Writes data to an open fork.

void PBWriteForkAsync (
    FSForkIOParam *paramBlock
);

paramBlock

A pointer to a parameter block

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. If there is not enough space on the volume to write requestCount bytes, then dskFulErr is returned.

• forkRefNum

  On input, the reference number of the fork to write to.

• positionMode

  On input, the base location for the start of the write. The caller can hint to the File Manager whether the data being written should or should not be cached. Set the appropriate bits in positionMode. See “Position Mode Constants” for more information.

• positionOffset

  On input, the offset from base location for the start of the write.

• requestCount

  On input, the number of bytes to write.

• buffer

  A pointer to the data toe write.

• actualCount

  On output, the number of bytes actually written. This parameter is optional; if you don’t want it, set actualCount to NULL. The actualCount should be equal to requestCount unless there was an error during the read operation.

Data is written starting at the position specified by positionMode and positionOffset. The call will attempt to write requestCount bytes from the buffer pointed at by the buffer parameter.

The fork’s current position is set to point immediately after the last byte written (that is, the initial position plus actualCount).

You can open the fork using the FSOpenFork call.

AVAILABILITY

Supported in Carbon. Available in Mac OS 9, and later when Carbon 1.0.2 or later is present.

© 2000 Apple Computer, Inc. — (Last Updated 5/8/2000)