NAME¶
acpid - Advanced Configuration and Power Interface event daemon
SYNOPSIS¶
acpid [
options]
DESCRIPTION¶
acpid is designed to notify user-space programs of ACPI events.
acpid should be started during the system boot, and will run as a
background process, by default. It will open an events file (
/proc/acpi/event by default) and attempt to read whole lines which
represent ACPI events. If the events file does not exist,
acpid will
attempt to connect to the Linux kernel via the input layer and netlink. When
an ACPI event is received from one of these sources,
acpid will examine
a list of rules, and execute the rules that match the event.
acpid will
ignore all incoming ACPI events if a lock file exists (
/var/lock/acpid
by default).
Rules are defined by simple configuration files.
acpid will look
in a configuration directory (
/etc/acpi/events by default), and parse
all regular files with names that consist entirely of upper and lower case
letters, digits, underscores, and hyphens (similar to
run-parts(8)). Each file
must define two things: an
event and an
action. Any blank lines,
or lines where the first character is a hash ('#') are ignored. Extraneous
lines are flagged as warnings, but are not fatal. Each line has three tokens:
the key, a literal equal sign, and the value. The key can be up to 63
characters, and is case-insensitive (but whitespace matters). The value can be
up to 511 characters, and is case and whitespace sensitive.
The event value is a regular expression (see
regcomp(3)), against which events
are matched.
The action value is a commandline, which will be invoked via
/bin/sh
whenever an event matching the rule in question occurs. The commandline may
include shell-special characters, and they will be preserved. The only special
characters in an action value are "%" escaped. The string
"%e" will be replaced by the literal text of the event for which the
action was invoked. This string may contain spaces, so the commandline must
take care to quote the "%e" if it wants a single token. The string
"%%" will be replaced by a literal "%". All other
"%" escapes are reserved, and will cause a rule to not load.
This feature allows multiple rules to be defined for the same event (though no
ordering is guaranteed), as well as one rule to be defined for multiple
events. To force
acpid to reload the rule configuration, send it a
SIGHUP.
In addition to rule files,
acpid also accepts connections on a UNIX
domain socket (
/var/run/acpid.socket by default). Any application may
connect to this socket. Once connected,
acpid will send the text of all
ACPI events to the client. The client has the responsibility of filtering for
messages about which it cares.
acpid will not close the client socket
except in the case of a SIGHUP or
acpid exiting.
For faster startup, this socket can be passed in as stdin so that
acpid
need not create the socket. In addition, if a socket is passed in as stdin,
acpid will not daemonize. It will be run in foreground. This behavior
is provided to support
systemd(1).
acpid will log all of its activities, as well as the stdout and stderr of
any actions, to syslog.
All the default files and directories can be changed with commandline options.
OPTIONS¶
- -c, --confdir directory
- This option changes the directory in which acpid
looks for rule configuration files. Default is
/etc/acpi/events.
- -C, --clientmax number
- This option changes the maximum number of non-root socket
connections which can be made to the acpid socket. Default is
256.
- -d, --debug
- This option increases the acpid debug level by one.
If the debug level is non-zero, acpid will run in the foreground,
and will log to stderr, in addition to the regular syslog.
- -e, --eventfile filename
- This option changes the event file from which acpid
reads events. Default is /proc/acpi/event.
- -n, --netlink
- This option forces acpid to use the Linux kernel
input layer and netlink interface for ACPI events.
- -f, --foreground
- This option keeps acpid in the foreground by not
forking at startup.
- -l, --logevents
- This option tells acpid to log information about all
events and actions.
- -L, --lockfile filename
- This option changes the lock file used to stop event
processing. Default is /var/lock/acpid.
- -g, --socketgroup
groupname
- This option changes the group ownership of the UNIX domain
socket to which acpid publishes events.
- -m, --socketmode mode
- This option changes the permissions of the UNIX domain
socket to which acpid publishes events. Default is
0666.
- -s, --socketfile filename
- This option changes the name of the UNIX domain socket
which acpid opens. Default is /var/run/acpid.socket.
- -S, --nosocket filename
- This option tells acpid not to open a UNIX domain
socket. This overrides the -s option, and negates all other socket
options.
- -p, --pidfile filename
- This option tells acpid to use the specified file as
its pidfile. If the file exists, it will be removed and over-written.
Default is /var/run/acpid.pid.
- -v, --version
- Print version information and exit.
- -h, --help
- Show help and exit.
EXAMPLE¶
This example will shut down your system if you press the power button.
Create a file named /etc/acpi/events/power that contains the following:
-
event=button/power
action=/etc/acpi/power.sh "%e"
Then create a file named /etc/acpi/power.sh that contains the following:
- /sbin/shutdown -h now "Power button pressed"
Now, when
acpid is running, a press of the power button will cause the
rule in /etc/acpi/events/power to trigger the script in /etc/acpi/power.sh.
The script will then shut down the system.
DEPENDENCIES¶
acpid should work on any linux kernel released since 2003.
FILES¶
/proc/acpi/event
/dev/input/event*
/etc/acpi/
/var/run/acpid.socket
/var/run/acpid.pid
/var/lock/acpid
BUGS¶
There are no known bugs. To file bug reports, see
AUTHORS below.
SEE ALSO¶
regcomp(3),
sh(1),
socket(2),
connect(2),
systemd(1),
acpi_listen(8),
kacpimon(8)
AUTHORS¶
Ted Felix (www.tedfelix.com)
Tim Hockin <thockin@hockin.org>
Andrew Henroid