Commands tagged nc

solution that works for me

This one is tried and tested for Ubuntu 12.04. Works great for tailing any file over http.

Send apache log to syslog-ng server without change configuration of syslog.

Just add in httpd.conf or vhost conf.

This is sneaky.

First, start a listening service on your box.

On the target you will create a new descriptor which is assigned to a network node. Then you will read and write to that descriptor.

You can send it to the background like this:

Now everything you type in our local listening server will get executed on the target and the output of the commands will be piped back to the client.

Create an image of "device" and send it to another machine through the network ("target" and "port" sets the ip and port the stream will be sent to), outputting a progress bar

On the machine that will receive, compress and store the file, use:

Optionally, add the -v4g switch at the end of the line in order to split the file every 4 gigabytes (or set another size: accepted suffixes are k, m and g).

The file will be compressed using 7z format, lzma2 algorithm, with maximum compression level and solid file activated.

The compression stage will be executed on the machine which will store the image. It was planned this way because the processor on that machine was faster, and being on a gigabit network, transfering the uncompressed image wasn't much of a problem.

Allow to launch nc like a daemon, in background until you still stop it.

(like this command: http://www.commandlinefu.com/commands/view/9978 )

For send script or commands from the client to the server, use nc too, like that :

cat script.sh | nc server 1025

echo "service openvpn restart" | nc server 1025

The loop's inside doesn't do anything, but we can add echo -e "\nCommand received\n" .

Allow to launch nc like a daemon, in background until you still stop it.

You can stop it with kill %1 (jobs method) or kill PID.

The -k option can force nc to listen another connection, but if you use redirection, it will work only one time.

The loop's inside doesn't do anything, but we can imagine to send a message to screen when a connection is established

Very simple web server listening on port 80 will serve index.html file or whatever file you like pointing your browser at http://your-IP-address/index.html for example.

If your web server is down for maintenance and you'd like to inform your visitors about it, quickly and easily, you just have to put into the index.html file the right HTML code and you are done! Of course you need to be root to run the command using port 80.

uses fifo and sets to a specific port. In this case 4201.

Better solution in case of many clients, imo.

On the another machine write this command.

pv -r /dev/zero | nc 192.168.1.1 7777

It will show live throughput between two machine.The destination machine ip is at our example 192.168.1.1

You must multiply by 8 for the network calculation.

You must install pv and netcat commands for this commands usage.

kerim@bayner.com

http://www.bayner.com/

Doesn't work so well if you connect from windows. Linux only sends LF where windows wants CRLF. The alternative command works better with windows, however it uses script and a named pipe.

run 'nc yourip 5000', 'nc yourip 5001' or 'nc yourip 5002' elsewhere will produce an exact same mirror of your shell. This is handy when you want to show someone else some amazing stuff in your shell without giving them control over it.

for udp

nmap -sU -p 80 hostname

@putnamhill, no need if statement in that case.

&& is a AND and || is a OR

Requires netcat.

Simple one-liner for scanning a range of hosts, you can also scan a range of ports with Netcat by ex.: nc -v -n -z -w 1 192.168.0.1 21-443

Useful when Nmap is not available:)

Range declaration like X..X "for i in {21..29}" is only works with bash 3.0+

It bypasses encryption overhead of SSH and depending on configuration can be significantly faster.

It's recommended to use only in trusted networks.

Pipe whatever you want to this function, it will, if everything goes well, be redirected to a channel or a user on an IRC server.

Please note that :

- I am not responsible of flood excesses you might provoke.

- that function does not reply to PINGs from the server. That's the reason why I first write in a temporary file. Indeed, I don't want to wait for inputs while being connected to the server. However, according to the configuration of the server and the length of your file, you may timeout before finishing.

- Concerning the server, the variable content must be on the form "irc.server.org 6667" (or any other port). If you want to make some tests, you can also create a fake IRC server on "localhost 55555" by using

- Concerning the target, you can choose a channel (beginning with a '#' like "#chan") or a user (like "user")

- The other variables have obvious names.