Creates a dispatch I/O channel with the associated path name.
- iOS 5.0+
- macOS 10.7+
- Mac Catalyst 13.0+Beta
- tvOS 9.0+
- watchOS 2.0+
The type of channel to create. For a list of possible options, see
_io _type _t
The file system path to open and use for the channel I/O. This path is opened using the open system call.
The flags to pass to the open function when opening the path.
The mode to pass to the open function when creating a file at the specified path. If you are not creating a file, specify
The dispatch queue to associate with the channel. This queue is used to execute the channel’s clean up handler. The channel retains this queue.
The block to enqueue when the system relinquishes control of the channel’s file descriptor. This channel takes a single parameter that indicates the reason why control was relinquished. If the
errorparameter contains a non zero value, control was relinquished because there was an error creating the channel; otherwise, this value should be
The dispatch I/O channel or
NULL if an error occurred. The returned object is retained before it is returned; it is your responsibility to close the channel and then release this object when you are done using it.
This function associates the specified path with the channel but does not open a file descriptor for that path until you perform the first I/O operation. While it is open, the channel owns the file descriptor. The channel closes the file descriptor and calls its cleanup handler when one of the following occurs:
You close the channel by calling the
An unrecoverable error occurs on the file descriptor.
All references to the channel are released.