All commands (14,187)

  • Edit a file on a remote host using vim


    55
    vim scp://username@host//path/to/somefile
    adminzim · 2009-02-18 15:09:53 18
  • git remove files which have been deleted

    It deletes all removed files, updates what was modified, and adds new files.


    54
    git add -u
    donnoman · 2009-09-16 00:13:14 23
  • Generate a random password 30 characters long

    Find random strings within /dev/urandom. Using grep filter to just Alphanumeric characters, and then print the first 30 and remove all the line feeds. Show Sample Output


    54
    strings /dev/urandom | grep -o '[[:alnum:]]' | head -n 30 | tr -d '\n'; echo
    jbcurtis · 2009-02-16 00:39:28 27
  • Graph # of connections for each hosts.

    Written for linux, the real example is how to produce ascii text graphs based on a numeric value (anything where uniq -c is useful is a good candidate). Show Sample Output


    53
    netstat -an | grep ESTABLISHED | awk '{print $5}' | awk -F: '{print $1}' | sort | uniq -c | awk '{ printf("%s\t%s\t",$2,$1) ; for (i = 0; i < $1; i++) {printf("*")}; print "" }'
    knassery · 2009-04-27 22:02:19 24
  • Job Control

    You're running a script, command, whatever.. You don't expect it to take long, now 5pm has rolled around and you're ready to go home... Wait, it's still running... You forgot to nohup it before running it... Suspend it, send it to the background, then disown it... The ouput wont go anywhere, but at least the command will still run... Show Sample Output


    53
    ^Z $bg $disown
    fall0ut · 2009-03-17 21:52:52 27
  • Show apps that use internet connection at the moment. (Multi-Language)

    for one line per process: ss -p | cat for established sockets only: ss -p | grep STA for just process names: ss -p | cut -f2 -sd\" or ss -p | grep STA | cut -f2 -d\"


    52
    ss -p
    Escher · 2009-09-19 21:55:01 14
  • Record a screencast and convert it to an mpeg

    Grab X11 input and create an MPEG at 25 fps with the resolution 800x600


    51
    ffmpeg -f x11grab -r 25 -s 800x600 -i :0.0 /tmp/outputFile.mpg
    dcabanis · 2009-06-05 21:11:17 16
  • Monitor progress of a command

    Pipe viewer is a terminal-based tool for monitoring the progress of data through a pipeline. It can be inserted into any normal pipeline between two processes to give a visual indication of how quickly data is passing through, how long it has taken, how near to completion it is, and an estimate of how long it will be until completion. Source: http://www.catonmat.net/blog/unix-utilities-pipe-viewer/ Show Sample Output


    51
    pv access.log | gzip > access.log.gz
    p3k · 2009-02-06 08:50:40 227
  • Get the 10 biggest files/folders for the current direcotry


    51
    du -s * | sort -n | tail
    bambambazooka · 2009-02-05 11:18:43 33
  • Show numerical values for each of the 256 colors in bash

    Same as http://www.commandlinefu.com/commands/view/5876, but for bash. This will show a numerical value for each of the 256 colors in bash. Everything in the command is a bash builtin, so it should run on any platform where bash is installed. Prints one color per line. If someone is interested in formatting the output, paste the alternative.


    49
    for code in {0..255}; do echo -e "\e[38;05;${code}m $code: Test"; done
    scribe · 2010-06-19 02:14:42 14
  • Recursively remove all empty directories


    49
    find . -type d -empty -delete
    jmcantrell · 2010-03-23 15:21:33 20
  • Search for a <pattern> string inside all files in the current directory

    This is how I typically grep. -R recurse into subdirectories, -n show line numbers of matches, -i ignore case, -s suppress "doesn't exist" and "can't read" messages, -I ignore binary files (technically, process them as having no matches, important for showing inverted results with -v) I have grep aliased to "grep --color=auto" as well, but that's a matter of formatting not function.


    49
    grep -RnisI <pattern> *
    birnam · 2009-09-22 15:09:43 31
  • Convert seconds to human-readable format

    This example, for example, produces the output, "Fri Feb 13 15:26:30 EST 2009"


    49
    date -d@1234567890
    kFiddle · 2009-04-11 22:26:41 21
  • Monitor the queries being run by MySQL

    Watch is a very useful command for periodically running another command - in this using mysqladmin to display the processlist. This is useful for monitoring which queries are causing your server to clog up. More info here: http://codeinthehole.com/archives/2-Monitoring-MySQL-processes.html


    49
    watch -n 1 mysqladmin --user=<user> --password=<password> processlist
    root · 2009-02-16 11:21:16 134
  • Nice weather forecast on your shell

    Change Seville for your prefered city. Show Sample Output


    48
    curl wttr.in/seville
    nordri · 2016-08-28 09:43:38 33
  • Search commandlinefu.com from the command line using the API

    Usage: cmdfu hello world Show Sample Output


    48
    cmdfu(){ curl "http://www.commandlinefu.com/commands/matching/$@/$(echo -n $@ | openssl base64)/plaintext"; }
    knoopx · 2009-08-19 02:18:24 73
  • Display a cool clock on your terminal

    This command displays a clock on your terminal which updates the time every second. Press Ctrl-C to exit. A couple of variants: A little bit bigger text: watch -t -n1 "date +%T|figlet -f big" You can try other figlet fonts, too. Big sideways characters: watch -n 1 -t '/usr/games/banner -w 30 $(date +%M:%S)' This requires a particular version of banner and a 40-line terminal or you can adjust the width ("30" here). Show Sample Output


    48
    watch -t -n1 "date +%T|figlet"
    dennisw · 2009-06-21 01:02:37 39
  • Processor / memory bandwidthd? in GB/s

    Read 32GB zero's and throw them away. How fast is your system? Show Sample Output


    48
    dd if=/dev/zero of=/dev/null bs=1M count=32768
    jacquesloonen · 2009-02-16 12:22:18 213
  • Create a quick back-up copy of a file

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


    48
    cp file.txt{,.bak}
    root · 2009-01-26 12:11:29 95
  • pretend to be busy in office to enjoy a cup of coffee

    just make some data scrolling off the terminal. wow.


    47
    cat /dev/urandom | hexdump -C | grep "ca fe"
    BOYPT · 2010-09-27 08:20:44 22
  • Remove security limitations from PDF documents using ghostscript

    Remove security from PDF document using this very simple command on Linux and OSX. You need ghostscript for this baby to work.


    47
    gs -q -dNOPAUSE -dBATCH -sDEVICE=pdfwrite -sOutputFile=OUTPUT.pdf -c .setpdfwrite -f INPUT.pdf
    deijmaster · 2009-12-14 21:30:22 27
  • Check your unread Gmail from the command line

    Checks the Gmail ATOM feed for your account, parses it and outputs a list of unread messages. For some reason sed gets stuck on OS X, so here's a Perl version for the Mac: curl -u username:password --silent "https://mail.google.com/mail/feed/atom" | tr -d '\n' | awk -F '<entry>' '{for (i=2; i<=NF; i++) {print $i}}' | perl -pe 's/^<title>(.*)<\/title>.*<name>(.*)<\/name>.*$/$2 - $1/' If you want to see the name of the last person, who added a message to the conversation, change the greediness of the operators like this: curl -u username:password --silent "https://mail.google.com/mail/feed/atom" | tr -d '\n' | awk -F '<entry>' '{for (i=2; i<=NF; i++) {print $i}}' | perl -pe 's/^<title>(.*)<\/title>.*?<name>(.*?)<\/name>.*$/$2 - $1/' Show Sample Output


    47
    curl -u username:password --silent "https://mail.google.com/mail/feed/atom" | tr -d '\n' | awk -F '<entry>' '{for (i=2; i<=NF; i++) {print $i}}' | sed -n "s/<title>\(.*\)<\/title.*name>\(.*\)<\/name>.*/\2 - \1/p"
    postrational · 2009-09-07 21:56:40 46
  • Makes the permissions of file2 the same as file1

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


    46
    chmod --reference file1 file2
    rpavlick · 2010-03-31 12:05:48 13
  • Send pop-up notifications on Gnome

    The title is optional. Options: -t: expire time in milliseconds. -u: urgency (low, normal, critical). -i: icon path. On Debian-based systems you may need to install the 'libnotify-bin' package. Useful to advise when a wget download or a simulation ends. Example: wget URL ; notify-send "Done"


    46
    notify-send ["<title>"] "<body>"
    o6291408 · 2009-04-29 10:05:20 21
  • 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-%r@%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.


    46
    ssh -MNf <user>@<host>
    raphink · 2009-02-26 14:11:19 21
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Lists all listening ports together with the PID of the associated process
This command is more portable than it's cousin netstat. It works well on all the BSDs, GNU/Linux, AIX and Mac OS X. You won't find lsof by default on Solaris or HPUX by default, but packages exist around the web for installation, if needed, and the command works as shown. This is the most portable command I can find that lists listening ports and their associated pid.

Get list of servers with a specific port open
Change the -p argument for the port number. See "man nmap" for different ways to specify address ranges.

Detect illegal access to kernel space, potentially useful for Meltdown detection
Based on capsule8 agent examples, not rigorously tested

List only directories, one per line
Alternatively, $ ls -F | grep /\$ but will break on directories containing newlines. Or the safe, POSIX sh way (but will miss dotfiles): $ for i in *; do test -d "./$i" && printf "%s\n" "$i"; done

Force the script to be started as root
Will run the script as root and exit if the wrong or no password is given. Also will keep the parameters active if any where given.

Get a diff of two json arrays
jq is amazing for manipulating json on the commandline, but the developers have some weird ideas about how to handle shell redirections. This command works around them. Further reading: https://github.com/stedolan/jq/issues/1110

Find usb device in realtime
Using this command you can track a moment when usb device was attached.

Empty Bind9 cache
Occasionally, to force zone updating, cache flush is necessary. The use of this command is better than restart the Bind9 process.

Output files without comments or empty lines
better integration. works on all Unices works one bash and ksh.

Find a file's package or list a package's contents.
This is the fastest method to search the Debian package database. Requires the dlocate package. The dlocate db updates periodically, but you may force an update with # dlocate-update

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