Provided by: pulseaudio_1.1-0ubuntu15_amd64 bug

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
              configuration  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
              implemented 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
              PulseAudio without --start which would fail if PA is already running. PulseAudio is
              guaranteed to be fully initialized when this call returns. Implies --daemon.

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

       --check
              Return 0 as return code when the PulseAudio  daemon  is  already  running  for  the
              calling  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
              configuration 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
              negligible 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
              configure 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
              disallows additional module loading during runtime  and  on  user  request.  It  is
              highly  recommended  when  --system  is  used  (see above). Note however, that this
              breaks certain features like automatic module loading on hot plug.

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

       --module-idle-time=SECS
              Unload autoloaded modules 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
              specified 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     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}
              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.

       --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
              possible 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,
              PulseAudio 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
              configure PulseAudio dynamically during runtime. Equivalent to --load=module-cli.

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

FILES

       ~/.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.

       ~/.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.

       ~/.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
       calling  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
       PulseAudio  and  may  also  be enabled with the approriate option in daemon.conf. Negative
       nice levels can only be enabled when the appropriate resource  limit  RLIMIT_NICE  is  set
       (see setrlimit(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
       variables 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 <mzchyfrnhqvb (at) 0pointer (dot) net>; PulseAudio is  available
       from http://pulseaudio.org/

SEE ALSO

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