ncat端口转发

EXAMPLES
       Connect to example.org on TCP port 8080.
           ncat example.org 8080

       Listen for connections on TCP port 8080.
           ncat -l 8080

       Redirect TCP port 8080 on the local machine to host on port 80.
           ncat --sh-exec "ncat example.org 80" -l 8080 --keep-open

       Bind to TCP port 8081 and attach /bin/bash for the world to access freely.
           ncat --exec "/bin/bash" -l 8081 --keep-open

       Bind a shell to TCP port 8081, limit access to hosts on a local network, and limit the maximum number of simultaneous connections to 3.
           ncat --exec "/bin/bash" --max-conns 3 --allow 192.168.0.0/24 -l 8081 --keep-open

       Connect to smtphost:25 through a SOCKS4 server on port 1080.
           ncat --proxy socks4host --proxy-type socks4 --proxy-auth user smtphost 25

       Create an HTTP proxy server on localhost port 8888.
           ncat -l --proxy-type http localhost 8888

       Send a file over TCP port 9899 from host2 (client) to host1 (server).
           HOST1$ ncat -l 9899 > outputfile

           HOST2$ ncat HOST1 9899 < inputfile

       Transfer in the other direction, turning Ncat into a “one file” server.
           HOST1$ ncat -l 9899 < inputfile

           HOST2$ ncat HOST1 9899 > outputfile