interacting with bitcoin over docker I've created a docker container of an ubuntu machine, loaded it up with all the dependencies specified in the unix build doc and then built bitcoin and run it with the following command: 

./src/bitcoind


after that there's no output or evidence that anything is happening, the terminal is just hanging there, clearly something is going on- but I don't know/can't see what it is. 

how can I examine the activity? For instance, see the coins that are being generated in my wallet, etc. 

I've tried this proposed solution, i.e. to write 

bitcoind getinfo


but I got the error 

Error: There is no RPC client functionality in bitcoind anymore. Use the bitcoin-cli utility instead.




Regarding -regtest

I tried with: 

./src/bitcoin-cli -regtest &amp;


and I got the error:

too few parameters (need at least command)
the terminal is just hanging there


Yes, if you want it to run in the background, you need to run with the -daemon flag.


  how can I examine the activity?


You can look at the debug.log file (in the datadir), or you can run with the -printtoconsole flag. You can increase the verbosity using the -debug flag (or specify a specific category, for example -debug=mempool; to see the various debug categories and more, use -help).


  For instance, see the coins that are being generated in my wallet, etc. 


The built-in miner was removed in Bitcoin Core v0.13.0, as it was not even useful for testing purposes anymore. If you want coins, you'll need to either buy them, get someone to send you some, or run a mining setup (which at the time of writing almost certainly requires custom ASIC hardware).


  I've tried this proposed solution, i.e. to write
  
  
    bitcoind getinfo
  


You need to use bitcoin-cli now to communicate with bitcoind (since a few years ago...). The getinfo command still works but is deprecated. More specific information can be obtained using the RPC calls:


getblockchaininfo
getpeerinfo
getnetworkinfo
getwalletinfo
gettxoutsetinfo
getaddednodeinfo
getmempoolinfo