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2011-03-12 - Confoo 2011 presentation
Slides are available from the commandlinefu presentation at Confoo 2011: http://presentations.codeinthehole.com/confoo2011/
2011-01-04 - Moderation now required for new commands
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Commands tagged bash from sorted by
Terminal - Commands tagged bash - 706 results
ls ${PATH//:/ }
2012-04-26 19:45:52
User: Zulu
Functions: ls

List all commands present on system by folder.

PATH contains all command folder separated by ':'. With ${PATH//:/ }, we change ':' in space and create a list of folder for ls command.
2012-04-15 16:42:32
User: moollaza

"What it actually shows is going to be dependent on the commands you've previously entered.

When you do this, bash looks for the last command that you entered that contains the substring "ls", in my case that was "lsof ...". If the command that bash finds is what you're looking for, just hit Enter to execute it. You can also edit the command to suit your current needs before executing it (use the left and right arrow keys to move through it).

If you're looking for a different command, hit Ctrl+R again to find a matching command further back in the command history. You can also continue to type a longer substring to refine the search, since searching is incremental.

Note that the substring you enter is searched for throughout the command, not just at the beginning of the command." - http://www.linuxjournal.com/content/using-bash-history-more-efficiently

for k in $(git branch | sed /\*/d); do echo "$(git log -1 --pretty=format:"%ct" $k) $k"; done | sort -r | awk '{print $2}'
2012-04-07 11:19:00
User: dahuie
Functions: awk echo sed sort
Tags: bash git sed awk

Simpler and without all of the coloring gimmicks. This just returns a list of branches with the most recent first. This should be useful for cleaning your remotes.

eval <command> ${INBACK:-&}
2012-04-05 03:50:57
User: Zulu
Functions: eval
Tags: bash eval nohup

If $INBACK is set, command will launch in foreground and inverse.

Very useful in script !

We could apply the inverse comportement like that :

eval command ${INBACK:+&}

sudo dpkg-reconfigure keyboard-configuration
2012-03-27 21:07:45
Functions: sudo

Bash snippet to force GNU/Linux keyboard settings, layout and configuration.

Usefull when some GNU/Linux distributions such as *Ubuntu's store only limited configation options due to demonstration purposes on LiveUSB or Live persistent devices.

Overcomes the English QWERTY to French AZERTY settings failure.

Code bash en ligne de commande pour forcer l'adoption du clavier AZERTY sur les cl? USB bootable en Ubuntu.

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 $lpf...
2012-03-23 19:00:30
User: fpunktk
Functions: tail
tail() { thbin="/usr/bin/tail"; if [ "${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.

alias tail='tail -n $((${LINES:-`tput lines 2>/dev/null||echo -n 80`} - 7))'
2012-03-22 02:44:11
User: AskApache
Functions: alias echo

Run the alias command, then issue

ps aux | tail

and resize your terminal window (putty/console/hyperterm/xterm/etc) then issue the same command and you'll understand.

${LINES:-`tput lines 2>/dev/null||echo -n 12`}

Insructs the shell that if LINES is not set or null to use the output from `tput lines` ( ncurses based terminal access ) to get the number of lines in your terminal. But furthermore, in case that doesn't work either, it will default to using the default of 80.

The default for TAIL is to output the last 10 lines, this alias changes the default to output the last x lines instead, where x is the number of lines currently displayed on your terminal - 7. The -7 is there so that the top line displayed is the command you ran that used TAIL, ie the prompt.

Depending on whether your PS1 and/or PROMPT_COMMAND output more than 1 line (mine is 3) you will want to increase from -2. So with my prompt being the following, I need -7, or - 5 if I only want to display the commandline at the top. ( http://www.askapache.com/linux/bash-power-prompt.html )


[7995:7993 - 0:186] 06:26:49 Thu Apr 08 [askapache@n1-backbone5:/dev/pts/0 +1] ~

In most shells the LINES variable is created automatically at login and updated when the terminal is resized (28 linux, 23/20 others for SIGWINCH) to contain the number of vertical lines that can fit in your terminal window. Because the alias doesn't hard-code the current LINES but relys on the $LINES variable, this is a dynamic alias that will always work on a tty device.

for w in $(tr 'A-Z ,."()?!;:' 'a-z\n' < sample.txt); do echo ${#w} $w; done | sort -u | sort -n
2012-03-15 14:14:11
User: flatcap
Functions: echo sort tr
Tags: bash sort tr

Take a file and ,."()?!;: give a list of all the words in order of increasing length.

First of all use tr to map all alphabetic characters to lower case and also strip out any puntuation.

A-Z become a-z

,."()?!;: all become \n (newline)

I've ignored - (hyphen) and ' (apostrophe) because they occur in words.

Next use bash to print the length ${#w} and the word

Finally sort the list numerically (sort -n) and remove any duplicates (sort -u).

Note: sort -nu performs strangely on this list. It outputs one word per length.

while read l; do echo -e "$l"; done <1.txt >2.txt
2012-03-13 14:27:49
User: knoppix5
Functions: echo read
Tags: bash read

Bash only, no sed, no awk. Multiple spaces/tabs if exists INSIDE the line will be preserved. Empty lines stay intact, except they will be cleaned from spaces and tabs if any available.

for ((x=0;;x+=5)); do sleep 5; hours=$(($x/3600)); minutes=$(($x%3600/60)); seconds=$(($x%60)); echo "$hours hours $minutes minutes $seconds seconds have elapsed" | festival --tts & done
2012-03-06 22:58:43
User: mrklaw
Functions: echo sleep

Says time every 5 seconds in hours, minutes and seconds using festival.

for ((x=0;;x+=5)); do sleep 5; echo $x | festival --tts & done
2012-03-06 21:17:51
User: mrklaw
Functions: echo sleep

works the same, but uses festival instead of espeak

2012-03-04 00:30:56
User: alphapapa
Tags: bash hotkey

Just like "!$", except it does it instantly. Then you can hit enter if you want.

command <<< word
2012-02-29 03:14:54
User: adeverteuil
Functions: command
Tags: bash stdin

Don't do this:

echo word | command

Using a bash "here strings" and "here documents" look leeter than piping echo into the command. Also prevents subshell execution. Word is also expanded as usual.

find . -depth -name '* *' -execdir bash \-c 'a="{}";mv -f "$a" ${a// /_}' \;
2012-02-28 04:03:40
User: DewiMorgan
Functions: bash find mv

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.

for ((x=0;;x+=5)); do sleep 5; espeak $x & done
2012-02-22 00:26:57
User: adeverteuil
Functions: sleep
Tags: audio bash timer

Useful contexts :

You are doing yoga or some other physical training in which you are holding a position.

Or you practice the pomodoro productivity technique.

Or your girlfriend said "We're leaving in 40 minutes".

Design details:

sleep executes before espeak to give you a 5 seconds head start.

espeak is run in the background so it doesn't mess up the timing.

testt(){ o=abcdefghLkprsStuwxOGN;echo $@;for((i=0;i<${#o};i++));do c=${o:$i:1};test -$c $1 && help test | sed "/^ *-$c/!d;1q;s/^[^T]*/-$c /;s/ if/ -/";done; }
2012-02-21 16:54:53
User: AskApache
Functions: echo sed test

Applies each file operator using the built-in test.

testt /home/askapache/.sq


-a True - file exists.

-d True - file is a directory.

-e True - file exists.

-r True - file is readable by you.

-s True - file exists and is not empty.

-w True - the file is writable by you.

-x True - the file is executable by you.

-O True - the file is effectively owned by you.

-G True - the file is effectively owned by your group.

-N True - the file has been modified since it was last read.

Full Function:

testt ()


local dp;

until [ -z "${1:-}" ]; do


[[ ! -a "$1" ]] && dp="$PWD/$dp";

command ls -w $((${COLUMNS:-80}-20)) -lA --color=tty -d "$dp";

[[ -d "$dp" ]] && find "$dp" -mount -depth -wholename "$dp" -printf '%.5m %10M %#15s %#9u %-9g %#5U %-5G %Am/%Ad/%AY %Cm/%Cd/%CY %Tm/%Td/%TY [%Y] %p\n' -a -quit 2> /dev/null;

for f in a b c d e f g h L k p r s S t u w x O G N;


test -$f "$dp" && help test | sed "/-$f F/!d" | sed -e 's#^[\t ]*-\([a-zA-Z]\{1\}\) F[A-Z]*[\t ]* True if#-\1 "'$dp'" #g';





grep $'\t' sample.txt
cmdfu(){ local t=~/cmdfu;echo -e "\n# $1 {{{1">>$t;curl -s "commandlinefu.com/commands/matching/$1/`echo -n $1|base64`/plaintext"|sed '1,2d;s/^#.*/& {{{2/g'>$t;vim -u /dev/null -c "set ft=sh fdm=marker fdl=1 noswf" -M $t;rm $t; }
2012-02-21 05:43:16
User: AskApache
Functions: echo rm sed vim

Here is the full function (got trunctated), which is much better and works for multiple queries.

function cmdfu () {

local t=~/cmdfu;

until [[ -z $1 ]]; do

echo -e "\n# $1 {{{1" >> $t;

curl -s "commandlinefu.com/commands/matching/$1/`echo -n $1|base64`/plaintext" | sed '1,2d;s/^#.*/& {{{2/g' | tee -a $t > $t.c;

sed -i "s/^# $1 {/# $1 - `grep -c '^#' $t.c` {/" $t;



vim -u /dev/null -c "set ft=sh fdm=marker fdl=1 noswf" -M $t;

rm $t $t.c


Searches commandlinefu for single/multiple queries and displays syntax-highlighted, folded, and numbered results in vim.

mtr google.com
2012-02-19 22:27:48
User: d_voge

You need to have mtr installed on your host.

for i in {1..30}; do ping -t $i -c 1 google.com; done | grep "Time to live exceeded"
2012-02-19 13:37:04
User: fossilet
Functions: grep ping

This command uses ping to get the routers' IP addresses to the destination host as traceroute does. If you know what I mean..

sed -e 's/[;|][[:space:]]*/\n/g' .bash_history | cut --delimiter=' ' --fields=1 | sort | uniq --count | sort --numeric-sort --reverse | head --lines=20
regenerateCSR () { openssl genrsa -out $2 2048; openssl x509 -x509toreq -in $1 -out $3 -signkey $2; }
echo -n '#!'$(which awk)
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
2012-02-09 20:29:24
User: misterich
Functions: chmod sudo

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

echo -n "IP Address or Machine Name: "; read IP; ping -c 1 -q $IP >/dev/null 2>&1 && echo -e "\e[00;32mOnline\e[00m" || echo -e "\e[00;31mOffline\e[00m"
2012-02-09 07:00:03
User: crlf
Functions: echo ping read
Tags: bash echo IP ping

I have used single packet, and in a silent mode with no display of ping stats. This is with color and UI improvement to the http://www.commandlinefu.com/commands/view/10220/check-if-a-machine-is-online. It is as per the enhancements suggested.