func (file *File) Readdirnames(count int) (names []string, err Error) {
// If this file has no dirinfo, create one.
if file.dirinfo == nil {
file.dirinfo = new(dirInfo)
// The buffer must be at least a block long.
// TODO(r): use fstatfs to find fs block size.
file.dirinfo.buf = make([]byte, blockSize)
}
d := file.dirinfo
size := count
if size < 0 {
size = 100
}
names = make([]string, 0, size) // Empty with room to grow.
for count != 0 {
// Refill the buffer if necessary
if d.bufp >= d.nbuf {
var errno int
d.nbuf, errno = syscall.Getdents(file.fd, d.buf)
if errno != 0 {
return names, NewSyscallError("getdents", errno)
}
if d.nbuf <= 0 {
break // EOF
}
d.bufp = 0
}
// Drain the buffer
for count != 0 && d.bufp < d.nbuf {
dirent := (*syscall.Dirent)(unsafe.Pointer(&d.buf[d.bufp]))
d.bufp += int(dirent.Reclen)
if dirent.Ino == 0 { // File absent in directory.
continue
}
bytes := (*[len(dirent.Name)]byte)(unsafe.Pointer(&dirent.Name[0]))
var name = string(bytes[0:clen(bytes)])
if name == "." || name == ".." { // Useless names
continue
}
count--
if len(names) == cap(names) {
nnames := make([]string, len(names), 2*len(names))
for i := 0; i < len(names); i++ {
nnames[i] = names[i]
}
names = nnames
}
names = names[0 : len(names)+1]
names[len(names)-1] = name
}
}
return names, nil
}
// Check that "." and ".." exists. syscall.Getdents is linux specific.
func TestSpecialEntries(t *testing.T) {
tc := NewTestCase(t)
defer tc.Cleanup()
d, err := os.Open(tc.mnt)
if err != nil {
t.Fatalf("Open failed: %v", err)
}
defer d.Close()
buf := make([]byte, 100)
n, err := syscall.Getdents(int(d.Fd()), buf)
if n == 0 {
t.Errorf("directory is empty, entries '.' and '..' are missing")
}
}
