Re: pg_ls_tmpdir to show directories and shared filesets (andpg_ls_*)

About v11, ISTM that the recursive function should check for symbolic 
links and possibly avoid them:

  sh> cd data/base
  sh> ln -s .. foo

  psql> SELECT * FROM pg_ls_dir_recurse('.');
  ERROR:  could not stat file
"./base/foo/base/foo/base/foo/base/foo/base/foo/base/foo/base/foo/base/foo/base/foo/base/foo/base/foo/base/foo/base/foo/base/foo/base/foo/base/foo/base/foo/base/foo/base/foo/base/foo/base/foo/base/foo/base/foo/base/foo/base/foo/base/foo/base/foo/base/foo/base/foo/base/foo/base/foo/base/foo/base/foo/base/foo/base/foo/base/foo/base/foo/base/foo/base/foo/base/foo/base/foo":
Toomany levels of symbolic links
 
  CONTEXT:  SQL function "pg_ls_dir_recurse" statement 1

This probably means using lstat instead of (in supplement to?) stat, and 
probably tell if something is a link, and if so not recurse in them.

-- 
Fabien.