SQLite

  unsigned char *aData;
  iStart = (iPg-1)*pagesize;
  fprintf(stdout, "Page %d:   (offsets 0x%x..0x%x)\n",
          iPg, iStart, iStart+pagesize-1);
  aData = print_byte_range(iStart, pagesize, 0);
  free(aData);
}


/* Print a line of decode output showing a 4-byte integer.
*/
static void print_decode_line(
  unsigned char *aData,      /* Content being decoded */
  int ofst, int nByte,       /* Start and size of decode */
  const char *zMsg           /* Message to append */

  }
  if( showCellContent && cType!=5 ){
    nDesc += describeContent(a, nLocal, &zDesc[nDesc-1]);
  }
  *pzDesc = zDesc;
  return nLocal+n;
}

/* Print an offset followed by nByte bytes.  Add extra white-space
** at the end so that subsequent text is aligned.
*/
static void printBytes(
  unsigned char *aData,      /* Content being decoded */
  unsigned char *aStart,     /* Start of content to be printed */
  int nByte                  /* Number of bytes to print */
){
  int j;
  printf(" %03x: ", (int)(aStart-aData));
  for(j=0; j<9; j++){
    if( j>=nByte ){
      printf("   ");
    }else{
      printf("%02x ", aStart[j]);
    }
  }
}


/*
** Write a full decode on stdout for the cell at a[ofst].
** Assume the page contains a header of size szPgHdr bytes.
*/
static void decodeCell(
  unsigned char *a,       /* Page content (without the page-1 header) */
  unsigned pgno,          /* Page number */
  int iCell,              /* Cell index */
  int szPgHdr,            /* Size of the page header.  0 or 100 */
  int ofst                /* Cell begins at a[ofst] */
){
  int i, j, k;
  int leftChild;
  i64 nPayload;
  i64 rowid;
  i64 nHdr;
  i64 iType;
  int nLocal;
  unsigned char *x = a + ofst;
  unsigned char *end;
  unsigned char cType = a[0];

  printf("Decode cell[%d] on page %d offset %04x....\n",
         iCell, pgno, szPgHdr+ofst);
  if( cType<=5 ){
    leftChild = ((x[0]*256 + x[1])*256 + x[2])*256 + x[3];
    printBytes(a, x, 4);
    printf("left child page:: %d\n", leftChild);
    x += 4;
  }
  if( cType!=5 ){
    i = decodeVarint(x, &nPayload);
    printBytes(a, x, i);
    nLocal = localPayload(nPayload, cType);
    printf("bytes of payload: %d  (local: %d)\n", (int)nPayload, nLocal);
    x += i;
  }else{
    nPayload = nLocal = 0;
  }
  end = x + nLocal;
  if( cType==5 || cType==13 ){
    i = decodeVarint(x, &rowid);
    printBytes(a, x, i);
    printf("rowid: %lld\n", rowid);
    x += i;
  }
  if( nLocal>0 ){
    i = decodeVarint(x, &nHdr);
    printBytes(a, x, i);
    printf("record header size: %d\n", (int)nHdr);
    j = i;
    k = 0;
    while( x+j<end && j<nHdr ){
       const char *zTypeName;
       int sz = 0;
       char zNm[30];
       i = decodeVarint(x+j, &iType);
       printBytes(a, x+j, i);
       printf("column[%d] type code: %d - ", k++, (int)iType);
       switch( iType ){
         case 0:  zTypeName = "NULL";    sz = 0;  break;
         case 1:  zTypeName = "int8";    sz = 1;  break;
         case 2:  zTypeName = "int16";   sz = 2;  break;
         case 3:  zTypeName = "int24";   sz = 3;  break;
         case 4:  zTypeName = "int32";   sz = 4;  break;
         case 5:  zTypeName = "int48";   sz = 6;  break;
         case 6:  zTypeName = "int64";   sz = 8;  break;
         case 7:  zTypeName = "double";  sz = 8;  break;
         case 8:  zTypeName = "zero";    sz = 0;  break;
         case 9:  zTypeName = "one";     sz = 0;  break;
         case 10:
         case 11: zTypeName = "error";   sz = 0;  break;
         default: {
           sz = (int)(iType-12)/2;
           sprintf(zNm, (iType&1)==0 ? "blob(%d)" : "text(%d)", sz);
           zTypeName = zNm;
           break;
         }
       }
       printf("%s\n", zTypeName);
       j += i;
    }
  }
  if( j<nLocal ){
    printBytes(a, x+j, 0);
    printf("%d bytes of content\n", nLocal-j);
  }
  if( nLocal<nPayload ){
    printBytes(a, x+nLocal, 4);
    printf("first overflow page: %d\n", decodeInt32(x+nLocal));
  }
}


/*
** Decode a btree page
*/
static void decode_btree_page(
  unsigned char *a,   /* Page content */
  int pgno,           /* Page number */
  int hdrSize,        /* Size of the page header.  0 or 100 */
  char *zArgs         /* Flags to control formatting */
){
  const char *zType = "unknown";
  int nCell;
  int i, j;
  int iCellPtr;
  int showCellContent = 0;
  int showMap = 0;
  int cellToDecode = -2;
  char *zMap = 0;
  switch( a[0] ){
    case 2:  zType = "index interior node";  break;
    case 5:  zType = "table interior node";  break;
    case 10: zType = "index leaf";           break;
    case 13: zType = "table leaf";           break;
  }
  while( zArgs[0] ){
    switch( zArgs[0] ){
      case 'c': showCellContent = 1;  break;
      case 'm': showMap = 1;          break;
      case 'd': {
        if( !isdigit(zArgs[1]) ){
          cellToDecode = -1;
        }else{
          cellToDecode = 0;
          while( isdigit(zArgs[1]) ){
            zArgs++;
            cellToDecode = cellToDecode*10 + zArgs[0] - '0';
          }
        }
        break;
      }
    }
    zArgs++;
  }
  nCell = a[3]*256 + a[4];
  iCellPtr = (a[0]==2 || a[0]==5) ? 12 : 8;
  if( cellToDecode==(-2) ){
    printf("Decode of btree page %d:\n", pgno);
    print_decode_line(a, 0, 1, zType);
    print_decode_line(a, 1, 2, "Offset to first freeblock");
    print_decode_line(a, 3, 2, "Number of cells on this page");

    print_decode_line(a, 5, 2, "Offset to cell content area");
    print_decode_line(a, 7, 1, "Fragmented byte count");
    if( a[0]==2 || a[0]==5 ){
      print_decode_line(a, 8, 4, "Right child");



    }
    if( nCell>0 ){
      printf(" key: lx=left-child n=payload-size r=rowid\n");
    }
  }else if( cellToDecode>=nCell ){
    printf("Page %d has only %d cells\n", pgno, nCell);
    return;
  }
  if( showMap ){
    zMap = malloc(pagesize);
    memset(zMap, '.', pagesize);
    memset(zMap, '1', hdrSize);
    memset(&zMap[hdrSize], 'H', iCellPtr);
    memset(&zMap[hdrSize+iCellPtr], 'P', 2*nCell);

      memset(&zMap[cofst], '*', n);
      zMap[cofst] = '[';
      zMap[cofst+n-1] = ']';
      sprintf(zBuf, "%d", i);
      j = strlen(zBuf);
      if( j<=n-2 ) memcpy(&zMap[cofst+1], zBuf, j);
    }
    if( cellToDecode==(-2) ){
      printf(" %03x: cell[%d] %s\n", cofst, i, zDesc);
    }else if( cellToDecode==(-1) || cellToDecode==i ){
      decodeCell(a, pgno, i, hdrSize, cofst-hdrSize);
    }
  }
  if( showMap ){
    for(i=0; i<pagesize; i+=64){
      printf(" %03x: %.64s\n", i, &zMap[i]);
    }
    free(zMap);
  }
}

/*
** Decode a freelist trunk page.
*/
static void decode_trunk_page(
  int pgno,             /* The page number */

    "    pgidx           Index of how each page is used\n"
    "    ptrmap          Show all PTRMAP page content\n"
    "    NNN..MMM        Show hex of pages NNN through MMM\n"
    "    NNN..end        Show hex of pages NNN through end of file\n"
    "    NNNb            Decode btree page NNN\n"
    "    NNNbc           Decode btree page NNN and show content\n"
    "    NNNbm           Decode btree page NNN and show a layout map\n"
    "    NNNbdCCC        Decode cell CCC on btree page NNN\n"
    "    NNNt            Decode freelist trunk page NNN\n"
    "    NNNtd           Show leaf freelist pages on the decode\n"
    "    NNNtr           Recurisvely decode freelist starting at NNN\n"
  );
}

int main(int argc, char **argv){