SNDIOCTL(1) General Commands Manual SNDIOCTL(1)
NAME
sndioctl — manipulate audio device controls
SYNOPSIS
sndioctl [−dimnqv] [−f device] [command ...]
DESCRIPTION
The sndioctl utility can display or manipulate controls of sndio(7) audio devices, like the output level. The options are as follows:
−d
Dump the raw list of available controls and exit. Useful as a debugging tool.
−f device
Use this sndio(7) audio device.
−i
Display characteristics of requested controls instead of their values.
−m
Monitor and display audio controls changes.
−n
Suppress printing of the variable name.
−q
Suppress all printing when setting a variable.
−v
Enable verbose mode, a.k.a. multi-channel mode. By default controls affecting different channels of the same stream are disguised as a single mono control to hide details that are not essential.
If no commands are specified, all valid controls are displayed on stdout. Unless −d, −m, −n, or −i are used, displayed lines are valid commands. The set of available controls depends on the audio device.
Commands use the following two formats to display and change controls respectively:
[group/]stream[channel].function
[group/]stream[channel].function=value
On the left-hand side are specified the control group (if any), the affected stream name, and the optional channel number. Examples of left-hand side terms:
output.level
output[0].level
If the channel number (including the brackets) is omitted, the command is applied to all channels.
Values are numbers between 0 and 1. Two-state controls (switches) take either 0 or 1 as value, typically corresponding to the off and on states respectively.
If a decimal is prefixed by the plus (minus) sign then the given value is added to (subtracted from) the current value of the control. If "!" is used instead of a number, then the switch is toggled.
EXAMPLES
Increase the level control affecting all output channels by 10% of the maximum:
$ sndioctl output.level=+0.1
Mute all output channels:
$ sndioctl output.mute=1
Toggle the above mute control:
$ sndioctl output.mute=!
Allow audio recording and set all input channels to 50%:
# sysctl
kern.audio.record=1
$ sndioctl input.mute=0 input.level=0.5
SEE ALSO
sioctl_open(3) GNU $Mdocdate$ SNDIOCTL(1)