Provided by: pulseaudio_0.9.14-0ubuntu20_i386 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)