Position Mode Constants
Together with an offset, specify a position within a fork.
enum {
fsAtMark = 0,
fsFromStart = 1,
fsFromLEOF = 2,
fsFromMark = 3
};
Constants
fsAtMark
The starting point is the access path’s current position. The offset is ignored.
Available in Mac OS X v10.0 and later.
fsFromStart
The starting point is offset bytes from the start of the fork. The offset must be non-negative.
Available in Mac OS X v10.0 and later.
fsFromLEOF
The starting point is offset bytes from the logical end of the fork. The offset must not be positive.
Available in Mac OS X v10.0 and later.
fsFromMark
The starting point is offset bytes from the access path’s current position. The offset may be positive or negative.
Available in Mac OS X v10.0 and later.
Discussion
These constants are used in the ioPosMode and positionMode fields and parameters of the HFS and HFS Plus file access functions. These functions include those for reading from and writing to files or forks, changing the current position within a file or fork, changing the size of a file or fork, and allocating space to a file or fork.
For the FSReadFork and FSWriteFork calls, you may also add either of the pleaseCacheMask or noCacheMask constants to hint whether the data should be cached or not. See Cache Constants.
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