jac@yoko.rutgers.edu (Jonathan A. Chandross) (05/02/91)
Submitted-by: Andy McFadden (fadden@cory.berkeley.edu)
Posting-number: Volume 1, Source:32
Archive-name: archive/unix/nulib/part01.10
Architecture: UNIX
Version-number: 3.03
Nulib allows handles many of the archiving formats used on the Apple.
Very handy indeed.
Enjoy.
=README
-Nulib v3.03 (February 1991)
-- Fixed XENIX problems with includes and libs (Ron Higgins).
-- Fixed bug in directory expansion (Larry W. Virden).
-NuLib v3.02
-- Silenced screaming about bad dates (Larry W. Virden).
-- Fixed glitches in nulib.lnk and nulib.mak (Bruce Kahn).
-NuLib v3.01
-- Fixed non-compression bug in ShrinkIt LZW (Scott Blackman).
-
-NuLib v3.0 README (September 1990)
-
-New items in 3.0:
-- ShrinkIt LZW compression
-- UNIX 12-bit and 16-bit compression
-- New archive listing format (similar to ARC and ZOO)
-
-Things work much better if you read the documentation file (now available
-on the archive site... sorry I didn't put it up sooner). If you want to
-use UNIX compress to store files, READ THE DOCUMENTATION FIRST. Not only
-does it tell you how to do it, but it has some warnings about compatibility.
-
-Note that v3.0 does *NOT* unpack archives compressed with GS/ShrinkIt. The
-problem is that NuLib cannot at present decode LZW/II compression. You can
-read comments and extract files that were added without compression, but
-that's about it.
-
-To compile this on a UNIX-type system, edit the file "nudefs.h". Several
-systems are predefined; the default is a BSD UNIX system. If you want
-to run this on something other than BSD, comment out the #define statements
-(using "/*" and "*/"), and uncomment the appropriate statements. Then,
-type "make" to execute the Makefile. If all goes well, you will be
-left with an executable file called "nulib". If all does not go well,
-double check "nudefs.h". Send some mail to me if you can't get it to work
-at all.
-
-Currently AT&T 3B2 machines seem to be very uncooperative. If somebody gets
-NuLib to run on one, please let me know. The problem is in the directory
-manipulation routines (struct dirent, opendir(), readdir(), etc).
-
-To make the MS-DOS version, use the nulib.mak and nulib.lnk files with MS C
-(supplied by Bruce Kahn). To make the APW version, put all the files in
-one directory, and make a subdirectory called "OBJ". Put the "linked.scr"
-and "linker.scr" files in OBJ, and then "make.apw". This will compile all
-the files. When it finishes, change to OBJ and "alink linked.scr" (standard
-linker) or "alink linker.scr" (ZapLink). The makefile used to do this
-automatically, but with only 1.25MB of RAM you have to exit APW to purge
-all the memory used by the compiler, and and then restart APW and
-run the linker.
-
-In both cases, BE SURE to modify "nudefs.h" first. If you don't, the
-compilation will halt in "numain.c" on a line which reminds you to change
-"nudefs.h" (I tended to forget about this). Also, make sure all the file
-types are set to SRC, and the auxtype to CC. These are changed with the
-commands "filetype" and "change", respectively.
-
-Please send bug reports, ideas, or gripes to fadden@cory.berkeley.edu, or to
-one of the addresses mentioned in the documentation or under the "-hw"
-option.
-
-Known bugs:
- - Under some systems, using UNIX compress on a file which does not compress
-will cause the archive's EOF to be larger than it should be. This slack
-space will be used up if you add more files to the archive (with NuLib
-anyway; no guarantees about ShrinkIt or GS/ShrinkIt, but there's no reason
-why they shouldn't work).
-
-(just to make things clear: if the file being compressed doesn't get any
-smaller, the compression halts and the file is simply stored uncompressed.
-Because of the way compress works, on some systems the space that would
-have been occupied by more compressed data is left attached to the file.
-The ShrinkIt compression does not suffer from this problem. If you add
-more stuff to the file, NuLib will fill the slack space first, NOT just
-append to the end of the file).
-
-Things to come:
- - LZW/II decompression (for GS/ShrinkIt archives)
- - Support for UNIX tar archives
- - CRLF translations while adding files
- - Better handling of comments
-
-Don't hold your breath waiting for these...
-
-I can be reached at:
- fadden@cory.berkeley.edu (primary e-mail account)
- fadden@hermes.berkeley.edu (secondary e-mail, since primary is buggy)
-
-All this stuff, and documentation as well, is available via anonymous FTP at:
- avalanche.berkeley.edu
- tornado.berkeley.edu
- headcrash.berkeley.edu
- ...
-in pub/Apple2
-
=nucomp.c
-/*
- * nucomp.c - code to perform UNIX style LZW compression
- *
- * NuLib v3.0 February 1991 Freeware (distribute, don't sell)
- * By Andy McFadden (fadden@cory.berkeley.edu)
- *
- * This is the main compression code from compress v4.3. Modifications
- * have been made to integrate it with NuLib (primarily in that it no longer
- * uses stdin/stdout), but it's functionally the same.
- */
-#ifdef APW
-segment "Compress"
-#endif
-
-#include "nudefs.h"
-#include "nupak.h"
-#define MAIN /* cause nucomp.h to alloc global vars */
-
-/*@H************************ < COMPRESS API > ****************************
-* *
-* compress : compapi.c <current version of compress algorithm> *
-* *
-* port by : Donald J. Gloistein *
-* *
-* Source, Documentation, Object Code: *
-* released to Public Domain. This code is based on code as documented *
-* below in release notes. *
-* *
-*--------------------------- Module Description --------------------------*
-* Contains source code for modified Lempel-Ziv method (LZW) compression *
-* and decompression. *
-* *
-* This code module can be maintained to keep current on releases on the *
-* Unix system. The command shell and dos modules can remain the same. *
-* *
-*--------------------------- Implementation Notes --------------------------*
-* *
-* compiled with : compress.h compress.fns compress.c *
-* linked with : compress.obj compusi.obj *
-* *
-* problems: *
-* *
-* *
-* CAUTION: Uses a number of defines for access and speed. If you change *
-* anything, make sure about side effects. *
-* *
-* Compression: *
-* Algorithm: use open addressing double hashing (no chaining) on the *
-* prefix code / next character combination. We do a variant of Knuth's *
-* algorithm D (vol. 3, sec. 6.4) along with G. Knott's relatively-prime *
-* secondary probe. Here, the modular division first probe is gives way *
-* to a faster exclusive-or manipulation. *
-* Also block compression with an adaptive reset was used in original code, *
-* whereby the code table is cleared when the compression ration decreases *
-* but after the table fills. This was removed from this edition. The table *
-* is re-sized at this point when it is filled , and a special CLEAR code is *
-* generated for the decompressor. This results in some size difference from *
-* straight version 4.0 joe Release. But it is fully compatible in both v4.0 *
-* and v4.01 *
-* *
-* Decompression: *
-* This routine adapts to the codes in the file building the "string" table *
-* on-the-fly; requiring no table to be stored in the compressed file. The *
-* tables used herein are shared with those of the compress() routine. *
-* *
-* Initials ---- Name --------------------------------- *
-* DjG Donald J. Gloistein, current port to MsDos 16 bit *
-* Plus many others, see rev.hst file for full list *
-* LvR Lyle V. Rains, many thanks for improved implementation *
-* of the compression and decompression routines. *
-*************************************************************************@H*/
-
-#include <stdio.h>
-#define assert(x)
-#include "nucomp.h" /* contains the rest of the include file declarations */
-
-FILE *nustdin, *nustdout; /* NuLib: use these instead of stdin/stdout */
-long nubytes_read, nucomp_thread_eof; /* NuLib: used in nextcode (decomp) */
-
-/* NuLib: pulled this out of nextcode() so we can initialize it every time */
-static int prevbits = 0;
-/* NuLib: pulled out of putcode() */
-static int oldbits = 0;
-
-static int offset;
-static long int in_count ; /* length of input */
-static long int bytes_out; /* length of compressed output */
-static long int max_bytes_out; /* NuLib: max #of bytes to output */
-
-static CODE prefxcode, nextfree;
-static CODE highcode;
-static CODE maxcode;
-static HASH hashsize;
-static int bits;
-
-
-/*
- * The following two parameter tables are the hash table sizes and
- * maximum code values for various code bit-lengths. The requirements
- * are that Hashsize[n] must be a prime number and Maxcode[n] must be less
- * than Maxhash[n]. Table occupancy factor is (Maxcode - 256)/Maxhash.
- * Note: I am using a lower Maxcode for 16-bit codes in order to
- * keep the hash table size less than 64k entries.
- */
-CONST HASH hs[] = {
- 0x13FF, /* 12-bit codes, 75% occupancy */
- 0x26C3, /* 13-bit codes, 80% occupancy */
- 0x4A1D, /* 14-bit codes, 85% occupancy */
- 0x8D0D, /* 15-bit codes, 90% occupancy */
- 0xFFD9 /* 16-bit codes, 94% occupancy, 6% of code values unused */
-};
-#define Hashsize(maxb) (hs[(maxb) -MINBITS])
-
-CONST CODE mc[] = {
- 0x0FFF, /* 12-bit codes */
- 0x1FFF, /* 13-bit codes */
- 0x3FFF, /* 14-bit codes */
- 0x7FFF, /* 15-bit codes */
- 0xEFFF /* 16-bit codes, 6% of code values unused */
-};
-#define Maxcode(maxb) (mc[(maxb) -MINBITS])
-
-#define allocx(type,ptr,size) \
- (((ptr) = (type FAR *) emalloc((unsigned int)(size),sizeof(type))) == NULLPTR(type) \
- ? NOMEM : OK \
- )
-
-#define free_array(type,ptr,offset) \
- if (ptr != NULLPTR(type)) { \
- efree((ALLOCTYPE FAR *)((ptr) + (offset))); \
- (ptr) = NULLPTR(type); \
- }
-
- /*
- * Macro to allocate new memory to a pointer with an offset value.
- */
-#define alloc_array(type, ptr, size, offset) \
- ( allocx(type, ptr, (size) - (offset)) != OK \
- ? NOMEM \
- : (((ptr) -= (offset)), OK) \
- )
-
-static char FAR *sfx = NULLPTR(char) ;
-#define suffix(code) sfx[code]
-
-
-#ifdef SPLIT_PFX
- static CODE FAR *pfx[2] = {NULLPTR(CODE), NULLPTR(CODE)};
-#else
- static CODE FAR *pfx = NULLPTR(CODE);
-#endif
-
-
-#ifdef SPLIT_HT
- static CODE FAR *ht[2] = {NULLPTR(CODE),NULLPTR(CODE)};
-#else
- static CODE FAR *ht = NULLPTR(CODE);
-#endif
-
-
-int alloc_tables(maxcode, hashsize)
- CODE maxcode;
- HASH hashsize;
-{
- static CODE oldmaxcode = 0;
- static HASH oldhashsize = 0;
-
- if (hashsize > oldhashsize) {
-#ifdef SPLIT_HT
- free_array(CODE,ht[1], 0);
- free_array(CODE,ht[0], 0);
-#else
- free_array(CODE,ht, 0);
-#endif
- oldhashsize = 0;
- }
-
- if (maxcode > oldmaxcode) {
-#ifdef SPLIT_PFX
- free_array(CODE,pfx[1], 128);
- free_array(CODE,pfx[0], 128);
-#else
- free_array(CODE,pfx, 256);
-#endif
- free_array(char,sfx, 256);
-
- if ( alloc_array(char, sfx, maxcode + 1, 256)
-#ifdef SPLIT_PFX
- || alloc_array(CODE, pfx[0], (maxcode + 1) / 2, 128)
- || alloc_array(CODE, pfx[1], (maxcode + 1) / 2, 128)
-#else
- || alloc_array(CODE, pfx, (maxcode + 1), 256)
-#endif
- ) {
- oldmaxcode = 0;
- exit_stat = NOMEM;
- return(NOMEM);
- }
- oldmaxcode = maxcode;
- }
- if (hashsize > oldhashsize) {
- if (
-#ifdef SPLIT_HT
- alloc_array(CODE, ht[0], (hashsize / 2) + 1, 0)
- || alloc_array(CODE, ht[1], hashsize / 2, 0)
-#else
- alloc_array(CODE, ht, hashsize, 0)
-#endif
- ) {
- oldhashsize = 0;
- exit_stat = NOMEM;
- return(NOMEM);
- }
- oldhashsize = hashsize;
- }
- return (OK);
-}
-
-# ifdef SPLIT_PFX
- /*
- * We have to split pfx[] table in half,
- * because it's potentially larger than 64k bytes.
- */
-# define prefix(code) (pfx[(code) & 1][(code) >> 1])
-# else
- /*
- * Then pfx[] can't be larger than 64k bytes,
- * or we don't care if it is, so we don't split.
- */
-# define prefix(code) (pfx[code])
-# endif
-
-
-/* The initializing of the tables can be done quicker with memset() */
-/* but this way is portable through out the memory models. */
-/* If you use Microsoft halloc() to allocate the arrays, then */
-/* include the pragma #pragma function(memset) and make sure that */
-/* the length of the memory block is not greater than 64K. */
-/* This also means that you MUST compile in a model that makes the */
-/* default pointers to be far pointers (compact or large models). */
-/* See the file COMPUSI.DOS to modify function emalloc(). */
-
-# ifdef SPLIT_HT
- /*
- * We have to split ht[] hash table in half,
- * because it's potentially larger than 64k bytes.
- */
-# define probe(hash) (ht[(hash) & 1][(hash) >> 1])
-# define init_tables() \
- { \
- hash = hashsize >> 1; \
- ht[0][hash] = 0; \
- while (hash--) ht[0][hash] = ht[1][hash] = 0; \
- highcode = ~(~(CODE)0 << (bits = INITBITS)); \
- nextfree = (block_compress ? FIRSTFREE : 256); \
- }
-
-# else
-
- /*
- * Then ht[] can't be larger than 64k bytes,
- * or we don't care if it is, so we don't split.
- */
-# define probe(hash) (ht[hash])
-# define init_tables() \
- { \
- hash = hashsize; \
- while (hash--) ht[hash] = 0; \
- highcode = ~(~(CODE)0 << (bits = INITBITS)); \
- nextfree = (block_compress ? FIRSTFREE : 256); \
- }
-
-# endif
-
-#ifdef COMP40
-/* table clear for block compress */
-/* this is for adaptive reset present in version 4.0 joe release */
-/* DjG, sets it up and returns TRUE to compress and FALSE to not compress */
-int cl_block ()
-{
- register long int rat;
-
- checkpoint = in_count + CHECK_GAP;
-#ifndef NDEBUG
- if ( debug ) {
- fprintf ( stderr, "count: %ld, ratio: ", in_count );
- prratio ( stderr, in_count, bytes_out );
- fprintf ( stderr, "\n");
- }
-#endif
-
- if(in_count > 0x007fffff) { /* shift will overflow */
- rat = bytes_out >> 8;
- if(rat == 0) /* Don't divide by zero */
- rat = 0x7fffffff;
- else
- rat = in_count / rat;
- }
- else
- rat = (in_count << 8) / bytes_out; /* 8 fractional bits */
-
- if ( rat > ratio ){
- ratio = rat;
- return FALSE;
- }
- else {
- ratio = 0;
-#ifndef NDEBUG
- if(debug)
- fprintf ( stderr, "clear\n" );
-#endif
- return TRUE; /* clear the table */
- }
- return FALSE; /* don't clear the table */
-}
-#endif
-
-/*
- * compress stdin to stdout <-- nope
- * NuLib: compress thread_eof bytes from srcfd, writing to dstfd
- * Sets up a few things and then calls u_compress.
- */
-int u_compress(srcfd, dstfd, thread_eof)
-int srcfd, dstfd;
-long thread_eof;
-{
- int src2, dst2;
- long srcposn, dstposn;
- static char *procName = "u_compress";
-
- if ((srcposn = lseek(srcfd, 0L, S_REL)) < 0)
- Fatal("Bad posn lseek(1)", procName);
- if ((dstposn = lseek(dstfd, 0L, S_REL)) < 0)
- Fatal("Bad posn lseek(2)", procName);
-
- src2 = dup(srcfd);
- dst2 = dup(dstfd);
-
- /* NuLib: open new stdin/stdout, and seek */
- if ((nustdin = fdopen(src2, FREAD_STR)) == NULL)
- Fatal("can't fdopen() nustdin", procName);
- if ((nustdout = fdopen(dst2, FWRITE_STR)) == NULL)
- Fatal("can't fdopen() nustdout", procName);
- setvbuf(nustdin,xbuf,_IOFBF,XBUFSIZE); /* make the buffers larger */
- setvbuf(nustdout,zbuf,_IOFBF,ZBUFSIZE); /* (note setvbuf is a macro) */
- if (fseek(nustdin, srcposn, S_ABS) < 0) /* seek may not be needed */
- Fatal("Bad stream posn lseek(1)", procName);
- if (fseek(nustdout, dstposn, S_ABS) < 0)
- Fatal("Bad stream posn lseek(2)", procName);
-
- oldbits = 0; /* init for putcode() */
- compress(thread_eof);
- check_error();
-
- fclose(nustdin); /* note this closes the duped fd */
- fclose(nustdout);
- return (exit_stat);
-}
-
-void compress(thread_eof)
-long thread_eof;
-{
- int c,adjbits;
- register HASH hash;
- register CODE code;
- HASH hashf[256];
-
- max_bytes_out = thread_eof; /* NuLib: don't exceed original size */
- maxcode = Maxcode(maxbits);
- hashsize = Hashsize(maxbits);
-
-#ifdef COMP40
-/* Only needed for adaptive reset */
- checkpoint = CHECK_GAP;
- ratio = 0;
-#endif
-
- adjbits = maxbits -10;
- for (c = 256; --c >= 0; ){
- hashf[c] = ((( c &0x7) << 7) ^ c) << adjbits;
- }
- exit_stat = OK;
- if (alloc_tables(maxcode, hashsize)) /* exit_stat already set */
- return;
- init_tables();
- /* if not zcat or filter (NuLib: never happens) */
- if(is_list && !zcat_flg) { /* Open output file */
- if (freopen(ofname, WRITE_FILE_TYPE, nustdout) == NULL) {
- exit_stat = NOTOPENED;
- return;
- }
- if (!quiet)
- fprintf(stderr, "%s: ",ifname);
- setvbuf(nustdout,zbuf,_IOFBF,ZBUFSIZE);
- }
- /*
- * Check the input stream for previously seen strings. We keep
- * adding characters to the previously seen prefix string until we
- * get a character which forms a new (unseen) string. We then send
- * the code for the previously seen prefix string, and add the new
- * string to our tables. The check for previous strings is done by
- * hashing. If the code for the hash value is unused, then we have
- * a new string. If the code is used, we check to see if the prefix
- * and suffix values match the current input; if so, we have found
- * a previously seen string. Otherwise, we have a hash collision,
- * and we try secondary hash probes until we either find the current
- * string, or we find an unused entry (which indicates a new string).
- */
- if (!nomagic) {
- putc(magic_header[0], nustdout); /* was putchar() */
- putc(magic_header[1], nustdout); /* was putchar() */
- putc((char)(maxbits | block_compress), nustdout); /*was putchar*/
- if(ferror(nustdout)){ /* check it on entry */
- exit_stat = WRITEERR;
- return;
- }
- bytes_out = 3L; /* includes 3-byte header mojo */
- }
- else
- bytes_out = 0L; /* no 3-byte header mojo */
- in_count = 1L;
- offset = 0;
-
- if ((c = getc(nustdin)) == EOF) { /* NuLib: was getchar() */
- exit_stat = ferror(nustdin) ? READERR : OK;
- return;
- }
- prefxcode = (CODE)c;
-
- while ((c = getc(nustdin)) != EOF) { /* NuLib: was getchar() */
- in_count++;
-
-/* NuLib : May not be compressing entire file, so can't rely on EOF for end */
- if (in_count > thread_eof) break;
-
- hash = prefxcode ^ hashf[c];
- /* I need to check that my hash value is within range
- * because my 16-bit hash table is smaller than 64k.
- */
- if (hash >= hashsize)
- hash -= hashsize;
- if ((code = probe(hash)) != UNUSED) {
- if (suffix(code) != (char)c || prefix(code) != prefxcode) {
- /* hashdelta is subtracted from hash on each iteration of
- * the following hash table search loop. I compute it once
- * here to remove it from the loop.
- */
- HASH hashdelta = (0x120 - c) << (adjbits);
- do {
- /* rehash and keep looking */
- assert(code >= FIRSTFREE && code <= maxcode);
- if (hash >= hashdelta) hash -= hashdelta;
- else hash += (hashsize - hashdelta);
- assert(hash < hashsize);
- if ((code = probe(hash)) == UNUSED)
- goto newcode;
- } while (suffix(code) != (char)c || prefix(code) != prefxcode);
- }
- prefxcode = code;
- }
- else {
- newcode: {
- putcode(prefxcode, bits);
- code = nextfree;
- assert(hash < hashsize);
- assert(code >= FIRSTFREE);
- assert(code <= maxcode + 1);
- if (code <= maxcode) {
- probe(hash) = code;
- prefix(code) = prefxcode;
- suffix(code) = (char)c;
- if (code > highcode) {
- highcode += code;
- ++bits;
- }
- nextfree = code + 1;
- }
-#ifdef COMP40
- else if (in_count >= checkpoint && block_compress ) {
- if (cl_block()){
-#else
- else if (block_compress){
-#endif
- putcode((CODE)c, bits);
- putcode((CODE)CLEAR,bits);
- init_tables();
- if ((c = getc(nustdin)) == EOF) /* NuLib: was getchar*/
- break;
- in_count++;
-#ifdef COMP40
- }
-#endif
- }
- prefxcode = (CODE)c;
- }
- }
- }
- putcode(prefxcode, bits);
- putcode((CODE)CLEAR, 0);
- if (ferror(nustdout)){ /* check it on exit */
- exit_stat = WRITEERR;
- return;
- }
- /*
- * Print out stats on stderr
- */
- if(zcat_flg == 0 && !quiet) {
-#ifndef NDEBUG
- fprintf( stderr,
- "%ld chars in, (%ld bytes) out, compression factor: ",
- in_count, bytes_out );
- prratio( stderr, in_count, bytes_out );
- fprintf( stderr, "\n");
- fprintf( stderr, "\tCompression as in compact: " );
- prratio( stderr, in_count-bytes_out, in_count );
- fprintf( stderr, "\n");
- fprintf( stderr, "\tLargest code (of last block) was %d (%d bits)\n",
- prefxcode - 1, bits );
-#else
- fprintf( stderr, "Compression: " );
- prratio( stderr, in_count-bytes_out, in_count );
-#endif /* NDEBUG */
- }
- if(bytes_out > in_count) /* if no savings */
- exit_stat = NOSAVING;
-
- packedSize = bytes_out; /* NuLib : return packed size in global */
-
- return ;
-}
-
-CONST UCHAR rmask[9] = {0x00, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f, 0xff};
-
-void putcode(code,bits)
-CODE code;
-register int bits;
-{
- static UCHAR outbuf[MAXBITS];
- register UCHAR *buf;
- register int shift;
- register int ok_to_write; /* NuLib (kludge... sorry) */
-
- ok_to_write = (exit_stat != NOSAVING);
-
- if (bits != oldbits) {
- if (bits == 0) {
- /* bits == 0 means EOF, write the rest of the buffer. */
- if (offset > 0) {
- int x = ((offset+7) >> 3); /* NuLib */
-
- if ((bytes_out + x) > max_bytes_out) { /* NuLib */
- /* compression failed. There's no clean way of bailing out
- /* (could use setjmp/longjmp, but that may not be supported
- /* on all systems), so just don't write anything.
- */
- exit_stat = NOSAVING;
- ok_to_write = FALSE;
- } else {
-/* fwrite(outbuf,1,(offset +7) >> 3, nustdout);*/
- fwrite(outbuf,1, x, nustdout);
- }
-/* bytes_out += ((offset +7) >> 3);*/
- bytes_out += x;
- }
- offset = 0;
- oldbits = 0;
- fflush(nustdout);
- return;
- }
- else {
- /* Change the code size. We must write the whole buffer,
- * because the expand side won't discover the size change
- * until after it has read a buffer full.
- */
- if (offset > 0) {
- if (ok_to_write) fwrite(outbuf, 1, oldbits, nustdout);
- bytes_out += oldbits;
- offset = 0;
- }
- oldbits = bits;
-#ifndef NDEBUG
- if ( debug )
- fprintf( stderr, "\nChange to %d bits\n", bits );
-#endif /* !NDEBUG */
- }
- }
- /* Get to the first byte. */
- buf = outbuf + ((shift = offset) >> 3);
- if ((shift &= 7) != 0) {
- *(buf) |= (*buf & rmask[shift]) | (UCHAR)(code << shift);
- *(++buf) = (UCHAR)(code >> (8 - shift));
- if (bits + shift > 16)
- *(++buf) = (UCHAR)(code >> (16 - shift));
- }
- else {
- /* Special case for fast execution */
- *(buf) = (UCHAR)code;
- *(++buf) = (UCHAR)(code >> 8);
- }
- if ((offset += bits) == (bits << 3)) {
- bytes_out += bits;
- if (ok_to_write) fwrite(outbuf,1,bits,nustdout);
- offset = 0;
- }
- return;
-}
-
-int nextcode(codeptr)
-CODE *codeptr;
-/* Get the next code from input and put it in *codeptr.
- * Return (TRUE) on success, or return (FALSE) on end-of-file.
- * Adapted from COMPRESS V4.0.
- */
-{
- register CODE code;
- static int size;
- static UCHAR inbuf[MAXBITS];
- register int shift;
- UCHAR *bp;
-
- /* If the next entry is a different bit-size than the preceeding one
- * then we must adjust the size and scrap the old buffer.
- */
- if (prevbits != bits) {
- prevbits = bits;
- size = 0;
- }
- /* If we can't read another code from the buffer, then refill it.
- */
- if (size - (shift = offset) < bits) {
- static int bytesize; /* NuLib: sigh */
- /* Read more input and convert size from # of bytes to # of bits */
-
- /* NuLib: stop after comp_thread_eof bytes */
- if (nubytes_read >= nucomp_thread_eof)
- return(NO);
-
- /* NuLib: replace old fread command with... */
- /*
- if ((size = fread(inbuf, 1, bits, nustdin) << 3) <= 0 || ferror(nustdin))
- return(NO);
- */
-
- bytesize = fread(inbuf, 1, bits, nustdin);
- if (nubytes_read + bits > nucomp_thread_eof) {
- bytesize = nucomp_thread_eof - nubytes_read;
- }
- size = bytesize << 3;
- if (size <= 0 || ferror(nustdin))
- return (NO);
-
- /* NuLib: increment nubytes_read */
- nubytes_read += (long) bytesize;
-
- offset = shift = 0;
- }
- /* Get to the first byte. */
- bp = inbuf + (shift >> 3);
- /* Get first part (low order bits) */
- code = (*bp++ >> (shift &= 7));
- /* high order bits. */
- code |= *bp++ << (shift = 8 - shift);
- if ((shift += 8) < bits) code |= *bp << shift;
- *codeptr = code & highcode;
- offset += bits;
- return (TRUE);
-}
-
-/*
- * NuLib: uncompress comp_thread_eof bytes from srcfd, writing to dstfd
- * Sets up a few things and then calls compress.
- */
-int u_decompress(srcfd, dstfd, comp_thread_eof)
-int srcfd, dstfd;
-long comp_thread_eof;
-{
- int src2, dst2;
- long srcposn, dstposn;
- static char *procName = "u_decompress";
-
- if ((srcposn = lseek(srcfd, 0L, S_REL)) < 0)
- Fatal("Bad posn lseek(1)", procName);
- if ((dstposn = lseek(dstfd, 0L, S_REL)) < 0)
- Fatal("Bad posn lseek(2)", procName);
-
- src2 = dup(srcfd);
- dst2 = dup(dstfd);
-
- /* NuLib: open new stdin/stdout, and seek */
- if ((nustdin = fdopen(src2, FREAD_STR)) == NULL)
- Fatal("can't fdopen() nustdin", procName);
- if ((nustdout = fdopen(dst2, FWRITE_STR)) == NULL)
- Fatal("can't fdopen() nustdout", procName);
- setvbuf(nustdin,zbuf,_IOFBF,ZBUFSIZE); /* make the buffers larger */
- setvbuf(nustdout,xbuf,_IOFBF,XBUFSIZE); /* (note order diff from comp) */
- if (fseek(nustdin, srcposn, S_ABS) < 0) /* seek may not be needed */
- Fatal("Bad stream posn lseek(1)", procName);
- if (fseek(nustdout, dstposn, S_ABS) < 0)
- Fatal("Bad stream posn lseek(2)", procName);
-
- /* Check the magic number */
- if (!nomagic) {
- if ((getc(nustdin)!=(magic_header[0] & 0xFF)) /* NuLib: was getchar*/
- || (getc(nustdin)!=(magic_header[1] & 0xFF))) {/* NuLib: was getchar*/
- fprintf(stderr, "decompress: not in compressed format\n");
- return(-1); /* NuLib: was exit(ERROR) */
- }
- maxbits = getc(nustdin); /* set -b from file (NuLib: was getchar) */
- block_compress = maxbits & BLOCK_MASK;
- maxbits &= BIT_MASK;
- if(maxbits > MAXBITS) {
- fprintf(stderr,
- "decompress: compressed with %d bits, can only handle %d bits\n",
- maxbits, MAXBITS);
- return(-1); /* NuLib: was exit(ERROR) */
- }
- nubytes_read = 3L;
- } else {
- nubytes_read = 0L;
- }
-
- nucomp_thread_eof = comp_thread_eof;
-/* printf("src file posn = %ld\n", ftell(nustdin));*/
- prevbits = 0; /* init for nextcode() */
- decompress();
- check_error();
-
- fclose(nustdin); /* note this closes the duped fd */
- fclose(nustdout);
- return (exit_stat);
-}
-
-void decompress()
-{
- register int i;
- register CODE code;
- char sufxchar;
- CODE savecode;
- FLAG fulltable, cleartable;
- static char token[MAXTOKLEN]; /* String buffer to build token */
-
- exit_stat = OK;
-
- if (alloc_tables(maxcode = ~(~(CODE)0 << maxbits),0)) /* exit_stat already set */
- return;
-
- /* if not zcat or filter (NuLib: never) */
- if(is_list && !zcat_flg) { /* Open output file */
- if (freopen(ofname, WRITE_FILE_TYPE, nustdout) == NULL) {
- exit_stat = NOTOPENED;
- return;
- }
- if (!quiet)
- fprintf(stderr, "%s: ",ifname);
- setvbuf(nustdout,xbuf,_IOFBF,XBUFSIZE);
- }
- cleartable = TRUE;
- savecode = CLEAR;
- offset = 0;
- do {
- if ((code = savecode) == CLEAR && cleartable) {
- highcode = ~(~(CODE)0 << (bits = INITBITS));
- fulltable = FALSE;
- nextfree = (cleartable = block_compress) == FALSE ? 256 : FIRSTFREE;
- if (!nextcode(&prefxcode))
- break;
- putc((sufxchar = (char)prefxcode), nustdout);
- continue;
- }
- i = 0;
- if (code >= nextfree && !fulltable) {
- if (code != nextfree){
- exit_stat = CODEBAD;
-/* fprintf(stderr, "Bad code; nubytes_read = %ld\n", nubytes_read); */
- /* CDEBUG */
- return ; /* Non-existant code */
- }
- /* Special case for sequence KwKwK (see text of article) */
- code = prefxcode;
- token[i++] = sufxchar;
- }
- /* Build the token string in reverse order by chasing down through
- * successive prefix tokens of the current token. Then output it.
- */
- while (code >= 256) {
-#ifndef NDEBUG
- /* These are checks to ease paranoia. Prefix codes must decrease
- * monotonically, otherwise we must have corrupt tables. We can
- * also check that we haven't overrun the token buffer.
- */
- if (code <= prefix(code)){
- exit_stat= TABLEBAD;
- return;
- }
- if (i >= MAXTOKLEN){
- exit_stat = TOKTOOBIG;
- return;
- }
-#endif
- token[i++] = suffix(code);
- code = prefix(code);
- }
- putc(sufxchar = (char)code, nustdout);
- while (--i >= 0)
- putc(token[i], nustdout);
- if (ferror(nustdout)) {
- exit_stat = WRITEERR;
- return;
- }
- /* If table isn't full, add new token code to the table with
- * codeprefix and codesuffix, and remember current code.
- */
- if (!fulltable) {
- code = nextfree;
- assert(256 <= code && code <= maxcode);
- prefix(code) = prefxcode;
- suffix(code) = sufxchar;
- prefxcode = savecode;
- if (code++ == highcode) {
- if (highcode >= maxcode) {
- fulltable = TRUE;
- --code;
- }
- else {
- ++bits;
- highcode += code; /* nextfree == highcode + 1 */
- }
- }
- nextfree = code;
- }
-
- } while (nextcode(&savecode));
- exit_stat = (ferror(nustdin))? READERR : OK;
-
- return ;
-}
-
-
-/*
- * These are routines pulled out of "compress.c" from compress v4.3.
- */
-void prratio(stream, num, den)
-FILE *stream;
-long int num, den;
-{
- register int q; /* Doesn't need to be long */
-
- if(num > 214748L) { /* 2147483647/10000 */
- q = (int) (num / (den / 10000L));
- }
- else {
- q = (int) (10000L * num / den); /* Long calculations, though */
- }
- if (q < 0) {
- putc('-', stream);
- q = -q;
- }
- fprintf(stream, "%d.%02d%%", q / 100, q % 100);
-}
-
-/*
- * Check exit status from compress() and decompress()
- *
- * exit_stat is a global var. Either returns something interesting or
- * bails out completely.
- */
-int check_error() /* returning OK continues with processing next file */
-{
- prog_name = prgName; /* NuLib: set prog_name to "nulib" */
-
- switch(exit_stat) {
- case OK:
- return (OK);
- case NOMEM:
- if (do_decomp)
- fprintf(stderr,"%s: not enough memory to decompress '%s'.\n", prog_name, ifname);
- else
- fprintf(stderr,"%s: not enough memory to compress '%s'.\n", prog_name, ifname);
- return(OK);
- case SIGNAL_ERROR:
- fprintf(stderr,"%s: error setting signal interupt.\n",prog_name);
- exit(ERROR);
- break;
- case READERR:
- fprintf(stderr,"%s: read error on input '%s'.\n", prog_name, ifname);
- break;
- case WRITEERR:
- fprintf(stderr,"%s: write error on output '%s'.\n", prog_name, ofname);
- break;
- case TOKTOOBIG:
- fprintf(stderr,"%s: token too long in '%s'.\n", prog_name, ifname);
- break;
- case INFILEBAD:
- fprintf(stderr, "%s: '%s' in unknown compressed format.\n", prog_name, ifname);
- break;
- case CODEBAD:
- fprintf(stderr,"%s: file token bad in '%s'.\n", prog_name,ifname);
- break;
- case TABLEBAD:
- fprintf(stderr,"%s: internal error -- tables corrupted.\n", prog_name);
- break;
- case NOTOPENED:
- fprintf(stderr,"%s: could not open output file %s\n",prog_name,ofname);
- exit(ERROR);
- break;
- case NOSAVING:
- if (force)
- exit_stat = OK;
- return (OK);
- default:
- fprintf(stderr,"%s: internal error -- illegal return value = %d.\n", prog_name,exit_stat);
- }
- if (!zcat_flg && !keep_error){
- fclose(nustdout); /* won't get here without an error */
- unlink ( ofname );
- }
- exit(exit_stat);
- return(ERROR);
-}
-
-/*
- * These are routines from "compusi.c"
- */
-void version()
-{
-#ifdef XENIX
-#ifndef NDEBUG
- fprintf(stderr, "%s\nOptions: Xenix %s MAXBITS = %d\n", rcs_ident,
- "DEBUG",MAXBITS);
-#else
- fprintf(stderr, "%s\nOptions: Xenix MAXBITS = %d\n", rcs_ident,MAXBITS);
-#endif
-#else
-#ifndef NDEBUG
- fprintf(stderr, "%s\nOptions: Unix %s MAXBITS = %d\n", rcs_ident,
- "DEBUG",MAXBITS);
-#else
- fprintf(stderr, "%s\nOptions: Unix MAXBITS = %d\n", rcs_ident,MAXBITS);
-#endif
-#endif
-}
-
-ALLOCTYPE FAR *emalloc(x,y)
-unsigned int x;
-int y;
-{
- ALLOCTYPE FAR *p;
- p = (ALLOCTYPE FAR *)ALLOCATE(x,y);
- return(p);
-}
-
-void efree(ptr)
-ALLOCTYPE FAR *ptr;
-{
- FREEIT(ptr);
-}
-
+ END OF ARCHIVE