| | Open Sound System |
| Do you have problems with sound/audio application development? Don't panic! Click here for help! |
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.
Usefulness of this call is very limited. It's provided only for completeness of the API. OSS API doesn't have any concept of card. Any information returned by this ioctl calld is reserved exclusively for the utility programs included in the OSS package. Applications should not try to use for this information in any ways.
This ioctl call is supported by all OSS devices, including audio, mixer and MIDI devices.
You can use the SNDCTL_SYSINFO ioctl to find out how many cards and pseudo devices there are in the system.
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.
| ossinfo.c | The ossinfo program that is included in the OSS package. |