Modern computers support the Advanced Configuration and Power Interface (ACPI) to allow intelligent power management on your system and to query battery and configuration status. . ACPID is a completely flexible, totally extensible daemon for delivering ACPI events. It listens on a file (/proc/acpi/event) and when an event occurs, executes programs to handle the event. The programs it executes are configured through a set of configuration files, which can be dropped into place by packages or by the admin.