Why am I getting “permission denied” error message when running Linux find command

Question

I am executing the following command:

find / -name ben

I've been wondering, why is there so many permission denied when running the above command? Even those directories that doesn't contain the name ben show up.

Answer 1

In order to search for a file, you need to be able to read all directories.

If a directory that is searched does not grant you read and "execute" permissions, you get a permission denied error from the find program.

If the read permission for you is missing, then you cannot see what files are in such a directory.

If the "execute" (search) permission is missing for you, then you cannot chdir into that diectory and as a result, you cannot ceck sub-directories in that directory.

Every operating system needs (for security reasons) directories that cannot be searched by ordinary people and other users may have closed their home directory as well.