/* decode.c - Don Yang (uguu.org)

   12/01/01
                                                                           */
/*@ -shiftsigned -type @*/

#include<stdio.h>
#include<stdlib.h>
#include<string.h>


static char Line[256];
static int Pos, BitCount;

static int GetBit(FILE *infile);

/******************************************************************** main */
int main(int argc, char **argv)
{
   static char dict[11] = ",.`':\"\nx %X";
   static char output[4096];
   FILE *infile, *outfile;
   int i, j, offset, length, ref;

   infile = stdin;
   outfile = stdout;
   if( argc > 1 )
   {
      if( (infile = fopen(argv[1], "rt")) == NULL )
         return printf("Can not open %s\n", argv[1]);
      if( argc > 2 )
      {
         if( (outfile = fopen(argv[2], "wt+")) == NULL )
         {
            (void)fclose(infile);
            return printf("Can not create %s\n", argv[2]);
         }
      }
   }


   Line[Pos = BitCount = 0] = '\0';
   offset = 0;
   while( (j = GetBit(infile)) != -1 )
   {
      for(i = length = 0; i < 5; i++)
         length = (length << 1) | GetBit(infile);
      if( j == 0 )
      {
         for(i = ref = 0; i < 5; i++)
            ref = (ref << 1) | GetBit(infile);
         for(i = 0; i < length; i++)
         {
            output[offset] = output[offset - ref];
            offset++;
         }
      }
      else
      {
         for(i = 0; i < length; i++)
         {
            if( GetBit(infile) != 0 )
            {
               if( GetBit(infile) != 0 )
               {
                  for(j = ref = 0; j < 3; j++)
                     ref = (ref << 1) | GetBit(infile);
                  output[offset++] = dict[ref];
               }
               else
               {
                  output[offset++] = GetBit(infile) != 0 ? 'X' : '%';
               }
            }
            else
            {
               output[offset++] = ' ';
            }
         }
      }
   }
   output[offset] = '\0';
   (void)fputs(output, outfile);

   fprintf(stderr, "%d bits\n", BitCount);


   (void)fclose(infile);
   (void)fclose(outfile);
   return 0;

} /* main() */

/****************************************************************** GetBit */
static int GetBit(FILE *infile)
{
   while( Line[Pos] != '0' && Line[Pos] != '1' )
   {
      if( Line[Pos] == '\0' || Line[Pos] == '\n' )
      {
         do
         {
            if( fgets(Line, 256, infile) == NULL )
               return -1;
         } while( strchr(Line, ':') != NULL );
         Pos = 0;
         continue;
      }
      Pos++;
   }

   BitCount++;
   printf("%c", Line[Pos]);
   return Line[Pos++] - '0';

} /* GetBit() */