Commands tagged bash (821)

  • Thanks for the submit! My alternative produces summaries only for directories. The original post additionally lists all files in the current directory. Sometimes the files, they just clutter up the output. Once the big directory is located, *then* worry about which file(s) are consuming so much space.


    -1
    du -kd | egrep -v "/.*/" | sort -n
    rmbjr60 · 2010-03-30 15:40:35 3
  • The shell has perfectly adequate pattern matching for simple expressions. Show Sample Output


    -1
    function ends_in_y() { case $(date +%A) in *y ) true ;; * ) false ;; esac } ; ends_in_y && echo ok
    unixmonkey9199 · 2010-04-06 22:18:52 3
  • Essentially the same as funky's alias, but will not traverse filesystems and has nicer formatting. Show Sample Output


    -1
    alias dush="du -xsm * | sort -n | awk '{ printf(\"%4s MB ./\",\$1) ; for (i=1;i<=NF;i++) { if (i>1) printf(\"%s \",\$i) } ; printf(\"\n\") }' | tail"
    dopeman · 2010-07-15 10:38:27 4
  • forces user to rw, group to r, and other to no access. files will not be marked executable. directories will be executable for users and groups only. Show Sample Output


    -1
    chmod -R u=rw-x+X,g=r-x+X,o= .
    donnoman · 2010-07-16 18:42:00 5
  • Output the html from xkcd's index.html, filter out the html tags, and then view it in gwenview. Show Sample Output


    -1
    gwenview `wget -O - http://xkcd.com/ | grep 'png' | grep '<img src="http://imgs.xkcd.com/comics/' | sed s/title=\".*//g | sed 's/.png\"/.png/g' | sed 's/<img src=\"//g'`
    hunterm · 2010-08-24 22:21:51 4
  • Shorter version with curl and awk


    -1
    eog `curl 'http://xkcd.com/' | awk -F "ng): |</h" '/embedding/{print $2}'`
    dog · 2010-08-25 14:04:30 3
  • It works in every linux box Show Sample Output


    -1
    cat /proc/cpuinfo
    magicjohnson_ · 2010-09-24 09:27:58 3
  • The command was too long for the command box, so here it is: echo $(( `wget -qO - http://i18n.counter.li.org/ | grep 'users registered' | sed 's/.*\<font size=7\>//g' | tr '\>' ' ' | sed 's/<br.*//g' | tr ' ' '\0'` + `curl --silent http://www.dudalibre.com/gnulinuxcounter?lang=en | grep users | head -2 | tail -1 | sed 's/.*<strong>//g' | sed 's/<\/strong>.*//g'` )) This took me about an hour to do. It uses wget and curl because, dudalibre.com blocks wget, and wget worked nicely for me. Show Sample Output


    -1
    Check the Description below.
    hunterm · 2010-10-07 04:22:32 3
  • Often times you run a command in the terminal and you don't realize it's going to take forever. You can open a new terminal, but you lose the local history of the suspended one. You can stop the running command using , but that may produce undesirable side-effects. suspends the job, and (assuming you have no other jobs running in the background) %1 resumes it. Appending & tells it to run in the background. You now have a job running concurrently with your terminal. Note this will still print any output to the same terminal you're working on. Tested on zsh and bash. Show Sample Output


    -1
    <ctrl+z> %1 &
    joem86 · 2010-10-25 17:43:38 5
  • Just added view with the eog viewer.


    -1
    wget -O xkcd_$(date +%y-%m-%d).png `lynx --dump http://xkcd.com/|grep png`; eog xkcd_$(date +%y-%m-%d).png
    theanalyst · 2010-10-27 13:42:55 3
  • Uses xargs to call the second grep with the first grep's results as arguments


    -1
    grep -l bar *.log | xargs grep -l foo
    dlebauer · 2011-01-10 19:54:46 3
  • This will tighten up security for your box. The default value for PermitRootLogin sadly is 'yes'.


    -1
    s=/etc/ssh/sshd_config;r=PermitRootLogin;cp $s{,.old}&& if grep $r $s;then sed "s/$r yes/$r no/" $s.old > $s; else echo $r no >> $s;fi
    kzh · 2011-01-30 23:41:59 11
  • Here's a bash version using an array.


    -1
    a=(*); echo ${a[$((RANDOM % ${#a[@]}))]}
    putnamhill · 2011-03-18 13:24:52 3
  • Sometimes you might need to have two copies of data that is in tar. You might unpack, and then copy, but if IO is slow, you might lower it by automatically writing it twice (or more times)


    -1
    mkdir copy{1,2}; gzip -dc file.tar.gz | tee >( tar x -C copy1/ ) | tar x -C copy2/
    depesz · 2011-04-14 17:02:05 5

  • -1
    echo $(( $( date +%s ) - $( stat -c %Y * | sort -nr | head -n 1 ) ))
    depesz · 2011-05-12 14:29:45 3
  • urldecode files in current directrory


    -1
    ls * | while read fin;do fout=$(echo -n $fin | sed -e's/%\([0-9A-F][0-9A-F]\)/\\\\\x\1/g' | xargs echo -e);if [ "$fout" != "$fin" ];then echo "mv '$fin' '$fout'";fi;done | bash -x
    pawelb1973 · 2011-05-18 07:24:54 82
  • Newer versions of Dropbox let you choose the location for your Dropbox folder. If you use script to put things into your Dropbox folder (todo list, screenshots, torrents etc.) but have the Dropbox folder in different locations on your other computers this lets you use the same script on all systems without having to tell it where the Dropbox folder is. Show Sample Output


    -1
    sqlite3 $HOME/.dropbox/config.db "select value from config where key like '%dropbox_path%'"
    mobilediesel · 2011-06-05 08:26:02 13
  • Outputs the real time it takes a Redis ping to run in thousands of a second without any proceeding 0's. Useful for logging or scripted action.


    -1
    TIME=$( { time redis-cli PING; } 2>&1 ) ; echo $TIME | awk '{print $3}' | sed 's/0m//; s/\.//; s/s//; s/^0.[^[1-9]*//g;'
    allrightname · 2011-08-11 19:09:49 4

  • -1
    RANGE=`wc -l /usr/share/dict/words | sed 's/^\([0-9]*\) .*$/\1/'`; for i in {1..4}; do let "N = $RANDOM % $RANGE"; sed -n -e "${N}p" /usr/share/dict/words | tr -d '\n'; done; RANGE=100; let "N = $RANDOM % $RANGE"; echo $N
    unixmonkey24597 · 2011-08-16 07:04:57 3
  • uses fifo and sets to a specific port. In this case 4201.


    -1
    mkfifo ._b; nc -lk 4201 0<._b | /bin/bash &>._b;
    gt · 2011-08-21 05:22:41 3
  • This is an "argument calculator" funktion. The precision is set to 4 and you can use dot (.) or comma (,) as decimal mark (which is great for german users with a comma on the numpad).


    -1
    calc() { echo "scale=4; ${*//,/.}" | bc -l; }
    fpunktk · 2011-10-24 19:58:20 4
  • Schematics: command [options] [paste your variable here] parameter command [options] [paste entire column of variables here] parameter ... (hard-code command "c" and parameter "e" according to your wishes: in example shown command = "cp -a" and parameter = "~") Features: - Quick exchange only variable part of a long command line - Make variable part to be an entire column of data (i.e. file list) - Full control while processing every single item Hints: Paste column of data from anywhere. I.e. utilize the Block Select Mode to drag, select and copy columns (In KDE Konsole with Ctrl+Alt pressed, or only Ctrl pressed in GNOME Terminal respectively). Disadvantages: You can paste only one single variable in a row. If there are more space separated variables in a row only first one will be processed, but you can arrange your variables in a column instead. To transpose rows to columns or vice versa look at Linux manual pages for 'cut' and 'paste'. TODO: - add edit mode to vary command "c" and parameter "e" on the fly - add one edit mode more to handle every list item different - add y/n/a (=All) instead of only y(=default)/n to allowed answers Disclaimer: The code is not optimized, only the basic idea is presented here. It's up to you to shorten code or extend the functionality. Show Sample Output


    -1
    c="cp -a";e="~";echo -e "\npaste\n";i=0;k="1"; while [[ "$k" != "" ]]; do read -a k;r[i]=$k;((i++));done;i=0;while :;do t=${r[i]};[ "$t" == "" ] && break; g=$(echo $c ${r[i]} $e);echo -e $g "\ny/n?";read y;[ "$y" != "n" ] && eval $g;((i++));done
    knoppix5 · 2011-12-04 12:45:44 4
  • Mac install ssh-copy-id From there on out, you would upload keys to a server like this: (make sure to double quote the full path to your key) ssh-copy-id -i "/PATH/TO/YOUR/PRIVATE/KEY" username@server or, if your SSH server uses a different port (often, they will require that the port be '2222' or some other nonsense: (note the double quotes on *both* the "/path/to/key" and "user@server -pXXXX"): ssh-copy-id -i "/PATH/TO/YOUR/PRIVATE/KEY" "username@server -pXXXX" ...where XXXX is the ssh port on that server


    -1
    sudo curl "http://hg.mindrot.org/openssh/raw-file/c746d1a70cfa/contrib/ssh-copy-id" -o /usr/bin/ssh-copy-id && sudo chmod 755 /usr/bin/ssh-copy-id
    misterich · 2012-02-09 20:29:24 5
  • You need to have mtr installed on your host.


    -1
    mtr google.com
    d_voge · 2012-02-19 22:27:48 3
  • tail() { thbin="/usr/bin/tail"; if [ "${1:0:1}" != "-" ]; then fc=$(($#==0?1:$#)); lpf="$((($LINES - 3 - 2 * $fc) / $fc))"; lpf="$(($lpf<1?2:$lpf))"; [ $fc -eq 1 ] && $thbin -n $lpf "$@" | /usr/bin/fold -w $COLUMNS | $thbin -n $lpf || $thbin -n $lpf "$@"; else $thbin "$@"; fi; unset lpf fc thbin; } This is a function that implements an improved version of tail. It tries to limit the number of lines so that the screen is filled completely. It works with pipes, single and multiple files. If you add different options to tail, they will overwrite the settings from the function. It doesn't work very well when too many files (with wrapped lines) are specified. Its optimised for my three-line prompt. It also works for head. Just s/tail/head/g Don't set 'thbin="tail"', this might lead to a forkbomb.


    -1
    tail() { thbin="/usr/bin/tail"; if [ "${1:0:1}" != "-" ]; then fc=$(($#==0?1:$#)); lpf="$((($LINES - 3 - 2 * $fc) / $fc))"; lpf="$(($lpf<1?2:$lpf))"; [ $fc -eq 1 ] && $thbin -n $lpf "$@" | /usr/bin/fold -w $COLUMNS | $thbin -n $lpf || $thbin -n $lpf...
    fpunktk · 2012-03-23 19:00:30 3
  • ‹ First  < 27 28 29 30 31 >  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

Limit the transfer rate and size of data over a pipe
This example will close the pipe after transferring 100MB at a speed of 3MB per second.

no # comments, blank lines, white space. # can start in any column
The shortest and most complete comment/blank line remover... Any line where the first non-whitespace character is # (ie, indented # comments), and all null and blank lines are removed. Use the alias as a filter: $ noc /etc/hosts or $ grep server /etc/hosts | noc Change to nawk depending awk versions.

Monitor incoming connections of proxies and balancers.
Maybe this will help you to monitor your load balancers or reverse proxies if you happen to use them. This is useful to discover TIME OUTS and this will let you know if one or more of your application servers is not connected by checking.

Convert embedded spaces in filenames to "_" (underscore)
This command converts filenames with embedded spaces in the current directory replacing spaces with the underscore ("_") character.

Fetch the current human population of Earth
Fetches the world population JSON data from the US census and parses it uses jshon

Create a continuous digital clock in Linux terminal
Same effect, only shell commands.

Extract dd-image from VirtualBox VDI container and mount it
Tested with NTFS and found on this site: http://forensicir.blogspot.com/2008/01/virtualbox-and-forensics-tools.html The first 32256 bytes is the MBR

Binary search/replace
Replace all instances of "A" with "B" in file "source" saved as file "destination". !! IF A/B is multi-byte, then separate bytes with spaces like so: "s/20\ 0A/00/g".

Run the built in PHP-server in current folder
You must have PHP 5.4.0 or later to be able to run the built in server. This web server is designed for developmental purposes only, and should not be used in production. URI requests are served from the current working directory where PHP was started, unless the -t option is used to specify an explicit document root. If a URI request does not specify a file, then either index.php or index.html in the given directory are returned. If neither file exists, then a 404 response code is returned. If a PHP file is given on the command line when the web server is started it is treated as a "router" script. The script is run at the start of each HTTP request. If this script returns FALSE, then the requested resource is returned as-is. Otherwise the script's output is returned to the browser. Standard MIME types are returned for files with extensions: .css, .gif, .htm, .html, .jpe, .jpeg, .jpg, .js, .png, .svg, and .txt. The .htm and .svg extensions are recognized from PHP 5.4.4 onwards. More information here: http://php.net/manual/en/features.commandline.webserver.php

Get all mac address
I prefer the ip command to ifconfig as ifconfig is supposedly going to be deprecated. Certain IP address aliases can only be seen with the ip command (such as the ones applied by RHCS).


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: