All commands (14,029)

  • Remove a line in a text file. Useful to fix

    In this case it's better do to use the dedicated tool


    44
    ssh-keygen -R <the_offending_host>
    bunam · 2010-07-11 19:37:24 0
  • To print a specific line from a file

    You can get one specific line during any procedure. Very interesting to be used when you know what line you want. Show Sample Output


    44
    sed -n 5p <file>
    Waldirio · 2009-10-15 11:00:48 3
  • Open Finder from the current Terminal location

    I did not know this, i'd like to share...


    44
    open .
    vigo · 2009-06-10 10:55:20 14
  • Create a persistent connection to a machine

    Create a persistent SSH connection to the host in the background. Combine this with settings in your ~/.ssh/config: Host host ControlPath ~/.ssh/master-%[email protected]%h:%p ControlMaster no All the SSH connections to the machine will then go through the persisten SSH socket. This is very useful if you are using SSH to synchronize files (using rsync/sftp/cvs/svn) on a regular basis because it won't create a new socket each time to open an ssh connection.


    44
    ssh -MNf <user>@<host>
    raphink · 2009-02-26 14:11:19 4
  • Makes the permissions of file2 the same as file1

    Also works with: chgrp --reference file1 file2 chown --reference file1 file2


    43
    chmod --reference file1 file2
    rpavlick · 2010-03-31 12:05:48 1
  • Show a 4-way scrollable process tree with full details.

    If you want a visual representation of the parent/child relationships between processes, this is one easy way to do it. It's useful in debugging collections of shell scripts, because it provides something like a call traceback. When a shell script breaks, just remember "awwfux".


    43
    ps awwfux | less -S
    ToyKeeper · 2009-07-04 09:39:28 4
  • Create a quick back-up copy of a file

    Uses shell expansion to create a back-up called file.txt.bak


    43
    cp file.txt{,.bak}
    root · 2009-01-26 12:11:29 1
  • Nice weather forecast on your shell

    Change Seville for your prefered city. Show Sample Output


    42
    curl wttr.in/seville
    nordri · 2016-08-28 09:43:38 9
  • Start COMMAND, and kill it if still running after 5 seconds


    42
    timeout 5s COMMAND
    kev · 2011-11-19 06:14:33 2
  • Attach screen over ssh

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


    42
    ssh -t remote_host screen -r
    recursiverse · 2009-07-23 06:15:04 7
  • Remove all files previously extracted from a tar(.gz) file.


    41
    tar -tf <file.tar.gz> | xargs rm -r
    prayer · 2009-07-06 22:23:11 3
  • Run a command only when load average is below a certain threshold

    Good for one off jobs that you want to run at a quiet time. The default threshold is a load average of 0.8 but this can be set using atrun. Show Sample Output


    41
    echo "rm -rf /unwanted-but-large/folder" | batch
    root · 2009-02-04 19:07:52 3
  • List all bash shortcuts

    This command shows the various shortcuts that can be use in bash, including Ctrl+L, Ctrl+R, etc... You can translate "\C-y" to Ctrl+y, for example. Show Sample Output


    40
    bind -P
    ricardofunke · 2012-05-28 18:51:59 3
  • RTFM function

    RTFMFTW.


    40
    rtfm() { help [email protected] || man [email protected] || $BROWSER "http://www.google.com/[email protected]"; }
    hunterm · 2011-01-05 02:53:38 2
  • Broadcast your shell thru ports 5000, 5001, 5002 ...

    run 'nc yourip 5000', 'nc yourip 5001' or 'nc yourip 5002' elsewhere will produce an exact same mirror of your shell. This is handy when you want to show someone else some amazing stuff in your shell without giving them control over it.


    40
    script -qf | tee >(nc -kl 5000) >(nc -kl 5001) >(nc -kl 5002)
    clvv · 2010-10-11 07:55:30 12
  • Eavesdrop on your system

    This command takes a snapshot of the open files for a PID 1234 then waits 10 seconds and takes another snapshot of the same PID, it then displays the difference between each snapshot to give you an insight into what the application is doing.


    39
    diff <(lsof -p 1234) <(sleep 10; lsof -p 1234)
    zlemini · 2010-03-15 22:55:32 1
  • directly ssh to host B that is only accessible through host A

    Of course you need to be able to access host A for this ;-)


    39
    ssh -t hostA ssh hostB
    0x89 · 2009-08-27 21:35:19 4
  • Retry the previous command until it exits successfully


    38
    until !!; do :; done
    unixmonkey21806 · 2013-05-14 18:08:54 3
  • What is my public IP-address?

    Short command, easy to remember


    38
    curl ifconfig.me
    CodSpirit · 2010-08-01 13:56:01 0
  • Edit a google doc with vim

    Google just released a new commend line tool offering all sorts of new services from the commend line. One of them is uploading a youtube video but there are plenty more google services to interact with. Download it here: http://code.google.com/p/googlecl/ Manual: http://code.google.com/p/googlecl/wiki/Manual This specific command courtesy of lifehacker:http://lifehacker.com/5568817/ Though all can be found in manual page linked above. Show Sample Output


    38
    google docs edit --title "To-Do List" --editor vim
    spiffwalker · 2010-06-21 16:15:42 3
  • Run a file system check on your next boot.

    The empty file /forcefsck causes the file system check fsck to be run next time you boot up, after which it will be removed. This works too: sudo >/forcefsck


    38
    sudo touch /forcefsck
    johnraff · 2009-10-29 17:04:47 6
  • List only the directories

    -d: list directory entries instead of contents, and do not dereference symbolic links


    38
    ls -d */
    brianmuckian · 2009-10-08 22:07:22 2
  • which program is this port belongs to ?

    Sometimes you need to use a port that is already opened by some program , and you don't know who to "kill" for it to release - so, now you do ! Show Sample Output


    38
    lsof -i tcp:80
    ar_levi · 2009-04-16 14:51:53 7
  • Share a terminal screen with others

    If you enable multiuser, then you can permit others to share your screen session. The following conditions apply: 1. screen must be suid root; 2. "multiuser on" must be configured in ~/.screenrc; 3. control the others user(s) access with "aclchg": # ----- from ~/.screenrc-users ----- aclchg someuser +rx "#?" #enable r/o access to "someuser" aclchg someuser -x "#,at,aclchg,acladd,acldel,quit" # don't allow these aclchg otheruser +rwx "#?" # enable r/w access to "otheruser" aclchg otheruser -x "#,at,aclchg,acladd,acldel,quit" # don't allow them to use these commands # ----- After doing this (once), you start your session with: $ screen Then, the other user can join your terminal session(s) with youruserid: $ screen -r youruserid/ Note: the trailing "/" is required. Multiple users can share the same screen simultaneously, each with independent access controlled precisely with "aclchg" in the ~/.screenrc file. I use the following setup: # ~/.screenrc-base # default screenrc on any host source $HOME/.screenrc-base source $HOME/.screenrc-$HOST source $HOME/.screenrc-users # ----- Then, the base configurations are in ~/.screenrc-base; the host-specific configurations are in ~/.screenrc-$HOST, and the user configurations are in ~/.screenrc-users. The host-specific .screenrc file might contain some host-specific screen commands; e.g.: # ~/.screen-myhost # ----- screen -t 'anywhere' /bin/tcsh screen -t 'anywhere1' /bin/tcsh # ---- The .screenrc-base contains: # ~/.screenrc-base ## I find typing ^a (Control-a) awkward. So I set the escape key to CTRL-j instead of a. escape ^Jj termcapinfo xterm* [email protected]:[email protected]: autodetach on zombie kr verbose on multiuser on


    38
    % screen -r someuser/
    totoro · 2009-03-25 23:59:38 1
  • Synchronize date and time with a server over ssh

    Shorter, easier to remember version of cmd#7636 NTP is better, but there are situations where it can't be used. In those cases, you can do this to sync the local time to a server. Show Sample Output


    37
    date --set="$(ssh [email protected] date)"
    splante · 2011-08-30 20:03:06 3
  • ‹ First  < 3 4 5 6 7 >  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

list block devices
Shows all block devices in a tree with descruptions of what they are.

Generate a random password 30 characters long
This command is similar to the alternate, except with head(1), you can pick as many passwords as you wish to generate by changing the number of lines you wish to preview.

Create full backups of individual folders using find and tar-gzip
Problem: I wanted to backup user data individually. In this example, all user data is located in "/mnt/storage/profiles", and about 25 folders inside, each with a username ( /mnt/storage/profiles/mike; /mnt/storage/profiles/lucy ...) I need each individual folder backed up, not the whole "/mnt/storage/profiles". So, using find while excluding directories depth and creating two variables (tarfile=username & desdir=destination), tar will create a .tgz file for each folder, resulting in a "mike_full.tgz" and "lucy_full.tgz".

Update a namecheap @ A record to point to your current internet-facing IP address
Sets the @ A record for your domain hosted by namecheap to your current internet-facing IP address, logs success or failure with syslog, and logs the data returned to /root/dnsupdate. Change the XXX's as appropriate. More info at: http://www.namecheap.com/support/knowledgebase/article.aspx/29/

Play 89.3 @TheCurrent and get system notifications on song changes.
Plays the mp3 stream of The Current as a background job. When you are done run: $ fg %1 then to exit Quite possible with Growl for mac I'd guess, although have not tried. Libnotify needed for notification, stream will still work otherwise

use wget to check if a remote file exists
put your link [url] to check if exist the remote file

bash alias for sdiff: differ
this is just okey

Harder, Faster, Stronger SSH clients
We force IPv4, compress the stream, specify the cypher stream to be Blowfish. I suppose you could use aes256-ctr as well for cypher spec. I'm of course leaving out things like master control sessions and such as that may not be available on your shell although that would speed things up as well.

list files recursively by size

Find the package that installed a command

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: