The nfdump tools collect and process netflow data on the command line.
Nfdump tools:
nfcapd     - netflow collector daemon
nfdump     - netflow dump
nfprofile  - netflow profiler
nfreplay   - netflow replay
nfclean.pl - cleanup old data - installed as example
ft2nfdump  - read flow-tools format - optional tool
sfcapd     - sflow collector daemon - optional tool