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#define INCL_DOSMONITORS
 
USHORT DosMonRead(pbInBuffer, fWait, pbDataBuf, pcbDataBuf)
PBYTE pbInBuffer;      /* pointer to buffer for monitor input     */
USHORT fWait;          /* wait/no-wait flag                       */
PBYTE pbDataBuf;       /* pointer to buffer for data records      */
PUSHORT pcbDataBuf;    /* pointer to variable with size of buffer */
 
The DosMonRead function reads data records from the device associated with
the specified monitor and copies the records to a buffer.
 
Parameter   Description
────────────────────────────────────────────────────────────────────────────
 
pbInBuffer  Points to the buffer for monitor input. This handle must have
            been registered previously by using the DosMonReg function.
 
fWait       Specifies whether the function should wait for input. If this
            parameter is DCWW_WAIT, the function waits until input is ready.
            If this parameter is DCWW_NOWAIT, no input is ready, and the
            function returns immediately.
 
pbDataBuf   Points to the buffer that receives the data records.
 
pcbDataBuf  Points to a variable. When this function is called, the variable
            specifies the size (in bytes) of the buffer that receives the
            data records. When the function returns, this variable contains
            the number of bytes copied from the data record to the buffer.
 
Return Value
 
The return value is zero if the function is successful. Otherwise, it is an
error value, which may be one of the following:
 
     ERROR_MON_BUFFER_EMPTY
     ERROR_MON_BUFFER_TOO_SMALL
     ERROR_MON_INVALID_PARMS
 
Comments
 
Device monitors must respond rapidly to avoid delaying input and output
(I/O). (This rapid response is especially important for keyboard monitors.)
A monitor process should be written so that any threads that read and write
the monitor data run at a high priority. These threads should never perform
operations that might delay them, such as waiting for I/O or a semaphore.
The monitor process can have other threads running at normal priority to
handle such operations.
 
See Also
 
DosMonClose, DosMonOpen, DosMonReg, DosMonWrite
 
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