enable universe repository (if not enabled) sudo add-apt-repository universe Install the other netcat using synaptic. (To do this, the universe repository must be enabled.) sudo apt-get install netcat-traditional type sudo update-alternatives –config nc Select the option /bin/nc.traditional type nc -h output: [v1.10-38] connect to somewhere: nc [-options] hostname port[s] [ports] … listen for inbound: nc … Read more
Create a bash script called client.sh: #!/bin/bash cat someFile while read FOO; do echo $FOO >&3 if [[ $FOO =~ `printf “.*\x00\x1c.*”` ]]; then break fi done Then invoke netcat from your main script like so: 3>&1 nc -c ./client.sh somehost 1234 (You’ll need bash version 3 for the regexp matching). This assumes that the … Read more
When nc is listening to a UDP socket, it ‘locks on’ to the source port and source IP of the first packet it receives. Check out this trace: socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP) = 3 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0 bind(3, {sa_family=AF_INET, sin_port=htons(10000), sin_addr=inet_addr(“127.0.0.1”)}, 16) = 0 recvfrom(3, “f\n”, 2048, MSG_PEEK, {sa_family=AF_INET, sin_port=htons(52832), sin_addr=inet_addr(“127.0.0.1”)}, [16]) … Read more
Keep it Simple until nc -z 127.0.0.1 25565 do echo … sleep 1 done Just let the shell deal with the exit status implicitly The shell can deal with the exit status (recorded in $?) in two ways, explicit, and implicit. Explicit: status=$?, which allows for further processing. Implicit: For every statement, in your mind, … Read more
Simultaneous connections are not possible with netcat. You should use something like ucspi-tcp‘s tcpserver tool or leverage xinetd since you’re on Linux. See: https://superuser.com/questions/232747/netcat-as-a-multithread-server Consecutive connections could be handled through a shell script that restarts netcat after it finishes.
You must listen on the public interface. You’re currently listening on localhost where no one outside of your computer can connect. Your milage may vary, but with my implementation of netcat I have to use this command line to listen on all the public interfaces. netcat -vv -l 0.0.0.0 6666
Does it work if you just use nc? I think you should try something a little simpler: import socket def netcat(hostname, port, content): s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) s.connect((hostname, port)) s.sendall(content) s.shutdown(socket.SHUT_WR) while 1: data = s.recv(1024) if len(data) == 0: break print(“Received:”, repr(data)) print(“Connection closed.”) s.close() I added the shutdown call because maybe your device … Read more
Have you tried ssh -t remotemachine <some command> -t option from the ssh man page: -t Force pseudo-tty allocation. This can be used to execute arbitrary screen-based programs on a remote machine, which can be very useful, e.g. when implementing menu services. Multiple -t options force tty allocation, even if ssh has no local tty. … Read more
If you use ncat instead of nc your command line works fine with multiple connections but (as you pointed out) without -p. ncat -l 2000 -k -c ‘xargs -n1 echo’ ncat is available at http://nmap.org/ncat/. P.S. with the original the Hobbit’s netcat (nc) the -c flag is not supported. Update: -k (–keep-open) is now required … Read more
Of course you could dig in standards searched for google, but actually if you want to get only a single URL, it isn’tââââ worth the effort. You could also start a netcat in listening mode on a port: nc -l 64738 (Sometimes nc -l -p 64738 is the correct argument list) …and then do a … Read more