Function

CFURLResourceIsReachable(_:_:)

Returns whether the resource pointed to by a file URL can be reached.

Declaration

func CFURLResourceIsReachable(_ url: CFURL!, _ error: UnsafeMutablePointer<Unmanaged<CFError>?>!) -> Bool

Parameters

url

The URL to check.

error

The error that occurred when the resource could not be reached.

Return Value

true if the resource is reachable; otherwise, false.

Discussion

This function synchronously checks if the file at the provided URL is reachable. Checking reachability is appropriate when making decisions that do not require other immediate operations on the resource, such as periodic maintenance of user interface state that depends on the existence of a specific document. For example, you might remove an item from a download list if the user deletes the file.

If your app must perform operations on the file, such as opening it or copying resource properties, it is more efficient to attempt the operation and handle any failure that may occur.

If this function returns false, the object pointer referenced by error is populated with additional information.

See Also

Getting URL Properties

func CFURLGetBaseURL(CFURL!) -> CFURL!

Returns the base URL of a given URL if it exists.

func CFURLGetBytes(CFURL!, UnsafeMutablePointer<UInt8>!, CFIndex) -> CFIndex

Returns by reference the byte representation of a URL object.

func CFURLGetTypeID() -> CFTypeID

Returns the type identifier for the CFURL opaque type.

Beta Software

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