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May 19, 2015 - A Look At The New Commandlinefu
I've put together a short writeup on what kind of newness you can expect from the next iteration of clfu. Check it out here.
March 2, 2015 - New Management
I'm Jon, I'll be maintaining and improving clfu. Thanks to David for building such a great resource!

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Terminal - All commands - 12,230 results
git rev-list --reverse --topo-order master... | while read rev; do git checkout preview; git cherry-pick $rev || break; done
2015-04-23 14:28:06
User: shadyvb
Functions: read
Tags: git preview

Creating feature-branches off master, and trying to merge them in an integration branch (preview), sometimes causes conflicts because the feature-branch might hold changes from 'master' that aren't on preview yet. So this ensures only the commits added to the feature-branch are moved to integration (preview).

Note: This assumes you're currently on the feature-branch. Adjust 'master/preview' branch names to suit your environment.

tail +### MYFILE
2015-04-23 11:49:15
User: pooderbill
Functions: tail

Useful for finding newly added lines to a file, tail + can be used to show only the lines starting at some offset. A syslog scanner would look at the file for the first time, then record the end_of_file record number using wc -l. Later (hours, days), scan only at the lines that were added since the last scan.

Blocking ip: arp -s ip_of_host 0, Unblocking ip: arp -d ip_blocked
2015-04-22 19:00:13
User: andregyn62
Functions: arp

When you block any hosts using this method, the hosts can't do anything in the network.

The block is applied on firewall or gateway of the network.

:bufdo :%s/<what-was>/replace-to/g | w!
2015-04-22 15:05:47

you open multiple files and you have a pattern to be replace on each one of them.

For example the pattern is like this spread across hundred's of files.



The goal is to remove the hyphen ('-') and replace with space on file{1..3}

It should look like

package1 1.12

package2 2.33

Here how it can be done.

vim file{1..3}

:bufdo :%s/-\([0-9]\)/ \1/g | w!

"a1" 2L, 30C written

"a2" 2L, 30C written

"a3" 2L, 27C written

ffmpeg -ss 00:00:00.000 -t 10 -i filename.avi -vf scale=320:-1 -r 10 /tmp/output.gif
2015-04-22 06:52:03
User: maxwux

-ss start time

-t duration

-i file name

-vf scale=320:-1 scale 320 X auto

-r fps

view + LOGFILE
2015-04-21 11:23:01
User: pooderbill

view is the command: vi -r which opens a file in read-only mode. The + character jumps to the bottom of the logfile where the most relevant information starts. Other aliases can be created for commonly viewed logfiles.

git diff --word-diff --color-words | aha > index.html && firefox index.html
2015-04-20 13:09:44
User: pooderbill
Functions: ps
Tags: grep function ps

ps and grep is a dangerous combination -- grep tries to match everything on each line (thus the all too common: grep -v grep hack). ps -C doesn't use grep, it uses the process table for an exact match. Thus, you'll get an accurate list with: ps -fC sh rather finding every process with sh somewhere on the line.

openssl req -nodes -newkey rsa:2048 -keyout server.key -out server.csr -subj "/C=BR/ST=State/L=City/O=Company Inc./OU=IT/CN=domain.com"
fold -sw 20 <(echo "Long Text to be wrapped with \"\n\"") |sed ':a;N;$!ba;s/ *\n/\\n/g'
2015-04-16 21:06:53
User: alecthegeek
Functions: echo fold sed

I used this fragment with Imagemagick convert so that I can place long text strings in pictures. The "\n" gets converted to a true newline in the image.

So this fragment uses fold command to wrap the line and then sed to convert newlines (and any trailing spaces on the line) to the text "\n"

find -name pom.xml | while read f; do cd $(dirname "$f"); mvn clean; cd -; done;
2015-04-15 21:24:49
User: glaudiston
Functions: cd dirname find read

this command is used to locate all pom.xml files, access the dir and do a mvn clean, but I do recommend you to disable network interfaces to not download dependencies packages to be faster.

awk -F"|" 'BEGIN {OFS="|"} NR==1 {for (b=1;b<=NF;b++) {hdr[b]=$b} } NR > 1 {for (i=1;i<=NF;i++) {if(length($i) > max[i]) max[i] = length($i)} } END {for (i=1;i <= NF;i++) print hdr[i],max[i]+0}' pipe_delimited_file.psv
find /PATHNAME -type l | while read nullsymlink ; do wrongpath=$(readlink "$nullsymlink") ; right=$(echo "$wrongpath" | sed s'|OLD_STRING|NEW_STRING|') ; ln -fs "$right" "$nullsymlink" ; done
2015-04-14 14:58:41
User: iDudo
Functions: echo find ln read readlink sed

After you run this script, you can check status for broken symlink with this command:

find -L . -type l

docker stop $(docker ps -a -q); docker rm $(docker ps -a -q)
2015-04-14 13:34:15
User: das_shark
Functions: ps rm

Will stop all running containers, then remove all containers

**This isn't for selectively handling containers, it removes everything**

env DISPLAY=:0 /usr/bin/gedit ~/df.txt && wmctl -a gedit
2015-04-12 13:48:31
User: knoppix5
Functions: env

Usage example: display output of a command running in the background at desired time

The example in details: report disk quotas and that backup process will start soon

In my /etc/crontab file I added following four lines for weekly automatic incremental backup:


52 13 * * 7 root mount /dev/sda3 /media/da2dc69c-92cc-4249-b2c3-9b00847e7106


53 13 * * 7 knoppix5 df -h >~/df.txt


54 13 * * 7 knoppix5 env DISPLAY=:0 /usr/bin/gedit ~/df.txt && wmctl -a gedit


55 13 * * 7 root /home/knoppix5/rdiff-backup.sh


line one: as root mount media for backup on Sunday 13:52

line two: as user knoppix5 write out to text file in home directory the free space of all mounted disks on Sunday 13:53

line three: in front of you open and display a very simple text editor (I prefer gedit) with content of previously reported disk usage at Sunday 13:54

wmctl -a gedit means (from the manual):

-a Switch to the desktop containing the window , raise the window, and give it focus.

line four: as root run incremental backup script rdiff-backup.sh as root on Sunday 13:54


my rdiff-backup.sh, with root permissions backups in short time (writes only changes from the last backup) the etire linux system (except excluded - i.e. you don't want backup recursively your backup disk), looks like this (Show sample output):

netstat -anp | grep :80 | grep ESTABLISHED | wc -l
2015-04-10 19:32:31
User: krizzo
Functions: grep netstat wc
Tags: session

This counts all established sessions on port 80. You can change :80 to any port number you want to check.

sudo lsof -i -n | grep sshd | grep sshuser | grep :[PORT-RANGE] | grep -v IPv6 | awk -F\: '{print $2}' | grep -v http | awk -F" " '{print $1}'
2015-04-09 15:41:11
User: das_shark
Functions: awk grep sshd sudo

gets network ports

only ones for the sshd service

only logged in a specific user (changed for public posting)

only in a specific localhost:port range

not IPv6

Only the part of the response after the ":" character

Only the part of the response before the 1st space

Output is just the rssh port

debugfs -R "stat <$(stat --printf=%i filename)>" /dev/sdaX | grep crtime
2015-04-09 01:23:56
User: pggx999
Functions: debugfs grep

Return the creation date of a file on ext2, 3, 4 filesystems, because stat command won't show it.

Useful on ubuntu, debian, and else

runonchange () { local cmd=( "$@" ) ; while inotifywait --exclude '.*\.swp' -qqre close_write,move,create,delete $1 ; do "${cmd[@]:1}" ; done ; }
2015-04-08 17:42:03
User: funollet


runonchange /etc/nginx nginx -t

Ignores vim temp files. Depends on 'inotify-tools' for monitoring of file changes. Alternative to tools like 'entr', 'watchr'.

awk '{print $0+0}' <(echo -2; echo +3;)
2015-04-08 09:19:24
Functions: awk echo

The leading plus sign is removed - Minus sign is left intact

a=$(b=$(($LINES/2));f() { for c in $(seq $b); do for i in $(seq $c);do echo x;done|xargs echo;done };paste <(f) <(f|tac|tr 'x' '-') <(f|tac|tr 'x' '-') <(f)|tr '\t' ' ');(cat <<<"$a"|tac;cat <<<"$a")|tr '-' ' '
watch -n 10 -d eval "sensors | grep RPM | sed -e 's/.*: *//;s/ RPM.*//'"
2015-04-07 14:28:32
User: omap7777
Functions: eval watch

Uses the lm-sensors package in Linux to display fan speed. Grep RPM is used to discover lines containing the text RPM, and sed is used to edit out everything but the RPM number. The watch utility is used to update the display every 10 seconds and -d highlights any changes from the previous value. The eval function of Bash is used to execute the command enclosed in the ".." string.

xset -display :0 q | grep ' Monitor is On' > /dev/null && xset -display :0 dpms force off || xset -display :0 dpms force on
2015-04-06 19:04:04
User: electrotux
Functions: grep

Queries whether the monitor is on according to DPMS. If true then turns the monitor off, if false turns it on. The -display option on xset means the command will work from sessions other than the console, such as ssh or a cron'd script. Command should display any errors if there are any problems (eg no X available), otherwise no output if successful.

mail tech@commandlinefu.com
2015-04-06 13:43:04
User: flatcap
Functions: mail

Welcome to Jon H. (@fart), the new maintainer of CommandLineFu.


In the absence of a forum, I encourage people welcome him, here, in the comments.


Also... What would you like to improve/change about the site?

pandoc --from=markdown --to=rst --output=README.rst README.md