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.
Note
Some other packages may handle some ACPI events as well and they may conflict with this package. For example, elogind-252.9 (read the documentation for Handle*=
in logind.conf(5)
for details) and UPower-1.90.2 (used by many desktop environments such as GNOME, KDE, and XFCE for handling ACPI events). If you've installed such a package and it's enough for your use case, this package is probably not needed. If you really need this package, you must be careful configuring it and the other packages handling ACPI events to avoid conflicts. Notably, elogind-252.9 handles some ACPI events by default, so the handling of these events by elogind-252.9 should be disabled first if handling these events with acpid (again, read logind.conf(5)
for details).
Note
Development versions of BLFS may not build or run some packages properly if LFS or dependencies have been updated since the most recent stable versions of the books.
Package Information
Installation of acpid
Install acpid by running the following commands:
./configure --prefix=/usr \
--docdir=/usr/share/doc/acpid-2.0.34 &&
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-2.0.34
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). The example also disables the default handling of the lid close event by elogind-252.9 when the system is on battery and not connected to any external monitor, in order to avoid a conflict:
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
mkdir -pv /etc/elogind/logind.conf.d
echo HandleLidSwitch=ignore
> /etc/elogind/logind.conf.d/acpi.conf
Unfortunately, not every computer labels ACPI events in the same way (for example, the lid may be recognized as LID0
instead of LID
). To determine how your buttons are recognized, use the acpi_listen tool. Also, look in the samples
directory under /usr/share/doc/acpid-2.0.34
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-20231119 package.
make install-acpid