#include <stdio.h>
#include <string.h>
#include "dir.h" /* for fnsplit() */
#include "rle8.h"
#include "StdAfx.h"
int main(int argc, char **argv)
{
register int cur_char; /* a character */
register unsigned int i; /* generic index variable */
register unsigned short run_len = 0; /* length of character run so far */
int run_char; /* which char run is of */
unsigned int j; /* another index variable */
unsigned short seq_len=0; /* length of non-run sequence */
char scratch_space[256]; /* string scratch space */
char seq[MAX_LEN]; /* buffer for uncompressible data */
char orig_name[MAXFILE+MAXEXT]; /* original filename */
char drive[MAXDRIVE], /* needed for fnsplit() */
dir[MAXDIR], /* needed for fnsplit() */
filename[MAXFILE], /* 8 chars, orig name */
ext[MAXEXT]; /* 3 chars, orig ext */
char outfile_name[MAXFILE+MAXEXT]; /* output filename */
unsigned long orig_total; /* total number of unencoded bytes */
unsigned long rle_total; /* total number of encoded bytes */
FILE *infile; /* file ptr to input file (uncompressed) */
FILE *outfile; /* file ptr to output file (compressed) */
errno_t err;
FILE *file;
char *infile_name;
fnsplit(argv[1], drive, dir, filename, ext); /* get filename */
strcpy_s(orig_name, filename);
strcat_s(orig_name, ext);
strcpy_s(outfile_name, filename); /* build output filename */
strcat_s(outfile_name, ".r8");
if (argc != 2)
{
puts("Usage: RLE8 filename.ext compresses file to filename.r8");
return 1;
}
puts("rle8 by Shaun Case 1991 public domain.");
infile_name=argv[1];
if ((err=fopen_s(&file,infile_name, "rb")) == NULL)
{
strcpy_s(scratch_space, "Uable to open ");
strcat_s(scratch_space, infile_name);
puts(scratch_space);
return 1;
}
if ((err=fopen_s(&file,outfile_name, "wb")) == NULL)
{
strcpy_s(scratch_space, "Uable to open ");
strcat_s(scratch_space, outfile_name);
puts(scratch_space);
return 1;
}
for (i = 0; i < 13; i++) /* write original filename */
fputc(orig_name[i], outfile);
while (!feof(infile))
{
cur_char = fgetc(infile);
if (feof(infile))
continue;
if (seq_len ==0) /* haven't got a sequence yet */
{
if (run_len == 0) /* start a new run */
{
run_char = cur_char;
++run_len;
continue;
}
if (run_char == cur_char) /* got another char in the run */
if (++run_len == MAX_LEN)
{
fputc((int)MAX_RUN_HEADER, outfile);
fputc((int) run_char, outfile);
run_len = 0;
continue;
}
/* got a different character */
/* than the run we were building */
if (run_len > 2) /* so write out the run and */
/* start a new one of the new */
/* character. */
{
fputc((int)(RUN | run_len), outfile);
fputc((int)run_char, outfile);
run_len = 1;
run_char = cur_char;
continue;
}
/* run was only one or two chars, make a seq out of it instead */
for (j = 0; j < run_len; j++); /* copy 1 or 2 char run to seq[] */
{
seq[seq_len] = run_char;
++seq_len;
if (seq_len == MAX_LEN) /* if seq[] is full, write to disk */
{
fputc((int)MAX_SEQ_HEADER, outfile);
for (i = 0; i < seq_len; i++)
fputc((int)seq[i], outfile);
seq_len = 0;
}
}
run_len = 0;
seq[seq_len++] = cur_char;
if (seq_len == MAX_LEN) /* if seq[] is full, write to disk */
{
fputc((int)MAX_SEQ_HEADER, outfile);
for (i = 0; i < seq_len; i++)
fputc((int)seq[i], outfile);
seq_len = 0;
}
}
else /* a sequence exists */
{
if (run_len != 0) /* if a run exists */
{
if (cur_char == run_char ) /* add to run! Yay. */
{
++run_len;
if (run_len == MAX_LEN) /* if run is full */
{
/* write sequence that precedes run */
fputc((int)(SEQ | seq_len), outfile);
for (i = 0; i < seq_len; i++)
fputc((int)seq[i], outfile);
/* write run */
fputc((int)(RUN | run_len), outfile);
fputc((int)run_char, outfile);
/* and start out fresh */
seq_len = run_len = 0;
} /* end write full run with existing sequence */
continue;
} /* end add to run for sequence exists */
/* we couldn't add to the run, and a preceding sequence */
/* exists, so write the sequence and the run, and */
/* try starting a new run with the current character. */
/* write sequence that precedes run */
fputc((int)(SEQ | seq_len), outfile);
for (i = 0; i < seq_len; i++)
fputc((int)seq[i], outfile);
/* write run */
fputc((int)(RUN | run_len), outfile);
fputc((int)run_char, outfile);
/* and start a new run w/ cur_char */
seq_len = 0;
run_len = 1;
run_char = cur_char;
continue;
} /* end can't add to existing run, and preceding seq exists */
/* no run exists, but a sequences does. Try to create a run */
/* by looking at cur_char and the last char of the sequence. */
/* if that fails, add the char to the sequence. */
/* if the sequence is full, write it to disk. (Slightly non */
/* optimal; we could wait one more char. A small thing to fix */
/* if someone gets the urge... */
if (seq[seq_len - 1] == cur_char) /* if we can make a run */
{
run_char = cur_char;
run_len = 2;
--seq_len;
continue;
}
/* couldn't make a run, add char to seq. Maybe next time */
/* around... */
seq[seq_len++] = cur_char;
if (seq_len == MAX_LEN) /* if the sequence is full, write out */
{
fputc((int)MAX_SEQ_HEADER, outfile);
for (i = 0; i < MAX_LEN; i++)
fputc((int)seq[i], outfile);
seq_len = 0;
}
} /* end branch on sequence exists */
} /* done with whole file */
/* there may be stuff left that hasn't been written yet; if so, write it */
if (seq_len != 0) /* write sequence that precedes run */
{
fputc((int)(SEQ | seq_len), outfile);
for (i = 0; i < seq_len; i++)
fputc((int)seq[i], outfile);
}
if (run_len != 0) /* write run */
{
fputc((int)(RUN | run_len), outfile);
fputc((int)run_char, outfile);
}
fclose(infile);
fclose (outfile);
return 0;
} /* end main() */
