diff --git a/README.md b/README.md
index 903499b..f4de2ec 100644
--- a/README.md
+++ b/README.md
@@ -11,7 +11,7 @@ Roadmap:
   - branch [`wasi`](https://github.com/ncruces/go-sqlite3/tree/wasi) uses `test_demovfs.c` directly
 - [x] come up with a simple, nice API, enough for simple queries
 - [ ] file locking, compatible with SQLite on Windows/Unix
-- [ ] shared-memory, compatible with SQLite on Windows/Unix
+- [ ] ~shared-memory, compatible with SQLite on Windows/Unix~
 
 Benchmarks:
 
diff --git a/conn.go b/conn.go
index 307bc50..e201ae4 100644
--- a/conn.go
+++ b/conn.go
@@ -3,14 +3,11 @@ package sqlite3
 import (
 	"bytes"
 	"context"
-	"io/fs"
 	"os"
-	"path/filepath"
 	"strconv"
 
 	"github.com/tetratelabs/wazero"
 	"github.com/tetratelabs/wazero/api"
-	"github.com/tetratelabs/wazero/experimental/writefs"
 )
 
 type Conn struct {
@@ -22,29 +19,16 @@ type Conn struct {
 	files  []*os.File
 }
 
-func Open(name string) (conn *Conn, err error) {
-	return OpenFlags(name, OPEN_READWRITE|OPEN_CREATE)
+func Open(filename string) (conn *Conn, err error) {
+	return OpenFlags(filename, OPEN_READWRITE|OPEN_CREATE)
 }
 
-func OpenFlags(name string, flags OpenFlag) (conn *Conn, err error) {
+func OpenFlags(filename string, flags OpenFlag) (conn *Conn, err error) {
 	once.Do(compile)
 
-	var fs fs.FS
-	if name != ":memory:" {
-		dir := filepath.Dir(name)
-		name = filepath.Base(name)
-		fs, err = writefs.NewDirFS(dir)
-		if err != nil {
-			return nil, err
-		}
-	}
-
 	ctx := context.Background()
 	cfg := wazero.NewModuleConfig().
 		WithName("sqlite3-" + strconv.FormatUint(counter.Add(1), 10))
-	if fs != nil {
-		cfg = cfg.WithFS(fs)
-	}
 	module, err := wasm.InstantiateModule(ctx, module, cfg)
 	if err != nil {
 		return nil, err
@@ -57,7 +41,7 @@ func OpenFlags(name string, flags OpenFlag) (conn *Conn, err error) {
 
 	c := newConn(module)
 	c.ctx = context.WithValue(ctx, connContext{}, c)
-	namePtr := c.newString(name)
+	namePtr := c.newString(filename)
 	connPtr := c.new(ptrSize)
 	defer c.free(namePtr)
 	defer c.free(connPtr)
@@ -227,7 +211,7 @@ func (c *Conn) getString(ptr, maxlen uint32) string {
 }
 
 func getString(memory api.Memory, ptr, maxlen uint32) string {
-	mem, ok := memory.Read(ptr, maxlen)
+	mem, ok := memory.Read(ptr, maxlen+1)
 	if !ok {
 		mem, ok = memory.Read(ptr, memory.Size()-ptr)
 		if !ok {
diff --git a/vfs.go b/vfs.go
index 6c045af..1ef97ea 100644
--- a/vfs.go
+++ b/vfs.go
@@ -51,8 +51,8 @@ func vfsExit(ctx context.Context, mod api.Module, exitCode uint32) {
 	panic(sys.NewExitError(mod.Name(), exitCode))
 }
 
-func vfsRandomness(ctx context.Context, mod api.Module, vfs, nByte, zOut uint32) uint32 {
-	mem, ok := mod.Memory().Read(zOut, nByte)
+func vfsRandomness(ctx context.Context, mod api.Module, pVfs, nByte, zByte uint32) uint32 {
+	mem, ok := mod.Memory().Read(zByte, nByte)
 	if !ok {
 		panic(rangeErr)
 	}
@@ -60,52 +60,52 @@ func vfsRandomness(ctx context.Context, mod api.Module, vfs, nByte, zOut uint32)
 	return uint32(n)
 }
 
-func vfsSleep(ctx context.Context, vfs, microseconds uint32) uint32 {
-	time.Sleep(time.Duration(microseconds) * time.Microsecond)
+func vfsSleep(ctx context.Context, pVfs, nMicro uint32) uint32 {
+	time.Sleep(time.Duration(nMicro) * time.Microsecond)
 	return _OK
 }
 
-func vfsCurrentTime(ctx context.Context, mod api.Module, vfs, out uint32) uint32 {
+func vfsCurrentTime(ctx context.Context, mod api.Module, pVfs, prNow uint32) uint32 {
 	day := julianday.Float(time.Now())
-	if ok := mod.Memory().WriteFloat64Le(out, day); !ok {
+	if ok := mod.Memory().WriteFloat64Le(prNow, day); !ok {
 		panic(rangeErr)
 	}
 	return _OK
 }
 
-func vfsCurrentTime64(ctx context.Context, mod api.Module, vfs, out uint32) uint32 {
+func vfsCurrentTime64(ctx context.Context, mod api.Module, pVfs, piNow uint32) uint32 {
 	day, nsec := julianday.Date(time.Now())
 	msec := day*86_400_000 + nsec/1_000_000
-	if ok := mod.Memory().WriteUint64Le(out, uint64(msec)); !ok {
+	if ok := mod.Memory().WriteUint64Le(piNow, uint64(msec)); !ok {
 		panic(rangeErr)
 	}
 	return _OK
 }
 
-func vfsFullPathname(ctx context.Context, mod api.Module, vfs, zName, nOut, zOut uint32) uint32 {
-	name := getString(mod.Memory(), zName, _MAX_PATHNAME)
-	s, err := filepath.Abs(name)
+func vfsFullPathname(ctx context.Context, mod api.Module, pVfs, zRelative, nFull, zFull uint32) uint32 {
+	rel := getString(mod.Memory(), zRelative, _MAX_PATHNAME)
+	abs, err := filepath.Abs(rel)
 	if err != nil {
 		return uint32(IOERR)
 	}
 
-	siz := uint32(len(s) + 1)
-	if siz > nOut {
+	siz := uint32(len(abs) + 1)
+	if siz > nFull {
 		return uint32(IOERR)
 	}
-	mem, ok := mod.Memory().Read(zOut, siz)
+	mem, ok := mod.Memory().Read(zFull, siz)
 	if !ok {
 		panic(rangeErr)
 	}
 
-	mem[len(s)] = 0
-	copy(mem, s)
+	mem[len(abs)] = 0
+	copy(mem, abs)
 	return _OK
 }
 
-func vfsDelete(ctx context.Context, mod api.Module, vfs, zName, syncDir uint32) uint32 {
-	name := getString(mod.Memory(), zName, _MAX_PATHNAME)
-	err := os.Remove(name)
+func vfsDelete(ctx context.Context, mod api.Module, pVfs, zPath, syncDir uint32) uint32 {
+	path := getString(mod.Memory(), zPath, _MAX_PATHNAME)
+	err := os.Remove(path)
 	if errors.Is(err, fs.ErrNotExist) {
 		return _OK
 	}
@@ -113,7 +113,7 @@ func vfsDelete(ctx context.Context, mod api.Module, vfs, zName, syncDir uint32)
 		return uint32(IOERR_DELETE)
 	}
 	if syncDir != 0 {
-		f, err := os.Open(filepath.Dir(name))
+		f, err := os.Open(filepath.Dir(path))
 		if err == nil {
 			err = f.Sync()
 			f.Close()
@@ -125,9 +125,9 @@ func vfsDelete(ctx context.Context, mod api.Module, vfs, zName, syncDir uint32)
 	return _OK
 }
 
-func vfsAccess(ctx context.Context, mod api.Module, vfs, zName, flags, pResOut uint32) uint32 {
-	name := getString(mod.Memory(), zName, _MAX_PATHNAME)
-	fi, err := os.Stat(name)
+func vfsAccess(ctx context.Context, mod api.Module, pVfs, zPath, flags, pResOut uint32) uint32 {
+	path := getString(mod.Memory(), zPath, _MAX_PATHNAME)
+	fi, err := os.Stat(path)
 
 	var res uint32
 	if flags == uint32(ACCESS_EXISTS) {
@@ -164,7 +164,7 @@ func vfsAccess(ctx context.Context, mod api.Module, vfs, zName, flags, pResOut u
 	return _OK
 }
 
-func vfsOpen(ctx context.Context, mod api.Module, vfs, zName, file, flags, pOutFlags uint32) uint32 {
+func vfsOpen(ctx context.Context, mod api.Module, pVfs, zName, pFile, flags, pOutFlags uint32) uint32 {
 	name := getString(mod.Memory(), zName, _MAX_PATHNAME)
 	c := ctx.Value(connContext{}).(*Conn)
 
@@ -186,7 +186,7 @@ func vfsOpen(ctx context.Context, mod api.Module, vfs, zName, file, flags, pOutF
 		return uint32(CANTOPEN)
 	}
 
-	if ok := mod.Memory().WriteUint32Le(file+ptrSize, c.getFile(f)); !ok {
+	if ok := mod.Memory().WriteUint32Le(pFile+ptrSize, c.getFile(f)); !ok {
 		panic(rangeErr)
 	}
 	if pOutFlags == 0 {
@@ -198,8 +198,8 @@ func vfsOpen(ctx context.Context, mod api.Module, vfs, zName, file, flags, pOutF
 	return _OK
 }
 
-func vfsClose(ctx context.Context, mod api.Module, file uint32) uint32 {
-	id, ok := mod.Memory().ReadUint32Le(file + ptrSize)
+func vfsClose(ctx context.Context, mod api.Module, pFile uint32) uint32 {
+	id, ok := mod.Memory().ReadUint32Le(pFile + ptrSize)
 	if !ok {
 		panic(rangeErr)
 	}
@@ -213,8 +213,8 @@ func vfsClose(ctx context.Context, mod api.Module, file uint32) uint32 {
 	return _OK
 }
 
-func vfsFile(ctx context.Context, mod api.Module, file uint32) *os.File {
-	id, ok := mod.Memory().ReadUint32Le(file + ptrSize)
+func vfsFile(ctx context.Context, mod api.Module, pFile uint32) *os.File {
+	id, ok := mod.Memory().ReadUint32Le(pFile + ptrSize)
 	if !ok {
 		panic(rangeErr)
 	}
@@ -223,14 +223,14 @@ func vfsFile(ctx context.Context, mod api.Module, file uint32) *os.File {
 	return c.files[id]
 }
 
-func vfsRead(ctx context.Context, mod api.Module, file, buf, iAmt uint32, iOfst uint64) uint32 {
-	mem, ok := mod.Memory().Read(buf, iAmt)
+func vfsRead(ctx context.Context, mod api.Module, pFile, zBuf, iAmt uint32, iOfst uint64) uint32 {
+	mem, ok := mod.Memory().Read(zBuf, iAmt)
 	if !ok {
 		panic(rangeErr)
 	}
 
-	f := vfsFile(ctx, mod, file)
-	n, err := f.ReadAt(mem, int64(iOfst))
+	file := vfsFile(ctx, mod, pFile)
+	n, err := file.ReadAt(mem, int64(iOfst))
 	if n == int(iAmt) {
 		return _OK
 	}
@@ -243,41 +243,41 @@ func vfsRead(ctx context.Context, mod api.Module, file, buf, iAmt uint32, iOfst
 	return uint32(IOERR_SHORT_READ)
 }
 
-func vfsWrite(ctx context.Context, mod api.Module, file, buf, iAmt uint32, iOfst uint64) uint32 {
-	mem, ok := mod.Memory().Read(buf, iAmt)
+func vfsWrite(ctx context.Context, mod api.Module, pFile, zBuf, iAmt uint32, iOfst uint64) uint32 {
+	mem, ok := mod.Memory().Read(zBuf, iAmt)
 	if !ok {
 		panic(rangeErr)
 	}
 
-	f := vfsFile(ctx, mod, file)
-	_, err := f.WriteAt(mem, int64(iOfst))
+	file := vfsFile(ctx, mod, pFile)
+	_, err := file.WriteAt(mem, int64(iOfst))
 	if err != nil {
 		return uint32(IOERR_WRITE)
 	}
 	return _OK
 }
 
-func vfsTruncate(ctx context.Context, mod api.Module, file uint32, size uint64) uint32 {
-	f := vfsFile(ctx, mod, file)
-	err := f.Truncate(int64(size))
+func vfsTruncate(ctx context.Context, mod api.Module, pFile uint32, nByte uint64) uint32 {
+	file := vfsFile(ctx, mod, pFile)
+	err := file.Truncate(int64(nByte))
 	if err != nil {
 		return uint32(IOERR_TRUNCATE)
 	}
 	return _OK
 }
 
-func vfsSync(ctx context.Context, mod api.Module, file, flags uint32) uint32 {
-	f := vfsFile(ctx, mod, file)
-	err := f.Sync()
+func vfsSync(ctx context.Context, mod api.Module, pFile, flags uint32) uint32 {
+	file := vfsFile(ctx, mod, pFile)
+	err := file.Sync()
 	if err != nil {
 		return uint32(IOERR_FSYNC)
 	}
 	return _OK
 }
 
-func vfsFileSize(ctx context.Context, mod api.Module, file, pSize uint32) uint32 {
-	f := vfsFile(ctx, mod, file)
-	off, err := f.Seek(0, io.SeekEnd)
+func vfsFileSize(ctx context.Context, mod api.Module, pFile, pSize uint32) uint32 {
+	file := vfsFile(ctx, mod, pFile)
+	off, err := file.Seek(0, io.SeekEnd)
 	if err != nil {
 		return uint32(IOERR_SEEK)
 	}