Commands tagged ssh (186)

  • Will return the SSH server key information for each host you have in your ~/.ssh/known_hosts file, including key size, key fingerprint, key IP address or domain name, and key type. Show Sample Output


    11
    ssh-keygen -l -f ~/.ssh/known_hosts
    atoponce · 2010-12-05 04:03:07 1
  • This creates an archive that does the following: rsync:: (Everyone seems to like -z, but it is much slower for me) -a: archive mode - rescursive, preserves owner, preserves permissions, preserves modification times, preserves group, copies symlinks as symlinks, preserves device files. -H: preserves hard-links -A: preserves ACLs -X: preserves extended attributes -x: don't cross file-system boundaries -v: increase verbosity --numeric-ds: don't map uid/gid values by user/group name --delete: delete extraneous files from dest dirs (differential clean-up during sync) --progress: show progress during transfer ssh:: -T: turn off pseudo-tty to decrease cpu load on destination. -c arcfour: use the weakest but fastest SSH encryption. Must specify "Ciphers arcfour" in sshd_config on destination. -o Compression=no: Turn off SSH compression. -x: turn off X forwarding if it is on by default. Flip: rsync -aHAXxv --numeric-ids --delete --progress -e "ssh -T -c arcfour -o Compression=no -x" [source_dir] [dest_host:/dest_dir]


    11
    rsync -aHAXxv --numeric-ids --delete --progress -e "ssh -T -c arcfour -o Compression=no -x" user@<source>:<source_dir> <dest_dir>
    somaddict · 2012-12-26 13:46:23 2
  • This is useful for example if you are on ssh in a server and the server goes down without letting you out. This is part of a larget sets of escape sequences provided by ssh. You can find them with ~? Here's the list: ~. - terminate connection (and any multiplexed sessions) ~B - send a BREAK to the remote system ~C - open a command line ~R - request rekey ~V/v - decrease/increase verbosity (LogLevel) ~^Z - suspend ssh ~# - list forwarded connections ~& - background ssh (when waiting for connections to terminate) ~? - this message ~~ - send the escape character by typing it twice (Note that escapes are only recognized immediately after newline.) Show Sample Output


    11
    <Return>~.
    carlesso · 2013-06-26 13:34:58 0
  • This command will bypass checking the host key of the target server against the local known_hosts file. When you SSH to a server whose host key does not match the one stored in your local machine's known_hosts file, you'll get a error like " WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!" that indicates a key mismatch. If you know the key has legitimately changed (like the server was reinstalled), a permanent solution is to remove the stored key for that server in known_hosts. However, there are some occasions where you may not want to make the permanent change. For example, you've done some port-forwarding trickery with ssh -R or ssh -L, and are doing ssh user@localhost to connect over the port-forwarding to some other machine (not actually your localhost). Since this is usually temporary, you probably don't want to change the known_hosts file. This command is useful for those situations. Credit: Command found at http://linuxcommando.blogspot.com/2008/10/how-to-disable-ssh-host-key-checking.html. Further discussion of how it works is there also. Note this is a bit different than command #5307 - with that one you will still be prompted to store the unrecognized key, whereas this one won't prompt you for the key at all.


    10
    ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no username@host
    dmmst19 · 2012-04-20 01:54:04 0
  • This command checks for the number of times when someone has tried to login to your server and failed. If there are a lot, then that user is being targeted on your system and you might want to make sure that user either has remote logins disabled, or has a strong password, or both. If your output has an "invalid" line, it is a summary of all logins from users that don't exist on your system. Show Sample Output


    9
    zgrep "Failed password" /var/log/auth.log* | awk '{print $9}' | sort | uniq -c | sort -nr | less
    dbart · 2009-03-03 13:45:56 4
  • you may create an alias also, which I did ;-) alias sshu="ssh -o UserKnownHostsFile=/dev/null "


    9
    ssh -o UserKnownHostsFile=/dev/null root@192.168.1.1
    oernii2 · 2010-04-08 14:55:58 0

  • 9
    mussh -h host1 host2 host3 -c uptime
    george_007 · 2010-08-29 03:04:51 2
  • 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. Show Sample Output


    9
    ssh vm-user@`VBoxManage guestproperty get "vm-name" "/VirtualBox/GuestInfo/Net/0/V4/IP" | awk '{ print $2 }'`
    lucasrangit · 2011-05-04 18:01:36 0
  • Here how to recover the remote backup over ssh Show Sample Output


    8
    ssh user@host "cat /path/to/backup/backupfile.tar.bz2" |tar jpxf -
    mack · 2010-03-24 01:35:28 2
  • This will allow you to convert an audio file to wav format, and send it via ssh to a player on the other computer, which will open and play it there. Of course, substitute your information for the sound file and remote address You do not have to use paplay on the remote end, as it is a PulseAudio thing. If the remote end uses ALSA, you should use aplay instead. If it uses OSS, you should berate them about having a lousy sound system. Also, you're not limited to transmitting encoded as wav either, it's just that AFAIK, most systems don't come with mp3 codecs, but will play wav files fine. If you know SoX is installed on the remote end and has mp3 codecs, you can use the following instead: cat Klaxon.mp3 |ssh thelab@company.com play -t mp3 - this will transmit as mp3. Again, use your specific information. if you're not playing mp3s, use another type with the -t option


    7
    sox Klaxon.mp3 -t wav - |ssh thelab@company.com paplay
    camocrazed · 2010-07-29 23:23:39 0
  • The command uses ssh(1) to get to a remote host, uses tar(1) to archive a remote directory, prints the result to STDOUT, which is piped to gzip(1) to compress to a local file. In other words, we are archiving and compressing a remote directory to our local box.


    7
    ssh user@host "tar -cf - /path/to/dir" | gzip > dir.tar.gz
    atoponce · 2011-12-14 15:54:57 7
  • Securely stream a file from a remote server (and save it locally). Useful if you're impatient and want to watch a movie immediately and download it at the same time without using extra bandwidth. This is an extension of snipertyler's idea. Note: This command uses an encrypted connection, unlike the original. Show Sample Output


    7
    ssh USER@HOST cat REMOTE_FILE.mp4 | tee LOCAL_FILE.mp4 | mplayer -
    flatcap · 2013-11-28 11:25:26 4
  • 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 user@server Show Sample Output


    6
    ssh user@server | tee logfilename
    bassu · 2009-04-17 19:17:02 2
  • It grabs all the database names granted for the $MYSQLUSER and gzip them to a remote host via SSH.


    6
    for I in $(mysql -e 'show databases' -u root --password=root -s --skip-column-names); do mysqldump -u root --password=root $I | gzip -c | ssh user@server.com "cat > /remote/$I.sql.gz"; done
    juliend2 · 2010-03-07 15:03:12 1
  • ssh_config is the system-wide configuration file for ssh. For per-user configuration, which allows for different settings for each host: echo 'ServerAliveInterval 60' >> ~/.ssh/ssh_config On OSX: echo 'ServerAliveInterval 60' >> ~/.ssh/config or echo 'ServerAliveInterval 60' >> ~/etc/ssh_config


    6
    echo 'ServerAliveInterval 60' >> /etc/ssh/ssh_config
    rpavlick · 2010-03-31 09:22:54 2
  • The above command will send 4GB of data from one host to the next over the network, without consuming any unnecessary disk on either the client nor the host. This is a quick and dirty way to benchmark network speed without wasting any time or disk space. Of course, change the byte size and count as necessary. This command also doesn't rely on any extra 3rd party utilities, as dd, ssh, cat, /dev/zero and /dev/null are installed on all major Unix-like operating systems. Show Sample Output


    6
    dd if=/dev/zero bs=4096 count=1048576 | ssh user@host.tld 'cat > /dev/null'
    atoponce · 2010-06-08 18:49:51 5
  • Require: - tsocks (deb pkg) - A working SOCKS proxy. It's easy with ssh: $ ssh -N -D localhost:1080 your.home.pc -p 443 - tsocks configuration in your /etc/tsocks.conf (for the previous): server = 127.0.0.1 server_port = 1080


    6
    tsocks <program>
    prayer · 2010-07-11 14:16:06 0
  • This one doesn't need to convert to wav.


    6
    ssh [user]@[address] "mpg321 -" < [file].mp3
    leovailati · 2010-07-30 00:23:13 0
  • Run local scripts on remote server. "-T Disable pseudo-tty allocation"


    6
    ssh -T user@server < script.sh
    dlebauer · 2011-01-10 20:09:55 1
  • 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


    5
    ssf -f -N -L 4321:home.network.com:25 user@home.network.com
    dcabanis · 2009-06-05 23:12:02 1
  • 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.


    5
    ssh user@machine_A dd if=/dev/dvd0 > dvddump.iso
    kamathln · 2009-09-11 18:08:36 5
  • this command from the source server and this follow in the destination server: ssh user@localhost -p 8888


    5
    ssh -f -N -R 8888:localhost:22 user@somedomain.org
    0disse0 · 2012-02-08 20:24:38 0
  • Use as: $ s host1 Will ssh to remote host upon first invocation. Then use C-a d to detatch. Running "s host1" again will resume the shell session on the remote host. Only useful in LAN environment. You'd want to start the screen on the remote host over a WAN. Adapted from Hack 34 in Linux Server Hacks 2nd Addition.


    5
    s() { screen -d -RR -m -S "$1" -t "$USER"@"$1" ssh "$1"; }
    salamando · 2012-09-07 23:02:52 0
  • While `sshfs $REMOTE_HOST:$REMOTE_PATH $LOCAL_PATH` "pulls" a directory from the remote server to the local host, the above command does the reverse and "pushes" a directory from the local host to the remote server. This makes use of the "slave" option of sshfs which instructs it to communicate over plain stdin/stdout and the `dpipe` tool from vde2 to connect the sftp-server stdout to the sshfs stdin and vice-versa.


    5
    dpipe /usr/lib/openssh/sftp-server = ssh $REMOTE_HOST sshfs whatever:$LOCAL_PATH $REMOTE_PATH -o slave
    em · 2014-03-25 17:40:34 0
  • Bash process substitution which curls the website 'hashbang.sh' and executes the shell script embedded in the page. This is obviously not the most secure way to run something like this, and we will scold you if you try. The smarter way would be: Download locally over SSL > curl https://hashbang.sh >> hashbang.sh Verify integrty with GPG (If available) > gpg --recv-keys 0xD2C4C74D8FAA96F5 > gpg --verify hashbang.sh Inspect source code > less hashbang.sh Run > chmod +x hashbang.sh > ./hashbang.sh


    5
    sh <(curl hashbang.sh)
    lrvick · 2015-03-15 21:02:01 2
  •  < 1 2 3 4 >  Last ›

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

recursively change file name from uppercase to lowercase (or viceversa)
Example of zsh globing, glob qualifier, and substitution: -Q state that the parameter will contain a glob qualifier. (**/)(*) is recursive (.) is our glob qualifier, with states the match is a file "." The first parameter $1, is then substituted with $2 but with lowercasing '(L)' ... a (U) would of course be from lower to upper.

Combines an arbitrary number of transparent png files into one file
This one liner; combines all sequentially numbered files; in this example IMG_0001.png to IMG_1121.png by generating the shell script, making the shell script executable and then running the shell script to combine the 1121 png into a single png file named _final.png tested on Mac OS X 10.6.3 with ImageMagick 6.5.8-0 2009-11-22 Q16 http://www.imagemagick.org

get a directory from one machine to another using tar and ssh

Update twitter via curl

Fibonacci numbers with awk
recursive version, "pure" AWK

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

watch iptables counters
Watch the number of packets/bytes coming through the firewall. Useful in setting up new iptables rules or chains. Use this output to reorder rules for efficiency.

create random numbers within range for conjob usage
if you need to install cron jobs in a given time range.

Display the definition of a shell function
Display the code of a previously defined shell function.

Push your present working directory to a stack that you can pop later
If are a Bash user and you are in a directory and need to go else where for a while but don't want to lose where you were, use pushd instead of cd. cd /home/complicated/path/.I/dont/want/to/forget pushd /tmp cd thing/in/tmp popd (returns you to /home/complicated/path/.I/dont/want/to/forget)


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: