Beyond Linux® From Scratch - Version 7.8

Chapter 12. System Utilities

acpid-2.0.25

Introduction to acpid

The acpid (Advanced Configuration and Power Interface event daemon) is a completely flexible, totally extensible daemon for delivering ACPI events. It listens on netlink interface 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 user.

This package is known to build and work properly using an LFS-7.8 platform.

Package Information

User Notes: http://wiki.linuxfromscratch.org/blfs/wiki/acpid

Installation of acpid

Install acpid by running the following commands: 

./configure --prefix=/usr \
            --docdir=/usr/share/doc/acpid-2.0.25 &&
make

This package does not come with a test suite.

Now, as the root user: 

make install &&

install -v -m755 -d /etc/acpi/events &&

cp -r samples /usr/share/doc/acpid-2.0.25

Configuring acpid

acpid is configured by user defined events. Place event files under /etc/acpi/events directory. If an event occurs, acpid recurses through the event files in order to see if the regex defined after "event" matches. If they do, action is executed.

The following brief example will suspend the system when the laptop lid is closed (it requires pm-utils-1.4.1): 

cat > /etc/acpi/events/lid << "EOF"
event=button/lid
action=/etc/acpi/lid.sh
EOF

cat > /etc/acpi/lid.sh << "EOF"
#!/bin/sh
/bin/grep -q open /proc/acpi/button/lid/LID/state && exit 0
/usr/sbin/pm-suspend
EOF
chmod +x /etc/acpi/lid.sh

Unfortunately, not every computer labels ACPI events in the same way. To determine how your buttons are recognized, use the acpi_listen tool. Also, look in package documentation's samples directory for more examples.

Boot Script

To automatically start acpid when the system is rebooted, install the /etc/rc.d/init.d/acpid boot script from the blfs-bootscripts-20150924 package. 

make install-acpid

Contents

Installed Programs: acpid, acpi_listen, and kacpimon
Installed Libraries: None
Installed Directories: /etc/acpi and /usr/share/doc/acpid-2.0.25

Short Descriptions

acpid

is a program that listens for ACPI events and executes the rules that match the received event.

acpi_listen

is a simple tool which connects to acpid and listens for events.

kacpimon

is a monitor program that connects to three sources of ACPI events (events file, netlink and input layer) and then reports on what it sees while it is connected.

Last updated on 2015-09-20 15:38:20 -0700