acpid(8)                                                                                                                acpid(8)



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, under-
       scores, 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  charac-
       ters,  and  is  case-insensitive (but whitespace matters).  The value can be up to 511 characters, and is case and white-
       space 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.

       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)

AUTHORS
       Ted Felix (www.tedfelix.com)
       Tim Hockin <thockinAThockin.org>
       Andrew Henroid




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