Determines the current position of the file mark before reading from or writing to an open file.

OSErr PBGetFPosAsync (
    ParmBlkPtr paramBlock
);

Parameter descriptions

paramBlock

A pointer to a basic File Manager parameter block.

function result

A result code.

DISCUSSION

The relevant fields of the parameter block are:

• ioCompletion

  On input, a pointer to a completion routine.

• ioResult

  On output, the result code of the function.

• ioRefNum

  On input, the file reference number for the file whose mark you wish to get.

• ioReqCount

  On output, set to 0.

• ioActCount

  On output, set to 0

• ioPosMode

  On output, set to 0

• ioPosOffset

  On output, the current position of the mark

The value returned in ioPosOffset is zero-based. Thus, a call to PBGetFPosAsync returns 0 if you call it when the file mark is positioned at the beginning of the file.

AVAILABILITY

Supported in Carbon. Available in Carbon 1.0.2 and later when running Mac OS 8.1 or later.

© 2000 Apple Computer, Inc. (Last Updated 6/30/2000)