Open Sound System
OSS 4.x Programmer's Guide

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Reads the S/PDIF interface status.


oss_digital_control ctl;
ioctl(fd, SNDCTL_DSP_READCTL, &ctl);

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.


This ioctl call can be used to read the status and setup information of a digital audio (S/PDIF or AES/EBU) interface. Please see the Digital audio interface status and setup section for more information.

Compatibility issues

This call is supported only by OSS 4.0 compatible drivers. However this is not an issue if the application uses SNDCTL_DSP_READCTL as documented.

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

spdif_in_debug.cA program that prints the S/PDIF receiver status.

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