APC UPS in Centos 5.x

$ <span style="text-decoration: underline;">sudo yum install apcups*</span>
...
---> Package apcupsd.x86_64 0:3.14.3-1.el5.rf set to be updated
...
$ <span style="text-decoration: underline;">sudo /sbin/chkconfig --list apcupsd</span>
apcupsd         0:off   1:off   2:on    3:on    4:on    5:on    6:off

Before you start the apcupsd service, edit /etc/apcupsd/apcupsd.conf and set the cable type (to usb for most modern units) and other parameters as needed... then:

$ <span style="text-decoration: underline;">sudo /etc/init.d/apcupsd start</span>