Hide

What's this?

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/

Get involved!

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.

Universal configuration monitoring and system of record for IT.
Hide

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:

Hide

News

May 19, 2015 - A Look At The New Commandlinefu
I've put together a short writeup on what kind of newness you can expect from the next iteration of clfu. Check it out here.
March 2, 2015 - New Management
I'm Jon, I'll be maintaining and improving clfu. Thanks to David for building such a great resource!
Hide

Top Tags

Hide

Functions

Commands tagged ssh from sorted by
Terminal - Commands tagged ssh - 177 results
ssh-keygen -l -f /etc/ssh/ssh_host_rsa_key.pub && ssh-keygen -l -f /etc/ssh/ssh_host_dsa_key.pub
2009-10-26 17:52:41
Functions: ssh ssh-keygen
Tags: ssh bash
4

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.

ssh [email protected]_A dd if=/dev/dvd0 > dvddump.iso
2009-09-11 18:08:36
User: kamathln
Functions: dd ssh
Tags: ssh dvd dump
5

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.

Advantages :

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.

diff <(ssh server01 'cd config; find . -type f -exec md5sum {} \;| sort -k 2') <(ssh server02 'cd config;find . -type f -exec md5sum {} \;| sort -k 2')
2009-09-11 15:24:59
User: arcege
Functions: diff find md5sum sort ssh
14

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.

dsh -M -c -f servers -- "command HERE"
2009-08-31 12:08:38
User: foob4r
Tags: ssh multiple
4

dsh - Distributed shell, or dancer?s shell ;-)

you can put your servers into /etc/dsh/machines.list than you don't have to serperate them by commata or group them in different files and only run commands for this groups

dsh -M -c -a -- "apt-get update"

ssh [email protected] [anycommand](i.e uptime,w)
2009-08-29 04:27:37
User: unixbhaskar
Functions: ssh
Tags: ssh shell
-3

Once it is connected to the remote server by that ssh protocol,the mentioned command will start working on that server.

ssh middlehost "ssh -a [email protected] '> nicescript'" < nicescript
2009-08-26 20:25:12
User: 0x89
Functions: ssh
Tags: ssh scp
0

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..

for i in 192.168.1.{61..71};do ping -c 1 $i &> /dev/null && echo $i;fi;done
2009-08-26 06:04:24
User: AlecSchueler
Functions: echo ping
Tags: Network ssh bash
-2

If you need to ssh into a computer on the local network but you're unsure of the ip to use, then ping them and see if you get a response. If you do, print out the address you got it from. Adjust the range to suit your network.

rsync -az /home/user/test [email protected]:/tmp/
2009-08-25 10:45:15
User: peshay
Functions: rsync
Tags: ssh file move
14

copy files to a ssh server with gzip compression

cat nicescript |ssh middlehost "cat | ssh -a [email protected] 'cat > nicescript'"
2009-08-25 08:11:12
User: syladmin
Functions: cat ssh
Tags: ssh scp
4

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.

tar -cf - /home/user/test | gzip -c | ssh [email protected] 'cd /tmp; tar xfz -'
2009-08-24 18:35:38
User: esplinter
Functions: gzip ssh tar
Tags: ssh file move
11

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 [email protected] 'cd /tmp; tar xf -'

xinit -- :1
2009-07-31 23:42:28
User: flux
Tags: ssh X X11 xinit
3

This starts a very basic X session, with just a simple xterm. You can use this xterm to launch your preferred distant session.

ssh -X [email protected] gnome-session

Try also startkde or fluxbox or xfce4-session.

To switch between your two X servers, use CTRL+ALT+F7 and CTRL+ALT+F8.

ssh -t remote_host screen -r
2009-07-23 06:15:04
User: recursiverse
Functions: screen ssh
Tags: ssh screen
41

Directly attach a remote screen session (saves a useless parent bash process)

pbpaste | ssh [email protected] 'cat > ~/my_new_file.txt'
2009-07-14 16:32:03
User: mikedamage
Functions: ssh
Tags: ssh osx clipboard
3

Redirects the contents of your clipboard through a pipe, to a remote machine via SSH.

# dd if=/dev/sda | gzip -c | ssh [email protected] 'dd of=/mnt/backups/sda.dd'
ssh -f -N -L 5432:talk.google.com:5222 [email protected]
2009-06-05 23:17:21
User: dcabanis
Functions: ssh
Tags: ssh
12

If your firewall or proxy at your location prevents connection to a particular host or port, you can use ssh to tunnel to your home server and do it there instead.

ssf -f -N -L 4321:home.network.com:25 [email protected]
2009-06-05 23:12:02
User: dcabanis
Tags: ssh
5

Uses ssh as tunnel tunnel for an other connection.

-f runs ssh in the background -N tell that there is no command to run -L deals with the forwarding aspect where the first number is the local port number, the second is parameter is the name of the server to forward to and the third parameter is the port number on that server. The last part of the command is the usual ssh form consisting of the user name and remote server name

alias s='ssh -l root'
2009-05-07 15:57:12
User: GouNiNi
Functions: alias
-20

When you have to manage lot of servers, it's boring to type ssh [email protected] for each connection. Now you can type juste "s someting" and you are connected.

You can too add bash_completion script to complet with tab the name of your servers. This will be the next tips from me ;)

ssh [email protected] | tee logfilename
2009-04-17 19:17:02
User: bassu
Functions: ssh tee
6

Optionally, you can create a new function to do this with a custom command. Edit $HOME/.bashrc and add:

myssh () { ssh $1 | tee sshlog ; }

Save it.

At command prompt:

myssh [email protected]
diff <(ssh alice cat /etc/apt/sources.list) <(ssh bob cat /etc/apt/sources.list)
ssh -vN hostname 2>&1 | grep "remote software version"
2009-03-31 18:28:41
User: sud0er
Functions: grep hostname ssh
Tags: ssh
3

I used this to confirm an upgrade to an SSH daemon was successful

[[ $(COLUMNS=200 ps faux | awk '/grep/ {next} /ssh -N -R 4444/ {i++} END {print i}') ]] || nohup ssh -N -R 4444:localhost:22 [email protected] &
2009-03-31 09:39:59
User: j0rn
Functions: awk nohup ps ssh
Tags: ssh cronjob
4

I find it ugly & sexy at the same time isn't it ?

ssh -NL 2000:remotehost:22 remotehost
ssh -fX <user>@<host> <program>
2009-03-10 15:02:35
User: prayer
Functions: ssh
Tags: ssh
15
ssh -X example.org xeyes

The SSH server configuration requires:

X11Forwarding yes # this is default in Debian

And it's convenient too:

Compression delayed

stty -echo; ssh -t HOSTNAME "sudo some_command"; stty echo
2009-03-04 19:44:36
User: jmcantrell
Functions: ssh stty
Tags: ssh sudo
3

The ssh command alone will execute the sudo command remotely, but the password will be visible in the terminal as you type it. The two stty commands disable the terminal from echoing the password back to you, which makes the remote sudo act as it does locally.

ssh -t reachable_host ssh unreachable_host
2009-03-03 23:21:36
User: patko
Functions: ssh
Tags: ssh
145

Unreachable_host is unavailable from local network, but it's available from reachable_host's network. This command creates a connection to unreachable_host through "hidden" connection to reachable_host.