Inside Macintosh: Devices /

Chapter 7 - Serial Driver / Serial Driver Reference

Serial Driver Routines /

SerGetBuf

You can use the SerGetBuf function to determine the number of characters available in the driver's input buffer.

FUNCTION SerGetBuf (refNum: Integer; VAR count: LongInt): OSErr;

refNum

The driver reference number of the serial input driver.

count

On exit, the number of characters in the input buffer.

DESCRIPTION

The SerGetBuf function returns, in the count parameter, the number of characters present in the input buffer.

ASSEMBLY-LANGUAGE INFORMATION

The SerGetBuf function is equivalent to a Device Manager status request with a csCode value of 2. The count value is returned in csParam as a long word (csParam[0] = count).

RESULT CODES

noErr

0

No error