Are you looking for FAQ: what is netcat and how do I use it?
Kevin Smith of Shadetree Software has allowed us to mirror this from his site.
This is a slightly newer version that the one currently circulating on the net.
The original version would read standard in and write it to the network port. The new version also monitors the network port for data being returned. Anything read back from the network port is put out on stdout.
Argument handling has been changed slightly
For debug output just use -d instead of -d 1
The space betwen the argument letter and the argument option is now optional.netcat -hhost -p9100instead ofnetcat -h host -p 9100
Debug output looks like
echo "`date`\f\c" | netcat -d -hspot -p9100 Host: spot Port: 9100 gethostbyname(spot)=0x408b10 ip = 192.168.200.207 socket()=4 connect()=0 >(s0)(r29)(s4)(w29) >(s0)(r0)EOF from 0--disconnecting