Script started on Fri Feb 14 10:29:18 2003
uhunix2:~/212% cat makefile
lzdecompress: lzdecompress.o decompress.o
        gcc lzdecompress.o decompress.o -o lzdecompress

lzdecompress.o: lzdecompress.c lz.h
        gcc -c lzdecompress.c

decompress.o: decompress.c lz.h
        gcc -c decompress.c

uhunix2:~/212% cat lz.h

#include <stdio.h>

#define PROC 4096  /*width of processed bytes array*/
#define UNPROC 16  /*widht of unprocessed bytes array*/

/* in lzdecompress.c */
void usage();  

/* in decompress.c */
void decompress(FILE *fileInp, FILE *fileOutp, short verbose); 
void shiftOn(char nextChar, int *a, FILE *fileOutp);

uhunix2:~/212% cat lzdecompress.c
/*lzdecompress.c  */
/*Decompresses a file that was compressed with LZ compression */
/*Author: Zach Tomaszewski
/*Date: 1 October */

#include "lz.h"

FILE *fileInp;  /*compressed file */
FILE *fileOutp; /*decompressed file */
short verbose = 0;     /* true (1) or false (0) */

int main(int argc, char *argv[]) 
{
  switch (argc){
   case 3:   /*two arguments */
     fileInp = fopen(argv[1], "rb");
     fileOutp = fopen(argv[2], "wb");
     break;
   case 4:
     if (strcmp(argv[1], "-v")==0){
       verbose = 1;
       fileInp = fopen(argv[2], "rb");
       fileOutp = fopen(argv[3], "wb");
     }else{
       usage();
     }
     break;
   default:   /* number of arguments: 0, 1, >4 */
     usage();
     break;
  }

  /* check that files are really open and ready */
  if (fileInp==NULL) {
    puts("Error: Could not open given input file.");
    exit(1);
  }
  if (fileOutp==NULL) {
    puts("Error: Could not open output file.");
    exit(1);
  }

  decompress(fileInp, fileOutp, verbose);

  /*close files */
  fclose(fileInp);
  fclose(fileOutp);

}/*end main */


/* 
 Gives a usage message for this program 
*/
void usage() 
{
 puts("");
 puts("LZdecompress decompresses a file compressed using an LZ technique.");  
 puts("\nUsage:  lzcompress [-v] [compressed input file] [file to output] \n");
 puts("-v\t verbose. Gives extra debugging information.");
 puts("");
 exit(0);
}



uhunix2:~/212% cat decompress.c
/* decompress.c                                                      */
/* Part of LZdecompress, this set of functions does most of the work */
/*  of the decompression                                             */
/* Author: Zach Tomaszewski                                          */
/* Date:  17 February 2003                                           */

#include "lz.h"

  
/*
 Takes a file to read from and writes out to the given fileOut.
 If verbose is 1, prints out debugging info
*/
void decompress(FILE *fileInp, FILE *fileOutp, short verbose) {
  int i;  //loop or counting var
  unsigned int next1 = 0, next2 = 0; //next pair of bytes read from file

  int a[PROC];   //array holding bytes being processed
  for (i=0; i < PROC; i++) { //a[] initialized to NIL
     a[i] = ' ';
  }

  while ((next1 = getc(fileInp)) != EOF) {    
    if (next1 == 0) { //single character
      next2 = getc(fileInp);
      shiftOn(next2, a, fileOutp);
    }else {  //complicated abbrev.
        next2 = getc(fileInp);
        next1 = next1<<8;
        next1 = next1 | next2;  //combined both into next 1.  
        next2 = next1;      //copied
        next1 = next1>>12; //leaving 4 bits: number of characters to repeat
        next2 = next2 & 0x0fff; //shaving off first 4 bits. 
        for (i=0; i<= next1; i++){ //since shifting each time, need next2
                                   //from same position next1 times
          shiftOn(a[next2], a, fileOutp);
        }
    } 
      
    if (verbose) {
      for (i=PROC-32; i<PROC; i++){ 
          printf("%c", a[i]);
      }
      printf(" |<\n");
    }
  }//end while

}//end decompress 


/*
 Given a character, an array, and a file, shiftOn adds the character
  to the file.  It then shifts the a[] to the left by one space, 
  adding the character to the right end of a[].
  Relies on the UNPROC and PROC constants.
*/
void shiftOn(char nextChar, int *a, FILE *fileOutp) {
  int i;  //loop/couting var

  //start from left side and shift everything one to left
  for(i = 0; i < PROC-1; i++){
     a[i] = a[i+1];
  }
  //add nextChar to end...
  a[PROC-1] = nextChar;
  //...and to file
  putc(nextChar, fileOutp);
}  
uhunix2:~/212% make
gcc -c lzdecompress.c
gcc -c decompress.c
gcc lzdecompress.o decompress.o -o lzdecompress
uhunix2:~/212% lzdecompress se.cmp se.out
uhunix2:~/212% lzdecompress rand.cmp rand.out
uhunix2:~/212% lzdecompress declares.cmp declares.out
uhunix2:~/212% lzdecompress msdev.cmp msdev.out
uhunix2:~/212% sha1 se.out
File: se.out  Size = 648 bits, or 81 bytes
SHA1 HASH: e2632519: c8ab80ba: dba6203d: 5230db75: 916fbf22

uhunix2:~/212% sha1 se.txt
File: se.txt  Size = 648 bits, or 81 bytes
SHA1 HASH: e2632519: c8ab80ba: dba6203d: 5230db75: 916fbf22

uhunix2:~/212% sha1 rand.out
File: rand.out  Size = 400 bits, or 50 bytes
SHA1 HASH: ede624a1: ff9536df: faa1d12d: 4205a736: af15db5b

uhunix2:~/212% sha1 rand.bin
File: rand.bin  Size = 400 bits, or 50 bytes
SHA1 HASH: ede624a1: ff9536df: faa1d12d: 4205a736: af15db5b

uhunix2:~/212% sha1 declares.out
File: declares.out  Size = 66336 bits, or 8292 bytes
SHA1 HASH: 4fcb5b03: bc2fb710: ad74e7a3: e62ebf77: 516ec786

uhunix2:~/212% sha1 declares.txt
File: declares.txt  Size = 66336 bits, or 8292 bytes
SHA1 HASH: 4fcb5b03: bc2fb710: ad74e7a3: e62ebf77: 516ec786

uhunix2:~/212% sha1 msdev.out
File: msdev.out  Size = 2163248 bits, or 270406 bytes
SHA1 HASH: 792a4f77: d2521648: 2b2f397d: 716ba0dc: 5ce1aedb

uhunix2:~/212% sha1 msdev.exe
File: msdev.exe  Size = 2163248 bits, or 270406 bytes
SHA1 HASH: 792a4f77: d2521648: 2b2f397d: 716ba0dc: 5ce1aedb

uhunix2:~/212% exit
uhunix2% ^D
script done on Fri Feb 14 10:35:55 2003