Sending
Command Messages
The Microsoft
Windows operating system provides two functions for sending command messages to
devices and to query devices for error information: mciSendCommand and mciGetErrorString. The mciSendCommand function
sends a command message to an MCI device. The mciGetErrorString function
returns the error string corresponding to an error number.
The mciSendCommand
function returns zero if successful. If the function fails, the low-order word
of the return value contains an error code. You can pass this error code to mciGetErrorString
to get a text description of it.