SQLite

    v = (v<<7) + (z[i]&0x7f);
    if( (z[i]&0x80)==0 ){ *pVal = v; return i+1; }
  }
  v = (v<<8) + (z[i]&0xff);
  *pVal = v;
  return 9;
}

/*
** Extract a big-endian 32-bit integer
*/
static unsigned int decodeInt32(const unsigned char *z){
  return (z[0]<<24) + (z[1]<<16) + (z[2]<<8) + z[3];
}

/* Report an out-of-memory error and die.
*/
static void out_of_memory(void){
  fprintf(stderr,"Out of memory...\n");
  exit(1);
}

    int cofst = iCellPtr + i*2;
    char *zDesc;
    cofst = a[cofst]*256 + a[cofst+1];
    describeCell(a[0], &a[cofst-hdrSize], &zDesc);
    printf(" %03x: cell[%d] %s\n", cofst, i, zDesc);
  }
}

/*
** Decode a freelist trunk page.
*/
static void decode_trunk_page(
  int pgno,             /* The page number */
  int pagesize,         /* Size of each page */
  int detail,           /* Show leaf pages if true */
  int recursive         /* Follow the trunk change if true */
){
  int n, i, k;
  unsigned char *a;
  while( pgno>0 ){
    a = getContent((pgno-1)*pagesize, pagesize);
    printf("Decode of freelist trunk page %d:\n", pgno);
    print_decode_line(a, 0, 4, "Next freelist trunk page");
    print_decode_line(a, 4, 4, "Number of entries on this page");
    if( detail ){
      n = (int)decodeInt32(&a[4]);
      for(i=0; i<n; i++){
        unsigned int x = decodeInt32(&a[8+4*i]);
        char zIdx[10];
        sprintf(zIdx, "[%d]", i);
        printf("  %5s %7u", zIdx, x);
        if( i%5==4 ) printf("\n");
      }
      if( i%5!=0 ) printf("\n");
    }
    if( !recursive ){
      pgno = 0;
    }else{
      pgno = (int)decodeInt32(&a[0]);
    }
    free(a);
  }
}

/*
** Print a usage comment
*/
static void usage(const char *argv0){
  fprintf(stderr, "Usage %s FILENAME ?args...?\n\n", argv0);
  fprintf(stderr,
    "args:\n"
    "    dbheader        Show database header\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"
    "    NNNt            Decode freelist trunk page NNN\n"
    "    NNNtd           Show leave freelist pages on the decode\n"
    "    NNNtr           Recurisvely decode freelist starting at NNN\n"
  );
}

int main(int argc, char **argv){
  struct stat sbuf;
  unsigned char zPgSz[2];
  if( argc<2 ){
    usage(argv[0]);
    exit(1);
  }
  db = open(argv[1], O_RDONLY);
  if( db<0 ){
    fprintf(stderr,"%s: can't open %s\n", argv[0], argv[1]);
    exit(1);
  }
  zPgSz[0] = 0;
  zPgSz[1] = 0;
  lseek(db, 16, SEEK_SET);
  read(db, zPgSz, 2);
  pagesize = zPgSz[0]*256 + zPgSz[1]*65536;
  if( pagesize==0 ) pagesize = 1024;
  printf("Pagesize: %d\n", pagesize);
  fstat(db, &sbuf);
  mxPage = sbuf.st_size/pagesize;
  printf("Available pages: 1..%d\n", mxPage);
  if( argc==2 ){
    int i;

          ofst = (iStart-1)*pagesize;
          nByte = pagesize;
        }
        a = getContent(ofst, nByte);
        decode_btree_page(a, iStart, hdrSize);
        free(a);
        continue;
      }else if( zLeft && zLeft[0]=='t' ){
        unsigned char *a;
        int detail = 0;
        int recursive = 0;
        int i;
        for(i=1; zLeft[i]; i++){
          if( zLeft[i]=='r' ) recursive = 1;
          if( zLeft[i]=='d' ) detail = 1;
        }
        decode_trunk_page(iStart, pagesize, detail, recursive);
        continue;
      }else{
        iEnd = iStart;
      }
      if( iStart<1 || iEnd<iStart || iEnd>mxPage ){
        fprintf(stderr,
          "Page argument should be LOWER?..UPPER?.  Range 1 to %d\n",
          mxPage);