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pulseaudio(1) FreeBSD General Commands Manual 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 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).
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.
Note that a non-zero return value doesn't necessarily mean that
PulseAudio is not usable. Even if the server is not running, it
may get automatically started via PulseAudio's autospawning
mechanism or systemd's socket activation, or the environment
might be such that checking for processes doesn't work (for
example, the running server might not show up in a container,
even if the server is accessible via a socket). Also disabling
PID files with --use-pid-file=no prevents --check from detecting
running servers.
A more robust check in most situations would be to try
establishing a client connection to the server. Unfortunately
there's currently no --check-connection option to replace
--check, but running "pactl info" could be a pretty good
substitute.
--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. Note
that when running as a systemd service you should use
--daemonize=no for systemd notification to work.
--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 configured 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 rtkit is available and allows PulseAudio to enable
real-time scheduling, or we are configured to be run as system
daemon (see --system above).
--disallow-module-loading[=BOOL]
Disallow module loading after startup. This is a security
--exit-idle-time=SECS
Terminate the daemon after the last client quit and this time in
seconds passed. Use a negative value to disable this feature.
Defaults to 20.
When PulseAudio runs in the per-user mode and detects a login
session, then any positive value will be reset to 0 so that
PulseAudio will terminate immediately on logout. A positive
value therefore has effect only in environments where there's no
support for login session tracking (or if the user is logged in
without a session spawned, a.k.a. lingering). A negative value
can still be used to disable any automatic exit.
When PulseAudio runs in the system mode, automatic exit is
always disabled, so this option does nothing.
--scache-idle-time=SECS
Unload autoloaded samples from the cache when they 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 | --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,journal,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 journal logging is directed to
the systemd journal. If set to file:PATH, logging is directed to
the file indicated by PATH. newfile:PATH is otherwise 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 overwriting.
--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-
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 mechanism 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 or memfd 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).
--enable-memfd[=BOOL]
PulseAudio clients and the server can exchange audio data via
memfds - the anonymous Linux Kernel shared memory mechanism (on
kernels that support this). If disabled PulseAudio will
communicate via POSIX shared memory.
-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
~/.config/pulse/daemon.conf, /usr/local/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, /usr/local/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, /usr/local/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).
reconfiguration via a AF_UNIX socket. See pacmd(1) for more
information.
UNIX GROUPS AND USERS
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
privileges 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 can be a security risk on some
systems, since PulseAudio runs as user process, and giving realtime
scheduling privileges to a user 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 solve this
problem, PulseAudio uses rtkit to safely acquire real-time scheduling
when available.
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 appropriate 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 existence 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. The server string is a list of server
addresses separated by whitespace which are tried in turn. A server
address consists of an optional address type specifier (unix:, tcp:,
tcp4:, tcp6:), followed by a path or host address. A host address may
include an optional port number. A server address may be prefixed by a
string enclosed in {}. In this case the following server address is
ignored unless the prefix string equals the local hostname or the
machine id (/etc/machine-id).
$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_CLIENTCONFIG: path of file that shall be read instead of
client.conf (see above) for client configuration.
$PULSE_COOKIE: path of file that contains the PulseAudio authentication
cookie. Defaults to ~/.config/pulse/cookie.
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)