alsactl - Man Page

advanced controls for ALSA soundcard driver

Synopsis

alsactl [options] [store|restore|init] <card # or id or device>

alsactl monitor <card # or id>

alsactl info <card # or id>

alsactl [clean] <card # or id or device> [[control identifiers]]

alsactl is used to control advanced settings for the ALSA soundcard drivers. It supports multiple soundcards. If your card has features that you can't seem to control from a mixer application, you have come to the right place.

Commands

Introduction

The <card> argument is optional. If no soundcards are specified, setup for all cards will be saved, loaded or monitored.

store <card>

This command saves the current driver state for the selected soundcard to the configuration file.

restore <card>

This command loads driver state for the selected soundcard from the configuration file. If restoring fails (eventually partly), the init action is called.

nrestore <card>

This command is like restore, but it notifies also the daemon to do new rescan for available soundcards.

init <card>

This command tries to initialize all devices to a default state. If device is not known, error code 99 is returned.

daemon

This command manages to save periodically the sound state.

rdaemon

This command is like daemon but restore the sound state at first.

kill <cmd>

This command notifies the daemon to do the specified operation (quit, rescan, save_and_quit).

monitor <card>

This command is for monitoring the events received from the given control device.

info <card>

This command shows the general information in the YAML format collected from the given control device (sound card).

clean <card> [filter]

This command cleans the controls created by applications.

The optional element identifiers are accepted as a filter. One extra argument is parsed as an element identifiers.

Example: alsactl clean 0 "name='PCM'" "name='Mic Phantom'"

dump-state

This command dumps the current state (all cards) to stdout.

dump-cfg

This command dumps the current configuration (all cards) to stdout. Note that the configuration hooks are evaluated.

Options

-h, --help: Help: show available flags and commands.
-d, --debug: Use debug mode: a bit more verbose.
-v, --version: Print alsactl version number.
-f, --file: Select the configuration file to use. The default is /var/lib/alsa/asound.state.
-a, --config-dir: Select the boot / hotplug ALSA configuration directory to use. The default is /var/lib/alsa.
-l, --lock: Use the file locking to serialize the concurrent access to the state file (this option is default for the global state file).
-L, --no-lock: Do not use the file locking to serialize the concurrent access to the state file (including the global state file).
-O, --lock-state-file: Select the state lock file path.
-F, --force: Used with restore command. Try to restore the matching control elements as much as possible. This option is set as default now.
-g, --ignore: Used with store, restore and init commands. Do not show 'No soundcards found' and do not set an error exit code when soundcards are not installed.
-P, --pedantic: Used with restore command. Don't restore mismatching control elements. This option was the old default behavior.
-I, --no-init-fallback: Don't initialize cards if restore fails. Since version 1.0.18, alsactl tries to initialize the card with the restore operation as default. But this can cause incompatibility with the older version. The caller may expect that the state won't be touched if no state file exists. This option takes the restore behavior back to the older version by suppressing the initialization.
-r, --runstate: Save restore and init state to this file. The file will contain only errors. Errors are appended with the soundcard id to the end of file.
-R, --remove: Remove runstate file at first.
-E, --env #=#: Set environment variable (useful for init action or you may override ALSA_CONFIG_PATH to read different or optimized configuration - may be useful for "boot" scripts).
-i, --initfile: The configuration file for init. By default, PREFIX/share/alsa/init/00main is used.
-p, --period: The store period in seconds for the daemon command.
-e, --pid-file: The pathname to store the process-id file in the HDB UUCP format (ASCII).
-b, --background: Run the task in background.
-s, --syslog: Use syslog for messages.
-n, --nice: Set the process priority (see 'man nice')
-c, --sched-idle: Set the process scheduling policy to idle (SCHED_IDLE).
-D, --ucm-defaults: Execute also the 'defaults' section from the UCM configuration. The standard behaviour is to execute only 'once' section.
-U, --no-ucm: Skip the UCM init even if available. It may be useful for the test the legacy init configuration.

Files

/var/lib/alsa/asound.state (or whatever file you specify with the -f flag) is used to store current settings for your soundcards. The settings include all the usual soundcard mixer settings. More importantly, alsactl is capable of controlling other card-specific features that mixer apps usually don't know about.

The configuration file is generated automatically by running alsactl store. Editing the configuration file by hand may be necessary for some soundcard features (e.g. enabling/disabling automatic mic gain, digital output, joystick/game ports, some future MIDI routing options, etc).