discover the directory that prevents a file from being read in linux

Question

i'm getting a permission denied for a user in a really long path.

$ sudo sudo -u user cat /l/o/n/g/path/file
Permission denied

i'm pretty sure path and file have permissions for that user. Is there any easy way to find which of the other directories in /l/o/n/g does not?

Answer 1

This will redirect the standard output of find to /dev/null, and display only the errors (including permission denied) while accessing directories.

find . -type d > /dev/null

Answer 2

If you're okay with limiting the check to user/group/other permissions, use

namei -l /l/o/n/g/path/file