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pulseaudio(1)									    pulseaudio(1)

NAME
       pulseaudio - The PulseAudio Sound System

SYNOPSIS
       pulseaudio [options]

       pulseaudio --help

       pulseaudio --version

       pulseaudio --dump-conf

       pulseaudio --dump-modules

       pulseaudio --dump-resample-methods

       pulseaudio --cleanup-shm

       pulseaudio --start

       pulseaudio --kill

       pulseaudio --check

DESCRIPTION
       PulseAudio is a networked low-latency sound server for Linux, POSIX and Windows systems.

OPTIONS
       -h | --help
	      Show help.

       --version
	      Show version information.

       --dump-conf
	      Load the daemon configuration file daemon.conf (see below), parse remaining config-
	      uration options on the command line and dump the resulting daemon configuration, in
	      a format that is compatible with daemon.conf.

       --dump-modules
	      List available loadable modules. Combine with -v for a more elaborate listing.

       --dump-resample-methods
	      List available audio resamplers.

       --cleanup-shm
	      Identify	stale PulseAudio POSIX shared memory segments in /dev/shm and remove them
	      if possible. This is done implicitly whenever a new daemon starts up  or	a  client
	      tries  to  connect  to  a daemon. It should normally not be necessary to issue this
	      command by hand. Only available on systems with POSIX shared memory segments imple-
	      mented via a virtual file system mounted to /dev/shm (e.g. Linux).

       --start
	      Start PulseAudio if it is not running yet. This is different from starting PulseAu-
	      dio without --start which would fail if PA is already running. PulseAudio is  guar-
	      anteed to be fully initialized when this call returns. Implies --daemon.

       -k | --kill
	      Kill  an already running PulseAudio daemon of the calling user (Equivalent to send-
	      ing a SIGTERM).

       --check
	      Return 0 as return code when the PulseAudio daemon is already running for the call-
	      ing  user,  or  non-zero	otherwise.  Produces  no output on the console except for
	      errors to stderr.

       --system[=BOOL]
	      Run as system-wide instance instead of per-user. Please  note  that  this  disables
	      certain  features  of PulseAudio and is generally not recommended unless the system
	      knows no local users (e.g. is a thin client). This feature needs special configura-
	      tion  and  a  dedicated  UNIX user set up. It is highly recommended to combine this
	      with --disallow-module-loading (see below).

       -D | --daemonize[=BOOL]
	      Daemonize after startup, i.e. detach from the terminal.

       --fail[=BOOL]
	      Fail startup when any of the commands specified in the  startup  script  default.pa
	      (see below) fails.

       --high-priority[=BOOL]
	      Try  to  acquire a high Unix nice level. This will only succeed if the calling user
	      has a non-zero RLIMIT_NICE resource limit set (on systems that  support  this),  or
	      we're  called SUID root (see below), or we are configure to be run as system daemon
	      (see --system above). It is recommended to enable this, since it is only a negligi-
	      ble security risk (see below).

       --realtime[=BOOL]
	      Try  to acquire a real-time scheduling for PulseAudio's I/O threads. This will only
	      succeed if the calling user has a non-zero RLIMIT_RTPRIO	resource  limit  set  (on
	      systems  that  support this), or we're called SUID root (see below), or we are con-
	      figure to be run as system daemon (see --system above). It is recommended to enable
	      this only for trusted users, since it is a major security risk (see below).

       --disallow-module-loading[=BOOL]
	      Disallow	module	loading after startup. This is a security feature since it disal-
	      lows additional module loading during runtime and on user  request.  It  is  highly
	      recommended  when --system is used (see above). Note however, that this breaks cer-
	      tain features like automatic module loading on hot plug.

       --disallow-exit[=BOOL]
	      Disallow user requested exit

       --exit-idle-time=SECS
	      Terminate the daemon when idle and the specified number of seconds passed.

       --scache-idle-time=SECS
	      Unload autoloaded samples from the cache when the haven't been used for the  speci-
	      fied number of seconds.

       --log-level[=LEVEL]
	      If  an  argument	is  passed,  set  the log level to the specified value, otherwise
	      increase the configured verbosity level by one. The log levels are numerical from 0
	      to  4,  corresponding  to  error,  warn,	notice, info, debug. Default log level is
	      notice, i.e. all log messages with lower	log  levels  are  printed:  error,  warn,
	      notice.

       -v | --verbose
	      Increase	the  configured  verbosity  level by one (see --log-level above). Specify
	      multiple times to increase log level multiple times.

       --log-target={auto,syslog,stderr,file:PATH,newfile:PATH}
	      Specify the log target. If set to auto (which is	the  default),	then  logging  is
	      directed	to  syslog  when  --daemonize  is  passed, otherwise to STDERR. If set to
	      file:PATH, logging is directed to the file indicated by PATH. newfile:PATH is  oth-
	      erwise  the  same  as  file:PATH,  but existing files are never overwritten. If the
	      specified file already exists, a suffix is added to the file name  to  avoid  over-
	      writing.

       --log-meta[=BOOL]
	      Show source code location in log messages.

       --log-time[=BOOL]
	      Show timestamps in log messages.

       --log-backtrace=FRAMES
	      When  FRAMES is greater than 0, log for each message a stack trace up to the number
	      of specified stack frames.

       -p | --dl-search-path=PATH
	      Set the search path for dynamic shared objects (plugins).

       --resample-method=METHOD
	      Use the specified resampler by default (See --dump-resample-methods above for  pos-
	      sible values).

       --use-pid-file[=BOOL]
	      Create a PID file. If this options is disabled it is possible to run multiple sound
	      servers per user.

       --no-cpu-limit[=BOOL]
	      Do not install CPU load limiter on platforms that support it. By default,  PulseAu-
	      dio  will terminate itself when it notices that it takes up too much CPU time. This
	      is useful as a protection against system lockups when real-time scheduling is  used
	      (see  below).  Disabling	this  meachnism  is useful when debugging PulseAudio with
	      tools like valgrind(1) which slow down execution.

       --disable-shm[=BOOL]
	      PulseAudio clients and the server can exchange audio data via POSIX  shared  memory
	      segments	(on  systems  that support this). If disabled PulseAudio will communicate
	      exclusively over sockets. Please note that data transfer via shared memory segments
	      is always disabled when PulseAudio is running with --system enabled (see above).

       -L | --load="MODULE ARGUMENTS"
	      Load the specified plugin module with the specified arguments.

       -F | --file=FILENAME
	      Run  the	specified  script  on startup. May be specified multiple times to specify
	      multiple scripts to be run in order. Combine with -n  to	disable  loading  of  the
	      default script default.pa (see below).

       -C     Open  a command interpreter on STDIN/STDOUT after startup. This may be used to con-
	      figure PulseAudio dynamically during runtime. Equivalent to --load=module-cli.

       -n     Don't load default script file default.pa (see below) on startup.  Useful  in  con-
	      junction with -C or --file.

FILES
       ~/.config/pulse/daemon.conf,   /etc/pulse/daemon.conf:	configuration  settings  for  the
       PulseAudio daemon. If the version in the user's home directory does not exist  the  global
       configuration file is loaded. See pulse-daemon.conf(5) for more information.

       ~/.config/pulse/default.pa,  /etc/pulse/default.pa:  the  default  configuration script to
       execute when the PulseAudio daemon is started. If the version in the user's home directory
       does  not  exist  the  global  configuration  script is loaded. See default.pa(5) for more
       information.

       ~/.config/pulse/client.conf, /etc/pulse/client.conf: configuration settings for PulseAudio
       client applications. If the version in the user's home directory does not exist the global
       configuration file is loaded. See pulse-client.conf(5) for more information.

SIGNALS
       SIGINT, SIGTERM: the PulseAudio daemon will shut down (Same as --kill).

       SIGHUP: dump a long status report to STDOUT or syslog, depending on the configuration.

       SIGUSR1: load module-cli, allowing runtime reconfiguration via STDIN/STDOUT.

       SIGUSR2: load module-cli-protocol-unix, allowing runtime  reconfiguration  via  a  AF_UNIX
       socket. See pacmd(1) for more information.

UNIX GROUPS AND USERS
       Group pulse-rt: if the PulseAudio binary is marked SUID root, then membership of the call-
       ing user in this group  decides	whether  real-time  and/or  high-priority  scheduling  is
       enabled. Please note that enabling real-time scheduling is a security risk (see below).

       Group  pulse-access:  if  PulseAudio  is  running  as a system daemon (see --system above)
       access is granted to members of this group when	they  connect  via  AF_UNIX  sockets.  If
       PulseAudio is running as a user daemon this group has no meaning.

       User  pulse, group pulse: if PulseAudio is running as a system daemon (see --system above)
       and is started as root the daemon will drop priviliges and become a  normal  user  process
       using  this  user and group. If PulseAudio is running as a user daemon this user and group
       has no meaning.

REAL-TIME AND HIGH-PRIORITY SCHEDULING
       To minimize the risk of drop-outs during playback it is recommended to run PulseAudio with
       real-time scheduling if the underlying platform supports it. This decouples the scheduling
       latency of the PulseAudio daemon from the system load and is thus the  best  way  to  make
       sure that PulseAudio always gets CPU time when it needs it to refill the hardware playback
       buffers. Unfortunately this is a security risk on most systems, since PulseAudio  runs  as
       user  process,  and  giving  realtime scheduling priviliges to a user process always comes
       with the risk that the user misuses it to lock up the system -- which  is  possible  since
       making a process real-time effectively disables preemption.

       To  minimize  the  risk	PulseAudio by default does not enable real-time scheduling. It is
       however recommended to enable it on trusted systems. To	do  that  start  PulseAudio  with
       --realtime  (see  above) or enabled the appropriate option in daemon.conf. Since acquiring
       realtime scheduling is a priviliged operation on most systems, some special changes to the
       system  configuration  need  to be made to allow them to the calling user. Two options are
       available:

       On newer Linux systems the system resource limit RLIMIT_RTPRIO (see setrlimit(2) for  more
       information) can be used to allow specific users to acquire real-time scheduling. This can
       be configured in /etc/security/limits.conf, a resource limit of 9 is recommended.

       Alternatively, the SUID root bit can be set for the PulseAudio binary.  Then,  the  daemon
       will  drop  root priviliges immediately on startup, however retain the CAP_NICE capability
       (on systems that support it), but only if the calling user is a	member	of  the  pulse-rt
       group  (see  above).  For  all other users all capababilities are dropped immediately. The
       advantage of this solution is that the  real-time  priviliges  are  only  granted  to  the
       PulseAudio daemon -- not to all the user's processes.

       Alternatively, if the risk of locking up the machine is considered too big to enable real-
       time scheduling, high-priority scheduling can  be  enabled  instead  (i.e.  negative  nice
       level).	This can be enabled by passing --high-priority (see above) when starting PulseAu-
       dio and may also be enabled with the approriate option in daemon.conf. Negative nice  lev-
       els  can only be enabled when the appropriate resource limit RLIMIT_NICE is set (see setr-
       limit(2) for  more  information),  possibly  configured	in  /etc/security/limits.conf.	A
       resource limit of 31 (corresponding with nice level -11) is recommended.

ENVIRONMENT VARIABLES
       The PulseAudio client libraries check for the existance of the following environment vari-
       ables and change their local configuration accordingly:

       $PULSE_SERVER: the server string specifying the server to connect to when  a  client  asks
       for a sound server connection and doesn't explicitly ask for a specific server.

       $PULSE_SINK:  the symbolic name of the sink to connect to when a client creates a playback
       stream and doesn't explicitly ask for a specific sink.

       $PULSE_SOURCE: the symbolic name of the source to connect  to  when  a  client  creates	a
       record stream and doesn't explicitly ask for a specific source.

       $PULSE_BINARY: path of PulseAudio executable to run when server auto-spawning is used.

       $PULSE_CLIENTCONFIG:  path  of  file that shall be read instead of client.conf (see above)
       for client configuration.

       These environment settings take precedence -- if set -- over  the  configuration  settings
       from client.conf (see above).

AUTHORS
       The  PulseAudio	Developers  <pulseaudio-discuss  (at) lists (dot) freedesktop (dot) org>;
       PulseAudio is available from http://pulseaudio.org/

SEE ALSO
       pulse-daemon.conf(5), default.pa(5), pulse-client.conf(5), pacmd(1)

Manuals 				       User				    pulseaudio(1)
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