ask NetworkManager whether the network is connected
' nm-online 'u nm-online [ OPTIONS ...]
nm-online is a utility to find out whether we are online . It is done by asking NetworkManager about its status . When run, nm-online waits until NetworkManager reports an active connection, or specified timeout expires . On exit, the returned status code should be checked (see the return codes below) .
By default NetworkManager waits for IPv4 dynamic addressing to complete but does not wait for the auto IPv6 dynamic addressing . To wait for IPv6 addressing to complete, either (1) change the network connection (Aqs IPv6 may -fail setting to no, and/or (2) change the IPv6 addressing method to manual or dhcp, to indicate that IPv6 connectivity is expected .
-h | --help Print help information .
-q | --quiet Don (Aqt print anything .
-s | --wait -for -startup Wait for NetworkManager startup to complete, rather than waiting for network connectivity specifically . Startup is considered complete once NetworkManager has activated (or attempted to activate) every auto -activate connection which is available given the current network state . (This is generally only useful at boot time; after startup has completed, nm-online -s will just return immediately, regardless of the current network state .)
-t | --timeout seconds Time to wait for a connection, in seconds . If the option is not provided, the default timeout is 30 seconds .
-x | --exit Exit immediately if NetworkManager is not running or connecting .
nm-online exits with status 0 if it succeeds, a value greater than 0 is returned if an error occurs .
0 Success already online or connection established within given timeout .
1 Offline or not online within given timeout .
2 Unknown or unspecified error .