Simulating -walletnotify option in Electrum When run in daemon mode, bitcoind accepts a parameter -walletnotify=&lt;cmd&gt; which runs &lt;cmd&gt; whenever a wallet transaction changes due to sending/receiving.

Is there a similar feature in Electrum?  If not, how can it be simulated?  

The watch_wallet script seems to do something similar but only works on individual addresses, not whole wallets.  In addition, it only prints a message.
An old question - by the time I saw it - but the Electrum daemon - assuming it is running on Linux of some type must be polled from an external source with software or a cron job.

see Checking/polling a balance of an address in Electrum via the command line/RPC