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Annotation of 43BSDReno/usr.bin/compress/compress.c, revision 1.1

1.1     ! root        1: /*
        !             2:  * Copyright (c) 1985, 1986 The Regents of the University of California.
        !             3:  * All rights reserved.
        !             4:  *
        !             5:  * This code is derived from software contributed to Berkeley by
        !             6:  * James A. Woods, derived from original work by Spencer Thomas
        !             7:  * and Joseph Orost.
        !             8:  *
        !             9:  * Redistribution and use in source and binary forms are permitted
        !            10:  * provided that: (1) source distributions retain this entire copyright
        !            11:  * notice and comment, and (2) distributions including binaries display
        !            12:  * the following acknowledgement:  ``This product includes software
        !            13:  * developed by the University of California, Berkeley and its contributors''
        !            14:  * in the documentation or other materials provided with the distribution
        !            15:  * and in all advertising materials mentioning features or use of this
        !            16:  * software. Neither the name of the University nor the names of its
        !            17:  * contributors may be used to endorse or promote products derived
        !            18:  * from this software without specific prior written permission.
        !            19:  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
        !            20:  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
        !            21:  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
        !            22:  */
        !            23: 
        !            24: #ifndef lint
        !            25: char copyright[] =
        !            26: "@(#) Copyright (c) 1985, 1986 The Regents of the University of California.\n\
        !            27:  All rights reserved.\n";
        !            28: #endif /* not lint */
        !            29: 
        !            30: #ifndef lint
        !            31: static char sccsid[] = "@(#)compress.c 5.12 (Berkeley) 6/1/90";
        !            32: #endif /* not lint */
        !            33: 
        !            34: /* 
        !            35:  * Compress - data compression program 
        !            36:  */
        !            37: #define        min(a,b)        ((a>b) ? b : a)
        !            38: 
        !            39: /*
        !            40:  * machine variants which require cc -Dmachine:  pdp11, z8000, pcxt
        !            41:  */
        !            42: 
        !            43: /*
        !            44:  * Set USERMEM to the maximum amount of physical user memory available
        !            45:  * in bytes.  USERMEM is used to determine the maximum BITS that can be used
        !            46:  * for compression.
        !            47:  *
        !            48:  * SACREDMEM is the amount of physical memory saved for others; compress
        !            49:  * will hog the rest.
        !            50:  */
        !            51: #ifndef SACREDMEM
        !            52: #define SACREDMEM      0
        !            53: #endif
        !            54: 
        !            55: #ifndef USERMEM
        !            56: # define USERMEM       450000  /* default user memory */
        !            57: #endif
        !            58: 
        !            59: #ifdef interdata               /* (Perkin-Elmer) */
        !            60: #define SIGNED_COMPARE_SLOW    /* signed compare is slower than unsigned */
        !            61: #endif
        !            62: 
        !            63: #ifdef pdp11
        !            64: # define BITS  12      /* max bits/code for 16-bit machine */
        !            65: # define NO_UCHAR      /* also if "unsigned char" functions as signed char */
        !            66: # undef USERMEM 
        !            67: #endif /* pdp11 */     /* don't forget to compile with -i */
        !            68: 
        !            69: #ifdef z8000
        !            70: # define BITS  12
        !            71: # undef vax            /* weird preprocessor */
        !            72: # undef USERMEM 
        !            73: #endif /* z8000 */
        !            74: 
        !            75: #ifdef pcxt
        !            76: # define BITS   12
        !            77: # undef USERMEM
        !            78: #endif /* pcxt */
        !            79: 
        !            80: #ifdef USERMEM
        !            81: # if USERMEM >= (433484+SACREDMEM)
        !            82: #  define PBITS        16
        !            83: # else
        !            84: #  if USERMEM >= (229600+SACREDMEM)
        !            85: #   define PBITS       15
        !            86: #  else
        !            87: #   if USERMEM >= (127536+SACREDMEM)
        !            88: #    define PBITS      14
        !            89: #   else
        !            90: #    if USERMEM >= (73464+SACREDMEM)
        !            91: #     define PBITS     13
        !            92: #    else
        !            93: #     define PBITS     12
        !            94: #    endif
        !            95: #   endif
        !            96: #  endif
        !            97: # endif
        !            98: # undef USERMEM
        !            99: #endif /* USERMEM */
        !           100: 
        !           101: #ifdef PBITS           /* Preferred BITS for this memory size */
        !           102: # ifndef BITS
        !           103: #  define BITS PBITS
        !           104: # endif BITS
        !           105: #endif /* PBITS */
        !           106: 
        !           107: #if BITS == 16
        !           108: # define HSIZE 69001           /* 95% occupancy */
        !           109: #endif
        !           110: #if BITS == 15
        !           111: # define HSIZE 35023           /* 94% occupancy */
        !           112: #endif
        !           113: #if BITS == 14
        !           114: # define HSIZE 18013           /* 91% occupancy */
        !           115: #endif
        !           116: #if BITS == 13
        !           117: # define HSIZE 9001            /* 91% occupancy */
        !           118: #endif
        !           119: #if BITS <= 12
        !           120: # define HSIZE 5003            /* 80% occupancy */
        !           121: #endif
        !           122: 
        !           123: #ifdef M_XENIX                 /* Stupid compiler can't handle arrays with */
        !           124: # if BITS == 16                        /* more than 65535 bytes - so we fake it */
        !           125: #  define XENIX_16
        !           126: # else
        !           127: #  if BITS > 13                        /* Code only handles BITS = 12, 13, or 16 */
        !           128: #   define BITS        13
        !           129: #  endif
        !           130: # endif
        !           131: #endif
        !           132: 
        !           133: /*
        !           134:  * a code_int must be able to hold 2**BITS values of type int, and also -1
        !           135:  */
        !           136: #if BITS > 15
        !           137: typedef long int       code_int;
        !           138: #else
        !           139: typedef int            code_int;
        !           140: #endif
        !           141: 
        !           142: #ifdef SIGNED_COMPARE_SLOW
        !           143: typedef unsigned long int count_int;
        !           144: typedef unsigned short int count_short;
        !           145: #else
        !           146: typedef long int         count_int;
        !           147: #endif
        !           148: 
        !           149: #ifdef NO_UCHAR
        !           150:  typedef char  char_type;
        !           151: #else
        !           152:  typedef       unsigned char   char_type;
        !           153: #endif /* UCHAR */
        !           154: char_type magic_header[] = { "\037\235" };     /* 1F 9D */
        !           155: 
        !           156: /* Defines for third byte of header */
        !           157: #define BIT_MASK       0x1f
        !           158: #define BLOCK_MASK     0x80
        !           159: /* Masks 0x40 and 0x20 are free.  I think 0x20 should mean that there is
        !           160:    a fourth header byte (for expansion).
        !           161: */
        !           162: #define INIT_BITS 9                    /* initial number of bits/code */
        !           163: 
        !           164: /*
        !           165:  * compress.c - File compression ala IEEE Computer, June 1984.
        !           166:  *
        !           167:  * Authors:    Spencer W. Thomas       (decvax!utah-cs!thomas)
        !           168:  *             Jim McKie               (decvax!mcvax!jim)
        !           169:  *             Steve Davies            (decvax!vax135!petsd!peora!srd)
        !           170:  *             Ken Turkowski           (decvax!decwrl!turtlevax!ken)
        !           171:  *             James A. Woods          (decvax!ihnp4!ames!jaw)
        !           172:  *             Joe Orost               (decvax!vax135!petsd!joe)
        !           173:  *
        !           174:  * $Header: compress.c,v 4.0 85/07/30 12:50:00 joe Release $
        !           175:  * $Log:       compress.c,v $
        !           176:  * Revision 4.0  85/07/30  12:50:00  joe
        !           177:  * Removed ferror() calls in output routine on every output except first.
        !           178:  * Prepared for release to the world.
        !           179:  * 
        !           180:  * Revision 3.6  85/07/04  01:22:21  joe
        !           181:  * Remove much wasted storage by overlaying hash table with the tables
        !           182:  * used by decompress: tab_suffix[1<<BITS], stack[8000].  Updated USERMEM
        !           183:  * computations.  Fixed dump_tab() DEBUG routine.
        !           184:  *
        !           185:  * Revision 3.5  85/06/30  20:47:21  jaw
        !           186:  * Change hash function to use exclusive-or.  Rip out hash cache.  These
        !           187:  * speedups render the megamemory version defunct, for now.  Make decoder
        !           188:  * stack global.  Parts of the RCS trunks 2.7, 2.6, and 2.1 no longer apply.
        !           189:  *
        !           190:  * Revision 3.4  85/06/27  12:00:00  ken
        !           191:  * Get rid of all floating-point calculations by doing all compression ratio
        !           192:  * calculations in fixed point.
        !           193:  *
        !           194:  * Revision 3.3  85/06/24  21:53:24  joe
        !           195:  * Incorporate portability suggestion for M_XENIX.  Got rid of text on #else
        !           196:  * and #endif lines.  Cleaned up #ifdefs for vax and interdata.
        !           197:  *
        !           198:  * Revision 3.2  85/06/06  21:53:24  jaw
        !           199:  * Incorporate portability suggestions for Z8000, IBM PC/XT from mailing list.
        !           200:  * Default to "quiet" output (no compression statistics).
        !           201:  *
        !           202:  * Revision 3.1  85/05/12  18:56:13  jaw
        !           203:  * Integrate decompress() stack speedups (from early pointer mods by McKie).
        !           204:  * Repair multi-file USERMEM gaffe.  Unify 'force' flags to mimic semantics
        !           205:  * of SVR2 'pack'.  Streamline block-compress table clear logic.  Increase 
        !           206:  * output byte count by magic number size.
        !           207:  * 
        !           208:  * Revision 3.0   84/11/27  11:50:00  petsd!joe
        !           209:  * Set HSIZE depending on BITS.  Set BITS depending on USERMEM.  Unrolled
        !           210:  * loops in clear routines.  Added "-C" flag for 2.0 compatibility.  Used
        !           211:  * unsigned compares on Perkin-Elmer.  Fixed foreground check.
        !           212:  *
        !           213:  * Revision 2.7   84/11/16  19:35:39  ames!jaw
        !           214:  * Cache common hash codes based on input statistics; this improves
        !           215:  * performance for low-density raster images.  Pass on #ifdef bundle
        !           216:  * from Turkowski.
        !           217:  *
        !           218:  * Revision 2.6   84/11/05  19:18:21  ames!jaw
        !           219:  * Vary size of hash tables to reduce time for small files.
        !           220:  * Tune PDP-11 hash function.
        !           221:  *
        !           222:  * Revision 2.5   84/10/30  20:15:14  ames!jaw
        !           223:  * Junk chaining; replace with the simpler (and, on the VAX, faster)
        !           224:  * double hashing, discussed within.  Make block compression standard.
        !           225:  *
        !           226:  * Revision 2.4   84/10/16  11:11:11  ames!jaw
        !           227:  * Introduce adaptive reset for block compression, to boost the rate
        !           228:  * another several percent.  (See mailing list notes.)
        !           229:  *
        !           230:  * Revision 2.3   84/09/22  22:00:00  petsd!joe
        !           231:  * Implemented "-B" block compress.  Implemented REVERSE sorting of tab_next.
        !           232:  * Bug fix for last bits.  Changed fwrite to putchar loop everywhere.
        !           233:  *
        !           234:  * Revision 2.2   84/09/18  14:12:21  ames!jaw
        !           235:  * Fold in news changes, small machine typedef from thomas,
        !           236:  * #ifdef interdata from joe.
        !           237:  *
        !           238:  * Revision 2.1   84/09/10  12:34:56  ames!jaw
        !           239:  * Configured fast table lookup for 32-bit machines.
        !           240:  * This cuts user time in half for b <= FBITS, and is useful for news batching
        !           241:  * from VAX to PDP sites.  Also sped up decompress() [fwrite->putc] and
        !           242:  * added signal catcher [plus beef in writeerr()] to delete effluvia.
        !           243:  *
        !           244:  * Revision 2.0   84/08/28  22:00:00  petsd!joe
        !           245:  * Add check for foreground before prompting user.  Insert maxbits into
        !           246:  * compressed file.  Force file being uncompressed to end with ".Z".
        !           247:  * Added "-c" flag and "zcat".  Prepared for release.
        !           248:  *
        !           249:  * Revision 1.10  84/08/24  18:28:00  turtlevax!ken
        !           250:  * Will only compress regular files (no directories), added a magic number
        !           251:  * header (plus an undocumented -n flag to handle old files without headers),
        !           252:  * added -f flag to force overwriting of possibly existing destination file,
        !           253:  * otherwise the user is prompted for a response.  Will tack on a .Z to a
        !           254:  * filename if it doesn't have one when decompressing.  Will only replace
        !           255:  * file if it was compressed.
        !           256:  *
        !           257:  * Revision 1.9  84/08/16  17:28:00  turtlevax!ken
        !           258:  * Removed scanargs(), getopt(), added .Z extension and unlimited number of
        !           259:  * filenames to compress.  Flags may be clustered (-Ddvb12) or separated
        !           260:  * (-D -d -v -b 12), or combination thereof.  Modes and other status is
        !           261:  * copied with copystat().  -O bug for 4.2 seems to have disappeared with
        !           262:  * 1.8.
        !           263:  *
        !           264:  * Revision 1.8  84/08/09  23:15:00  joe
        !           265:  * Made it compatible with vax version, installed jim's fixes/enhancements
        !           266:  *
        !           267:  * Revision 1.6  84/08/01  22:08:00  joe
        !           268:  * Sped up algorithm significantly by sorting the compress chain.
        !           269:  *
        !           270:  * Revision 1.5  84/07/13  13:11:00  srd
        !           271:  * Added C version of vax asm routines.  Changed structure to arrays to
        !           272:  * save much memory.  Do unsigned compares where possible (faster on
        !           273:  * Perkin-Elmer)
        !           274:  *
        !           275:  * Revision 1.4  84/07/05  03:11:11  thomas
        !           276:  * Clean up the code a little and lint it.  (Lint complains about all
        !           277:  * the regs used in the asm, but I'm not going to "fix" this.)
        !           278:  *
        !           279:  * Revision 1.3  84/07/05  02:06:54  thomas
        !           280:  * Minor fixes.
        !           281:  *
        !           282:  * Revision 1.2  84/07/05  00:27:27  thomas
        !           283:  * Add variable bit length output.
        !           284:  *
        !           285:  */
        !           286: static char rcs_ident[] = "$Header: compress.c,v 4.0 85/07/30 12:50:00 joe Release $";
        !           287: 
        !           288: #include <stdio.h>
        !           289: #include <ctype.h>
        !           290: #include <signal.h>
        !           291: #include <sys/types.h>
        !           292: #include <sys/stat.h>
        !           293: #ifdef notdef
        !           294: #include <sys/ioctl.h>
        !           295: #endif
        !           296: 
        !           297: #define ARGVAL() (*++(*argv) || (--argc && *++argv))
        !           298: 
        !           299: int n_bits;                            /* number of bits/code */
        !           300: int maxbits = BITS;                    /* user settable max # bits/code */
        !           301: code_int maxcode;                      /* maximum code, given n_bits */
        !           302: code_int maxmaxcode = 1 << BITS;       /* should NEVER generate this code */
        !           303: #ifdef COMPATIBLE              /* But wrong! */
        !           304: # define MAXCODE(n_bits)       (1 << (n_bits) - 1)
        !           305: #else
        !           306: # define MAXCODE(n_bits)       ((1 << (n_bits)) - 1)
        !           307: #endif /* COMPATIBLE */
        !           308: 
        !           309: #ifdef XENIX_16
        !           310: count_int htab0[8192];
        !           311: count_int htab1[8192];
        !           312: count_int htab2[8192];
        !           313: count_int htab3[8192];
        !           314: count_int htab4[8192];
        !           315: count_int htab5[8192];
        !           316: count_int htab6[8192];
        !           317: count_int htab7[8192];
        !           318: count_int htab8[HSIZE-65536];
        !           319: count_int * htab[9] = {
        !           320:        htab0, htab1, htab2, htab3, htab4, htab5, htab6, htab7, htab8 };
        !           321: 
        !           322: #define htabof(i)      (htab[(i) >> 13][(i) & 0x1fff])
        !           323: unsigned short code0tab[16384];
        !           324: unsigned short code1tab[16384];
        !           325: unsigned short code2tab[16384];
        !           326: unsigned short code3tab[16384];
        !           327: unsigned short code4tab[16384];
        !           328: unsigned short * codetab[5] = {
        !           329:        code0tab, code1tab, code2tab, code3tab, code4tab };
        !           330: 
        !           331: #define codetabof(i)   (codetab[(i) >> 14][(i) & 0x3fff])
        !           332: 
        !           333: #else  /* Normal machine */
        !           334: 
        !           335: #ifdef sel     /* gould base register braindamage */
        !           336: /*NOBASE*/
        !           337: count_int htab [HSIZE];
        !           338: unsigned short codetab [HSIZE];
        !           339: /*NOBASE*/
        !           340: #else
        !           341: count_int htab [HSIZE];
        !           342: unsigned short codetab [HSIZE];
        !           343: #endif sel
        !           344: 
        !           345: #define htabof(i)      htab[i]
        !           346: #define codetabof(i)   codetab[i]
        !           347: #endif /* XENIX_16 */
        !           348: code_int hsize = HSIZE;                        /* for dynamic table sizing */
        !           349: count_int fsize;
        !           350: 
        !           351: /*
        !           352:  * To save much memory, we overlay the table used by compress() with those
        !           353:  * used by decompress().  The tab_prefix table is the same size and type
        !           354:  * as the codetab.  The tab_suffix table needs 2**BITS characters.  We
        !           355:  * get this from the beginning of htab.  The output stack uses the rest
        !           356:  * of htab, and contains characters.  There is plenty of room for any
        !           357:  * possible stack (stack used to be 8000 characters).
        !           358:  */
        !           359: 
        !           360: #define tab_prefixof(i)        codetabof(i)
        !           361: #ifdef XENIX_16
        !           362: # define tab_suffixof(i)       ((char_type *)htab[(i)>>15])[(i) & 0x7fff]
        !           363: # define de_stack              ((char_type *)(htab2))
        !           364: #else  /* Normal machine */
        !           365: # define tab_suffixof(i)       ((char_type *)(htab))[i]
        !           366: # define de_stack              ((char_type *)&tab_suffixof(1<<BITS))
        !           367: #endif /* XENIX_16 */
        !           368: 
        !           369: code_int free_ent = 0;                 /* first unused entry */
        !           370: int exit_stat = 0;                     /* per-file status */
        !           371: int perm_stat = 0;                     /* permanent status */
        !           372: 
        !           373: code_int getcode();
        !           374: 
        !           375: Usage() {
        !           376: #ifdef DEBUG
        !           377: fprintf(stderr,"Usage: compress [-dDVfc] [-b maxbits] [file ...]\n");
        !           378: }
        !           379: int debug = 0;
        !           380: #else
        !           381: fprintf(stderr,"Usage: compress [-fvc] [-b maxbits] [file ...]\n");
        !           382: }
        !           383: #endif /* DEBUG */
        !           384: int nomagic = 0;       /* Use a 3-byte magic number header, unless old file */
        !           385: int zcat_flg = 0;      /* Write output on stdout, suppress messages */
        !           386: int precious = 1;      /* Don't unlink output file on interrupt */
        !           387: int quiet = 1;         /* don't tell me about compression */
        !           388: 
        !           389: /*
        !           390:  * block compression parameters -- after all codes are used up,
        !           391:  * and compression rate changes, start over.
        !           392:  */
        !           393: int block_compress = BLOCK_MASK;
        !           394: int clear_flg = 0;
        !           395: long int ratio = 0;
        !           396: #define CHECK_GAP 10000        /* ratio check interval */
        !           397: count_int checkpoint = CHECK_GAP;
        !           398: /*
        !           399:  * the next two codes should not be changed lightly, as they must not
        !           400:  * lie within the contiguous general code space.
        !           401:  */ 
        !           402: #define FIRST  257     /* first free entry */
        !           403: #define        CLEAR   256     /* table clear output code */
        !           404: 
        !           405: int force = 0;
        !           406: char ofname [100];
        !           407: #ifdef DEBUG
        !           408: int verbose = 0;
        !           409: #endif /* DEBUG */
        !           410: sig_t oldint;
        !           411: int bgnd_flag;
        !           412: 
        !           413: int do_decomp = 0;
        !           414: 
        !           415: /*****************************************************************
        !           416:  * TAG( main )
        !           417:  *
        !           418:  * Algorithm from "A Technique for High Performance Data Compression",
        !           419:  * Terry A. Welch, IEEE Computer Vol 17, No 6 (June 1984), pp 8-19.
        !           420:  *
        !           421:  * Usage: compress [-dfvc] [-b bits] [file ...]
        !           422:  * Inputs:
        !           423:  *     -d:         If given, decompression is done instead.
        !           424:  *
        !           425:  *      -c:         Write output on stdout, don't remove original.
        !           426:  *
        !           427:  *      -b:         Parameter limits the max number of bits/code.
        !           428:  *
        !           429:  *     -f:         Forces output file to be generated, even if one already
        !           430:  *                 exists, and even if no space is saved by compressing.
        !           431:  *                 If -f is not used, the user will be prompted if stdin is
        !           432:  *                 a tty, otherwise, the output file will not be overwritten.
        !           433:  *
        !           434:  *      -v:        Write compression statistics
        !           435:  *
        !           436:  *     file ...:   Files to be compressed.  If none specified, stdin
        !           437:  *                 is used.
        !           438:  * Outputs:
        !           439:  *     file.Z:     Compressed form of file with same mode, owner, and utimes
        !           440:  *     or stdout   (if stdin used as input)
        !           441:  *
        !           442:  * Assumptions:
        !           443:  *     When filenames are given, replaces with the compressed version
        !           444:  *     (.Z suffix) only if the file decreases in size.
        !           445:  * Algorithm:
        !           446:  *     Modified Lempel-Ziv method (LZW).  Basically finds common
        !           447:  * substrings and replaces them with a variable size code.  This is
        !           448:  * deterministic, and can be done on the fly.  Thus, the decompression
        !           449:  * procedure needs no input table, but tracks the way the table was built.
        !           450:  */
        !           451: 
        !           452: main( argc, argv )
        !           453: register int argc; char **argv;
        !           454: {
        !           455:     int overwrite = 0; /* Do not overwrite unless given -f flag */
        !           456:     char tempname[100];
        !           457:     char **filelist, **fileptr;
        !           458:     char *cp, *rindex(), *malloc();
        !           459:     struct stat statbuf;
        !           460:     void onintr(), oops();
        !           461: 
        !           462:     /* This bg check only works for sh. */
        !           463:     if ( (oldint = signal ( SIGINT, SIG_IGN )) != SIG_IGN ) {
        !           464:        signal ( SIGINT, onintr );
        !           465:        signal ( SIGSEGV, oops );
        !           466:     }
        !           467:     bgnd_flag = oldint != SIG_DFL;
        !           468: #ifdef notdef     /* This works for csh but we don't want it. */
        !           469:     { int tgrp;
        !           470:     if (bgnd_flag == 0 && ioctl(2, TIOCGPGRP, (char *)&tgrp) == 0 &&
        !           471:       getpgrp(0) != tgrp)
        !           472:        bgnd_flag = 1;
        !           473:     }
        !           474: #endif
        !           475:     
        !           476: #ifdef COMPATIBLE
        !           477:     nomagic = 1;       /* Original didn't have a magic number */
        !           478: #endif /* COMPATIBLE */
        !           479: 
        !           480:     filelist = fileptr = (char **)(malloc(argc * sizeof(*argv)));
        !           481:     *filelist = NULL;
        !           482: 
        !           483:     if((cp = rindex(argv[0], '/')) != 0) {
        !           484:        cp++;
        !           485:     } else {
        !           486:        cp = argv[0];
        !           487:     }
        !           488:     if(strcmp(cp, "uncompress") == 0) {
        !           489:        do_decomp = 1;
        !           490:     } else if(strcmp(cp, "zcat") == 0) {
        !           491:        do_decomp = 1;
        !           492:        zcat_flg = 1;
        !           493:     }
        !           494: 
        !           495: #ifdef BSD4_2
        !           496:     /* 4.2BSD dependent - take it out if not */
        !           497:     setlinebuf( stderr );
        !           498: #endif /* BSD4_2 */
        !           499: 
        !           500:     /* Argument Processing
        !           501:      * All flags are optional.
        !           502:      * -D => debug
        !           503:      * -V => print Version; debug verbose
        !           504:      * -d => do_decomp
        !           505:      * -v => unquiet
        !           506:      * -f => force overwrite of output file
        !           507:      * -n => no header: useful to uncompress old files
        !           508:      * -b maxbits => maxbits.  If -b is specified, then maxbits MUST be
        !           509:      *     given also.
        !           510:      * -c => cat all output to stdout
        !           511:      * -C => generate output compatible with compress 2.0.
        !           512:      * if a string is left, must be an input filename.
        !           513:      */
        !           514:     for (argc--, argv++; argc > 0; argc--, argv++) {
        !           515:        if (**argv == '-') {    /* A flag argument */
        !           516:            while (*++(*argv)) {        /* Process all flags in this arg */
        !           517:                switch (**argv) {
        !           518: #ifdef DEBUG
        !           519:                    case 'D':
        !           520:                        debug = 1;
        !           521:                        break;
        !           522:                    case 'V':
        !           523:                        verbose = 1;
        !           524:                        version();
        !           525:                        break;
        !           526: #else
        !           527:                    case 'V':
        !           528:                        version();
        !           529:                        break;
        !           530: #endif /* DEBUG */
        !           531:                    case 'v':
        !           532:                        quiet = 0;
        !           533:                        break;
        !           534:                    case 'd':
        !           535:                        do_decomp = 1;
        !           536:                        break;
        !           537:                    case 'f':
        !           538:                    case 'F':
        !           539:                        overwrite = 1;
        !           540:                        force = 1;
        !           541:                        break;
        !           542:                    case 'n':
        !           543:                        nomagic = 1;
        !           544:                        break;
        !           545:                    case 'C':
        !           546:                        block_compress = 0;
        !           547:                        break;
        !           548:                    case 'b':
        !           549:                        if (!ARGVAL()) {
        !           550:                            fprintf(stderr, "Missing maxbits\n");
        !           551:                            Usage();
        !           552:                            exit(1);
        !           553:                        }
        !           554:                        maxbits = atoi(*argv);
        !           555:                        goto nextarg;
        !           556:                    case 'c':
        !           557:                        zcat_flg = 1;
        !           558:                        break;
        !           559:                    case 'q':
        !           560:                        quiet = 1;
        !           561:                        break;
        !           562:                    default:
        !           563:                        fprintf(stderr, "Unknown flag: '%c'; ", **argv);
        !           564:                        Usage();
        !           565:                        exit(1);
        !           566:                }
        !           567:            }
        !           568:        }
        !           569:        else {          /* Input file name */
        !           570:            *fileptr++ = *argv; /* Build input file list */
        !           571:            *fileptr = NULL;
        !           572:            /* process nextarg; */
        !           573:        }
        !           574:        nextarg: continue;
        !           575:     }
        !           576: 
        !           577:     if(maxbits < INIT_BITS) maxbits = INIT_BITS;
        !           578:     if (maxbits > BITS) maxbits = BITS;
        !           579:     maxmaxcode = 1 << maxbits;
        !           580: 
        !           581:     if (*filelist != NULL) {
        !           582:        for (fileptr = filelist; *fileptr; fileptr++) {
        !           583:            exit_stat = 0;
        !           584:            if (do_decomp) {                    /* DECOMPRESSION */
        !           585:                /* Check for .Z suffix */
        !           586:                if (strcmp(*fileptr + strlen(*fileptr) - 2, ".Z") != 0) {
        !           587:                    /* No .Z: tack one on */
        !           588:                    strcpy(tempname, *fileptr);
        !           589:                    strcat(tempname, ".Z");
        !           590:                    *fileptr = tempname;
        !           591:                }
        !           592:                /* Open input file */
        !           593:                if ((freopen(*fileptr, "r", stdin)) == NULL) {
        !           594:                    perror(*fileptr);
        !           595:                    perm_stat = 1;
        !           596:                    continue;
        !           597:                }
        !           598:                /* Check the magic number */
        !           599:                if (nomagic == 0) {
        !           600:                    if ((getchar() != (magic_header[0] & 0xFF))
        !           601:                     || (getchar() != (magic_header[1] & 0xFF))) {
        !           602:                        fprintf(stderr, "%s: not in compressed format\n",
        !           603:                            *fileptr);
        !           604:                    continue;
        !           605:                    }
        !           606:                    maxbits = getchar();        /* set -b from file */
        !           607:                    block_compress = maxbits & BLOCK_MASK;
        !           608:                    maxbits &= BIT_MASK;
        !           609:                    maxmaxcode = 1 << maxbits;
        !           610:                    if(maxbits > BITS) {
        !           611:                        fprintf(stderr,
        !           612:                        "%s: compressed with %d bits, can only handle %d bits\n",
        !           613:                        *fileptr, maxbits, BITS);
        !           614:                        continue;
        !           615:                    }
        !           616:                }
        !           617:                /* Generate output filename */
        !           618:                strcpy(ofname, *fileptr);
        !           619:                ofname[strlen(*fileptr) - 2] = '\0';  /* Strip off .Z */
        !           620:            } else {                                    /* COMPRESSION */
        !           621:                if (strcmp(*fileptr + strlen(*fileptr) - 2, ".Z") == 0) {
        !           622:                        fprintf(stderr, "%s: already has .Z suffix -- no change\n",
        !           623:                            *fileptr);
        !           624:                    continue;
        !           625:                }
        !           626:                /* Open input file */
        !           627:                if ((freopen(*fileptr, "r", stdin)) == NULL) {
        !           628:                    perror(*fileptr);
        !           629:                    perm_stat = 1;
        !           630:                    continue;
        !           631:                }
        !           632:                stat ( *fileptr, &statbuf );
        !           633:                fsize = (long) statbuf.st_size;
        !           634:                /*
        !           635:                 * tune hash table size for small files -- ad hoc,
        !           636:                 * but the sizes match earlier #defines, which
        !           637:                 * serve as upper bounds on the number of output codes. 
        !           638:                 */
        !           639:                hsize = HSIZE;
        !           640:                if ( fsize < (1 << 12) )
        !           641:                    hsize = min ( 5003, HSIZE );
        !           642:                else if ( fsize < (1 << 13) )
        !           643:                    hsize = min ( 9001, HSIZE );
        !           644:                else if ( fsize < (1 << 14) )
        !           645:                    hsize = min ( 18013, HSIZE );
        !           646:                else if ( fsize < (1 << 15) )
        !           647:                    hsize = min ( 35023, HSIZE );
        !           648:                else if ( fsize < 47000 )
        !           649:                    hsize = min ( 50021, HSIZE );
        !           650: 
        !           651:                /* Generate output filename */
        !           652:                strcpy(ofname, *fileptr);
        !           653: #ifndef BSD4_2         /* Short filenames */
        !           654:                if ((cp=rindex(ofname,'/')) != NULL)    cp++;
        !           655:                else                                    cp = ofname;
        !           656:                if (strlen(cp) > 12) {
        !           657:                    fprintf(stderr,"%s: filename too long to tack on .Z\n",cp);
        !           658:                    continue;
        !           659:                }
        !           660: #endif  /* BSD4_2              Long filenames allowed */
        !           661:                strcat(ofname, ".Z");
        !           662:            }
        !           663:            /* Check for overwrite of existing file */
        !           664:            if (overwrite == 0 && zcat_flg == 0) {
        !           665:                if (stat(ofname, &statbuf) == 0) {
        !           666:                    char response[2];
        !           667:                    response[0] = 'n';
        !           668:                    fprintf(stderr, "%s already exists;", ofname);
        !           669:                    if (bgnd_flag == 0 && isatty(2)) {
        !           670:                        fprintf(stderr, " do you wish to overwrite %s (y or n)? ",
        !           671:                        ofname);
        !           672:                        fflush(stderr);
        !           673:                        read(2, response, 2);
        !           674:                        while (response[1] != '\n') {
        !           675:                            if (read(2, response+1, 1) < 0) {   /* Ack! */
        !           676:                                perror("stderr"); break;
        !           677:                            }
        !           678:                        }
        !           679:                    }
        !           680:                    if (response[0] != 'y') {
        !           681:                        fprintf(stderr, "\tnot overwritten\n");
        !           682:                        continue;
        !           683:                    }
        !           684:                }
        !           685:            }
        !           686:            if(zcat_flg == 0) {         /* Open output file */
        !           687:                if (freopen(ofname, "w", stdout) == NULL) {
        !           688:                    perror(ofname);
        !           689:                    perm_stat = 1;
        !           690:                    continue;
        !           691:                }
        !           692:                precious = 0;
        !           693:                if(!quiet)
        !           694:                        fprintf(stderr, "%s: ", *fileptr);
        !           695:            }
        !           696: 
        !           697:            /* Actually do the compression/decompression */
        !           698:            if (do_decomp == 0) compress();
        !           699: #ifndef DEBUG
        !           700:            else                        decompress();
        !           701: #else
        !           702:            else if (debug == 0)        decompress();
        !           703:            else                        printcodes();
        !           704:            if (verbose)                dump_tab();
        !           705: #endif /* DEBUG */
        !           706:            if(zcat_flg == 0) {
        !           707:                copystat(*fileptr, ofname);     /* Copy stats */
        !           708:                precious = 1;
        !           709:                if((exit_stat == 1) || (!quiet))
        !           710:                        putc('\n', stderr);
        !           711:            }
        !           712:        }
        !           713:     } else {           /* Standard input */
        !           714:        if (do_decomp == 0) {
        !           715:                compress();
        !           716: #ifdef DEBUG
        !           717:                if(verbose)             dump_tab();
        !           718: #endif /* DEBUG */
        !           719:                if(!quiet)
        !           720:                        putc('\n', stderr);
        !           721:        } else {
        !           722:            /* Check the magic number */
        !           723:            if (nomagic == 0) {
        !           724:                if ((getchar()!=(magic_header[0] & 0xFF))
        !           725:                 || (getchar()!=(magic_header[1] & 0xFF))) {
        !           726:                    fprintf(stderr, "stdin: not in compressed format\n");
        !           727:                    exit(1);
        !           728:                }
        !           729:                maxbits = getchar();    /* set -b from file */
        !           730:                block_compress = maxbits & BLOCK_MASK;
        !           731:                maxbits &= BIT_MASK;
        !           732:                maxmaxcode = 1 << maxbits;
        !           733:                fsize = 100000;         /* assume stdin large for USERMEM */
        !           734:                if(maxbits > BITS) {
        !           735:                        fprintf(stderr,
        !           736:                        "stdin: compressed with %d bits, can only handle %d bits\n",
        !           737:                        maxbits, BITS);
        !           738:                        exit(1);
        !           739:                }
        !           740:            }
        !           741: #ifndef DEBUG
        !           742:            decompress();
        !           743: #else
        !           744:            if (debug == 0)     decompress();
        !           745:            else                printcodes();
        !           746:            if (verbose)        dump_tab();
        !           747: #endif /* DEBUG */
        !           748:        }
        !           749:     }
        !           750:     exit(perm_stat ? perm_stat : exit_stat);
        !           751: }
        !           752: 
        !           753: static int offset;
        !           754: long int in_count = 1;                 /* length of input */
        !           755: long int bytes_out;                    /* length of compressed output */
        !           756: long int out_count = 0;                        /* # of codes output (for debugging) */
        !           757: 
        !           758: /*
        !           759:  * compress stdin to stdout
        !           760:  *
        !           761:  * Algorithm:  use open addressing double hashing (no chaining) on the 
        !           762:  * prefix code / next character combination.  We do a variant of Knuth's
        !           763:  * algorithm D (vol. 3, sec. 6.4) along with G. Knott's relatively-prime
        !           764:  * secondary probe.  Here, the modular division first probe is gives way
        !           765:  * to a faster exclusive-or manipulation.  Also do block compression with
        !           766:  * an adaptive reset, whereby the code table is cleared when the compression
        !           767:  * ratio decreases, but after the table fills.  The variable-length output
        !           768:  * codes are re-sized at this point, and a special CLEAR code is generated
        !           769:  * for the decompressor.  Late addition:  construct the table according to
        !           770:  * file size for noticeable speed improvement on small files.  Please direct
        !           771:  * questions about this implementation to ames!jaw.
        !           772:  */
        !           773: 
        !           774: compress() {
        !           775:     register long fcode;
        !           776:     register code_int i = 0;
        !           777:     register int c;
        !           778:     register code_int ent;
        !           779: #ifdef XENIX_16
        !           780:     register code_int disp;
        !           781: #else  /* Normal machine */
        !           782:     register int disp;
        !           783: #endif
        !           784:     register code_int hsize_reg;
        !           785:     register int hshift;
        !           786: 
        !           787: #ifndef COMPATIBLE
        !           788:     if (nomagic == 0) {
        !           789:        putchar(magic_header[0]); putchar(magic_header[1]);
        !           790:        putchar((char)(maxbits | block_compress));
        !           791:        if(ferror(stdout))
        !           792:                writeerr();
        !           793:     }
        !           794: #endif /* COMPATIBLE */
        !           795: 
        !           796:     offset = 0;
        !           797:     bytes_out = 3;             /* includes 3-byte header mojo */
        !           798:     out_count = 0;
        !           799:     clear_flg = 0;
        !           800:     ratio = 0;
        !           801:     in_count = 1;
        !           802:     checkpoint = CHECK_GAP;
        !           803:     maxcode = MAXCODE(n_bits = INIT_BITS);
        !           804:     free_ent = ((block_compress) ? FIRST : 256 );
        !           805: 
        !           806:     ent = getchar ();
        !           807: 
        !           808:     hshift = 0;
        !           809:     for ( fcode = (long) hsize;  fcode < 65536L; fcode *= 2L )
        !           810:        hshift++;
        !           811:     hshift = 8 - hshift;               /* set hash code range bound */
        !           812: 
        !           813:     hsize_reg = hsize;
        !           814:     cl_hash( (count_int) hsize_reg);           /* clear hash table */
        !           815: 
        !           816: #ifdef SIGNED_COMPARE_SLOW
        !           817:     while ( (c = getchar()) != (unsigned) EOF ) {
        !           818: #else
        !           819:     while ( (c = getchar()) != EOF ) {
        !           820: #endif
        !           821:        in_count++;
        !           822:        fcode = (long) (((long) c << maxbits) + ent);
        !           823:        i = ((c << hshift) ^ ent);      /* xor hashing */
        !           824: 
        !           825:        if ( htabof (i) == fcode ) {
        !           826:            ent = codetabof (i);
        !           827:            continue;
        !           828:        } else if ( (long)htabof (i) < 0 )      /* empty slot */
        !           829:            goto nomatch;
        !           830:        disp = hsize_reg - i;           /* secondary hash (after G. Knott) */
        !           831:        if ( i == 0 )
        !           832:            disp = 1;
        !           833: probe:
        !           834:        if ( (i -= disp) < 0 )
        !           835:            i += hsize_reg;
        !           836: 
        !           837:        if ( htabof (i) == fcode ) {
        !           838:            ent = codetabof (i);
        !           839:            continue;
        !           840:        }
        !           841:        if ( (long)htabof (i) > 0 ) 
        !           842:            goto probe;
        !           843: nomatch:
        !           844:        output ( (code_int) ent );
        !           845:        out_count++;
        !           846:        ent = c;
        !           847: #ifdef SIGNED_COMPARE_SLOW
        !           848:        if ( (unsigned) free_ent < (unsigned) maxmaxcode) {
        !           849: #else
        !           850:        if ( free_ent < maxmaxcode ) {
        !           851: #endif
        !           852:            codetabof (i) = free_ent++; /* code -> hashtable */
        !           853:            htabof (i) = fcode;
        !           854:        }
        !           855:        else if ( (count_int)in_count >= checkpoint && block_compress )
        !           856:            cl_block ();
        !           857:     }
        !           858:     /*
        !           859:      * Put out the final code.
        !           860:      */
        !           861:     output( (code_int)ent );
        !           862:     out_count++;
        !           863:     output( (code_int)-1 );
        !           864: 
        !           865:     /*
        !           866:      * Print out stats on stderr
        !           867:      */
        !           868:     if(zcat_flg == 0 && !quiet) {
        !           869: #ifdef DEBUG
        !           870:        fprintf( stderr,
        !           871:                "%ld chars in, %ld codes (%ld bytes) out, compression factor: ",
        !           872:                in_count, out_count, bytes_out );
        !           873:        prratio( stderr, in_count, bytes_out );
        !           874:        fprintf( stderr, "\n");
        !           875:        fprintf( stderr, "\tCompression as in compact: " );
        !           876:        prratio( stderr, in_count-bytes_out, in_count );
        !           877:        fprintf( stderr, "\n");
        !           878:        fprintf( stderr, "\tLargest code (of last block) was %d (%d bits)\n",
        !           879:                free_ent - 1, n_bits );
        !           880: #else /* !DEBUG */
        !           881:        fprintf( stderr, "Compression: " );
        !           882:        prratio( stderr, in_count-bytes_out, in_count );
        !           883: #endif /* DEBUG */
        !           884:     }
        !           885:     if(bytes_out > in_count)   /* exit(2) if no savings */
        !           886:        exit_stat = 2;
        !           887:     return;
        !           888: }
        !           889: 
        !           890: /*****************************************************************
        !           891:  * TAG( output )
        !           892:  *
        !           893:  * Output the given code.
        !           894:  * Inputs:
        !           895:  *     code:   A n_bits-bit integer.  If == -1, then EOF.  This assumes
        !           896:  *             that n_bits =< (long)wordsize - 1.
        !           897:  * Outputs:
        !           898:  *     Outputs code to the file.
        !           899:  * Assumptions:
        !           900:  *     Chars are 8 bits long.
        !           901:  * Algorithm:
        !           902:  *     Maintain a BITS character long buffer (so that 8 codes will
        !           903:  * fit in it exactly).  Use the VAX insv instruction to insert each
        !           904:  * code in turn.  When the buffer fills up empty it and start over.
        !           905:  */
        !           906: 
        !           907: static char buf[BITS];
        !           908: 
        !           909: #ifndef vax
        !           910: char_type lmask[9] = {0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80, 0x00};
        !           911: char_type rmask[9] = {0x00, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f, 0xff};
        !           912: #endif /* vax */
        !           913: 
        !           914: output( code )
        !           915: code_int  code;
        !           916: {
        !           917: #ifdef DEBUG
        !           918:     static int col = 0;
        !           919: #endif /* DEBUG */
        !           920: 
        !           921:     /*
        !           922:      * On the VAX, it is important to have the register declarations
        !           923:      * in exactly the order given, or the asm will break.
        !           924:      */
        !           925:     register int r_off = offset, bits= n_bits;
        !           926:     register char * bp = buf;
        !           927: 
        !           928: #ifdef DEBUG
        !           929:        if ( verbose )
        !           930:            fprintf( stderr, "%5d%c", code,
        !           931:                    (col+=6) >= 74 ? (col = 0, '\n') : ' ' );
        !           932: #endif /* DEBUG */
        !           933:     if ( code >= 0 ) {
        !           934: #ifdef vax
        !           935:        /* VAX DEPENDENT!! Implementation on other machines is below.
        !           936:         *
        !           937:         * Translation: Insert BITS bits from the argument starting at
        !           938:         * offset bits from the beginning of buf.
        !           939:         */
        !           940:        0;      /* Work around for pcc -O bug with asm and if stmt */
        !           941:        asm( "insv      4(ap),r11,r10,(r9)" );
        !           942: #else /* not a vax */
        !           943: /* 
        !           944:  * byte/bit numbering on the VAX is simulated by the following code
        !           945:  */
        !           946:        /*
        !           947:         * Get to the first byte.
        !           948:         */
        !           949:        bp += (r_off >> 3);
        !           950:        r_off &= 7;
        !           951:        /*
        !           952:         * Since code is always >= 8 bits, only need to mask the first
        !           953:         * hunk on the left.
        !           954:         */
        !           955:        *bp = (*bp & rmask[r_off]) | (code << r_off) & lmask[r_off];
        !           956:        bp++;
        !           957:        bits -= (8 - r_off);
        !           958:        code >>= 8 - r_off;
        !           959:        /* Get any 8 bit parts in the middle (<=1 for up to 16 bits). */
        !           960:        if ( bits >= 8 ) {
        !           961:            *bp++ = code;
        !           962:            code >>= 8;
        !           963:            bits -= 8;
        !           964:        }
        !           965:        /* Last bits. */
        !           966:        if(bits)
        !           967:            *bp = code;
        !           968: #endif /* vax */
        !           969:        offset += n_bits;
        !           970:        if ( offset == (n_bits << 3) ) {
        !           971:            bp = buf;
        !           972:            bits = n_bits;
        !           973:            bytes_out += bits;
        !           974:            do
        !           975:                putchar(*bp++);
        !           976:            while(--bits);
        !           977:            offset = 0;
        !           978:        }
        !           979: 
        !           980:        /*
        !           981:         * If the next entry is going to be too big for the code size,
        !           982:         * then increase it, if possible.
        !           983:         */
        !           984:        if ( free_ent > maxcode || (clear_flg > 0))
        !           985:        {
        !           986:            /*
        !           987:             * Write the whole buffer, because the input side won't
        !           988:             * discover the size increase until after it has read it.
        !           989:             */
        !           990:            if ( offset > 0 ) {
        !           991:                if( fwrite( buf, 1, n_bits, stdout ) != n_bits)
        !           992:                        writeerr();
        !           993:                bytes_out += n_bits;
        !           994:            }
        !           995:            offset = 0;
        !           996: 
        !           997:            if ( clear_flg ) {
        !           998:                maxcode = MAXCODE (n_bits = INIT_BITS);
        !           999:                clear_flg = 0;
        !          1000:            }
        !          1001:            else {
        !          1002:                n_bits++;
        !          1003:                if ( n_bits == maxbits )
        !          1004:                    maxcode = maxmaxcode;
        !          1005:                else
        !          1006:                    maxcode = MAXCODE(n_bits);
        !          1007:            }
        !          1008: #ifdef DEBUG
        !          1009:            if ( debug ) {
        !          1010:                fprintf( stderr, "\nChange to %d bits\n", n_bits );
        !          1011:                col = 0;
        !          1012:            }
        !          1013: #endif /* DEBUG */
        !          1014:        }
        !          1015:     } else {
        !          1016:        /*
        !          1017:         * At EOF, write the rest of the buffer.
        !          1018:         */
        !          1019:        if ( offset > 0 )
        !          1020:            fwrite( buf, 1, (offset + 7) / 8, stdout );
        !          1021:        bytes_out += (offset + 7) / 8;
        !          1022:        offset = 0;
        !          1023:        fflush( stdout );
        !          1024: #ifdef DEBUG
        !          1025:        if ( verbose )
        !          1026:            fprintf( stderr, "\n" );
        !          1027: #endif /* DEBUG */
        !          1028:        if( ferror( stdout ) )
        !          1029:                writeerr();
        !          1030:     }
        !          1031: }
        !          1032: 
        !          1033: /*
        !          1034:  * Decompress stdin to stdout.  This routine adapts to the codes in the
        !          1035:  * file building the "string" table on-the-fly; requiring no table to
        !          1036:  * be stored in the compressed file.  The tables used herein are shared
        !          1037:  * with those of the compress() routine.  See the definitions above.
        !          1038:  */
        !          1039: 
        !          1040: decompress() {
        !          1041:     register char_type *stackp;
        !          1042:     register int finchar;
        !          1043:     register code_int code, oldcode, incode;
        !          1044: 
        !          1045:     /*
        !          1046:      * As above, initialize the first 256 entries in the table.
        !          1047:      */
        !          1048:     maxcode = MAXCODE(n_bits = INIT_BITS);
        !          1049:     for ( code = 255; code >= 0; code-- ) {
        !          1050:        tab_prefixof(code) = 0;
        !          1051:        tab_suffixof(code) = (char_type)code;
        !          1052:     }
        !          1053:     free_ent = ((block_compress) ? FIRST : 256 );
        !          1054: 
        !          1055:     finchar = oldcode = getcode();
        !          1056:     if(oldcode == -1)  /* EOF already? */
        !          1057:        return;                 /* Get out of here */
        !          1058:     putchar( (char)finchar );          /* first code must be 8 bits = char */
        !          1059:     if(ferror(stdout))         /* Crash if can't write */
        !          1060:        writeerr();
        !          1061:     stackp = de_stack;
        !          1062: 
        !          1063:     while ( (code = getcode()) > -1 ) {
        !          1064: 
        !          1065:        if ( (code == CLEAR) && block_compress ) {
        !          1066:            for ( code = 255; code >= 0; code-- )
        !          1067:                tab_prefixof(code) = 0;
        !          1068:            clear_flg = 1;
        !          1069:            free_ent = FIRST - 1;
        !          1070:            if ( (code = getcode ()) == -1 )    /* O, untimely death! */
        !          1071:                break;
        !          1072:        }
        !          1073:        incode = code;
        !          1074:        /*
        !          1075:         * Special case for KwKwK string.
        !          1076:         */
        !          1077:        if ( code >= free_ent ) {
        !          1078:             *stackp++ = finchar;
        !          1079:            code = oldcode;
        !          1080:        }
        !          1081: 
        !          1082:        /*
        !          1083:         * Generate output characters in reverse order
        !          1084:         */
        !          1085: #ifdef SIGNED_COMPARE_SLOW
        !          1086:        while ( ((unsigned long)code) >= ((unsigned long)256) ) {
        !          1087: #else
        !          1088:        while ( code >= 256 ) {
        !          1089: #endif
        !          1090:            *stackp++ = tab_suffixof(code);
        !          1091:            code = tab_prefixof(code);
        !          1092:        }
        !          1093:        *stackp++ = finchar = tab_suffixof(code);
        !          1094: 
        !          1095:        /*
        !          1096:         * And put them out in forward order
        !          1097:         */
        !          1098:        do
        !          1099:            putchar ( *--stackp );
        !          1100:        while ( stackp > de_stack );
        !          1101: 
        !          1102:        /*
        !          1103:         * Generate the new entry.
        !          1104:         */
        !          1105:        if ( (code=free_ent) < maxmaxcode ) {
        !          1106:            tab_prefixof(code) = (unsigned short)oldcode;
        !          1107:            tab_suffixof(code) = finchar;
        !          1108:            free_ent = code+1;
        !          1109:        } 
        !          1110:        /*
        !          1111:         * Remember previous code.
        !          1112:         */
        !          1113:        oldcode = incode;
        !          1114:     }
        !          1115:     fflush( stdout );
        !          1116:     if(ferror(stdout))
        !          1117:        writeerr();
        !          1118: }
        !          1119: 
        !          1120: /*****************************************************************
        !          1121:  * TAG( getcode )
        !          1122:  *
        !          1123:  * Read one code from the standard input.  If EOF, return -1.
        !          1124:  * Inputs:
        !          1125:  *     stdin
        !          1126:  * Outputs:
        !          1127:  *     code or -1 is returned.
        !          1128:  */
        !          1129: 
        !          1130: code_int
        !          1131: getcode() {
        !          1132:     /*
        !          1133:      * On the VAX, it is important to have the register declarations
        !          1134:      * in exactly the order given, or the asm will break.
        !          1135:      */
        !          1136:     register code_int code;
        !          1137:     static int offset = 0, size = 0;
        !          1138:     static char_type buf[BITS];
        !          1139:     register int r_off, bits;
        !          1140:     register char_type *bp = buf;
        !          1141: 
        !          1142:     if ( clear_flg > 0 || offset >= size || free_ent > maxcode ) {
        !          1143:        /*
        !          1144:         * If the next entry will be too big for the current code
        !          1145:         * size, then we must increase the size.  This implies reading
        !          1146:         * a new buffer full, too.
        !          1147:         */
        !          1148:        if ( free_ent > maxcode ) {
        !          1149:            n_bits++;
        !          1150:            if ( n_bits == maxbits )
        !          1151:                maxcode = maxmaxcode;   /* won't get any bigger now */
        !          1152:            else
        !          1153:                maxcode = MAXCODE(n_bits);
        !          1154:        }
        !          1155:        if ( clear_flg > 0) {
        !          1156:            maxcode = MAXCODE (n_bits = INIT_BITS);
        !          1157:            clear_flg = 0;
        !          1158:        }
        !          1159:        size = fread( buf, 1, n_bits, stdin );
        !          1160:        if ( size <= 0 )
        !          1161:            return -1;                  /* end of file */
        !          1162:        offset = 0;
        !          1163:        /* Round size down to integral number of codes */
        !          1164:        size = (size << 3) - (n_bits - 1);
        !          1165:     }
        !          1166:     r_off = offset;
        !          1167:     bits = n_bits;
        !          1168: #ifdef vax
        !          1169:     asm( "extzv   r10,r9,(r8),r11" );
        !          1170: #else /* not a vax */
        !          1171:        /*
        !          1172:         * Get to the first byte.
        !          1173:         */
        !          1174:        bp += (r_off >> 3);
        !          1175:        r_off &= 7;
        !          1176:        /* Get first part (low order bits) */
        !          1177: #ifdef NO_UCHAR
        !          1178:        code = ((*bp++ >> r_off) & rmask[8 - r_off]) & 0xff;
        !          1179: #else
        !          1180:        code = (*bp++ >> r_off);
        !          1181: #endif /* NO_UCHAR */
        !          1182:        bits -= (8 - r_off);
        !          1183:        r_off = 8 - r_off;              /* now, offset into code word */
        !          1184:        /* Get any 8 bit parts in the middle (<=1 for up to 16 bits). */
        !          1185:        if ( bits >= 8 ) {
        !          1186: #ifdef NO_UCHAR
        !          1187:            code |= (*bp++ & 0xff) << r_off;
        !          1188: #else
        !          1189:            code |= *bp++ << r_off;
        !          1190: #endif /* NO_UCHAR */
        !          1191:            r_off += 8;
        !          1192:            bits -= 8;
        !          1193:        }
        !          1194:        /* high order bits. */
        !          1195:        code |= (*bp & rmask[bits]) << r_off;
        !          1196: #endif /* vax */
        !          1197:     offset += n_bits;
        !          1198: 
        !          1199:     return code;
        !          1200: }
        !          1201: 
        !          1202: char *
        !          1203: rindex(s, c)           /* For those who don't have it in libc.a */
        !          1204: register char *s, c;
        !          1205: {
        !          1206:        char *p;
        !          1207:        for (p = NULL; *s; s++)
        !          1208:            if (*s == c)
        !          1209:                p = s;
        !          1210:        return(p);
        !          1211: }
        !          1212: 
        !          1213: #ifdef DEBUG
        !          1214: printcodes()
        !          1215: {
        !          1216:     /*
        !          1217:      * Just print out codes from input file.  For debugging.
        !          1218:      */
        !          1219:     code_int code;
        !          1220:     int col = 0, bits;
        !          1221: 
        !          1222:     bits = n_bits = INIT_BITS;
        !          1223:     maxcode = MAXCODE(n_bits);
        !          1224:     free_ent = ((block_compress) ? FIRST : 256 );
        !          1225:     while ( ( code = getcode() ) >= 0 ) {
        !          1226:        if ( (code == CLEAR) && block_compress ) {
        !          1227:            free_ent = FIRST - 1;
        !          1228:            clear_flg = 1;
        !          1229:        }
        !          1230:        else if ( free_ent < maxmaxcode )
        !          1231:            free_ent++;
        !          1232:        if ( bits != n_bits ) {
        !          1233:            fprintf(stderr, "\nChange to %d bits\n", n_bits );
        !          1234:            bits = n_bits;
        !          1235:            col = 0;
        !          1236:        }
        !          1237:        fprintf(stderr, "%5d%c", code, (col+=6) >= 74 ? (col = 0, '\n') : ' ' );
        !          1238:     }
        !          1239:     putc( '\n', stderr );
        !          1240:     exit( 0 );
        !          1241: }
        !          1242: 
        !          1243: code_int sorttab[1<<BITS];     /* sorted pointers into htab */
        !          1244: 
        !          1245: dump_tab()     /* dump string table */
        !          1246: {
        !          1247:     register int i, first;
        !          1248:     register ent;
        !          1249: #define STACK_SIZE     15000
        !          1250:     int stack_top = STACK_SIZE;
        !          1251:     register c;
        !          1252: 
        !          1253:     if(do_decomp == 0) {       /* compressing */
        !          1254:        register int flag = 1;
        !          1255: 
        !          1256:        for(i=0; i<hsize; i++) {        /* build sort pointers */
        !          1257:                if((long)htabof(i) >= 0) {
        !          1258:                        sorttab[codetabof(i)] = i;
        !          1259:                }
        !          1260:        }
        !          1261:        first = block_compress ? FIRST : 256;
        !          1262:        for(i = first; i < free_ent; i++) {
        !          1263:                fprintf(stderr, "%5d: \"", i);
        !          1264:                de_stack[--stack_top] = '\n';
        !          1265:                de_stack[--stack_top] = '"';
        !          1266:                stack_top = in_stack((htabof(sorttab[i])>>maxbits)&0xff, 
        !          1267:                                      stack_top);
        !          1268:                for(ent=htabof(sorttab[i]) & ((1<<maxbits)-1);
        !          1269:                    ent > 256;
        !          1270:                    ent=htabof(sorttab[ent]) & ((1<<maxbits)-1)) {
        !          1271:                        stack_top = in_stack(htabof(sorttab[ent]) >> maxbits,
        !          1272:                                                stack_top);
        !          1273:                }
        !          1274:                stack_top = in_stack(ent, stack_top);
        !          1275:                fwrite( &de_stack[stack_top], 1, STACK_SIZE-stack_top, stderr);
        !          1276:                stack_top = STACK_SIZE;
        !          1277:        }
        !          1278:    } else if(!debug) { /* decompressing */
        !          1279: 
        !          1280:        for ( i = 0; i < free_ent; i++ ) {
        !          1281:           ent = i;
        !          1282:           c = tab_suffixof(ent);
        !          1283:           if ( isascii(c) && isprint(c) )
        !          1284:               fprintf( stderr, "%5d: %5d/'%c'  \"",
        !          1285:                           ent, tab_prefixof(ent), c );
        !          1286:           else
        !          1287:               fprintf( stderr, "%5d: %5d/\\%03o \"",
        !          1288:                           ent, tab_prefixof(ent), c );
        !          1289:           de_stack[--stack_top] = '\n';
        !          1290:           de_stack[--stack_top] = '"';
        !          1291:           for ( ; ent != NULL;
        !          1292:                   ent = (ent >= FIRST ? tab_prefixof(ent) : NULL) ) {
        !          1293:               stack_top = in_stack(tab_suffixof(ent), stack_top);
        !          1294:           }
        !          1295:           fwrite( &de_stack[stack_top], 1, STACK_SIZE - stack_top, stderr );
        !          1296:           stack_top = STACK_SIZE;
        !          1297:        }
        !          1298:     }
        !          1299: }
        !          1300: 
        !          1301: int
        !          1302: in_stack(c, stack_top)
        !          1303:        register c, stack_top;
        !          1304: {
        !          1305:        if ( (isascii(c) && isprint(c) && c != '\\') || c == ' ' ) {
        !          1306:            de_stack[--stack_top] = c;
        !          1307:        } else {
        !          1308:            switch( c ) {
        !          1309:            case '\n': de_stack[--stack_top] = 'n'; break;
        !          1310:            case '\t': de_stack[--stack_top] = 't'; break;
        !          1311:            case '\b': de_stack[--stack_top] = 'b'; break;
        !          1312:            case '\f': de_stack[--stack_top] = 'f'; break;
        !          1313:            case '\r': de_stack[--stack_top] = 'r'; break;
        !          1314:            case '\\': de_stack[--stack_top] = '\\'; break;
        !          1315:            default:
        !          1316:                de_stack[--stack_top] = '0' + c % 8;
        !          1317:                de_stack[--stack_top] = '0' + (c / 8) % 8;
        !          1318:                de_stack[--stack_top] = '0' + c / 64;
        !          1319:                break;
        !          1320:            }
        !          1321:            de_stack[--stack_top] = '\\';
        !          1322:        }
        !          1323:        return stack_top;
        !          1324: }
        !          1325: #endif /* DEBUG */
        !          1326: 
        !          1327: writeerr()
        !          1328: {
        !          1329:     perror ( ofname );
        !          1330:     unlink ( ofname );
        !          1331:     exit ( 1 );
        !          1332: }
        !          1333: 
        !          1334: copystat(ifname, ofname)
        !          1335: char *ifname, *ofname;
        !          1336: {
        !          1337:     struct stat statbuf;
        !          1338:     int mode;
        !          1339:     time_t timep[2];
        !          1340: 
        !          1341:     fclose(stdout);
        !          1342:     if (stat(ifname, &statbuf)) {              /* Get stat on input file */
        !          1343:        perror(ifname);
        !          1344:        return;
        !          1345:     }
        !          1346:     if ((statbuf.st_mode & S_IFMT/*0170000*/) != S_IFREG/*0100000*/) {
        !          1347:        if(quiet)
        !          1348:                fprintf(stderr, "%s: ", ifname);
        !          1349:        fprintf(stderr, " -- not a regular file: unchanged");
        !          1350:        exit_stat = 1;
        !          1351:        perm_stat = 1;
        !          1352:     } else if (statbuf.st_nlink > 1) {
        !          1353:        if(quiet)
        !          1354:                fprintf(stderr, "%s: ", ifname);
        !          1355:        fprintf(stderr, " -- has %d other links: unchanged",
        !          1356:                statbuf.st_nlink - 1);
        !          1357:        exit_stat = 1;
        !          1358:        perm_stat = 1;
        !          1359:     } else if (exit_stat == 2 && (!force)) { /* No compression: remove file.Z */
        !          1360:        if(!quiet)
        !          1361:                fprintf(stderr, " -- file unchanged");
        !          1362:     } else {                   /* ***** Successful Compression ***** */
        !          1363:        exit_stat = 0;
        !          1364:        mode = statbuf.st_mode & 07777;
        !          1365:        if (chmod(ofname, mode))                /* Copy modes */
        !          1366:            perror(ofname);
        !          1367:        chown(ofname, statbuf.st_uid, statbuf.st_gid);  /* Copy ownership */
        !          1368:        timep[0] = statbuf.st_atime;
        !          1369:        timep[1] = statbuf.st_mtime;
        !          1370:        utime(ofname, timep);   /* Update last accessed and modified times */
        !          1371:        if (unlink(ifname))     /* Remove input file */
        !          1372:            perror(ifname);
        !          1373:        if(!quiet)
        !          1374:                fprintf(stderr, " -- replaced with %s", ofname);
        !          1375:        return;         /* Successful return */
        !          1376:     }
        !          1377: 
        !          1378:     /* Unsuccessful return -- one of the tests failed */
        !          1379:     if (unlink(ofname))
        !          1380:        perror(ofname);
        !          1381: }
        !          1382: 
        !          1383: void
        !          1384: onintr ( )
        !          1385: {
        !          1386:     if (!precious)
        !          1387:        unlink ( ofname );
        !          1388:     exit ( 1 );
        !          1389: }
        !          1390: 
        !          1391: void
        !          1392: oops ( )       /* wild pointer -- assume bad input */
        !          1393: {
        !          1394:     if ( do_decomp ) 
        !          1395:        fprintf ( stderr, "uncompress: corrupt input\n" );
        !          1396:     unlink ( ofname );
        !          1397:     exit ( 1 );
        !          1398: }
        !          1399: 
        !          1400: cl_block ()            /* table clear for block compress */
        !          1401: {
        !          1402:     register long int rat;
        !          1403: 
        !          1404:     checkpoint = in_count + CHECK_GAP;
        !          1405: #ifdef DEBUG
        !          1406:        if ( debug ) {
        !          1407:                fprintf ( stderr, "count: %ld, ratio: ", in_count );
        !          1408:                prratio ( stderr, in_count, bytes_out );
        !          1409:                fprintf ( stderr, "\n");
        !          1410:        }
        !          1411: #endif /* DEBUG */
        !          1412: 
        !          1413:     if(in_count > 0x007fffff) {        /* shift will overflow */
        !          1414:        rat = bytes_out >> 8;
        !          1415:        if(rat == 0) {          /* Don't divide by zero */
        !          1416:            rat = 0x7fffffff;
        !          1417:        } else {
        !          1418:            rat = in_count / rat;
        !          1419:        }
        !          1420:     } else {
        !          1421:        rat = (in_count << 8) / bytes_out;      /* 8 fractional bits */
        !          1422:     }
        !          1423:     if ( rat > ratio ) {
        !          1424:        ratio = rat;
        !          1425:     } else {
        !          1426:        ratio = 0;
        !          1427: #ifdef DEBUG
        !          1428:        if(verbose)
        !          1429:                dump_tab();     /* dump string table */
        !          1430: #endif
        !          1431:        cl_hash ( (count_int) hsize );
        !          1432:        free_ent = FIRST;
        !          1433:        clear_flg = 1;
        !          1434:        output ( (code_int) CLEAR );
        !          1435: #ifdef DEBUG
        !          1436:        if(debug)
        !          1437:                fprintf ( stderr, "clear\n" );
        !          1438: #endif /* DEBUG */
        !          1439:     }
        !          1440: }
        !          1441: 
        !          1442: cl_hash(hsize)         /* reset code table */
        !          1443:        register count_int hsize;
        !          1444: {
        !          1445: #ifndef XENIX_16       /* Normal machine */
        !          1446:        register count_int *htab_p = htab+hsize;
        !          1447: #else
        !          1448:        register j;
        !          1449:        register long k = hsize;
        !          1450:        register count_int *htab_p;
        !          1451: #endif
        !          1452:        register long i;
        !          1453:        register long m1 = -1;
        !          1454: 
        !          1455: #ifdef XENIX_16
        !          1456:     for(j=0; j<=8 && k>=0; j++,k-=8192) {
        !          1457:        i = 8192;
        !          1458:        if(k < 8192) {
        !          1459:                i = k;
        !          1460:        }
        !          1461:        htab_p = &(htab[j][i]);
        !          1462:        i -= 16;
        !          1463:        if(i > 0) {
        !          1464: #else
        !          1465:        i = hsize - 16;
        !          1466: #endif
        !          1467:        do {                            /* might use Sys V memset(3) here */
        !          1468:                *(htab_p-16) = m1;
        !          1469:                *(htab_p-15) = m1;
        !          1470:                *(htab_p-14) = m1;
        !          1471:                *(htab_p-13) = m1;
        !          1472:                *(htab_p-12) = m1;
        !          1473:                *(htab_p-11) = m1;
        !          1474:                *(htab_p-10) = m1;
        !          1475:                *(htab_p-9) = m1;
        !          1476:                *(htab_p-8) = m1;
        !          1477:                *(htab_p-7) = m1;
        !          1478:                *(htab_p-6) = m1;
        !          1479:                *(htab_p-5) = m1;
        !          1480:                *(htab_p-4) = m1;
        !          1481:                *(htab_p-3) = m1;
        !          1482:                *(htab_p-2) = m1;
        !          1483:                *(htab_p-1) = m1;
        !          1484:                htab_p -= 16;
        !          1485:        } while ((i -= 16) >= 0);
        !          1486: #ifdef XENIX_16
        !          1487:        }
        !          1488:     }
        !          1489: #endif
        !          1490:        for ( i += 16; i > 0; i-- )
        !          1491:                *--htab_p = m1;
        !          1492: }
        !          1493: 
        !          1494: prratio(stream, num, den)
        !          1495: FILE *stream;
        !          1496: long int num, den;
        !          1497: {
        !          1498:        register int q;                 /* Doesn't need to be long */
        !          1499: 
        !          1500:        if(num > 214748L) {             /* 2147483647/10000 */
        !          1501:                q = num / (den / 10000L);
        !          1502:        } else {
        !          1503:                q = 10000L * num / den;         /* Long calculations, though */
        !          1504:        }
        !          1505:        if (q < 0) {
        !          1506:                putc('-', stream);
        !          1507:                q = -q;
        !          1508:        }
        !          1509:        fprintf(stream, "%d.%02d%%", q / 100, q % 100);
        !          1510: }
        !          1511: 
        !          1512: version()
        !          1513: {
        !          1514:        fprintf(stderr, "%s, Berkeley 5.12 6/1/90\n", rcs_ident);
        !          1515:        fprintf(stderr, "Options: ");
        !          1516: #ifdef vax
        !          1517:        fprintf(stderr, "vax, ");
        !          1518: #endif
        !          1519: #ifdef NO_UCHAR
        !          1520:        fprintf(stderr, "NO_UCHAR, ");
        !          1521: #endif
        !          1522: #ifdef SIGNED_COMPARE_SLOW
        !          1523:        fprintf(stderr, "SIGNED_COMPARE_SLOW, ");
        !          1524: #endif
        !          1525: #ifdef XENIX_16
        !          1526:        fprintf(stderr, "XENIX_16, ");
        !          1527: #endif
        !          1528: #ifdef COMPATIBLE
        !          1529:        fprintf(stderr, "COMPATIBLE, ");
        !          1530: #endif
        !          1531: #ifdef DEBUG
        !          1532:        fprintf(stderr, "DEBUG, ");
        !          1533: #endif
        !          1534: #ifdef BSD4_2
        !          1535:        fprintf(stderr, "BSD4_2, ");
        !          1536: #endif
        !          1537:        fprintf(stderr, "BITS = %d\n", BITS);
        !          1538: }

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