User i have setup

[cacti@localhost] [/usr/share/cacti]
$ ls -l /usr/share/cacti/scripts/linux_memory.pl
ls: /usr/share/cacti/scripts/linux_memory.pl: Permission denied


special user
[root@localhost] [~]
# ls -l /usr/share/cacti/scripts/linux_memory.pl
-rwxr-xr-x 1 cacti cacti 174 Jan 12 09:40 /usr/share/cacti/scripts/linux_memory.pl