/** List all filenames in directory */
public DirEnt[] list() {
File[] files = dir.listFiles();
DirEnt[] ents = new DirEnt[files.length];
for (int n = 0; n < files.length; n++) ents[n] = new DirEnt(files[n], n);
return ents;
}
/** Create a unix file that represents a native directory */
public NativeDirFD(NativeFileSystem fs, File dir) {
if (!dir.isDirectory()) throw new RuntimeException("not a dir: " + dir);
this.fs = fs;
this.dir = dir;
}