Retrieve Cisco Config with wget

On the router or switch:

#conf t
#ip http server
#ip http authentication local
#username cisco priv 15 pass cisco

Then on your PC:

wget --user cisco --password cisco http://192.168.0.1/level/15/exec/show/running-config/view/full  -O cisco-config.txt
(substitute your IP address for 192.168.0.1). 

Show Tech-support:

wget --user cisco --password cisco http://192.168.0.1/level/15/exec/show/tech-support/CR  -O show-tech.txt