commandlinefu.com is the place to record those command-line gems that you return to again and again.
Delete that bloated snippets file you've been using and share your personal repository with the world. 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.
If you have a new feature suggestion or find a bug, please get in touch via http://commandlinefu.uservoice.com/
You can sign-in using OpenID credentials, or register a traditional username and password.
First-time OpenID users will be automatically assigned a username which can be changed after signing in.
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.
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:
Creates the .ssh directory on the remote host with proper permissions, if it doesnt exist. Appends your public key to authorized_keys, and verifies it has proper permissions. (if it didnt exist it may have been created with undesireable permissions).
*Korn shell syntax, may or may not work with bash
This one is a bit more robust -- the remote machine may not have an .ssh directory, and it may not have an authorized_keys file, but if it does already, and you want to replace your ssh public key for some reason, this will work in that case as well, without duplicating the entry.
pub key in ./ssh/authorized_keys needed because ssh-ed ssh can't ask for the password.
analyze traffic remotely over ssh w/ wireshark
When using tcpdump, specify -U option to prevent buffering and -iany to see all interfaces.
Create a secure tunnelled connection for access to a remote MySQL database.
For example, connect with MySQL Workbench to firstname.lastname@example.org:13306.
Requires you to have password free login to remote host ;)
Requires xclip and notify-send (If you want to put into clipboard and be notified when action is completed).
DATE=$(date +%Y-%m-%d_%H-%M-%S)-$(($(date +%N)/10000000));
HOST="ssh host of your choice";
DEST="destination folder without trailing slash";
URL="URL for file if uploaded to web enabled dir ie.
import -window root png:- | ssh $HOST "cat > $DEST/screenshot_$DATE.png";
echo $URL | xclip; notify-send -u low "Screenshot Taken" "Entire screen.\nCopied to clipboard"
This command will:
1. open an SSH tunnel to
2. go to background
3. wait for 10 seconds for the connection
4. during the 10 seconds wait it will localy run 'rdesktop' to connect to the remote host through the created SSH tunnel.
Password-less log in can be achieved (when server allows it) by adding '-p ' to the 'rdesktop' command
Now at the end of the rsa.pub file, there is our comment like=
If you need to xdebug a remote php application, which is behind a firewall, and you have an ssh daemon running on that machine. you can redirect port 9000 on that machine over to your local machine from which you run your xdebug client (I am using phpStorm)
So, run this command on your local machine and start your local xdebug client, to start debugging.
Tomcat webapps are often remote links
To start X11 display only on your local machine: xeyes &
Extensions to basic command: ssh -X -f user@remotehost xcalc -bg black -fg green
(also works on Ubuntu) Copies the 'install,' 'hold,' 'deinstall' and 'purge' states of packages on the remote machine to be matched on the local machine. Note: if packages were installed on the local machine that were never installed on the remote machine, they will not be deinstalled by this operation.
This takes the stream created by apache requests containing jsp and funnels them to another server. I'm using this for simulating real time traffic. The nice command gives ssh maximum CPU cycles, awk & grep strip out everything served by apache. Putting parallel on curl is important because curl is synchronous and waits for the response. Yes, I thought about using wget but it didn't seem any easier. Also, if you figure out how to run this in the background let me know. Every time I background it it stops. If you have multiple front end servers just run multiple instances of this.
Booting the VM headless via VBoxHeadless requires knowledge of the VM's network in order to connect. Using VBoxManage in this way and you can SSH to the VM without first looking up the current IP, which changes depending on how you have your VM configured.
Sometimes you need to compare two config files on different servers. Put the file names into the above script and let 'er rip.
This uses ssh to transfer the contents of one Mac's clipboard to another's. This only works with plain text, sadly. Trying to transfer images will just clear out the remote machine's clipboard, and rich text will be converted to plain text. Using the "Remote Login" must be enabled on the remote machine (via System Preferences' Sharing panel) for this to work.
Admittedly, I'd never have thought of this without the earlier examples, but here's one that you can execute from your workstation to just display the image from another, without separately doing a file transfer, etc. By the way, I hear a loud beep coming from the other room, so I guess it's not too stealthy :-D