Open Sound System
OSS 4.x Programmer's Guide

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SNDCTL_MIX_NRMIX

Get number of mixer devices in the system

Usage

int nmix;

ioctl(fd, SNDCTL_MIX_NRMIX, &nmix);

The above code fragment lacks all error checks for clarity. Real world applications must always check for the errors and handle them as described below. Also most OSS ioctl calls will return information in the argument variable and it's usually necessary to check it too.

Description

This ioctl call returns the number of mixer devices available in the system.

OSS ioctl return values

The return value from the OSS ioctl calls will be -1 if a fatal error occurred. Other values mean that the ioctl call was more or less successful. However in most cases the application must check the value returned in the argument to see what was the accepted value.

Please see the Possible error codes (errno) returned by OSS calls section for more info about the error codes returned by OSS.

Sample programs