To display IP addresses assigned to router’s interfaces (excluding interfaces with no IP address) use show ip interface brief | exclude unassigned command.

Here is a sample printout:

C1#show ip int brief | excl unassigned  
Interface                  IP-Address      OK? Method Status                Protocol
FastEthernet0/0            172.16.0.1      YES NVRAM  up                    up      
Serial1/0                  10.0.7.17       YES NVRAM  up                    up      
Loopback0                  10.0.1.1        YES NVRAM  up                    up      
Tunnel0                    192.168.0.1     YES manual up                    up      

You could define an alias to create a new IOS command generating this printout, for example, alias exec ipconfig show ip interface brief | exclude unassigned.