ARC for System V R2 (2 of 3)
aeusemrs at csun.UUCP
aeusemrs at csun.UUCP
Tue Feb 3 12:13:21 AEST 1987
#! /bin/sh
# This is a shell archive, meaning:
# 1. Remove everything above the #! /bin/sh line.
# 2. Save the resulting text in a file.
# 3. Execute the file with /bin/sh (not csh) to create the files:
# arclzw.c
# arcmatch.c
# arcmisc.c
# arcpack.c
# This archive created: Mon Feb 2 17:59:35 1987
export PATH; PATH=/bin:$PATH
if test -f 'arclzw.c'
then
echo shar: will not over-write existing file "'arclzw.c'"
else
cat << \SHAR_EOF > 'arclzw.c'
/* ARC - Archive utility - ARCLZW
System V Version 1.0 based upon:
Version 1.88, created on 01/20/86 at 16:47:04
(C) COPYRIGHT 1985 by System Enhancement Associates; ALL RIGHTS RESERVED
By: Thom Henderson
Description:
This file contains the routines used to implement Lempel-Zev
data compression, which calls for building a coding table on
the fly. This form of compression is especially good for encoding
files which contain repeated strings, and can often give dramatic
improvements over traditional Huffman SQueezing.
Programming notes:
In this section I am drawing heavily on the COMPRESS program
from UNIX. The basic method is taken from "A Technique for High
Performance Data Compression", Terry A. Welch, IEEE Computer
Vol 17, No 6 (June 1984), pp 8-19. Also see "Knuth's Fundamental
Algorithms", Donald Knuth, Vol 3, Section 6.4.
As best as I can tell, this method works by tracing down a hash
table of code strings where each entry has the property:
if <string> <char> is in the table
then <string> is in the table.
*/
#include "arc.h"
/* definitions for older style crunching */
#define FALSE 0
#define TRUE !FALSE
#define TABSIZE 4096
#define NO_PRED 0xFFFF
#define EMPTY 0xFFFF
#define NOT_FND 0xFFFF
static unsigned INT inbuf; /* partial input code storage */
static INT sp; /* current stack pointer */
static struct entry /* string table entry format */
{ char used; /* true when this entry is in use */
unsigned INT next; /* ptr to next in collision list */
unsigned INT predecessor; /* code for preceeding string */
unsigned char follower; /* char following string */
} string_tab[TABSIZE]; /* the code string table */
/* definitions for the new dynamic Lempel-Zev crunching */
#define BITS 12 /* maximum bits per code */
#define HSIZE 5003 /* 80% occupancy */
#define INIT_BITS 9 /* initial number of bits/code */
static INT n_bits; /* number of bits/code */
static INT maxcode; /* maximum code, given n_bits */
#define MAXCODE(n) ((1<<(n)) - 1) /* maximum code calculation */
static INT maxcodemax = 1 << BITS; /* largest possible code (+1) */
static unsigned char buf[BITS]; /* input/output buffer */
static unsigned char lmask[9] = /* left side masks */
{ 0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80, 0x00 };
static unsigned char rmask[9] = /* right side masks */
{ 0x00, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f, 0xff};
static INT offset; /* byte offset for code output */
static long in_count; /* length of input */
static long bytes_out; /* length of compressed output */
static unsigned INT ent;
/* To save much memory (which we badly need at this point), we overlay
* the table used by the previous version of Lempel-Zev with those used
* by the new version. Since no two of these routines will be used
* together, we can safely do this. Note that the tables used for Huffman
* squeezing may NOT overlay these, since squeezing and crunching are done
* in parallel.
*/
static long htab[HSIZE]; /* hash code table (crunch) */
static unsigned INT codetab[HSIZE]; /* string code table (crunch) */
static unsigned INT *prefix = codetab; /* prefix code table (uncrunch) */
static unsigned char suffix[HSIZE]; /* suffix table (uncrunch) */
static INT free_ent; /* first unused entry */
static INT firstcmp; /* true at start of compression */
static unsigned char stack[HSIZE]; /* local push/pop stack */
/*
* block compression parameters -- after all codes are used up,
* and compression rate changes, start over.
*/
static INT clear_flg;
static long ratio;
#define CHECK_GAP 10000 /* ratio check interval */
static long checkpoint;
/*
* the next two codes should not be changed lightly, as they must not
* lie within the contiguous general code space.
*/
#define FIRST 257 /* first free entry */
#define CLEAR 256 /* table clear output code */
static INT cl_block(t) /* table clear for block compress */
FILE *t; /* our output file */
{
long rat;
INT putcode();
checkpoint = in_count + CHECK_GAP;
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;
else
{ ratio = 0;
setmem (htab,HSIZE*sizeof(long),0xff);
free_ent = FIRST;
clear_flg = 1;
putcode(CLEAR,t);
}
}
/*****************************************************************
*
* Output a given code.
* Inputs:
* code: A n_bits-bit integer. If == -1, then EOF. This assumes
* that n_bits =< (long)wordsize - 1.
* Outputs:
* Outputs code to the file.
* Assumptions:
* Chars are 8 bits long.
* Algorithm:
* Maintain a BITS character long buffer (so that 8 codes will
* fit in it exactly). When the buffer fills up empty it and start over.
*/
static INT putcode(code,t) /* output a code */
INT code; /* code to output */
FILE *t; /* where to put it */
{
INT r_off = offset; /* right offset */
INT bits = n_bits; /* bits to go */
unsigned char *bp = buf; /* buffer pointer */
INT n; /* index */
if(code >= 0) /* if a real code */
{ /*
* Get to the first byte.
*/
bp += (r_off >> 3);
r_off &= 7;
/*
* Since code is always >= 8 bits, only need to mask the first
* hunk on the left.
*/
*bp = (*bp&rmask[r_off]) | (code<<r_off) & lmask[r_off];
bp++;
bits -= (8 - r_off);
code >>= (8 - r_off);
/* Get any 8 bit parts in the middle (<=1 for up to 16 bits). */
if(bits >= 8)
{ *bp++ = code;
code >>= 8;
bits -= 8;
}
/* Last bits. */
if(bits)
*bp = code;
offset += n_bits;
if(offset == (n_bits << 3))
{ bp = buf;
bits = n_bits;
bytes_out += bits;
do
putc_pak(*bp++,t);
while(--bits);
offset = 0;
}
/*
* If the next entry is going to be too big for the code size,
* then increase it, if possible.
*/
if(free_ent>maxcode || clear_flg>0)
{ /*
* Write the whole buffer, because the input side won't
* discover the size increase until after it has read it.
*/
if(offset > 0)
{ bp = buf; /* reset pointer for writing */
bytes_out += n = n_bits;
while(n--)
putc_pak(*bp++,t);
}
offset = 0;
if(clear_flg) /* reset if clearing */
{ maxcode = MAXCODE(n_bits = INIT_BITS);
clear_flg = 0;
}
else /* else use more bits */
{ n_bits++;
if(n_bits == BITS)
maxcode = maxcodemax;
else
maxcode = MAXCODE(n_bits);
}
}
}
else /* dump the buffer on EOF */
{ bytes_out += n = (offset+7) / 8;
if(offset > 0)
while(n--)
putc_pak(*bp++,t);
offset = 0;
}
}
/*****************************************************************
*
* Read one code from the standard input. If EOF, return -1.
* Inputs:
* cmpin
* Outputs:
* code or -1 is returned.
*/
static INT getcode(f) /* get a code */
FILE *f; /* file to get from */
{
INT code;
static INT offset = 0, size = 0;
INT r_off, bits;
unsigned char *bp = buf;
if(clear_flg > 0 || offset >= size || free_ent > maxcode)
{ /*
* If the next entry will be too big for the current code
* size, then we must increase the size. This implies reading
* a new buffer full, too.
*/
if(free_ent > maxcode)
{ n_bits++;
if(n_bits == BITS)
maxcode = maxcodemax; /* won't get any bigger now */
else maxcode = MAXCODE(n_bits);
}
if(clear_flg > 0)
{ maxcode = MAXCODE(n_bits = INIT_BITS);
clear_flg = 0;
}
for(size=0; size<n_bits; size++)
{ if((code=getc_unp(f))==EOF)
break;
else buf[size] = code;
}
if(size <= 0)
return -1; /* end of file */
offset = 0;
/* Round size down to integral number of codes */
size = (size << 3)-(n_bits - 1);
}
r_off = offset;
bits = n_bits;
/*
* Get to the first byte.
*/
bp +=(r_off >> 3);
r_off &= 7;
/* Get first part (low order bits) */
code = (*bp++ >> r_off);
bits -= 8 - r_off;
r_off = 8 - r_off; /* now, offset into code word */
/* Get any 8 bit parts in the middle (<=1 for up to 16 bits). */
if(bits >= 8)
{ code |= *bp++ << r_off;
r_off += 8;
bits -= 8;
}
/* high order bits. */
code |= (*bp & rmask[bits]) << r_off;
offset += n_bits;
return code;
}
/*
* compress a file
*
* 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 do block compression with
* an adaptive reset, where the code table is cleared when the compression
* ratio decreases, but after the table fills. The variable-length output
* codes are re-sized at this point, and a special CLEAR code is generated
* for the decompressor.
*/
INT init_cm(f,t) /* initialize for compression */
FILE *f; /* file we will be compressing */
FILE *t; /* where we will put it */
{
offset = 0;
bytes_out = 1;
clear_flg = 0;
ratio = 0;
in_count = 1;
checkpoint = CHECK_GAP;
maxcode = MAXCODE(n_bits = INIT_BITS);
free_ent = FIRST;
setmem(htab,HSIZE*sizeof(long),0xff);
n_bits = INIT_BITS; /* set starting code size */
putc_pak(BITS,t); /* note our max code length */
firstcmp = 1; /* next byte will be first */
}
INT putc_cm(c,t) /* compress a character */
unsigned char c; /* character to compress */
FILE *t; /* where to put it */
{
static long fcode;
static INT hshift;
INT i;
INT disp;
if(firstcmp) /* special case for first byte */
{ ent = c; /* remember first byte */
hshift = 0;
for(fcode=(long)HSIZE; fcode<65536L; fcode*=2L)
hshift++;
hshift = 8 - hshift; /* set hash code range bund */
firstcmp = 0; /* no longer first */
return;
}
in_count++;
fcode =(long)(((long)c << BITS)+ent);
i = (c<<hshift)^ent; /* xor hashing */
if(htab[i]==fcode)
{ ent = codetab[i];
return;
}
else if(htab[i]<0) /* empty slot */
goto nomatch;
disp = HSIZE - i; /* secondary hash (after G.Knott) */
if(i == 0)
disp = 1;
probe:
if((i -= disp) < 0)
i += HSIZE;
if(htab[i] == fcode)
{ ent = codetab[i];
return;
}
if(htab[i] > 0)
goto probe;
nomatch:
putcode(ent,t);
ent = c;
if(free_ent < maxcodemax)
{ codetab[i] = free_ent++; /* code -> hashtable */
htab[i] = fcode;
}
else if((long)in_count >= checkpoint)
cl_block(t);
}
long pred_cm(t) /* finish compressing a file */
FILE *t; /* where to put it */
{
putcode(ent,t); /* put out the final code */
putcode(-1,t); /* tell output we are done */
return bytes_out; /* say how big it got */
}
/*
* Decompress a file. 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. See the definitions above.
*/
INT decomp(f,t) /* decompress a file */
FILE *f; /* file to read codes from */
FILE *t; /* file to write text to */
{
unsigned char *stackp;
INT finchar;
INT code, oldcode, incode;
if((code=getc_unp(f))!=BITS)
abort("File packed with %d bits, I can only handle %d",code,BITS);
n_bits = INIT_BITS; /* set starting code size */
clear_flg = 0;
/*
* As above, initialize the first 256 entries in the table.
*/
maxcode = MAXCODE(n_bits=INIT_BITS);
for(code = 255; code >= 0; code--)
{ prefix[code] = 0;
suffix[code] = (unsigned char)code;
}
free_ent = FIRST;
finchar = oldcode = getcode(f);
if(oldcode == -1) /* EOF already? */
return; /* Get out of here */
putc_ncr((char)finchar,t); /* first code must be 8 bits=char */
stackp = stack;
while((code = getcode(f))> -1)
{ if(code==CLEAR)
{ for(code = 255; code >= 0; code--)
prefix[code] = 0;
clear_flg = 1;
free_ent = FIRST - 1;
if((code=getcode(f))==-1)/* O, untimely death! */
break;
}
incode = code;
/*
* Special case for KwKwK string.
*/
if(code >= free_ent)
{ *stackp++ = finchar;
code = oldcode;
}
/*
* Generate output characters in reverse order
*/
while(code >= 256)
{ *stackp++ = suffix[code];
code = prefix[code];
}
*stackp++ = finchar = suffix[code];
/*
* And put them out in forward order
*/
do
putc_ncr(*--stackp,t);
while(stackp > stack);
/*
* Generate the new entry.
*/
if((code=free_ent) < maxcodemax)
{ prefix[code] = (unsigned short)oldcode;
suffix[code] = finchar;
free_ent = code+1;
}
/*
* Remember previous code.
*/
oldcode = incode;
}
}
/*************************************************************************
* Please note how much trouble it can be to maintain upwards *
* compatibility. All that follows is for the sole purpose of unpacking *
* files which were packed using an older method. *
*************************************************************************/
/* The h() pointer points to the routine to use for calculating a hash
value. It is set in the init routines to point to either of oldh()
or newh().
oldh() calculates a hash value by taking the middle twelve bits
of the square of the key.
newh() works somewhat differently, and was tried because it makes
ARC about 23% faster. This approach was abandoned because dynamic
Lempel-Zev (above) works as well, and packs smaller also. However,
inadvertent release of a developmental copy forces us to leave this in.
*/
static unsigned INT (*h)(); /* pointer to hash function */
static unsigned INT oldh(pred,foll) /* old hash function */
unsigned INT pred; /* code for preceeding string */
unsigned char foll; /* value of following char */
{
long local; /* local hash value */
local = (pred + foll) | 0x0800; /* create the hash key */
local *= local; /* square it */
return (local >> 6) & 0x0FFF; /* return the middle 12 bits */
}
static unsigned INT newh(pred,foll) /* new hash function */
unsigned INT pred; /* code for preceeding string */
unsigned char foll; /* value of following char */
{
return ((pred+foll)*15073)&0xFFF; /* faster hash */
}
/* The eolist() function is used to trace down a list of entries with
duplicate keys until the last duplicate is found.
*/
static unsigned INT eolist(index) /* find last duplicate */
unsigned INT index;
{
INT temp;
while(temp=string_tab[index].next) /* while more duplicates */
index = temp;
return index;
}
/* The hash() routine is used to find a spot in the hash table for a new
entry. It performs a "hash and linear probe" lookup, using h() to
calculate the starting hash value and eolist() to perform the linear
probe. This routine DOES NOT detect a table full condition. That
MUST be checked for elsewhere.
*/
static unsigned INT hash(pred,foll) /* find spot in the string table */
unsigned INT pred; /* code for preceeding string */
unsigned char foll; /* char following string */
{
unsigned INT local, tempnext; /* scratch storage */
struct entry *ep; /* allows faster table handling */
local = (*h)(pred,foll); /* get initial hash value */
if(!string_tab[local].used) /* if that spot is free */
return local; /* then that's all we need */
else /* else a collision has occured */
{ local = eolist(local); /* move to last duplicate */
/* We must find an empty spot. We start looking 101 places
down the table from the last duplicate.
*/
tempnext = (local+101) & 0x0FFF;
ep = &string_tab[tempnext]; /* initialize pointer */
while(ep->used) /* while empty spot not found */
{ if(++tempnext==TABSIZE) /* if we are at the end */
{ tempnext = 0; /* wrap to beginning of table*/
ep = string_tab;
}
else ++ep; /* point to next element in table */
}
/* local still has the pointer to the last duplicate, while
tempnext has the pointer to the spot we found. We use
this to maintain the chain of pointers to duplicates.
*/
string_tab[local].next = tempnext;
return tempnext;
}
}
/* The unhash() function is used to search the hash table for a given key.
Like hash(), it performs a hash and linear probe search. It returns
either the number of the entry (if found) or NOT_FND (if not found).
*/
static unsigned INT unhash(pred,foll) /* search string table for a key */
unsigned INT pred; /* code of preceeding string */
unsigned char foll; /* character following string */
{
unsigned INT local, offset; /* scratch storage */
struct entry *ep; /* this speeds up access */
local = (*h)(pred,foll); /* initial hash */
while(1)
{ ep = &string_tab[local]; /* speed up table access */
if((ep->predecessor==pred) && (ep->follower==foll))
return local; /* we have a match */
if(!ep->next) /* if no more duplicates */
return NOT_FND; /* then key is not listed */
local = ep->next; /* move on to next duplicate */
}
}
/* The init_tab() routine is used to initialize our hash table.
You realize, of course, that "initialize" is a complete misnomer.
*/
static INT init_tab() /* set ground state in hash table */
{
unsigned INT i; /* table index */
INT upd_tab();
setmem((char *)string_tab,sizeof(string_tab),0);
for(i=0; i<256; i++) /* list all single byte strings */
upd_tab(NO_PRED,i);
inbuf = EMPTY; /* nothing is in our buffer */
}
/* The upd_tab routine is used to add a new entry to the string table.
As previously stated, no checks are made to ensure that the table
has any room. This must be done elsewhere.
*/
INT upd_tab(pred,foll) /* add an entry to the table */
unsigned INT pred; /* code for preceeding string */
unsigned INT foll; /* character which follows string */
{
struct entry *ep; /* pointer to current entry */
/* calculate offset just once */
ep = &string_tab[hash(pred,foll)];
ep->used = TRUE; /* this spot is now in use */
ep->next = 0; /* no duplicates after this yet */
ep->predecessor = pred; /* note code of preceeding string */
ep->follower = foll; /* note char after string */
}
/* This algorithm encoded a file into twelve bit strings (three nybbles).
The gocode() routine is used to read these strings a byte (or two)
at a time.
*/
static INT gocode(fd) /* read in a twelve bit code */
FILE *fd; /* file to get code from */
{
unsigned INT localbuf, returnval;
if(inbuf==EMPTY) /* if on a code boundary */
{ if((localbuf=getc_unp(fd))==EOF) /* get start of next code */
return EOF; /* pass back end of file status */
localbuf &= 0xFF; /* mask down to true byte value */
if((inbuf=getc_unp(fd))==EOF) /* get end of code, start of next */
return EOF; /* this should never happen */
inbuf &= 0xFF; /* mask down to true byte value */
returnval = ((localbuf<<4)&0xFF0) + ((inbuf>>4)&0x00F);
inbuf &= 0x000F; /* leave partial code pending */
}
else /* buffer contains first nybble */
{ if((localbuf=getc_unp(fd))==EOF)
return EOF;
localbuf &= 0xFF;
returnval = localbuf + ((inbuf<<8)&0xF00);
inbuf = EMPTY; /* note no hanging nybbles */
}
return returnval; /* pass back assembled code */
}
static INT push(c) /* push char onto stack */
INT c; /* character to push */
{
stack[sp] = ((char) c); /* coerce integer into a char */
if(++sp >= TABSIZE)
abort("Stack overflow\n");
}
static INT pop() /* pop character from stack */
{
if(sp>0)
return ((INT) stack[--sp]); /* leave ptr at next empty slot */
else return EMPTY;
}
/***** LEMPEL-ZEV DECOMPRESSION *****/
static INT code_count; /* needed to detect table full */
static unsigned INT code; /* where we are so far */
static INT firstc; /* true only on first character */
INT init_ucr(new) /* get set for uncrunching */
INT new; /* true to use new hash function */
{
if(new) /* set proper hash function */
h = newh;
else h = oldh;
sp = 0; /* clear out the stack */
init_tab(); /* set up atomic code definitions */
code_count = TABSIZE - 256; /* note space left in table */
firstc = 1; /* true only on first code */
}
INT getc_ucr(f) /* get next uncrunched byte */
FILE *f; /* file containing crunched data */
{
unsigned INT c; /* a character of input */
INT code, newcode;
static INT oldcode, finchar;
struct entry *ep; /* allows faster table handling */
if(firstc) /* first code is always known */
{ firstc = FALSE; /* but next will not be first */
oldcode = gocode(f);
return finchar = string_tab[oldcode].follower;
}
if(!sp) /* if stack is empty */
{ if((code=newcode=gocode(f))==EOF)
return EOF;
ep = &string_tab[code]; /* initialize pointer */
if(!ep->used) /* if code isn't known */
{ code = oldcode;
ep = &string_tab[code]; /* re-initialize pointer */
push(finchar);
}
while(ep->predecessor!=NO_PRED)
{ push(ep->follower); /* decode string backwards */
code = ep->predecessor;
ep = &string_tab[code];
}
push(finchar=ep->follower); /* save first character also */
/* The above loop will terminate, one way or another,
with string_tab[code].follower equal to the first
character in the string.
*/
if(code_count) /* if room left in string table */
{ upd_tab(oldcode,finchar);
--code_count;
}
oldcode = newcode;
}
return pop(); /* return saved character */
}
SHAR_EOF
fi # end of overwriting check
if test -f 'arcmatch.c'
then
echo shar: will not over-write existing file "'arcmatch.c'"
else
cat << \SHAR_EOF > 'arcmatch.c'
/* ARC - Archive utility - ARCMATCH
System V Version 1.0 based upon:
Version 2.17, created on 12/17/85) at 20:32:18
(C) COPYRIGHT 1985 by System Enhancement Associates; ALL RIGHTS RESERVED
By: Thom Henderson
Description:
This file contains service routines needed to maintain an archive.
*/
#include "arc.h"
INT match(n,t) /* test name against template */
char *n; /* name to test */
char *t; /* template to test against */
{
/* first match name part */
while((*n && *n!='.') || (*t && *t!='.'))
{ if(*n!=*t && *t!='?') /* match fail? */
{ if(*t!='*') /* wildcard fail? */
return 0; /* then no match */
else /* else jump over wildcard */
{ while(*n && *n!='.')
n++;
while(*t && *t!='.')
t++;
break; /* name part matches wildcard */
}
}
else /* match good for this char */
{ n++; /* advance to next char */
t++;
}
}
if(*n && *n=='.') n++; /* skip extension delimiters */
if(*t && *t=='.') t++;
/* now match name part */
while(*n || *t)
{ if(*n!=*t && *t!='?') /* match fail? */
{ if(*t!='*') /* wildcard fail? */
return 0; /* then no match */
else return 1; /* else good enough */
}
else /* match good for this char */
{ n++; /* advance to next char */
t++;
}
}
return 1; /* match worked */
}
INT rempath(nargs,arg) /* remove paths from filenames */
INT nargs; /* number of names */
char *arg[]; /* pointers to names */
{
char *i, *rindex(); /* string index, reverse indexer */
INT n; /* index */
for(n=0; n<nargs; n++) /* for each supplied name */
{ i=rindex(arg[n],'/'); /* search for end of path */
if(i) /* if path was found */
arg[n] = i+1; /* then skip it */
}
}
SHAR_EOF
fi # end of overwriting check
if test -f 'arcmisc.c'
then
echo shar: will not over-write existing file "'arcmisc.c'"
else
cat << \SHAR_EOF > 'arcmisc.c'
/* ARC - Archive utility - ARCMISC
System V Version 1.0.
*/
#include <ctype.h>
#include "arc.h"
static INT _makefn(source,dest)
unsigned char *source;
unsigned char *dest;
{
int j;
setmem(dest, 17, 0); /* clear result field */
if (strlen (source) > 1 && source[1] == ':')
for (j = 0; j < 2;)
dest[j++] = *source++;
for (j = 3; *source && *source != '.'; ++source)
if (j < 11)
dest[j++] = *source;
for (j = 12; *source; ++source)
if (j < 16)
dest[j++] = *source;
}
/* make a file name using a template
*/
char *makefnam(rawfn,template,result)
unsigned char *rawfn; /* the original file name */
unsigned char *template; /* the template data */
unsigned char *result; /* where to place the result */
{
unsigned char et[17],er[17];
_makefn(template,et);
_makefn(rawfn,er);
*result=0; /* assure no data */
strcat(result,er[0]?er:et);
strcat(result,er[3]?er+3:et+3);
strcat(result,er[12]?er+12:et+12);
return ((char *)&result[0]);
}
/* convert a string to upper case */
upper(s) char *s; {
while (*s = toupper(*s)) ++s;
}
setmem(dest,size,c) char *dest,c; INT size; {
int i;
for (i = 0; i < size; dest[i] = c, i++);
}
abort(s,arg1,arg2,arg3) char *s; {
fprintf(stderr,"arc: ");
fprintf(stderr,s,arg1,arg2,arg3);
fprintf(stderr,"\n");
perror("arc system:");
exit(1);
}
rename(o, n) char *o, *n; {
return link(o, n) || unlink(o);
}
SHAR_EOF
fi # end of overwriting check
if test -f 'arcpack.c'
then
echo shar: will not over-write existing file "'arcpack.c'"
else
cat << \SHAR_EOF > 'arcpack.c'
/* ARC - Archive utility - ARCPACK
System V Version 1.0 based upon:
Version 3.37, created on 02/03/86 at 22:58:01
(C) COPYRIGHT 1985 by System Enhancement Associates; ALL RIGHTS RESERVED
By: Thom Henderson
Description:
This file contains the routines used to compress a file
when placing it in an archive.
*/
#include "arc.h"
/* stuff for non-repeat packing */
#define DLE 0x90 /* repeat sequence marker */
static unsigned char state; /* current packing state */
/* non-repeat packing states */
#define NOHIST 0 /* don't consider previous input*/
#define SENTCHAR 1 /* lastchar set, no lookahead yet */
#define SENDNEWC 2 /* run over, send new char next */
#define SENDCNT 3 /* newchar set, send count next */
/* packing results */
static long stdlen; /* length for standard packing */
static INT crcval; /* CRC check value */
INT pack(f,t,hdr) /* pack file into an archive */
FILE *f, *t; /* source, destination */
struct heads *hdr; /* pointer to header data */
{
INT c; /* one character of stream */
long ncrlen; /* length after packing */
long huflen; /* length after squeezing */
long lzwlen; /* length after crunching */
long pred_sq(), file_sq(); /* stuff for squeezing */
long pred_cm(); /* dynamic crunching cleanup */
char tnam[STRLEN]; /* temporary name buffer */
char *makefnam(); /* filename fixer upper */
FILE *crn = NULL; /* temporary crunch file */
INT getch();
INT getc_ncr();
INT putc_pak();
/* first pass - see which method is best */
if(!nocomp) /* if storage kludge not active */
{ if(note)
{ printf(" analyzing, "); fflush(stdout);}
if(arctemp) /* use temp area if specified */
sprintf(tnam,"%s.crn",arctemp);
else makefnam("$ARCTEMP.crn",arcname,tnam);
crn = fopen(tnam,"w+");
state = NOHIST; /* initialize ncr packing */
stdlen = ncrlen = 0; /* reset size counters */
crcval = 0; /* initialize CRC check value */
setcode(); /* initialize encryption */
init_cm(f,crn); /* initialize for crunching */
init_sq(); /* initialize for squeeze scan */
while((c=getc_ncr(f))!=EOF) /* for each byte of file */
{ ncrlen++; /* one more packed byte */
scan_sq(c); /* see what squeezing can do */
putc_cm(c,crn); /* see what crunching can do */
}
huflen = pred_sq(); /* finish up after squeezing */
lzwlen = pred_cm(crn); /* finish up after crunching */
}
else /* else kludge the method */
{ stdlen = 0; /* make standard look best */
ncrlen = huflen = lzwlen = 1;
}
/* standard set-ups common to all methods */
fseek(f,0L,0); /* rewind input */
hdr->crc = crcval; /* note CRC check value */
hdr->length = stdlen; /* set actual file length */
state = NOHIST; /* reinitialize ncr packing */
setcode(); /* reinitialize encryption */
/* choose and use the shortest method */
if(stdlen<=ncrlen && stdlen<=huflen && stdlen<=lzwlen)
{ if(note)
{ printf("storing, "); fflush(stdout);}/* store w/out compression */
hdrver = 2; /* note packing method */
stdlen = crcval = 0; /* recalc these for kludge */
while((c=getch(f))!=EOF) /* store it straight */
putc_pak(c,t);
hdr->crc = crcval;
hdr->length = hdr->size = stdlen;
}
else if(ncrlen<huflen && ncrlen<lzwlen)
{ if(note)
{ printf("packing, ");
fflush(stdout);} /* pack w/repeat suppression */
hdrver = 3; /* note packing method */
hdr->size = ncrlen; /* set data length */
while((c=getc_ncr(f))!=EOF)
putc_pak(c,t);
}
else if(huflen<lzwlen)
{ if(note)
{ printf("squeezing, "); fflush(stdout);}
hdrver = 4; /* note packing method */
hdr->size = file_sq(f,t); /* note final size */
}
else
{ if(note)
{ printf("crunching, "); fflush(stdout);}
hdrver = 8;
hdr->size = lzwlen; /* size should not change */
if(crn) /* if temp was created */
{ fseek(crn,0L,0); /* then copy over crunched temp */
while((c=fgetc(crn))!=EOF)
putc_tst(c,t);
}
else /* else re-crunch */
{ init_cm(f,t);
while((c=getc_ncr(f))!=EOF)
putc_cm(c,t);
pred_cm(t); /* finish up after crunching */
}
}
/* standard cleanups common to all methods */
if(crn) /* get rid of crunch temporary */
{ fclose(crn);
if(unlink(tnam) && warn)
{ printf("Cannot delete temporary file %s\n",tnam);
nerrs++;
}
}
if(note)
printf("done.\n");
}
/* Non-repeat compression - text is passed through normally, except that
a run of more than two is encoded as:
<char> <DLE> <count>
Special case: a count of zero indicates that the DLE is really a DLE,
not a repeat marker.
*/
INT getc_ncr(f) /* get bytes with collapsed runs */
FILE *f; /* file to get from */
{
static INT lastc; /* value returned on last call */
static INT repcnt; /* repetition counter */
static INT c; /* latest value seen */
switch(state) /* depends on our state */
{
case NOHIST: /* no relevant history */
state = SENTCHAR;
return lastc = getch(f); /* remember the value next time */
case SENTCHAR: /* char was sent. look ahead */
switch(lastc) /* action depends on char */
{
case DLE: /* if we sent a real DLE */
state = NOHIST; /* then start over again */
return 0; /* but note that the DLE was real */
case EOF: /* EOF is always a special case */
return EOF;
default: /* else test for a repeat */
for(repcnt=1; (c=getch(f))==lastc && repcnt<255; repcnt++)
; /* find end of run */
switch(repcnt) /* action depends on run size */
{
case 1: /* not a repeat */
return lastc = c; /* but remember value next time */
case 2: /* a repeat, but too short */
state = SENDNEWC; /* send the second one next time */
return lastc;
default: /* a run - compress it */
state = SENDCNT; /* send repeat count next time */
return DLE; /* send repeat marker this time */
}
}
case SENDNEWC: /* send second char of short run */
state = SENTCHAR;
return lastc = c;
case SENDCNT: /* sent DLE, now send count */
state = SENDNEWC;
return repcnt;
default:
abort("Bug - bad ncr state\n");
}
}
static INT getch(f) /* special get char for packing */
FILE *f; /* file to get from */
{
INT c; /* a char from the file */
if((c=fgetc(f))!=EOF) /* if not the end of file */
{ crcval = addcrc(crcval,c); /* then update CRC check value */
stdlen++; /* and bump length counter */
}
return c;
}
INT putc_pak(c,f) /* put a packed byte into archive */
char c; /* byte to put */
FILE *f; /* archive to put it in */
{
putc_tst(code(c),f); /* put encoded byte, with checks */
}
SHAR_EOF
fi # end of overwriting check
# End of shell archive
exit 0
--
Mike Stump, Cal State Univ, Northridge Comp Sci Department
uucp: {sdcrdcf, ihnp4, hplabs, ttidca, psivax, csustan}!csun!aeusemrs
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