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Open Sound System
OSS 4.x Programmer's Guide

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SNDCTL_DSP_NONBLOCK

Force non-blocking mode

Usage

ioctl(fd, SNDCTL_DSP_NONBLOCK, NULL);

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 is used to force non-blocking reads and writes regardless of the O_NONBLOCK file mode flag.

Compatibility issues

This call is supported by all compatible drivers. However new applications should use the standard O_NONBLOCK file mode flag instead.

Please look at the When OSS audio ioctl calls can be made section for information about DSP ioctl call ordering.

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

No sample programs available

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