ(s1, s2) (strcmp((s1),(s2)) == 0)
1767 /* ======================================================================== */
1768 // int main (argc, argv)
1771 int gzip_main(int argc, char ** argv)
1776 struct stat statBuf;
1784 /* Parse any options */
1785 while (--argc > 0 && **(++argv) == '-') {
1786 if (*((*argv)+1) == '\0') {
1790 while (*(++(*argv))) {
1791 fprintf(stderr, "**argv='%c'\n", **argv);
1802 foreground = signal(SIGINT, SIG_IGN) != SIG_IGN;
1804 (void) signal (SIGINT, (sig_type)abort_gzip);
1807 if (signal(SIGTERM, SIG_IGN) != SIG_IGN) {
1808 (void) signal(SIGTERM, (sig_type)abort_gzip);
1812 if (signal(SIGHUP, SIG_IGN) != SIG_IGN) {
1813 (void) signal(SIGHUP, (sig_type)abort_gzip);
1817 strncpy(z_suffix, Z_SUFFIX, sizeof(z_suffix)-1);
1818 z_len = strlen(z_suffix);
1820 /* Allocate all global buffers (for DYN_ALLOC option) */
1821 ALLOC(uch, inbuf, INBUFSIZ +INBUF_EXTRA);
1822 ALLOC(uch, outbuf, OUTBUFSIZ+OUTBUF_EXTRA);
1823 ALLOC(ush, d_buf, DIST_BUFSIZE);
1824 ALLOC(uch, window, 2L*WSIZE);
1826 ALLOC(ush, tab_prefix, 1L<<BITS);
1828 ALLOC(ush, tab_prefix0, 1L<<(BITS-1));
1829 ALLOC(ush, tab_prefix1, 1L<<(BITS-1));
1833 strcpy(ofname, "stdin");
1835 inFileNum=fileno(stdin);
1836 time_stamp = 0; /* time unknown by default */
1837 ifile_size = -1L; /* convention for unknown size */
1839 /* Open up the input file */
1842 strncpy(ifname, *argv, MAX_PATH_LEN);
1844 /* Open input fille */
1845 inFileNum=open( ifname, O_RDONLY);
1846 if (inFileNum < 0) {
1850 /* Get the time stamp on the input file. */
1851 result = stat(ifname, &statBuf);
1856 time_stamp = statBuf.st_ctime;
1857 ifile_size = statBuf.st_size;
1862 /* And get to work */
1863 strcpy(ofname, "stdout");
1864 outFileNum=fileno(stdout);
1865 SET_BINARY_MODE(fileno(stdout));
1867 clear_bufs(); /* clear input and output buffers */
1870 /* Actually do the compression/decompression. */
1871 zip(inFileNum, outFileNum);
1875 /* And get to work */
1876 strncpy(ofname, ifname, MAX_PATH_LEN-4);
1877 strcat(ofname, ".gz");
1880 /* Open output fille */
1881 outFileNum=open( ofname, O_RDWR|O_CREAT|O_EXCL|O_NOFOLLOW);
1882 if (outFileNum < 0) {
1886 SET_BINARY_MODE(outFileNum);
1887 /* Set permissions on the file */
1888 fchmod(outFileNum, statBuf.st_mode);
1890 clear_bufs(); /* clear input and output buffers */
1893 /* Actually do the compression/decompression. */
1894 result=zip(inFileNum, outFileNum);
1897 /* Delete the original file */
1903 if (unlink (delFileName) < 0) {
1904 perror (delFileName);
1912 /* ========================================================================
1913 * Free all dynamically allocated variables and exit with the given code.
1915 local void do_exit(int exitcode)
1917 static int in_exit = 0;
1919 if (in_exit) exit(exitcode);
1921 if (env != NULL) free(env), env = NULL;
1922 if (args != NULL) free((char*)args), args = NULL;
1935 /* trees.c -- output deflated data using Huffman coding
1936 * Copyright (C) 1992-1993 Jean-loup Gailly
1937 * This is free software; you can redistribute it and/or modify it under the
1938 * terms of the GNU General Public License, see the file COPYING.
1944 * Encode various sets of source values using variable-length
1945 * binary code trees.
1949 * The PKZIP "deflation" process uses several Huffman trees. The more
1950 * common source values are represented by shorter bit sequences.
1952 * Each code tree is stored in the ZIP file in a compressed form
1953 * which is itself a Huffman encoding of the lengths of
1954 * all the code strings (in ascending order by source values).
1955 * The actual code strings are reconstructed from the lengths in
1956 * the UNZIP process, as described in the "application note"
1957 * (APPNOTE.TXT) distributed as part of PKWARE's PKZIP program.
1962 * Data Compression: Techniques and Applications, pp. 53-55.
1963 * Lifetime Learning Publications, 1985. ISBN 0-534-03418-7.
1966 * Data Compression: Methods and Theory, pp. 49-50.
1967 * Computer Science Press, 1988. ISBN 0-7167-8156-5.
1971 * Addison-Wesley, 1983. ISBN 0-201-06672-6.
1975 * void ct_init (ush *attr, int *methodp)
1976 * Allocate the match buffer, initialize the various tables and save
1977 * the location of the internal file attribute (ascii/binary) and
1978 * method (DEFLATE/STORE)
1980 * void ct_tally (int dist, int lc);
1981 * Save the match info and tally the frequency counts.
1983 * long flush_block (char *buf, ulg stored_len, int eof)
1984 * Determine the best encoding for the current block: dynamic trees,
1985 * static trees or store, and output the encoded block to the zip
1986 * file. Returns the total compressed length for the file so far.
1992 /* ===========================================================================
1997 /* All codes must not exceed MAX_BITS bits */
1999 #define MAX_BL_BITS 7
2000 /* Bit length codes must not exceed MAX_BL_BITS bits */
2002 #define LENGTH_CODES 29
2003 /* number of length codes, not counting the special END_BLOCK code */
2005 #define LITERALS 256
2006 /* number of literal bytes 0..255 */
2008 #define END_BLOCK 256
2009 /* end of block literal code */
2011 #define L_CODES (LITERALS+1+LENGTH_CODES)
2012 /* number of Literal or Length codes, including the END_BLOCK code */
2015 /* number of distance codes */
2018 /* number of codes used to transfer the bit lengths */
2021 local int near extra_lbits[LENGTH_CODES] /* extra bits for each length code */
2022 = {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};
2024 local int near extra_dbits[D_CODES] /* extra bits for each distance code */
2025 = {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};
2027 local int near extra_blbits[BL_CODES]/* extra bits for each bit length code */
2028 = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7};
2030 #define STORED_BLOCK 0
2031 #define STATIC_TREES 1
2033 /* The three kinds of block type */
2037 # define LIT_BUFSIZE 0x2000
2040 # define LIT_BUFSIZE 0x4000
2042 # define LIT_BUFSIZE 0x8000
2046 #ifndef DIST_BUFSIZE
2047 # define DIST_BUFSIZE LIT_BUFSIZE
2049 /* Sizes of match buffers for literals/lengths and distances. There are
2050 * 4 reasons for limiting LIT_BUFSIZE to 64K:
2051 * - frequencies can be kept in 16 bit counters
2052 * - if compression is not successful for the first block, all input data is
2053 * still in the window so we can still emit a stored block even when input
2054 * comes from standard input. (This can also be done for all blocks if
2055 * LIT_BUFSIZE is not greater than 32K.)
2056 * - if compression is not successful for a file smaller than 64K, we can
2057 * even emit a stored file instead of a stored block (saving 5 bytes).
2058 * - creating new Huffman trees less frequently may not provide fast
2059 * adaptation to changes in the input data statistics. (Take for
2060 * example a binary file with poorly compressible code followed by
2061 * a highly compressible string table.) Smaller buffer sizes give
2062 * fast adaptation but have of course the overhead of transmitting trees
2064 * - I can't count above 4
2065 * The current code is general and allows DIST_BUFSIZE < LIT_BUFSIZE (to save
2066 * memory at the expense of compression). Some optimizations would be possible
2067 * if we rely on DIST_BUFSIZE == LIT_BUFSIZE.
2069 #if LIT_BUFSIZE > INBUFSIZ
2070 error cannot overlay l_buf and inbuf
2074 /* repeat previous bit length 3-6 times (2 bits of repeat count) */
2076 #define REPZ_3_10 17
2077 /* repeat a zero length 3-10 times (3 bits of repeat count) */
2079 #define REPZ_11_138 18
2080 /* repeat a zero length 11-138 times (7 bits of repeat count) */
2082 /* ===========================================================================
2086 /* Data structure describing a single value and its code string. */
2087 typedef struct ct_data {
2089 ush freq; /* frequency count */
2090 ush code; /* bit string */
2093 ush dad; /* father node in Huffman tree */
2094 ush len; /* length of bit string */
2098 #define Freq fc.freq
2099 #define Code fc.code
2103 #define HEAP_SIZE (2*L_CODES+1)
2104 /* maximum heap size */
2106 local ct_data near dyn_ltree[HEAP_SIZE]; /* literal and length tree */
2107 local ct_data near dyn_dtree[2*D_CODES+1]; /* distance tree */
2109 local ct_data near static_ltree[L_CODES+2];
2110 /* The static literal tree. Since the bit lengths are imposed, there is no
2111 * need for the L_CODES extra codes used during heap construction. However
2112 * The codes 286 and 287 are needed to build a canonical tree (see ct_init
2116 local ct_data near static_dtree[D_CODES];
2117 /* The static distance tree. (Actually a trivial tree since all codes use
2121 local ct_data near bl_tree[2*BL_CODES+1];
2122 /* Huffman tree for the bit lengths */
2124 typedef struct tree_desc {
2125 ct_data near *dyn_tree; /* the dynamic tree */
2126 ct_data near *static_tree; /* corresponding static tree or NULL */
2127 int near *extra_bits; /* extra bits for each code or NULL */
2128 int extra_base; /* base index for extra_bits */
2129 int elems; /* max number of elements in the tree */
2130 int max_length; /* max bit length for the codes */
2131 int max_code; /* largest code with non zero frequency */
2134 local tree_desc near l_desc =
2135 {dyn_ltree, static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS, 0};
2137 local tree_desc near d_desc =
2138 {dyn_dtree, static_dtree, extra_dbits, 0, D_CODES, MAX_BITS, 0};
2140 local tree_desc near bl_desc =
2141 {bl_tree, (ct_data near *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS, 0};
2144 local ush near bl_count[MAX_BITS+1];
2145 /* number of codes at each bit length for an optimal tree */
2147 local uch near bl_order[BL_CODES]
2148 = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15};
2149 /* The lengths of the bit length codes are sent in order of decreasing
2150 * probability, to avoid transmitting the lengths for unused bit length codes.
2153 local int near heap[2*L_CODES+1]; /* heap used to build the Huffman trees */
2154 local int heap_len; /* number of elements in the heap */
2155 local int heap_max; /* element of largest frequency */
2156 /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
2157 * The same heap array is used to build all trees.
2160 local uch near depth[2*L_CODES+1];
2161 /* Depth of each subtree used as tie breaker for trees of equal frequency */
2163 local uch length_code[MAX_MATCH-MIN_MATCH+1];
2164 /* length code for each normalized match length (0 == MIN_MATCH) */
2166 local uch dist_code[512];
2167 /* distance codes. The first 256 values correspond to the distances
2168 * 3 .. 258, the last 256 values correspond to the top 8 bits of
2169 * the 15 bit distances.
2172 local int near base_length[LENGTH_CODES];
2173 /* First normalized length for each code (0 = MIN_MATCH) */
2175 local int near base_dist[D_CODES];
2176 /* First normalized distance for each code (0 = distance of 1) */
2179 /* DECLARE(uch, l_buf, LIT_BUFSIZE); buffer for literals or lengths */
2181 /* DECLARE(ush, d_buf, DIST_BUFSIZE); buffer for distances */
2183 local uch near flag_buf[(LIT_BUFSIZE/8)];
2184 /* flag_buf is a bit array distinguishing literals from lengths in
2185 * l_buf, thus indicating the presence or absence of a distance.
2188 local unsigned last_lit; /* running index in l_buf */
2189 local unsigned last_dist; /* running index in d_buf */
2190 local unsigned last_flags; /* running index in flag_buf */
2191 local uch flags; /* current flags not yet saved in flag_buf */
2192 local uch flag_bit; /* current bit used in flags */
2193 /* bits are filled in flags starting at bit 0 (least significant).
2194 * Note: these flags are overkill in the current code since we don't
2195 * take advantage of DIST_BUFSIZE == LIT_BUFSIZE.
2198 local ulg opt_len; /* bit length of current block with optimal trees */
2199 local ulg static_len; /* bit length of current block with static trees */
2201 local ulg compressed_len; /* total bit length of compressed file */
2203 local ulg input_len; /* total byte length of input file */
2204 /* input_len is for debugging only since we can get it by other means. */
2206 ush *file_type; /* pointer to UNKNOWN, BINARY or ASCII */
2207 int *file_method; /* pointer to DEFLATE or STORE */
2210 extern ulg bits_sent; /* bit length of the compressed data */
2211 extern long isize; /* byte length of input file */
2214 extern long block_start; /* window offset of current block */
2215 extern unsigned near strstart; /* window offset of current string */
2217 /* ===========================================================================
2218 * Local (static) routines in this file.
2221 local void init_block OF((void));
2222 local void pqdownheap OF((ct_data near *tree, int k));
2223 local void gen_bitlen OF((tree_desc near *desc));
2224 local void gen_codes OF((ct_data near *tree, int max_code));
2225 local void build_tree OF((tree_desc near *desc));
2226 local void scan_tree OF((ct_data near *tree, int max_code));
2227 local void send_tree OF((ct_data near *tree, int max_code));
2228 local int build_bl_tree OF((void));
2229 local void send_all_trees OF((int lcodes, int dcodes, int blcodes));
2230 local void compress_block OF((ct_data near *ltree, ct_data near *dtree));
2231 local void set_file_type OF((void));
2235 # define send_code(c, tree) send_bits(tree[c].Code, tree[c].Len)
2236 /* Send a code of the given tree. c and tree must not have side effects */
2239 # define send_code(c, tree) \
2240 { if (verbose>1) fprintf(stderr,"\ncd %3d ",(c)); \
2241 send_bits(tree[c].Code, tree[c].Len); }
2244 #define d_code(dist) \
2245 ((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)])
2246 /* Mapping from a distance to a distance code. dist is the distance - 1 and
2247 * must not have side effects. dist_code[256] and dist_code[257] are never
2251 #define MAX(a,b) (a >= b ? a : b)
2252 /* the arguments must not have side effects */
2254 /* ===========================================================================
2255 * Allocate the match buffer, initialize the various tables and save the
2256 * location of the internal file attribute (ascii/binary) and method
2259 void ct_init(attr, methodp)
2260 ush *attr; /* pointer to internal file attribute */
2261 int *methodp; /* pointer to compression method */
2263 int n; /* iterates over tree elements */
2264 int bits; /* bit counter */
2265 int length; /* length value */
2266 int code; /* code value */
2267 int dist; /* distance index */
2270 file_method = methodp;
2271 compressed_len = input_len = 0L;
2273 if (static_dtree[0].Len != 0) return; /* ct_init already called */
2275 /* Initialize the mapping length (0..255) -> length code (0..28) */
2277 for (code = 0; code < LENGTH_CODES-1; code++) {
2278 base_length[code] = length;
2279 for (n = 0; n < (1<<extra_lbits[code]); n++) {
2280 length_code[length++] = (uch)code;
2283 Assert (length == 256, "ct_init: length != 256");
2284 /* Note that the length 255 (match length 258) can be represented
2285 * in two different ways: code 284 + 5 bits or code 285, so we
2286 * overwrite length_code[255] to use the best encoding:
2288 length_code[length-1] = (uch)code;
2290 /* Initialize the mapping dist (0..32K) -> dist code (0..29) */
2292 for (code = 0 ; code < 16; code++) {
2293 base_dist[code] = dist;
2294 for (n = 0; n < (1<<extra_dbits[code]); n++) {
2295 dist_code[dist++] = (uch)code;
2298 Assert (dist == 256, "ct_init: dist != 256");
2299 dist >>= 7; /* from now on, all distances are divided by 128 */
2300 for ( ; code < D_CODES; code++) {
2301 base_dist[code] = dist << 7;
2302 for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) {
2303 dist_code[256 + dist++] = (uch)code;
2306 Assert (dist == 256, "ct_init: 256+dist != 512");
2308 /* Construct the codes of the static literal tree */
2309 for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0;
2311 while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++;
2312 while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++;
2313 while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++;
2314 while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++;
2315 /* Codes 286 and 287 do not exist, but we must include them in the
2316 * tree construction to get a canonical Huffman tree (longest code
2319 gen_codes((ct_data near *)static_ltree, L_CODES+1);
2321 /* The static distance tree is trivial: */
2322 for (n = 0; n < D_CODES; n++) {
2323 static_dtree[n].Len = 5;
2324 static_dtree[n].Code = bi_reverse(n, 5);
2327 /* Initialize the first block of the first file: */
2331 /* ===========================================================================
2332 * Initialize a new block.
2334 local void init_block()
2336 int n; /* iterates over tree elements */
2338 /* Initialize the trees. */
2339 for (n = 0; n < L_CODES; n++) dyn_ltree[n].Freq = 0;
2340 for (n = 0; n < D_CODES; n++) dyn_dtree[n].Freq = 0;
2341 for (n = 0; n < BL_CODES; n++) bl_tree[n].Freq = 0;
2343 dyn_ltree[END_BLOCK].Freq = 1;
2344 opt_len = static_len = 0L;
2345 last_lit = last_dist = last_flags = 0;
2346 flags = 0; flag_bit = 1;
2350 /* Index within the heap array of least frequent node in the Huffman tree */
2353 /* ===========================================================================
2354 * Remove the smallest element from the heap and recreate the heap with
2355 * one less element. Updates heap and heap_len.
2357 #define pqremove(tree, top) \
2359 top = heap[SMALLEST]; \
2360 heap[SMALLEST] = heap[heap_len--]; \
2361 pqdownheap(tree, SMALLEST); \
2364 /* ===========================================================================
2365 * Compares to subtrees, using the tree depth as tie breaker when
2366 * the subtrees have equal frequency. This minimizes the worst case length.
2368 #define smaller(tree, n, m) \
2369 (tree[n].Freq < tree[m].Freq || \
2370 (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
2372 /* ===========================================================================
2373 * Restore the heap property by moving down the tree starting at node k,
2374 * exchanging a node with the smallest of its two sons if necessary, stopping
2375 * when the heap property is re-established (each father smaller than its
2378 local void pqdownheap(tree, k)
2379 ct_data near *tree; /* the tree to restore */
2380 int k; /* node to move down */
2383 int j = k << 1; /* left son of k */
2384 while (j <= heap_len) {
2385 /* Set j to the smallest of the two sons: */
2386 if (j < heap_len && smaller(tree, heap[j+1], heap[j])) j++;
2388 /* Exit if v is smaller than both sons */
2389 if (smaller(tree, v, heap[j])) break;
2391 /* Exchange v with the smallest son */
2392 heap[k] = heap[j]; k = j;
2394 /* And continue down the tree, setting j to the left son of k */
2400 /* ===========================================================================
2401 * Compute the optimal bit lengths for a tree and update the total bit length
2402 * for the current block.
2403 * IN assertion: the fields freq and dad are set, heap[heap_max] and
2404 * above are the tree nodes sorted by increasing frequency.
2405 * OUT assertions: the field len is set to the optimal bit length, the
2406 * array bl_count contains the frequencies for each bit length.
2407 * The length opt_len is updated; static_len is also updated if stree is
2410 local void gen_bitlen(desc)
2411 tree_desc near *desc; /* the tree descriptor */
2413 ct_data near *tree = desc->dyn_tree;
2414 int near *extra = desc->extra_bits;
2415 int base = desc->extra_base;
2416 int max_code = desc->max_code;
2417 int max_length = desc->max_length;
2418 ct_data near *stree = desc->static_tree;
2419 int h; /* heap index */
2420 int n, m; /* iterate over the tree elements */
2421 int bits; /* bit length */
2422 int xbits; /* extra bits */
2423 ush f; /* frequency */
2424 int overflow = 0; /* number of elements with bit length too large */
2426 for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0;
2428 /* In a first pass, compute the optimal bit lengths (which may
2429 * overflow in the case of the bit length tree).
2431 tree[heap[heap_max]].Len = 0; /* root of the heap */
2433 for (h = heap_max+1; h < HEAP_SIZE; h++) {
2435 bits = tree[tree[n].Dad].Len + 1;
2436 if (bits > max_length) bits = max_length, overflow++;
2437 tree[n].Len = (ush)bits;
2438 /* We overwrite tree[n].Dad which is no longer needed */
2440 if (n > max_code) continue; /* not a leaf node */
2444 if (n >= base) xbits = extra[n-base];
2446 opt_len += (ulg)f * (bits + xbits);
2447 if (stree) static_len += (ulg)f * (stree[n].Len + xbits);
2449 if (overflow == 0) return;
2451 Trace((stderr,"\nbit length overflow\n"));
2452 /* This happens for example on obj2 and pic of the Calgary corpus */
2454 /* Find the first bit length which could increase: */
2456 bits = max_length-1;
2457 while (bl_count[bits] == 0) bits--;
2458 bl_count[bits]--; /* move one leaf down the tree */
2459 bl_count[bits+1] += 2; /* move one overflow item as its brother */
2460 bl_count[max_length]--;
2461 /* The brother of the overflow item also moves one step up,
2462 * but this does not affect bl_count[max_length]
2465 } while (overflow > 0);
2467 /* Now recompute all bit lengths, scanning in increasing frequency.
2468 * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
2469 * lengths instead of fixing only the wrong ones. This idea is taken
2470 * from 'ar' written by Haruhiko Okumura.)
2472 for (bits = max_length; bits != 0; bits--) {
2476 if (m > max_code) continue;
2477 if (tree[m].Len != (unsigned) bits) {
2478 Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
2479 opt_len += ((long)bits-(long)tree[m].Len)*(long)tree[m].Freq;
2480 tree[m].Len = (ush)bits;
2487 /* ===========================================================================
2488 * Generate the codes for a given tree and bit counts (which need not be
2490 * IN assertion: the array bl_count contains the bit length statistics for
2491 * the given tree and the field len is set for all tree elements.
2492 * OUT assertion: the field code is set for all tree elements of non
2495 local void gen_codes (tree, max_code)
2496 ct_data near *tree; /* the tree to decorate */
2497 int max_code; /* largest code with non zero frequency */
2499 ush next_code[MAX_BITS+1]; /* next code value for each bit length */
2500 ush code = 0; /* running code value */
2501 int bits; /* bit index */
2502 int n; /* code index */
2504 /* The distribution counts are first used to generate the code values
2505 * without bit reversal.
2507 for (bits = 1; bits <= MAX_BITS; bits++) {
2508 next_code[bits] = code = (code + bl_count[bits-1]) << 1;
2510 /* Check that the bit counts in bl_count are consistent. The last code
2513 Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,
2514 "inconsistent bit counts");
2515 Tracev((stderr,"\ngen_codes: max_code %d ", max_code));
2517 for (n = 0; n <= max_code; n++) {
2518 int len = tree[n].Len;
2519 if (len == 0) continue;
2520 /* Now reverse the bits */
2521 tree[n].Code = bi_reverse(next_code[len]++, len);
2523 Tracec(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ",
2524 n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1));
2528 /* ===========================================================================
2529 * Construct one Huffman tree and assigns the code bit strings and lengths.
2530 * Update the total bit length for the current block.
2531 * IN assertion: the field freq is set for all tree elements.
2532 * OUT assertions: the fields len and code are set to the optimal bit length
2533 * and corresponding code. The length opt_len is updated; static_len is
2534 * also updated if stree is not null. The field max_code is set.
2536 local void build_tree(desc)
2537 tree_desc near *desc; /* the tree descriptor */
2539 ct_data near *tree = desc->dyn_tree;
2540 ct_data near *stree = desc->static_tree;
2541 int elems = desc->elems;
2542 int n, m; /* iterate over heap elements */
2543 int max_code = -1; /* largest code with non zero frequency */
2544 int node = elems; /* next internal node of the tree */
2546 /* Construct the initial heap, with least frequent element in
2547 * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
2548 * heap[0] is not used.
2550 heap_len = 0, heap_max = HEAP_SIZE;
2552 for (n = 0; n < elems; n++) {
2553 if (tree[n].Freq != 0) {
2554 heap[++heap_len] = max_code = n;
2561 /* The pkzip format requires that at least one distance code exists,
2562 * and that at least one bit should be sent even if there is only one
2563 * possible code. So to avoid special checks later on we force at least
2564 * two codes of non zero frequency.
2566 while (heap_len < 2) {
2567 int new = heap[++heap_len] = (max_code < 2 ? ++max_code : 0);
2570 opt_len--; if (stree) static_len -= stree[new].Len;
2571 /* new is 0 or 1 so it does not have extra bits */
2573 desc->max_code = max_code;
2575 /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
2576 * establish sub-heaps of increasing lengths:
2578 for (n = heap_len/2; n >= 1; n--) pqdownheap(tree, n);
2580 /* Construct the Huffman tree by repeatedly combining the least two
2584 pqremove(tree, n); /* n = node of least frequency */
2585 m = heap[SMALLEST]; /* m = node of next least frequency */
2587 heap[--heap_max] = n; /* keep the nodes sorted by frequency */
2588 heap[--heap_max] = m;
2590 /* Create a new node father of n and m */
2591 tree[node].Freq = tree[n].Freq + tree[m].Freq;
2592 depth[node] = (uch) (MAX(depth[n], depth[m]) + 1);
2593 tree[n].Dad = tree[m].Dad = (ush)node;
2595 if (tree == bl_tree) {
2596 fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)",
2597 node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq);
2600 /* and insert the new node in the heap */
2601 heap[SMALLEST] = node++;
2602 pqdownheap(tree, SMALLEST);
2604 } while (heap_len >= 2);
2606 heap[--heap_max] = heap[SMALLEST];
2608 /* At this point, the fields freq and dad are set. We can now
2609 * generate the bit lengths.
2611 gen_bitlen((tree_desc near *)desc);
2613 /* The field len is now set, we can generate the bit codes */
2614 gen_codes ((ct_data near *)tree, max_code);
2617 /* ===========================================================================
2618 * Scan a literal or distance tree to determine the frequencies of the codes
2619 * in the bit length tree. Updates opt_len to take into account the repeat
2620 * counts. (The contribution of the bit length codes will be added later
2621 * during the construction of bl_tree.)
2623 local void scan_tree (tree, max_code)
2624 ct_data near *tree; /* the tree to be scanned */
2625 int max_code; /* and its largest code of non zero frequency */
2627 int n; /* iterates over all tree elements */
2628 int prevlen = -1; /* last emitted length */
2629 int curlen; /* length of current code */
2630 int nextlen = tree[0].Len; /* length of next code */
2631 int count = 0; /* repeat count of the current code */
2632 int max_count = 7; /* max repeat count */
2633 int min_count = 4; /* min repeat count */
2635 if (nextlen == 0) max_count = 138, min_count = 3;
2636 tree[max_code+1].Len = (ush)0xffff; /* guard */
2638 for (n = 0; n <= max_code; n++) {
2639 curlen = nextlen; nextlen = tree[n+1].Len;
2640 if (++count < max_count && curlen == nextlen) {
2642 } else if (count < min_count) {
2643 bl_tree[curlen].Freq += count;
2644 } else if (curlen != 0) {
2645 if (curlen != prevlen) bl_tree[curlen].Freq++;
2646 bl_tree[REP_3_6].Freq++;
2647 } else if (count <= 10) {
2648 bl_tree[REPZ_3_10].Freq++;
2650 bl_tree[REPZ_11_138].Freq++;
2652 count = 0; prevlen = curlen;
2654 max_count = 138, min_count = 3;
2655 } else if (curlen == nextlen) {
2656 max_count = 6, min_count = 3;
2658 max_count = 7, min_count = 4;
2663 /* ===========================================================================
2664 * Send a literal or distance tree in compressed form, using the codes in
2667 local void send_tree (tree, max_code)
2668 ct_data near *tree; /* the tree to be scanned */
2669 int max_code; /* and its largest code of non zero frequency */
2671 int n; /* iterates over all tree elements */
2672 int prevlen = -1; /* last emitted length */
2673 int curlen; /* length of current code */
2674 int nextlen = tree[0].Len; /* length of next code */
2675 int count = 0; /* repeat count of the current code */
2676 int max_count = 7; /* max repeat count */
2677 int min_count = 4; /* min repeat count */
2679 /* tree[max_code+1].Len = -1; */ /* guard already set */
2680 if (nextlen == 0) max_count = 138, min_count = 3;
2682 for (n = 0; n <= max_code; n++) {
2683 curlen = nextlen; nextlen = tree[n+1].Len;
2684 if (++count < max_count && curlen == nextlen) {
2686 } else if (count < min_count) {
2687 do { send_code(curlen, bl_tree); } while (--count != 0);
2689 } else if (curlen != 0) {
2690 if (curlen != prevlen) {
2691 send_code(curlen, bl_tree); count--;
2693 Assert(count >= 3 && count <= 6, " 3_6?");
2694 send_code(REP_3_6, bl_tree); send_bits(count-3, 2);
2696 } else if (count <= 10) {
2697 send_code(REPZ_3_10, bl_tree); send_bits(count-3, 3);
2700 send_code(REPZ_11_138, bl_tree); send_bits(count-11, 7);
2702 count = 0; prevlen = curlen;
2704 max_count = 138, min_count = 3;
2705 } else if (curlen == nextlen) {
2706 max_count = 6, min_count = 3;
2708 max_count = 7, min_count = 4;
2713 /* ===========================================================================
2714 * Construct the Huffman tree for the bit lengths and return the index in
2715 * bl_order of the last bit length code to send.
2717 local int build_bl_tree()
2719 int max_blindex; /* index of last bit length code of non zero freq */
2721 /* Determine the bit length frequencies for literal and distance trees */
2722 scan_tree((ct_data near *)dyn_ltree, l_desc.max_code);
2723 scan_tree((ct_data near *)dyn_dtree, d_desc.max_code);
2725 /* Build the bit length tree: */
2726 build_tree((tree_desc near *)(&bl_desc));
2727 /* opt_len now includes the length of the tree representations, except
2728 * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
2731 /* Determine the number of bit length codes to send. The pkzip format
2732 * requires that at least 4 bit length codes be sent. (appnote.txt says
2733 * 3 but the actual value used is 4.)
2735 for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) {
2736 if (bl_tree[bl_order[max_blindex]].Len != 0) break;
2738 /* Update opt_len to include the bit length tree and counts */
2739 opt_len += 3*(max_blindex+1) + 5+5+4;
2740 Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld", opt_len, static_len));
2745 /* ===========================================================================
2746 * Send the header for a block using dynamic Huffman trees: the counts, the
2747 * lengths of the bit length codes, the literal tree and the distance tree.
2748 * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
2750 local void send_all_trees(lcodes, dcodes, blcodes)
2751 int lcodes, dcodes, blcodes; /* number of codes for each tree */
2753 int rank; /* index in bl_order */
2755 Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");
2756 Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,
2758 Tracev((stderr, "\nbl counts: "));
2759 send_bits(lcodes-257, 5); /* not +255 as stated in appnote.txt */
2760 send_bits(dcodes-1, 5);
2761 send_bits(blcodes-4, 4); /* not -3 as stated in appnote.txt */
2762 for (rank = 0; rank < blcodes; rank++) {
2763 Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
2764 send_bits(bl_tree[bl_order[rank]].Len, 3);
2766 Tracev((stderr, "\nbl tree: sent %ld", bits_sent));
2768 send_tree((ct_data near *)dyn_ltree, lcodes-1); /* send the literal tree */
2769 Tracev((stderr, "\nlit tree: sent %ld", bits_sent));
2771 send_tree((ct_data near *)dyn_dtree, dcodes-1); /* send the distance tree */
2772 Tracev((stderr, "\ndist tree: sent %ld", bits_sent));
2775 /* ===========================================================================
2776 * Determine the best encoding for the current block: dynamic trees, static
2777 * trees or store, and output the encoded block to the zip file. This function
2778 * returns the total compressed length for the file so far.
2780 ulg flush_block(buf, stored_len, eof)
2781 char *buf; /* input block, or NULL if too old */
2782 ulg stored_len; /* length of input block */
2783 int eof; /* true if this is the last block for a file */
2785 ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
2786 int max_blindex; /* index of last bit length code of non zero freq */
2788 flag_buf[last_flags] = flags; /* Save the flags for the last 8 items */
2790 /* Check if the file is ascii or binary */
2791 if (*file_type == (ush)UNKNOWN) set_file_type();
2793 /* Construct the literal and distance trees */
2794 build_tree((tree_desc near *)(&l_desc));
2795 Tracev((stderr, "\nlit data: dyn %ld, stat %ld", opt_len, static_len));
2797 build_tree((tree_desc near *)(&d_desc));
2798 Tracev((stderr, "\ndist data: dyn %ld, stat %ld", opt_len, static_len));
2799 /* At this point, opt_len and static_len are the total bit lengths of
2800 * the compressed block data, excluding the tree representations.
2803 /* Build the bit length tree for the above two trees, and get the index
2804 * in bl_order of the last bit length code to send.
2806 max_blindex = build_bl_tree();
2808 /* Determine the best encoding. Compute first the block length in bytes */
2809 opt_lenb = (opt_len+3+7)>>3;
2810 static_lenb = (static_len+3+7)>>3;
2811 input_len += stored_len; /* for debugging only */
2813 Trace((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u dist %u ",
2814 opt_lenb, opt_len, static_lenb, static_len, stored_len,
2815 last_lit, last_dist));
2817 if (static_lenb <= opt_lenb) opt_lenb = static_lenb;
2819 /* If compression failed and this is the first and last block,
2820 * and if the zip file can be seeked (to rewrite the local header),
2821 * the whole file is transformed into a stored file:
2825 if (stored_len <= opt_lenb && eof && compressed_len == 0L && seekable()) {
2827 /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */
2828 if (buf == (char*)0) error ("block vanished");
2830 copy_block(buf, (unsigned)stored_len, 0); /* without header */
2831 compressed_len = stored_len << 3;
2832 *file_method = STORED;
2836 } else if (stored_len+4 <= opt_lenb && buf != (char*)0) {
2837 /* 4: two words for the lengths */
2839 /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
2840 * Otherwise we can't have processed more than WSIZE input bytes since
2841 * the last block flush, because compression would have been
2842 * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
2843 * transform a block into a stored block.
2845 send_bits((STORED_BLOCK<<1)+eof, 3); /* send block type */
2846 compressed_len = (compressed_len + 3 + 7) & ~7L;
2847 compressed_len += (stored_len + 4) << 3;
2849 copy_block(buf, (unsigned)stored_len, 1); /* with header */
2853 } else if (static_lenb == opt_lenb) {
2855 send_bits((STATIC_TREES<<1)+eof, 3);
2856 compress_block((ct_data near *)static_ltree, (ct_data near *)static_dtree);
2857 compressed_len += 3 + static_len;
2859 send_bits((DYN_TREES<<1)+eof, 3);
2860 send_all_trees(l_desc.max_code+1, d_desc.max_code+1, max_blindex+1);
2861 compress_block((ct_data near *)dyn_ltree, (ct_data near *)dyn_dtree);
2862 compressed_len += 3 + opt_len;
2864 Assert (compressed_len == bits_sent, "bad compressed size");
2868 Assert (input_len == isize, "bad input size");
2870 compressed_len += 7; /* align on byte boundary */
2872 Tracev((stderr,"\ncomprlen %lu(%lu) ", compressed_len>>3,
2873 compressed_len-7*eof));
2875 return compressed_len >> 3;
2878 /* ===========================================================================
2879 * Save the match info and tally the frequency counts. Return true if
2880 * the current block must be flushed.
2882 int ct_tally (dist, lc)
2883 int dist; /* distance of matched string */
2884 int lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */
2886 l_buf[last_lit++] = (uch)lc;
2888 /* lc is the unmatched char */
2889 dyn_ltree[lc].Freq++;
2891 /* Here, lc is the match length - MIN_MATCH */
2892 dist--; /* dist = match distance - 1 */
2893 Assert((ush)dist < (ush)MAX_DIST &&
2894 (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) &&
2895 (ush)d_code(dist) < (ush)D_CODES, "ct_tally: bad match");
2897 dyn_ltree[length_code[lc]+LITERALS+1].Freq++;
2898 dyn_dtree[d_code(dist)].Freq++;
2900 d_buf[last_dist++] = (ush)dist;
2905 /* Output the flags if they fill a byte: */
2906 if ((last_lit & 7) == 0) {
2907 flag_buf[last_flags++] = flags;
2908 flags = 0, flag_bit = 1;
2910 /* Try to guess if it is profitable to stop the current block here */
2911 if ((last_lit & 0xfff) == 0) {
2912 /* Compute an upper bound for the compressed length */
2913 ulg out_length = (ulg)last_lit*8L;
2914 ulg in_length = (ulg)strstart-block_start;
2916 for (dcode = 0; dcode < D_CODES; dcode++) {
2917 out_length += (ulg)dyn_dtree[dcode].Freq*(5L+extra_dbits[dcode]);
2920 Trace((stderr,"\nlast_lit %u, last_dist %u, in %ld, out ~%ld(%ld%%) ",
2921 last_lit, last_dist, in_length, out_length,
2922 100L - out_length*100L/in_length));
2923 if (last_dist < last_lit/2 && out_length < in_length/2) return 1;
2925 return (last_lit == LIT_BUFSIZE-1 || last_dist == DIST_BUFSIZE);
2926 /* We avoid equality with LIT_BUFSIZE because of wraparound at 64K
2927 * on 16 bit machines and because stored blocks are restricted to
2932 /* ===========================================================================
2933 * Send the block data compressed using the given Huffman trees
2935 local void compress_block(ltree, dtree)
2936 ct_data near *ltree; /* literal tree */
2937 ct_data near *dtree; /* distance tree */
2939 unsigned dist; /* distance of matched string */
2940 int lc; /* match length or unmatched char (if dist == 0) */
2941 unsigned lx = 0; /* running index in l_buf */
2942 unsigned dx = 0; /* running index in d_buf */
2943 unsigned fx = 0; /* running index in flag_buf */
2944 uch flag = 0; /* current flags */
2945 unsigned code; /* the code to send */
2946 int extra; /* number of extra bits to send */
2948 if (last_lit != 0) do {
2949 if ((lx & 7) == 0) flag = flag_buf[fx++];
2951 if ((flag & 1) == 0) {
2952 send_code(lc, ltree); /* send a literal byte */
2953 Tracecv(isgraph(lc), (stderr," '%c' ", lc));
2955 /* Here, lc is the match length - MIN_MATCH */
2956 code = length_code[lc];
2957 send_code(code+LITERALS+1, ltree); /* send the length code */
2958 extra = extra_lbits[code];
2960 lc -= base_length[code];
2961 send_bits(lc, extra); /* send the extra length bits */
2964 /* Here, dist is the match distance - 1 */
2965 code = d_code(dist);
2966 Assert (code < D_CODES, "bad d_code");
2968 send_code(code, dtree); /* send the distance code */
2969 extra = extra_dbits[code];
2971 dist -= base_dist[code];
2972 send_bits(dist, extra); /* send the extra distance bits */
2974 } /* literal or match pair ? */
2976 } while (lx < last_lit);
2978 send_code(END_BLOCK, ltree);
2981 /* ===========================================================================
2982 * Set the file type to ASCII or BINARY, using a crude approximation:
2983 * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise.
2984 * IN assertion: the fields freq of dyn_ltree are set and the total of all
2985 * frequencies does not exceed 64K (to fit in an int on 16 bit machines).
2987 local void set_file_type()
2990 unsigned ascii_freq = 0;
2991 unsigned bin_freq = 0;
2992 while (n < 7) bin_freq += dyn_ltree[n++].Freq;
2993 while (n < 128) ascii_freq += dyn_ltree[n++].Freq;
2994 while (n < LITERALS) bin_freq += dyn_ltree[n++].Freq;
2995 *file_type = bin_freq > (ascii_freq >> 2) ? BINARY : ASCII;
2996 if (*file_type == BINARY && translate_eol) {
2997 warn("-l used on binary file", "");
3000 /* util.c -- utility functions for gzip support
3001 * Copyright (C) 1992-1993 Jean-loup Gailly
3002 * This is free software; you can redistribute it and/or modify it under the
3003 * terms of the GNU General Public License, see the file COPYING.
3008 #include <sys/types.h>
3010 #ifdef HAVE_UNISTD_H
3011 # include <unistd.h>
3017 #if defined(STDC_HEADERS) || !defined(NO_STDLIB_H)
3018 # include <stdlib.h>
3023 /* ===========================================================================
3024 * Copy input to output unchanged: zcat == cat with --force.
3025 * IN assertion: insize bytes have already been read in inbuf.
3028 int in, out; /* input and output file descriptors */
3031 while (insize != 0 && (int)insize != EOF) {
3032 write_buf(out, (char*)inbuf, insize);
3033 bytes_out += insize;
3034 insize = read(in, (char*)inbuf, INBUFSIZ);
3036 if ((int)insize == EOF && errno != 0) {
3039 bytes_in = bytes_out;
3043 /* ========================================================================
3044 * Put string s in lower case, return s.
3050 for (t = s; *t; t++) *t = tolow(*t);
3054 #if defined(NO_STRING_H) && !defined(STDC_HEADERS)
3056 /* Provide missing strspn and strcspn functions. */
3062 int strspn OF((const char *s, const char *accept));
3063 int strcspn OF((const char *s, const char *reject));
3065 /* ========================================================================
3066 * Return the length of the maximum initial segment
3067 * of s which contains only characters in accept.
3069 int strspn(s, accept)
3073 register const char *p;
3074 register const char *a;
3075 register int count = 0;
3077 for (p = s; *p != '\0'; ++p) {
3078 for (a = accept; *a != '\0'; ++a) {
3079 if (*p == *a) break;
3081 if (*a == '\0') return count;
3087 /* ========================================================================
3088 * Return the length of the maximum inital segment of s
3089 * which contains no characters from reject.
3091 int strcspn(s, reject)
3095 register int count = 0;
3097 while (*s != '\0') {
3098 if (strchr(reject, *s++) != NULL) return count;
3104 #endif /* NO_STRING_H */
3106 /* ========================================================================
3107 * Add an environment variable (if any) before argv, and update argc.
3108 * Return the expanded environment variable to be freed later, or NULL
3109 * if no options were added to argv.
3111 #define SEPARATOR " \t" /* separators in env variable */
3113 char *add_envopt(argcp, argvp, env)
3114 int *argcp; /* pointer to argc */
3115 char ***argvp; /* pointer to argv */
3116 char *env; /* name of environment variable */
3118 char *p; /* running pointer through env variable */
3119 char **oargv; /* runs through old argv array */
3120 char **nargv; /* runs through new argv array */
3121 int oargc = *argcp; /* old argc */
3122 int nargc = 0; /* number of arguments in env variable */
3124 env = (char*)getenv(env);
3125 if (env == NULL) return NULL;
3127 p = (char*)xmalloc(strlen(env)+1);
3128 env = strcpy(p, env); /* keep env variable intact */
3130 for (p = env; *p; nargc++ ) { /* move through env */
3131 p += strspn(p, SEPARATOR); /* skip leading separators */
3132 if (*p == '\0') break;
3134 p += strcspn(p, SEPARATOR); /* find end of word */
3135 if (*p) *p++ = '\0'; /* mark it */
3142 /* Allocate the new argv array, with an extra element just in case
3143 * the original arg list did not end with a NULL.
3145 nargv = (char**)calloc(*argcp+1, sizeof(char *));
3146 if (nargv == NULL) error("out of memory");
3150 /* Copy the program name first */
3151 if (oargc-- < 0) error("argc<=0");
3152 *(nargv++) = *(oargv++);
3154 /* Then copy the environment args */
3155 for (p = env; nargc > 0; nargc--) {
3156 p += strspn(p, SEPARATOR); /* skip separators */
3157 *(nargv++) = p; /* store start */
3158 while (*p++) ; /* skip over word */
3161 /* Finally copy the old args and add a NULL (usual convention) */
3162 while (oargc--) *(nargv++) = *(oargv++);
3166 /* ========================================================================
3167 * Display compression ratio on the given stream on 6 characters.
3169 void display_ratio(num, den, file)
3174 long ratio; /* 1000 times the compression ratio */
3177 ratio = 0; /* no compression */
3178 } else if (den < 2147483L) { /* (2**31 -1)/1000 */
3179 ratio = 1000L*num/den;
3181 ratio = num/(den/1000L);
3189 fprintf(file, "%2ld.%1ld%%", ratio / 10L, ratio % 10L);
3193 /* zip.c -- compress files to the gzip or pkzip format
3194 * Copyright (C) 1992-1993 Jean-loup Gailly
3195 * This is free software; you can redistribute it and/or modify it under the
3196 * terms of the GNU General Public License, see the file COPYING.
3200 #include <sys/types.h>
3202 #ifdef HAVE_UNISTD_H
3203 # include <unistd.h>
3209 local ulg crc; /* crc on uncompressed file data */
3210 long header_bytes; /* number of bytes in gzip header */
3212 /* ===========================================================================
3213 * Deflate in to out.
3214 * IN assertions: the input and output buffers are cleared.
3215 * The variables time_stamp and save_orig_name are initialized.
3218 int in, out; /* input and output file descriptors */
3220 uch flags = 0; /* general purpose bit flags */
3221 ush attr = 0; /* ascii/binary flag */
3222 ush deflate_flags = 0; /* pkzip -es, -en or -ex equivalent */
3228 /* Write the header to the gzip file. See algorithm.doc for the format */
3232 put_byte(GZIP_MAGIC[0]); /* magic header */
3233 put_byte(GZIP_MAGIC[1]);
3234 put_byte(DEFLATED); /* compression method */
3236 put_byte(flags); /* general flags */
3237 put_long(time_stamp);
3239 /* Write deflated file to zip file */
3243 ct_init(&attr, &method);
3244 lm_init(&deflate_flags);
3246 put_byte((uch)deflate_flags); /* extra flags */
3247 put_byte(OS_CODE); /* OS identifier */
3249 header_bytes = (long)outcnt;
3253 /* Write the crc and uncompressed size */
3256 header_bytes += 2*sizeof(long);
3263 /* ===========================================================================
3264 * Read a new buffer from the current input file, perform end-of-line
3265 * translation, and update the crc and input file size.
3266 * IN assertion: size >= 2 (for end-of-line translation)
3268 int file_read(buf, size)
3274 Assert(insize == 0, "inbuf not empty");
3276 len = read(ifd, buf, size);
3277 if (len == (unsigned)(-1) || len == 0) return (int)len;
3279 crc = updcrc((uch*)buf, len);