ewilts%Ins.MRC.AdhocNet.CA%Stasis.MRC.AdhocNet.CA%UNCAEDU.@CORNELLC.CCS.CORNELL.EDU.BITNET (Ed Wilts) (06/24/88)
$Part17:
$ File_is="ARCUNP.C"
$ Check_Sum_is=705508013
$ Copy SYS$Input VMS_SHAR_DUMMY.DUMMY
Xstatic char *RCSid = "$Header: arcunp.c,v 1.2 86/07/15 07:54:25 turner Exp $";
X
X/*
X * $Log:`009arcunp.c,v $
X * Hack-attack 1.3 86/12/20 01:23:45 wilhite@usceast.uucp
X * `009Bludgeoned into submission for VAX 11/780 BSD4.2
X *`009(ugly code, but fewer core dumps)
X *
X * Revision 1.2 86/07/15 07:54:25 turner
X *
X *
X * Revision 1.1 86/06/26 15:01:04 turner
X * initial version
X *
X *
X */
X
X/* ARC - Archive utility - ARCUNP
X
X$define(tag,$$segment(@1,$$index(@1,=)+1))#
X$define(version,Version $tag(
XTED_VERSION DB =3.16), created on $tag(
XTED_DATE DB =02/03/86) at $tag(
XTED_TIME DB =23:01:16))#
X$undefine(tag)#
X $version
X
X(C) COPYRIGHT 1985 by System Enhancement Associates; ALL RIGHTS RESERVED
X
X By: Thom Henderson
X
X Description:
X This file contains the routines used to expand a file
X when taking it out of an archive.
X
X Language:
X Computer Innovations Optimizing C86
X*/
X#include <stdio.h>
X#include "arc.h"
X
X/* stuff for repeat unpacking */
X
X#define DLE 0x90 /* repeat byte flag */
X
Xstatic INT state; /* repeat unpacking state */
X
X/* repeat unpacking states */
X
X#define NOHIST 0 /* no relevant history */
X#define INREP 1 /* sending a repeated value */
X
Xstatic INT crcval; /* CRC check value */
Xstatic long size; /* bytes to read */
X
XINT unpack(f,t,hdr) /* unpack an archive entry */
XFILE *f, *t; /* source, destination */
Xstruct heads *hdr; /* pointer to file header data */
X{
X INT c; /* one char of stream */
X INT putc_unp();
X INT putc_ncr();
X INT getc_unp();
X
X /* setups common to all methods */
X
X crcval = 0; /* reset CRC check value */
X size = hdr->size; /* set input byte counter */
X state = NOHIST; /* initial repeat unpacking state */
X setcode(); /* set up for decoding */
X
X /* use whatever method is appropriate */
X
X switch(hdrver) /* choose proper unpack method */
X {
X case 1: /* standard packing */
X case 2:
X while((c=getc_unp(f))!=EOF)
X putc_unp(c,t);
X break;
X
X case 3: /* non-repeat packing */
X while((c=getc_unp(f))!=EOF)
X putc_ncr(c,t);
X break;
X
X case 4: /* Huffman squeezing */
X init_usq(f);
X while((c=getc_usq(f))!=EOF)
X putc_ncr(c,t);
X break;
X
X case 5: /* Lempel-Zev compression */
X init_ucr(0);
X while((c=getc_ucr(f))!=EOF)
X putc_unp(c,t);
X break;
X
X case 6: /* Lempel-Zev plus non-repeat */
X init_ucr(0);
X while((c=getc_ucr(f))!=EOF)
X putc_ncr(c,t);
X break;
X
X case 7: /* L-Z plus ncr with new hash */
X init_ucr(1);
X while((c=getc_ucr(f))!=EOF)
X putc_ncr(c,t);
X break;
X
X case 8: /* dynamic Lempel-Zev */
X decomp(f,t);
X break;
X
X case 9:
X`009 sqdecomp(f,t);
X`009 break;
X
X default: /* unknown method */
X if(warn)
X { printf("I don't know how to unpack file %s\n",hdr->name);
X printf("I think you need a newer version of ARC\n");
X nerrs++;
X }
X fseek(f,hdr->size,1); /* skip over bad file */
X return 1; /* note defective file */
X }
X
X /* cleanups common to all methods */
X
X if((crcval&0xffff)!=(hdr->crc&0x0000ffff))
X { if(warn)
X { printf("WARNING: File %s fails CRC check\n",hdr->name);
X nerrs++;
X }
X return 1; /* note defective file */
X }
X return 0; /* file is okay */
X}
X
X/* This routine is used to put bytes in the output file. It also
X performs various housekeeping functions, such as maintaining the
X CRC check value.
X*/
X
XINT putc_unp(c,t) /* output an unpacked byte */
Xchar c; /* byte to output */
XFILE *t; /* file to output to */
X{
X crcval = addcrc(crcval,c); /* update the CRC check value */
X putc_tst(c,t);
X}
X
X/* This routine is used to decode non-repeat compression. Bytes are
X passed one at a time in coded format, and are written out uncoded.
X The data is stored normally, except that runs of more than two
X characters are represented as:
X
X <char> <DLE> <count>
X
X With a special case that a count of zero indicates a DLE as data,
X not as a repeat marker.
X*/
X
XINT putc_ncr(c,t) /* put NCR coded bytes */
Xunsigned char c; /* next byte of stream */
XFILE *t; /* file to receive data */
X{
X static INT lastc; /* last character seen */
X
X switch(state) /* action depends on our state */
X {
X case NOHIST: /* no previous history */
X if(c==DLE) /* if starting a series */
X state = INREP; /* then remember it next time */
X else putc_unp(lastc=c,t); /* else nothing unusual */
X return;
X
X case INREP: /* in a repeat */
X if(c) /* if count is nonzero */
X while(--c) /* then repeatedly ... */
X putc_unp(lastc,t); /* ... output the byte */
X else putc_unp(DLE,t); /* else output DLE as data */
X state = NOHIST; /* back to no history */
X return;
X
X default:
X abort("Bad NCR unpacking state (%d)",state);
X }
X}
X
X/* This routine provides low-level byte input from an archive. This
X routine MUST be used, as end-of-file is simulated at the end of
X the archive entry.
X*/
X
XINT getc_unp(f) /* get a byte from an archive */
XFILE *f; /* archive file to read */
X{
X if(!size) /* if no data left */
X return EOF; /* then pretend end of file */
X
X size--; /* deduct from input counter */
X return code(fgetc(f)); /* and return next decoded byte */
X}
X
$ GoSub Convert_File
$ File_is="ARCUSQ.C"
$ Check_Sum_is=85750201
$ Copy SYS$Input VMS_SHAR_DUMMY.DUMMY
Xstatic char *RCSid = "$Header: arcusq.c,v 1.2 86/07/15 07:54:30 turner Exp $";
X
X/*
X * $Log:`009arcusq.c,v $
X * Hack-attack 1.3 86/12/20 01:23:45 wilhite@usceast.uucp
X * `009Bludgeoned into submission for VAX 11/780 BSD4.2
X *`009(ugly code, but fewer core dumps)
X *
X * Revision 1.2 86/07/15 07:54:30 turner
X *
X *
X * Revision 1.1 86/06/26 15:01:07 turner
X * initial version
X *
X *
X */
X
X/* ARC - Archive utility - ARCUSQ
X
X$define(tag,$$segment(@1,$$index(@1,=)+1))#
X$define(version,Version $tag(
XTED_VERSION DB =3.13), created on $tag(
XTED_DATE DB =01/30/86) at $tag(
XTED_TIME DB =20:11:42))#
X$undefine(tag)#
X $version
X
X(C) COPYRIGHT 1985 by System Enhancement Associates; ALL RIGHTS RESERVED
X
X By: Thom Henderson
X
X Description:
X This file contains the routines used to expand a file
X which was packed using Huffman squeezing.
X
X Most of this code is taken from an USQ program by Richard
X Greenlaw, which was adapted to CI-C86 by Robert J. Beilstein.
X
X Language:
X Computer Innovations Optimizing C86
X*/
X#include <stdio.h>
X#include "arc.h"
X
X/* stuff for Huffman unsqueezing */
X
X#define ERROR (-1)
X
X#define SPEOF 256 /* special endfile token */
X#define NUMVALS 257 /* 256 data values plus SPEOF */
X
XEXTERN struct nd /* decoding tree */
X{ INT child[2]; /* left, right */
X} node[NUMVALS]; /* use large buffer */
X
Xstatic INT bpos; /* last bit position read */
Xstatic INT curin; /* last byte value read */
Xstatic INT numnodes; /* number of nodes in decode tree */
X
Xstatic INT get_int(f) /* get an integer */
XFILE *f; /* file to get it from */
X{
X INT i;
X
X i = getc_unp(f);
X return (short)(i | (getc_unp(f)<<8));
X}
X
XINT init_usq(f) /* initialize Huffman unsqueezing */
XFILE *f; /* file containing squeezed data */
X{
X INT i; /* node index */
X
X bpos = 99; /* force initial read */
X
X numnodes = get_int(f);
X
X if(numnodes<0 || numnodes>=NUMVALS)
X abort("File has an invalid decode tree");
X
X /* initialize for possible empty tree (SPEOF only) */
X
X node[0].child[0] = -(SPEOF + 1);
X node[0].child[1] = -(SPEOF + 1);
X
X for(i=0; i<numnodes; ++i) /* get decoding tree from file */
X { node[i].child[0] = get_int(f);
X node[i].child[1] = get_int(f);
X }
X}
X
XINT getc_usq(f) /* get byte from squeezed file */
XFILE *f; /* file containing squeezed data */
X{
X INT i; /* tree index */
X
X /* follow bit stream in tree to a leaf */
X
X for(i=0; i>=0; ) /* work down(up?) from root */
X { if(++bpos>7)
X { if((curin=getc_unp(f)) == ERROR)
X return(ERROR);
X bpos = 0;
X
X /* move a level deeper in tree */
X i = node[i].child[1&curin];
X }
X else i = node[i].child[1 & (curin >>= 1)];
X }
X
X /* decode fake node index to original data value */
X
X i = -(i + 1);
X
X /* decode special endfile token to normal EOF */
X
X i = (i==SPEOF) ? EOF : i;
X return i;
X}
X
$ GoSub Convert_File
$ Goto Part18