The filter

head t.txt; echo ... tail t.txt

%sort -r +1-2 t1_data.txt
%sort -r -n -k2 t1_data.txt
%grep ' [6-9]' t1_data.txt




steven@steven-laptop:~/Dropbox/9041/w02$ grep '\b[6-9]' t1_data.txt
2168678 84 DN
2186565 77 DN
2190546 78 DN
2223455 95 HD
steven@steven-laptop:~/Dropbox/9041/w02$ grep '\B[6-9]' t1_data.txt
2168678 84 DN
2186565 77 DN
2190546 78 DN
2210109 50 PS
2266365 55 PS

??
To find what filters are available: apropos keyword (but not cygwin

% nmap localhost -p 8080

Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2007-08-04 22:20 EST
Interesting ports on localhost (127.0.0.1):
PORT STATE SERVICE
8080/tcp closed http-proxy

cat -A //show all the character

% nmap localhost -p 7000-9000

Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2007-08-04 22:23 EST
All 2001 scanned ports on localhost (127.0.0.1) are closed