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:
If the remote doesn't export its desktop (eg fluxbox, blackbox etc) then you need to run a x11vnc server there and a vncviewer at the local end. This command does the lot for you - it assumes that you can 'ssh' to the box without a password and that x11vnc is installed at the remote end.
This command will copy a folder tree (keeping the parent folders) through ssh. It will:
- compress the data
- stream the compressed data through ssh
- decompress the data on the local folder
This command will take no additional space on the host machine (no need to create compressed tar files, transfer it and then delete it on the host).
There is some situations (like mirroring a remote machine) where you simply cant wait for a huge time taking scp command or cant compress the data to a tarball on the host because of file system space limitation, so this command can do the job quite well.
This command performs very well mainly when a lot of data is involved in the process. If you copying a low amount of data, use scp instead (easier to type)
This command will nicely dump a filesystem to STDOUT, compress it, encrypt it with the gpg key of your choice, throttle the the data stream to 60kb/s and finally use ssh to copy the contents to an image on a remote machine.
Get your server's fingerprints to give to users to verify when they ssh in. Publickey locations may vary by distro. Fingerprints should be provided out-of-band.
Forward connections to $HOSTNAME:8080 out to $HOST:80
Allows you to establish a tunnel (encapsulate packets) to your (Server B) remote server IP from your local host (Server A).
On Server B you can then connect to port 2001 which will forward all packets (encapsulated) to port 22 on Server A.
-- www.fir3net.com --
This command will dump a database on a remote stream to stdout, compress it, stream it to your local machine, decompress it and put it into a file called database.sql.You could even pipe it into mysql on your local machine to restore it immediately. I had to use this recently because the server I needed a backup from didn't have enough disk space.
Quick shortcut if you know the hostname and want to save yourself one step for looking up the IP address separately.
Launch a gui app remotely. In this example smplayer is installed on the remote machine, and movie.avi is in the remote user's home dir. Note that stdout/stderr is still local, so you'll have feedback locally, add '&>/dev/null' to suppress. This is surprisingly not well known (compared to running an X app locally via ssh -X). (NB. if your distro requires ~/.Xauthority file present, then try -fX if you have problems)
Resubmitted (and trimmed, thanks sitaram) due to ridiculous voting on previous submission. Fingers crossed, it gets a better rating this time.
You can use this to directly dump from machine A (with dvd drive) to machine B (without dvd drive) . I used this to copy dvd using my friend's machine to my netbook. Above command is to be issued on machine B.
1) No wasting time dumping first to machine A and then copying to Machine B.
2) You dont need to use space on Machine A. In fact, this will work even when Machine A doesnt have enough hdd space to dump the DVD.
Use -C ssh option on slow networks (enables compression).
you can replace "dd if=/dev/dvd" with any ripping command as long as it spews the iso to stdout.
This can be much faster than downloading one or both trees to a common servers and comparing the files there. After, only those files could be copied down for deeper comparison if needed.
Instead of looking for the right ip address, just pick whatever address you like and set a static ip mapping.
Connect to a machine running ssh using mac address by using the "arp" command
I wanted to keep a backup of my company database server on my local homeserver. After I found maatkit to sync databases, everything except security seemed fine. SSH takes care of that part.
The important thing to note in this command, is the "-n" flag.
Once it is connected to the remote server by that ssh protocol,the mentioned command will start working on that server.
Of course you need to be able to access host A for this ;-)
Stop tormenting the poor animal cat!
Also you should not that you need a private key not protected by a passphrase on middlehost that grants you access to securehost..
middlehost allows ssh access from where you are but not securehost.
Use nice ssh piping to simulate scp through A => B => C
setting up the shell function if left as an exercise for the reader. ;-)
Agent forwarding should avoid password typing.
Useful to move many files (thousands or millions files) over ssh. Faster than scp because this way you save a lot of tcp connection establishments (syn/ack packets).
If using a fast lan (I have just tested gigabyte ethernet) it is faster to not compress the data so the command would be:
tar -cf - /home/user/test | ssh user@sshServer 'cd /tmp; tar xf -'
I have a small embedded linux device that I wanted to use for sniffing my external network, but I didn't want to recompile/cross-compile snort for the embedded platform. So I used tcpdump over ssh to pass all the traffic as pcap data to a "normal" Linux system that then takes the pcap data and passes it to snort for processing.
Locally watch MySQL process list update every 5s on a remote host. While you watch pipe to a file. The file out put is messy though but hey at least you have a history of what you see.
Same as original just no $ at start