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# 1  
Old 08-13-2008
basic nc question

i'm doing this in one terminal:

nc -lu 7402

and it appears to start listening properly, then in another i do this:

echo "hello" | nc -u localhost 7402

and nothing happens on the listening terminal - what am i doing wrong?

thanks.
# 2  
Old 08-13-2008
Worked on my CentOS perfectly.
Code:
 nc -lu 7402
hello

Code:
# echo "hello" | nc -u localhost 7402


I would guess if its not working the port is blocked.
# 3  
Old 08-13-2008
damn, must be this osx implementation of bash..

thanks for trying it.
# 4  
Old 08-13-2008
Check for port blocking.
# 5  
Old 08-13-2008
how i do i do that?
# 6  
Old 08-13-2008
netstat will show you if some process has port nn open - ie., you cannot open it because it is blocked -
Code:
netstat | grep 'nodename\.23'

where 23 is the port you want to check
# 7  
Old 08-15-2008
thanks for this.

sorry, 1 more question - when i do nc with the -u option, it keeps running and doesn't give me the next prompt until i press ctrl-c. is there a way to stop this from happening? even if i put it in a script with exit 0 at the end this doesnt help.

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