Need help do a grep then get rid of the first line 1

[sillyVM]

Hey all your guru's.
I think I asked a similar question before using these commands. But I am still having trouble with a new line. Here is what I havve

#dinosaur:~/nmap-4.20$ nmap -A 199.67.4.21 -p 21 | grep 21/tcp | cut -f1 | awk '{ print $3 }'
Warning: File ./nmap-service-probes exists, but Nmap is using /usr/local/share/nmap/nmap-service-probes for security and consistency reasons.  set NMAPDIR=. to give priority to files in your local directory (may affect the other data files too).
ftp

Is there a way I only display the second line of the output? I only want to see "ftp". (last time i was asking how to get last column i think) Is there a tutorial to learn this? Is this shell scripting? >.< Thanks for all your help in advance!

 

[sillyVM]

I fixed application and got rid of that error message. So now it displays correctly. But I still dont' know how to grep my results as desired. Any suggeted reading will be more welcome. Thanks in advance!

 

[zeland]

Can't quite imagine what you want. But if you want the second line only, try:

... | head -n 2 | tail -n 1

--== Anything can go wrong. It's just a matter of how far wrong it will go till people think its right. ==--

 

[sillyVM]

I see what you mean, this is exactly what I wanted. Thank you very much. Do you know where can I learn more about these? any kind full tutorial?

 

[zeland]

I don't think there is any single tutorial that will teach you everything you need to know. For me it was just daily experience mucking around with all the available utilities to get my work done. Linux has given you all the tools, it's up to your imagination to piece things together.

--== Anything can go wrong. It's just a matter of how far wrong it will go till people think its right. ==--

 

[sillyVM]

very well. Thanks!