I can NOT do following! help

["Mohan Jayaweera" <mohanjayaweera gmail com>]

Hi all, my squid (direct) proxy serves clients well, but I can't
execute following commands.  can anybody help me. the box is Intel P4,
Redhat Enterprise Edition 4 WS.
Thanking You
Mohan Jayaweera

[kumara proxy ~]$ squid -k reconfigure
bash: squid: command not found
[kumara proxy ~]$ squid -k restart
bash: squid: command not found
[kumara proxy ~]$ squid -k shutdown
bash: squid: command not found
[kumara proxy ~]$