---
title: "SCNetworkReachabilitySetCallback(_:_:_:)"
framework: systemconfiguration
role: symbol
role_heading: Function
path: "systemconfiguration/scnetworkreachabilitysetcallback(_:_:_:)"
---

# SCNetworkReachabilitySetCallback(_:_:_:)

Assigns a client to the specified target, which receives callbacks when the reachability of the target changes.

## Declaration

```swift
func SCNetworkReachabilitySetCallback(_ target: SCNetworkReachability, _ callout: SCNetworkReachabilityCallBack?, _ context: UnsafeMutablePointer<SCNetworkReachabilityContext>?) -> Bool
```

## Parameters

- `target`: The network reference associated with the address or name to be checked for reachability.
- `callout`: The function to be called when the reachability of the target changes. If NULL, the current client for the target is removed.
- `context`: The reachability context associated with the callout. This value may be NULL.

## Return Value

Return Value TRUE if the notification client was successfully set; otherwise, FALSE.

## See Also

### Preparing to Determine Reachability

- [SCNetworkReachabilityGetTypeID()](systemconfiguration/scnetworkreachabilitygettypeid().md)
- [SCNetworkReachabilityScheduleWithRunLoop(_:_:_:)](systemconfiguration/scnetworkreachabilityschedulewithrunloop(_:_:_:).md)
- [SCNetworkReachabilityUnscheduleFromRunLoop(_:_:_:)](systemconfiguration/scnetworkreachabilityunschedulefromrunloop(_:_:_:).md)
- [SCNetworkReachabilitySetDispatchQueue(_:_:)](systemconfiguration/scnetworkreachabilitysetdispatchqueue(_:_:).md)