$ echo $EUID 1000 $ ls -ld /var/log/apache2 drwxr-x--- 2 root adm 12288 Mar 18 06:25 /var/log/apache2 $ ls -l /var/log/apache2 ls: cannot open directory /var/log/apache2: Permission denied $ perl -E 'say ((-e q-/var/log/apache2/access.log-) ? "exists" : "not exists: $!")' not exists: Permission denied # echo $EUID 0 # perl -E 'say ((-e q-/var/log/apache2/access.log-) ? "exists" : "not exists: $!")' exists