Advanced controls for alsa soundcard driver
alsactl [options] [store|restore|init] <card # or id or device>
alsactl monitor <card # or id>
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.
store saves the current driver state for the selected soundcard to the configuration file.
restore loads driver state for the selected soundcard from the configuration file. If restoring fails (eventually partly), the init action is called.
nrestore is like restore, but it notifies also the daemon to do new rescan for available soundcards.
init tries to initialize all devices to a default state. If device is not known, error code 99 is returned.
daemon manages to save periodically the sound state.
rdaemon like daemon but restore the sound state at first.
kill notifies the daemon to do the specified operation (quit, rescan, save_and_quit).
monitor is for monitoring the events received from the given control device.
If no soundcards are specified, setup for all cards will be saved, loaded or monitored.
Help: show available flags and commands.
Use debug mode: a bit more verbose.
Print alsactl version number.
Select the configuration file to use. The default is /var/lib/alsa/asound.state.
Use the file locking to serialize the concurrent access to the state file (this option is default for the global state file).
Do not use the file locking to serialize the concurrent access to the state file (including the global state file).
Select the state lock file path.
Used with restore command. Try to restore the matching control elements as much as possible. This option is set as default now.
Used with store and restore commands. Do not show 'No soundcards found' and do not set an error exit code when soundcards are not installed.
Used with restore command. Don't restore mismatching control elements. This option was the old default behavior.
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.
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.
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).
The configuration file for init. By default, PREFIX/share/alsa/init/00main is used.
The store period in seconds for the daemon command.
The pathname to store the process-id file in the HDB UUCP format (ASCII).
Run the task in background.
Use syslog for messages.
Set the process priority (see 'man nice')
Set the process scheduling policy to idle (SCHED_IDLE).
/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).