SQLite

      }
      if( isMemdb ){
        memcpy(zFullPathname, zFilename, nFilename);
      }else{
        rc = sqlite3OsFullPathname(pVfs, zFilename,
                                   nFullPathname, zFullPathname);
        if( rc ){



          sqlite3_free(zFullPathname);
          sqlite3_free(p);
          return rc;

        }
      }
#if SQLITE_THREADSAFE
      mutexOpen = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_OPEN);
      sqlite3_mutex_enter(mutexOpen);
      mutexShared = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);
      sqlite3_mutex_enter(mutexShared);

){
  int rc;
  DO_OS_MALLOC_TEST(0);
  /* 0x87f7f is a mask of SQLITE_OPEN_ flags that are valid to be passed
  ** down into the VFS layer.  Some SQLITE_OPEN_ flags (for example,
  ** SQLITE_OPEN_FULLMUTEX or SQLITE_OPEN_SHAREDCACHE) are blocked before
  ** reaching the VFS. */
  rc = pVfs->xOpen(pVfs, zPath, pFile, flags & 0x87f7f, pFlagsOut);
  assert( rc==SQLITE_OK || pFile->pMethods==0 );
  return rc;
}
int sqlite3OsDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){
  DO_OS_MALLOC_TEST(0);
  assert( dirSync==0 || dirSync==1 );
  return pVfs->xDelete(pVfs, zPath, dirSync);

  for(ii=(int)strlen(zDirname); ii>0 && zDirname[ii]!='/'; ii--);
  if( ii>0 ){
    zDirname[ii] = '\0';
  }else{
    if( zDirname[0]!='/' ) zDirname[0] = '.';
    zDirname[1] = 0;
  }
  fd = robust_open(zDirname, O_RDONLY|O_BINARY, 0);
  if( fd>=0 ){
    OSTRACE(("OPENDIR %-3d %s\n", fd, zDirname));
  }
  *pFd = fd;
  if( fd>=0 ) return SQLITE_OK;
  return unixLogError(SQLITE_CANTOPEN_BKPT, "openDirectory", zDirname);
}

        rc = SQLITE_NOMEM_BKPT;
        goto shm_open_err;
      }
    }

    if( pInode->bProcessLock==0 ){
      if( 0==sqlite3_uri_boolean(pDbFd->zPath, "readonly_shm", 0) ){
        pShmNode->hShm = robust_open(zShm, O_RDWR|O_CREAT,(sStat.st_mode&0777));

      }
      if( pShmNode->hShm<0 ){
        pShmNode->hShm = robust_open(zShm, O_RDONLY, (sStat.st_mode&0777));

        if( pShmNode->hShm<0 ){
          rc = unixLogError(SQLITE_CANTOPEN_BKPT, "open", zShm);
          goto shm_open_err;
        }
        pShmNode->isReadonly = 1;
      }

  sqlite3_file *pFile,         /* The file descriptor to be filled in */
  int flags,                   /* Input flags to control the opening */
  int *pOutFlags               /* Output flags returned to SQLite core */
){
  unixFile *p = (unixFile *)pFile;
  int fd = -1;                   /* File descriptor returned by open() */
  int openFlags = 0;             /* Flags to pass to open() */
  int eType = flags&0xFFFFFF00;  /* Type of file to open */
  int noLock;                    /* True to omit locking primitives */
  int rc = SQLITE_OK;            /* Function Return Code */
  int ctrlFlags = 0;             /* UNIXFILE_* flags */

  int isExclusive  = (flags & SQLITE_OPEN_EXCLUSIVE);
  int isDelete     = (flags & SQLITE_OPEN_DELETEONCLOSE);
  int isCreate     = (flags & SQLITE_OPEN_CREATE);

  ** open(). These must be calculated even if open() is not called, as
  ** they may be stored as part of the file handle and used by the 
  ** 'conch file' locking functions later on.  */
  if( isReadonly )  openFlags |= O_RDONLY;
  if( isReadWrite ) openFlags |= O_RDWR;
  if( isCreate )    openFlags |= O_CREAT;
  if( isExclusive ) openFlags |= (O_EXCL|O_NOFOLLOW);
  openFlags |= (O_LARGEFILE|O_BINARY);

  if( fd<0 ){
    mode_t openMode;              /* Permissions to create file with */
    uid_t uid;                    /* Userid for the file */
    gid_t gid;                    /* Groupid for the file */
    rc = findCreateFileMode(zName, flags, &openMode, &uid, &gid);
    if( rc!=SQLITE_OK ){

  int flags,              /* What do we want to learn about the zPath file? */
  int *pResOut            /* Write result boolean here */
){
  UNUSED_PARAMETER(NotUsed);
  SimulateIOError( return SQLITE_IOERR_ACCESS; );
  assert( pResOut!=0 );

  /* The spec says there are four possible values for flags.  But the
  ** SQLITE_ACCESS_READ flag is never used */
  assert( flags==SQLITE_ACCESS_EXISTS
       || flags==SQLITE_ACCESS_READWRITE
       || flags==SQLITE_ACCESS_SYMLINK );

  if( flags==SQLITE_ACCESS_EXISTS ){
    struct stat buf;
    *pResOut = (0==osStat(zPath, &buf) && buf.st_size>0);
  }else if( flags==SQLITE_ACCESS_READWRITE ){
    *pResOut = osAccess(zPath, W_OK|R_OK)==0;
  }else{
#if !defined(HAVE_LSTAT)
    *pResOut = 0;
#else
    struct stat buf;
    *pResOut = (0==osLstat(zPath, &buf) && S_ISLNK(buf.st_mode));
#endif
    assert( flags==SQLITE_ACCESS_SYMLINK );
  }
  return SQLITE_OK;
}

/*
**
*/

  char *zOut                    /* Output buffer */
){
#if !defined(HAVE_READLINK) || !defined(HAVE_LSTAT)
  return mkFullPathname(zPath, zOut, nOut);
#else
  int rc = SQLITE_OK;
  int nByte;
  int nLink = 1;                /* Number of symbolic links followed so far */
  const char *zIn = zPath;      /* Input path for each iteration of loop */
  char *zDel = 0;

  assert( pVfs->mxPathname==MAX_PATHNAME );
  UNUSED_PARAMETER(pVfs);

  /* It's odd to simulate an io-error here, but really this is just

        rc = unixLogError(SQLITE_CANTOPEN_BKPT, "lstat", zIn);
      }
    }else{
      bLink = S_ISLNK(buf.st_mode);
    }

    if( bLink ){

      if( zDel==0 ){
        zDel = sqlite3_malloc(nOut);
        if( zDel==0 ) rc = SQLITE_NOMEM_BKPT;
      }else if( ++nLink>SQLITE_MAX_SYMLINKS ){
        rc = SQLITE_CANTOPEN_BKPT;
      }

      if( rc==SQLITE_OK ){
        nByte = osReadlink(zIn, zDel, nOut-1);
        if( nByte<0 ){
          rc = unixLogError(SQLITE_CANTOPEN_BKPT, "readlink", zIn);

      rc = mkFullPathname(zIn, zOut, nOut);
    }
    if( bLink==0 ) break;
    zIn = zOut;
  }while( rc==SQLITE_OK );

  sqlite3_free(zDel);

  return rc;
#endif   /* HAVE_READLINK && HAVE_LSTAT */
}


#ifndef SQLITE_OMIT_LOAD_EXTENSION
/*

    const char *path,        /* path for the new unixFile */
    unixFile **ppFile,       /* unixFile created and returned by ref */
    int islockfile           /* if non zero missing dirs will be created */
) {
  int fd = -1;
  unixFile *pNew;
  int rc = SQLITE_OK;
  int openFlags = O_RDWR | O_CREAT;
  sqlite3_vfs dummyVfs;
  int terrno = 0;
  UnixUnusedFd *pUnused = NULL;

  /* 1. first try to open/create the file
  ** 2. if that fails, and this is a lock file (not-conch), try creating
  ** the parent directories and then try again.

    if( fd<0 && errno==ENOENT && islockfile ){
      if( proxyCreateLockPath(path) == SQLITE_OK ){
        fd = robust_open(path, openFlags, 0);
      }
    }
  }
  if( fd<0 ){
    openFlags = O_RDONLY;
    fd = robust_open(path, openFlags, 0);
    terrno = errno;
  }
  if( fd<0 ){
    if( islockfile ){
      return SQLITE_BUSY;
    }

  /* read the conch content */
  readLen = osPread(conchFile->h, buf, PROXY_MAXCONCHLEN, 0);
  if( readLen<PROXY_PATHINDEX ){
    sqlite3_snprintf(sizeof(errmsg),errmsg,"read error (len %d)",(int)readLen);
    goto end_breaklock;
  }
  /* write it out to the temporary break file */
  fd = robust_open(tPath, (O_RDWR|O_CREAT|O_EXCL), 0);
  if( fd<0 ){
    sqlite3_snprintf(sizeof(errmsg), errmsg, "create failed (%d)", errno);
    goto end_breaklock;
  }
  if( osPwrite(fd, buf, readLen, 0) != (ssize_t)readLen ){
    sqlite3_snprintf(sizeof(errmsg), errmsg, "write failed (%d)", errno);
    goto end_breaklock;

#  define NTDDI_WINBLUE                     0x06030000
#endif

#ifndef NTDDI_WINTHRESHOLD
#  define NTDDI_WINTHRESHOLD                0x06040000
#endif

/*
** This constant is needed by the winAccess function; therefore, define
** it when it is missing from the SDK header files.
*/
#ifndef FILE_ATTRIBUTE_REPARSE_POINT
#  define FILE_ATTRIBUTE_REPARSE_POINT      0x00000400
#endif

/*
** Check to see if the GetVersionEx[AW] functions are deprecated on the
** target system.  GetVersionEx was first deprecated in Win8.1.
*/
#ifndef SQLITE_WIN32_GETVERSIONEX
#  if defined(NTDDI_VERSION) && NTDDI_VERSION >= NTDDI_WINBLUE
#    define SQLITE_WIN32_GETVERSIONEX   0   /* GetVersionEx() is deprecated */

    case SQLITE_ACCESS_EXISTS:
      rc = attr!=INVALID_FILE_ATTRIBUTES;
      break;
    case SQLITE_ACCESS_READWRITE:
      rc = attr!=INVALID_FILE_ATTRIBUTES &&
             (attr & FILE_ATTRIBUTE_READONLY)==0;
      break;
    case SQLITE_ACCESS_SYMLINK:
      rc = attr!=INVALID_FILE_ATTRIBUTES &&
             (attr & FILE_ATTRIBUTE_REPARSE_POINT)!=0;
      break;
    default:
      assert(!"Invalid flags argument");
  }
  *pResOut = rc;
  OSTRACE(("ACCESS name=%s, pResOut=%p, *pResOut=%d, rc=SQLITE_OK\n",
           zFilename, pResOut, *pResOut));
  return SQLITE_OK;

  /* Compute and store the full pathname in an allocated buffer pointed
  ** to by zPathname, length nPathname. Or, if this is a temporary file,
  ** leave both nPathname and zPathname set to 0.
  */
  if( zFilename && zFilename[0] ){
    const char *z;
    if( (vfsFlags & SQLITE_OPEN_NOFOLLOW)!=0 ){
      int isLink = 0;
      int rc = sqlite3OsAccess(pVfs, zFilename, SQLITE_ACCESS_SYMLINK, &isLink);
      if( rc==SQLITE_OK && isLink ) rc = SQLITE_CANTOPEN_SYMLINK;
      if( rc ) return rc;
    }
    nPathname = pVfs->mxPathname+1;
    zPathname = sqlite3DbMallocRaw(0, nPathname*2);
    if( zPathname==0 ){
      return SQLITE_NOMEM_BKPT;
    }
    zPathname[0] = 0; /* Make sure initialized even if FullPathname() fails */
    rc = sqlite3OsFullPathname(pVfs, zFilename, nPathname, zPathname);









    nPathname = sqlite3Strlen30(zPathname);
    z = zUri = &zFilename[sqlite3Strlen30(zFilename)+1];
    while( *z ){
      z += strlen(z)+1;
      z += strlen(z)+1;
      nUri++;
    }

#define SQLITE_CONSTRAINT_VTAB         (SQLITE_CONSTRAINT | (9<<8))
#define SQLITE_CONSTRAINT_ROWID        (SQLITE_CONSTRAINT |(10<<8))
#define SQLITE_NOTICE_RECOVER_WAL      (SQLITE_NOTICE | (1<<8))
#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8))
#define SQLITE_WARNING_AUTOINDEX       (SQLITE_WARNING | (1<<8))
#define SQLITE_AUTH_USER               (SQLITE_AUTH | (1<<8))
#define SQLITE_OK_LOAD_PERMANENTLY     (SQLITE_OK | (1<<8))


/*
** CAPI3REF: Flags For File Open Operations
**
** These bit values are intended for use in the
** 3rd parameter to the [sqlite3_open_v2()] interface and
** in the 4th parameter to the [sqlite3_vfs.xOpen] method.

** checks whether the file is readable.  The SQLITE_ACCESS_READ constant is
** currently unused, though it might be used in a future release of
** SQLite.
*/
#define SQLITE_ACCESS_EXISTS    0
#define SQLITE_ACCESS_READWRITE 1   /* Used by PRAGMA temp_store_directory */
#define SQLITE_ACCESS_READ      2   /* Unused */
#define SQLITE_ACCESS_SYMLINK   3   /* Test if file is symbolic link */

/*
** CAPI3REF: Flags for the xShmLock VFS method
**
** These integer constants define the various locking operations
** allowed by the xShmLock method of [sqlite3_io_methods].  The
** following are the only legal combinations of flags to the

){
  int rc;                         /* access() return code */
  int eAccess = F_OK;             /* Second argument to access() */

  assert( flags==SQLITE_ACCESS_EXISTS       /* access(zPath, F_OK) */
       || flags==SQLITE_ACCESS_READ         /* access(zPath, R_OK) */
       || flags==SQLITE_ACCESS_READWRITE    /* access(zPath, R_OK|W_OK) */
       || flags==SQLITE_ACCESS_SYMLINK      /* Always false */
  );

  if( flags==SQLITE_ACCESS_SYMLINK ){
    /* For this demo implementation, assume that symlinks do not exist. */
    *pResOut = 0;
    return SQLITE_OK;
  }
  if( flags==SQLITE_ACCESS_READWRITE ) eAccess = R_OK|W_OK;
  if( flags==SQLITE_ACCESS_READ )      eAccess = R_OK;

  rc = access(zPath, eAccess);
  *pResOut = (rc==0);
  return SQLITE_OK;
}

  Testvfs *p = (Testvfs *)pVfs->pAppData;
  if( p->pScript && p->mask&TESTVFS_ACCESS_MASK ){
    int rc;
    char *zArg = 0;
    if( flags==SQLITE_ACCESS_EXISTS ) zArg = "SQLITE_ACCESS_EXISTS";
    if( flags==SQLITE_ACCESS_READWRITE ) zArg = "SQLITE_ACCESS_READWRITE";
    if( flags==SQLITE_ACCESS_READ ) zArg = "SQLITE_ACCESS_READ";
    if( flags==SQLITE_ACCESS_SYMLINK ) zArg = "SQLITE_ACCESS_SYMLINK";
    tvfsExecTcl(p, "xAccess", 
        Tcl_NewStringObj(zPath, -1), Tcl_NewStringObj(zArg, -1), 0, 0
    );
    if( tvfsResultCode(p, &rc) ){
      if( rc!=SQLITE_OK ) return rc;
    }else{
      Tcl_Interp *interp = p->interp;