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lzhuf_1.c
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1996-03-02
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23KB
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727 lines
/**************************************************************
lzhuf.c used in F6FBB BBS software
written by Haruyasu Yoshizaki 11/20/1988
some minor changes 4/6/1989
comments translated by Haruhiko Okumura 4/7/1989
adapatation and additions made by F6FBB - Jean-Paul ROUBELAT
**************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
/* crctab calculated by Mark G. Mendel, Network Systems Corporation */
static unsigned short crctab[256] = {
0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50a5, 0x60c6, 0x70e7,
0x8108, 0x9129, 0xa14a, 0xb16b, 0xc18c, 0xd1ad, 0xe1ce, 0xf1ef,
0x1231, 0x0210, 0x3273, 0x2252, 0x52b5, 0x4294, 0x72f7, 0x62d6,
0x9339, 0x8318, 0xb37b, 0xa35a, 0xd3bd, 0xc39c, 0xf3ff, 0xe3de,
0x2462, 0x3443, 0x0420, 0x1401, 0x64e6, 0x74c7, 0x44a4, 0x5485,
0xa56a, 0xb54b, 0x8528, 0x9509, 0xe5ee, 0xf5cf, 0xc5ac, 0xd58d,
0x3653, 0x2672, 0x1611, 0x0630, 0x76d7, 0x66f6, 0x5695, 0x46b4,
0xb75b, 0xa77a, 0x9719, 0x8738, 0xf7df, 0xe7fe, 0xd79d, 0xc7bc,
0x48c4, 0x58e5, 0x6886, 0x78a7, 0x0840, 0x1861, 0x2802, 0x3823,
0xc9cc, 0xd9ed, 0xe98e, 0xf9af, 0x8948, 0x9969, 0xa90a, 0xb92b,
0x5af5, 0x4ad4, 0x7ab7, 0x6a96, 0x1a71, 0x0a50, 0x3a33, 0x2a12,
0xdbfd, 0xcbdc, 0xfbbf, 0xeb9e, 0x9b79, 0x8b58, 0xbb3b, 0xab1a,
0x6ca6, 0x7c87, 0x4ce4, 0x5cc5, 0x2c22, 0x3c03, 0x0c60, 0x1c41,
0xedae, 0xfd8f, 0xcdec, 0xddcd, 0xad2a, 0xbd0b, 0x8d68, 0x9d49,
0x7e97, 0x6eb6, 0x5ed5, 0x4ef4, 0x3e13, 0x2e32, 0x1e51, 0x0e70,
0xff9f, 0xefbe, 0xdfdd, 0xcffc, 0xbf1b, 0xaf3a, 0x9f59, 0x8f78,
0x9188, 0x81a9, 0xb1ca, 0xa1eb, 0xd10c, 0xc12d, 0xf14e, 0xe16f,
0x1080, 0x00a1, 0x30c2, 0x20e3, 0x5004, 0x4025, 0x7046, 0x6067,
0x83b9, 0x9398, 0xa3fb, 0xb3da, 0xc33d, 0xd31c, 0xe37f, 0xf35e,
0x02b1, 0x1290, 0x22f3, 0x32d2, 0x4235, 0x5214, 0x6277, 0x7256,
0xb5ea, 0xa5cb, 0x95a8, 0x8589, 0xf56e, 0xe54f, 0xd52c, 0xc50d,
0x34e2, 0x24c3, 0x14a0, 0x0481, 0x7466, 0x6447, 0x5424, 0x4405,
0xa7db, 0xb7fa, 0x8799, 0x97b8, 0xe75f, 0xf77e, 0xc71d, 0xd73c,
0x26d3, 0x36f2, 0x0691, 0x16b0, 0x6657, 0x7676, 0x4615, 0x5634,
0xd94c, 0xc96d, 0xf90e, 0xe92f, 0x99c8, 0x89e9, 0xb98a, 0xa9ab,
0x5844, 0x4865, 0x7806, 0x6827, 0x18c0, 0x08e1, 0x3882, 0x28a3,
0xcb7d, 0xdb5c, 0xeb3f, 0xfb1e, 0x8bf9, 0x9bd8, 0xabbb, 0xbb9a,
0x4a75, 0x5a54, 0x6a37, 0x7a16, 0x0af1, 0x1ad0, 0x2ab3, 0x3a92,
0xfd2e, 0xed0f, 0xdd6c, 0xcd4d, 0xbdaa, 0xad8b, 0x9de8, 0x8dc9,
0x7c26, 0x6c07, 0x5c64, 0x4c45, 0x3ca2, 0x2c83, 0x1ce0, 0x0cc1,
0xef1f, 0xff3e, 0xcf5d, 0xdf7c, 0xaf9b, 0xbfba, 0x8fd9, 0x9ff8,
0x6e17, 0x7e36, 0x4e55, 0x5e74, 0x2e93, 0x3eb2, 0x0ed1, 0x1ef0
};
#define updcrc(cp, crc) ((crc << 8) ^ crctab[(cp & 0xff) ^ (crc >> 8)])
FILE *infile, *outfile;
unsigned long int textsize = 0, codesize = 0, printcount = 0;
unsigned int crc;
int version_1;
char wterr[] = "Can't write.";
void Error(char *message)
{
printf("\n%s\n", message);
exit(EXIT_FAILURE);
}
/********** LZSS compression **********/
#define N 2048 /* buffer size */
#define F 60 /* lookahead buffer size */
#define THRESHOLD 2
#define NIL N /* leaf of tree */
unsigned char
text_buf[N + F - 1];
int match_position, match_length,
lson[N + 1], rson[N + 257], dad[N + 1];
static int crc_fputc(int c, FILE *outfile)
{
crc = updcrc(c, crc);
return(putc(c, outfile));
}
static int crc_fgetc(FILE *infile)
{
int retour = getc(infile);
if (retour != -1) {
crc = updcrc(retour, crc);
}
return(retour);
}
void InitTree(void) /* initialize trees */
{
int i;
for (i = N + 1; i <= N + 256; i++)
rson[i] = NIL; /* root */
for (i = 0; i < N; i++)
dad[i] = NIL; /* node */
}
void InsertNode(int r) /* insert to tree */
{
int i, p, cmp;
unsigned char *key;
unsigned c;
cmp = 1;
key = &text_buf[r];
p = N + 1 + key[0];
rson[r] = lson[r] = NIL;
match_length = 0;
for ( ; ; ) {
if (cmp >= 0) {
if (rson[p] != NIL)
p = rson[p];
else {
rson[p] = r;
dad[r] = p;
return;
}
} else {
if (lson[p] != NIL)
p = lson[p];
else {
lson[p] = r;
dad[r] = p;
return;
}
}
for (i = 1; i < F; i++)
if ((cmp = key[i] - text_buf[p + i]) != 0)
break;
if (i > THRESHOLD) {
if (i > match_length) {
match_position = ((r - p) & (N - 1)) - 1;
if ((match_length = i) >= F)
break;
}
if (i == match_length) {
if ((c = ((r - p) & (N - 1)) - 1) < match_position) {
match_position = c;
}
}
}
}
dad[r] = dad[p];
lson[r] = lson[p];
rson[r] = rson[p];
dad[lson[p]] = r;
dad[rson[p]] = r;
if (rson[dad[p]] == p)
rson[dad[p]] = r;
else
lson[dad[p]] = r;
dad[p] = NIL; /* remove p */
}
void DeleteNode(int p) /* remove from tree */
{
int q;
if (dad[p] == NIL)
return; /* not registered */
if (rson[p] == NIL)
q = lson[p];
else
if (lson[p] == NIL)
q = rson[p];
else {
q = lson[p];
if (rson[q] != NIL) {
do {
q = rson[q];
} while (rson[q] != NIL);
rson[dad[q]] = lson[q];
dad[lson[q]] = dad[q];
lson[q] = lson[p];
dad[lson[p]] = q;
}
rson[q] = rson[p];
dad[rson[p]] = q;
}
dad[q] = dad[p];
if (rson[dad[p]] == p)
rson[dad[p]] = q;
else
lson[dad[p]] = q;
dad[p] = NIL;
}
/* Huffman coding */
#define N_CHAR (256 - THRESHOLD + F)
/* kinds of characters (character code = 0..N_CHAR-1) */
#define T (N_CHAR * 2 - 1) /* size of table */
#define R (T - 1) /* position of root */
#define MAX_FREQ 0x8000 /* updates tree when the */
/* root frequency comes to this value. */
typedef unsigned char uchar;
/* table for encoding and decoding the upper 6 bits of position */
/* for encoding */
uchar p_len[64] = {
0x03, 0x04, 0x04, 0x04, 0x05, 0x05, 0x05, 0x05,
0x05, 0x05, 0x05, 0x05, 0x06, 0x06, 0x06, 0x06,
0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06,
0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08,
0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08
};
uchar p_code[64] = {
0x00, 0x20, 0x30, 0x40, 0x50, 0x58, 0x60, 0x68,
0x70, 0x78, 0x80, 0x88, 0x90, 0x94, 0x98, 0x9C,
0xA0, 0xA4, 0xA8, 0xAC, 0xB0, 0xB4, 0xB8, 0xBC,
0xC0, 0xC2, 0xC4, 0xC6, 0xC8, 0xCA, 0xCC, 0xCE,
0xD0, 0xD2, 0xD4, 0xD6, 0xD8, 0xDA, 0xDC, 0xDE,
0xE0, 0xE2, 0xE4, 0xE6, 0xE8, 0xEA, 0xEC, 0xEE,
0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7,
0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE, 0xFF
};
/* for decoding */
uchar d_code[256] = {
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02,
0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02,
0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03,
0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03,
0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04,
0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06,
0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08,
0x09, 0x09, 0x09, 0x09, 0x09, 0x09, 0x09, 0x09,
0x0A, 0x0A, 0x0A, 0x0A, 0x0A, 0x0A, 0x0A, 0x0A,
0x0B, 0x0B, 0x0B, 0x0B, 0x0B, 0x0B, 0x0B, 0x0B,
0x0C, 0x0C, 0x0C, 0x0C, 0x0D, 0x0D, 0x0D, 0x0D,
0x0E, 0x0E, 0x0E, 0x0E, 0x0F, 0x0F, 0x0F, 0x0F,
0x10, 0x10, 0x10, 0x10, 0x11, 0x11, 0x11, 0x11,
0x12, 0x12, 0x12, 0x12, 0x13, 0x13, 0x13, 0x13,
0x14, 0x14, 0x14, 0x14, 0x15, 0x15, 0x15, 0x15,
0x16, 0x16, 0x16, 0x16, 0x17, 0x17, 0x17, 0x17,
0x18, 0x18, 0x19, 0x19, 0x1A, 0x1A, 0x1B, 0x1B,
0x1C, 0x1C, 0x1D, 0x1D, 0x1E, 0x1E, 0x1F, 0x1F,
0x20, 0x20, 0x21, 0x21, 0x22, 0x22, 0x23, 0x23,
0x24, 0x24, 0x25, 0x25, 0x26, 0x26, 0x27, 0x27,
0x28, 0x28, 0x29, 0x29, 0x2A, 0x2A, 0x2B, 0x2B,
0x2C, 0x2C, 0x2D, 0x2D, 0x2E, 0x2E, 0x2F, 0x2F,
0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D, 0x3E, 0x3F,
};
uchar d_len[256] = {
0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03,
0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03,
0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03,
0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03,
0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04,
0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04,
0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04,
0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04,
0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04,
0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04,
0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06,
0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06,
0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06,
0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06,
0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06,
0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06,
0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08,
0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08,
};
unsigned freq[T + 1]; /* frequency table */
int prnt[T + N_CHAR]; /* pointers to parent nodes, except for the */
/* elements [T..T + N_CHAR - 1] which are used to get */
/* the positions of leaves corresponding to the codes. */
int son[T]; /* pointers to child nodes (son[], son[] + 1) */
unsigned getbuf = 0;
uchar getlen = 0;
int GetBit(void) /* get one bit */
{
int i;
while (getlen <= 8) {
if ((i = crc_fgetc(infile)) < 0) i = 0;
getbuf |= i << (8 - getlen);
getlen += 8;
}
i = getbuf;
getbuf <<= 1;
getlen--;
return (i < 0);
}
int GetByte(void) /* get one byte */
{
unsigned i;
while (getlen <= 8) {
if ((i = crc_fgetc(infile)) == 0xffff) i = 0;
getbuf |= i << (8 - getlen);
getlen += 8;
}
i = getbuf;
getbuf <<= 8;
getlen -= 8;
return i >> 8;
}
unsigned putbuf = 0;
uchar putlen = 0;
void Putcode(int l, unsigned c) /* output c bits of code */
{
putbuf |= c >> putlen;
if ((putlen += l) >= 8) {
if (crc_fputc(putbuf >> 8, outfile) == EOF) {
Error(wterr);
}
if ((putlen -= 8) >= 8) {
if (crc_fputc(putbuf, outfile) == EOF) {
Error(wterr);
}
codesize += 2;
putlen -= 8;
putbuf = c << (l - putlen);
} else {
putbuf <<= 8;
codesize++;
}
}
}
/* initialization of tree */
void StartHuff(void)
{
int i, j;
for (i = 0; i < N_CHAR; i++) {
freq[i] = 1;
son[i] = i + T;
prnt[i + T] = i;
}
i = 0; j = N_CHAR;
while (j <= R) {
freq[j] = freq[i] + freq[i + 1];
son[j] = i;
prnt[i] = prnt[i + 1] = j;
i += 2; j++;
}
freq[T] = 0xffff;
prnt[R] = 0;
}
/* reconstruction of tree */
void reconst(void)
{
int i, j, k;
unsigned f, l;
/* collect leaf nodes in the first half of the table */
/* and replace the freq by (freq + 1) / 2. */
j = 0;
for (i = 0; i < T; i++) {
if (son[i] >= T) {
freq[j] = (freq[i] + 1) / 2;
son[j] = son[i];
j++;
}
}
/* begin constructing tree by connecting sons */
for (i = 0, j = N_CHAR; j < T; i += 2, j++) {
k = i + 1;
f = freq[j] = freq[i] + freq[k];
for (k = j - 1; f < freq[k]; k--);
k++;
l = (j - k) * 2;
memmove(&freq[k + 1], &freq[k], l);
freq[k] = f;
memmove(&son[k + 1], &son[k], l);
son[k] = i;
}
/* connect prnt */
for (i = 0; i < T; i++) {
if ((k = son[i]) >= T) {
prnt[k] = i;
} else {
prnt[k] = prnt[k + 1] = i;
}
}
}
/* increment frequency of given code by one, and update tree */
void update(int c)
{
int i, j, k, l;
if (freq[R] == MAX_FREQ) {
reconst();
}
c = prnt[c + T];
do {
k = ++freq[c];
/* if the order is disturbed, exchange nodes */
if (k > freq[l = c + 1]) {
while (k > freq[++l]);
l--;
freq[c] = freq[l];
freq[l] = k;
i = son[c];
prnt[i] = l;
if (i < T) prnt[i + 1] = l;
j = son[l];
son[l] = i;
prnt[j] = c;
if (j < T) prnt[j + 1] = c;
son[c] = j;
c = l;
}
} while ((c = prnt[c]) != 0); /* repeat up to root */
}
unsigned code, len;
void EncodeChar(unsigned c)
{
unsigned i;
int j, k;
i = 0;
j = 0;
k = prnt[c + T];
/* travel from leaf to root */
do {
i >>= 1;
/* if node's address is odd-numbered, choose bigger brother node */
if (k & 1) i += 0x8000;
j++;
} while ((k = prnt[k]) != R);
Putcode(j, i);
code = i;
len = j;
update(c);
}
void EncodePosition(unsigned c)
{
unsigned i;
/* output upper 6 bits by table lookup */
i = c >> 6;
Putcode(p_len[i], (unsigned)p_code[i] << 8);
/* output lower 6 bits verbatim */
Putcode(6, (c & 0x3f) << 10);
}
void EncodeEnd(void)
{
if (putlen) {
if (crc_fputc(putbuf >> 8, outfile) == EOF) {
Error(wterr);
}
codesize++;
}
}
int DecodeChar(void)
{
unsigned c;
c = son[R];
/* travel from root to leaf, */
/* choosing the smaller child node (son[]) if the read bit is 0, */
/* the bigger (son[]+1} if 1 */
while (c < T) {
c += GetBit();
c = son[c];
}
c -= T;
update(c);
return c;
}
int DecodePosition(void)
{
unsigned i, j, c;
/* recover upper 6 bits from table */
i = GetByte();
c = (unsigned)d_code[i] << 6;
j = d_len[i];
/* read lower 6 bits verbatim */
j -= 2;
while (j--) {
i = (i << 1) + GetBit();
}
return c | (i & 0x3f);
}
/* compression */
void Encode(void) /* compression */
{
int i, c, len, r, s, last_match_length;
char *ptr;
crc = 0;
if (version_1)
{
/* Reserves two bytes for the CRC */
if (fwrite(&crc, sizeof crc, 1, outfile) < 1)
Error(wterr); /* output crc of binary */
}
fseek(infile, 0L, 2);
textsize = ftell(infile);
ptr = (char *)&textsize;
for (i = 0 ; i < sizeof(textsize) ; i++)
crc_fputc(ptr[i], infile);
if (fwrite(&textsize, sizeof textsize, 1, outfile) < 1)
Error(wterr); /* output size of text */
if (textsize == 0)
return;
rewind(infile);
textsize = 0; /* rewind and re-read */
StartHuff();
InitTree();
s = 0;
r = N - F;
for (i = s; i < r; i++)
text_buf[i] = ' ';
for (len = 0; len < F && (c = getc(infile)) != EOF; len++)
text_buf[r + len] = c;
textsize = len;
for (i = 1; i <= F; i++)
InsertNode(r - i);
InsertNode(r);
do {
if (match_length > len)
match_length = len;
if (match_length <= THRESHOLD) {
match_length = 1;
EncodeChar(text_buf[r]);
} else {
EncodeChar(255 - THRESHOLD + match_length);
EncodePosition(match_position);
}
last_match_length = match_length;
for (i = 0; i < last_match_length &&
(c = getc(infile)) != EOF; i++) {
DeleteNode(s);
text_buf[s] = c;
if (s < F - 1)
text_buf[s + N] = c;
s = (s + 1) & (N - 1);
r = (r + 1) & (N - 1);
InsertNode(r);
}
if ((textsize += i) > printcount) {
printf("%12ld\r", textsize);
printcount += 1024;
}
while (i++ < last_match_length) {
DeleteNode(s);
s = (s + 1) & (N - 1);
r = (r + 1) & (N - 1);
if (--len) InsertNode(r);
}
} while (len > 0);
EncodeEnd();
printf("\n");
if (version_1)
{
/* Writes the CRC in the beginning of the file */
rewind(outfile);
if (fwrite(&crc, sizeof crc, 1, outfile) < 1)
Error(wterr); /* output crc of binary */
printf("CRC: %04x\n", crc);
}
printf("In : %ld bytes\n", textsize);
printf("Out: %ld bytes\n", codesize);
printf("Out/In: %.3f\n", (double)codesize / textsize);
}
void Decode(void) /* recover */
{
char *ptr;
int i, j, k, r, c;
unsigned long int count;
unsigned int crc_read;
if (version_1)
{
if (fread(&crc_read, sizeof crc_read, 1, infile) < 1)
Error("Can't read"); /* read size of text */
printf("File CRC = %04x\n", crc_read);
}
crc = 0;
textsize = 0;
ptr = (char *)&textsize;
for (i = 0 ; i < sizeof(textsize) ; i++)
ptr[i] = crc_fgetc(infile);
printf("File Size = %d\n", textsize);
if (textsize == 0)
return;
StartHuff();
for (i = 0; i < N - F; i++)
text_buf[i] = ' ';
r = N - F;
for (count = 0; count < textsize; ) {
c = DecodeChar();
if (c < 256) {
if (putc(c, outfile) == EOF) {
Error(wterr);
}
text_buf[r++] = c;
r &= (N - 1);
count++;
} else {
i = (r - DecodePosition() - 1) & (N - 1);
j = c - 255 + THRESHOLD;
for (k = 0; k < j; k++) {
c = text_buf[(i + k) & (N - 1)];
if (putc(c, outfile) == EOF) {
Error(wterr);
}
text_buf[r++] = c;
r &= (N - 1);
count++;
}
}
if (count > printcount) {
printf("%12ld\r", count);
printcount += 1024;
}
}
printf("%12ld\n", count);
if (version_1)
printf("Computed CRC = %04x\n", crc);
}
int main(int argc, char *argv[])
{
char *s;
if (argc != 4) {
printf("'lzhuf e[1] file1 file2' encodes file1 into file2.\n"
"'lzhuf d[1] file2 file1' decodes file2 into file1.\n");
return EXIT_FAILURE;
}
if ((s = argv[1], strpbrk(s, "D1E1d1e1") == NULL)
|| (s = argv[2], (infile = fopen(s, "rb")) == NULL)
|| (s = argv[3], (outfile = fopen(s, "wb")) == NULL)) {
printf("??? %s\n", s);
return EXIT_FAILURE;
}
version_1 = (argv[1][1] == '1');
if (toupper(*argv[1]) == 'E')
Encode();
else
Decode();
fclose(infile);
fclose(outfile);
return EXIT_SUCCESS;
}