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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
To try and put and end to the spamming, new commands require moderation before they will appear on the site.
2010-12-27 - Apologies for not banning the trolls sooner
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2010-09-24 - OAuth and pagination problems fixed
Apologies for the delay in getting Twitter's OAuth supported. Annoying pagination gremlin also fixed.




Commands using tail from sorted by
Terminal - Commands using tail - 233 results
nmap -sP | grep -v "Host" | tail -n +3 | tr '\n' ' ' | sed 's|Nmap|\nNmap|g' | grep "MAC Address" | cut -d " " -f5,8-15
2014-12-26 18:31:53
User: jaimerosario
Functions: cut grep sed tail tr

In the field, I needed to script a process to scan a specific vendor devices in the network. With the help of nmap, I got all the devices of that particular vendor, and started a scripted netcat session to download configuration files from a tftp server.

This is the nmap loop (part of the script). You can however, add another pipe with grep to filter the vendor/manufacturer devices only. If want to check the whole script, check in http://pastebin.com/ju7h4Xf4

tail -f access_log | awk '{print $1 , $12}'
2014-12-24 14:15:52
User: tyzbit
Functions: awk tail

Use this command to watch apache access logs in real time to see what pages are getting hit.

(ps -U nms -o pid,nlwp,cmd:500 | sort -n -k2) && (ps -U nms -o nlwp | tail -n +2 | paste -sd+ | bc)
2014-09-30 18:25:56
User: cmullican
Functions: paste ps sort tail

I occasionally need to see if a machine is hitting ulimit for threads, and what process is responsible. This gives me the total number, sorted low to high so the worst offender is at the end, then gives me the total number of threads, for convenience.

for file in $(find /var/backup -name "backup*" -type f |sort -r | tail -n +10); do rm -f $file; done ; tar czf /var/backup/backup-system-$(date "+\%Y\%m\%d\%H\%M-\%N").tgz --exclude /home/dummy /etc /home /opt 2>&- && echo "system backup ok"
2014-09-24 14:04:11
User: akiuni
Functions: date echo file find rm sort tail tar
Tags: backup Linux cron

this command can be added to crontab so as to execute a nightly backup of directories and store only the 10 last backup files.

tail -1f /var/opt/fds/logs/TraceEventLogFile.txt.0 | grep <msisdn> | tee <test-case-id>.trace | tr '|' '\n'
2014-08-21 19:29:07
User: neomefistox
Functions: grep tail tee tr

This command allows to follow up a trace on SDP (CS5.2), at the same time as the trace records are stored in the file with "raw" format.

Trace files in native format are useful to filter the records before to translation from '|' to '\n'.


grep -v OP_GET <raw-records>.trace | tr '|' '\n'
tail -f FILE | ccze
tail -f LOG_FILE | grep --line-buffered SEARCH_STR | cut -d " " -f 7-
2014-08-07 10:40:45
User: pjsb
Functions: cut grep tail
Tags: grep cut tail -f

Outputs / monitors the content of the LOG_FILE , which matches the SEARCH_STR. The output is cutted by spaces (as delimiter) starting from column 7 till the end.

find /var/log -type f -iregex '.*[^\.][^0-9]+$' -not -iregex '.*gz$' 2> /dev/null | xargs tail -n0 -f | ccze -A
2014-07-29 17:11:17
User: rubo77
Functions: find tail xargs
Tags: unix ccze logging

This will show all changes in all log files under /var/log/ that are regular files and don't end with `gz` nor with a number

bkname="test"; tobk="*" ; totalsize=$(du -csb $tobk | tail -1 | cut -f1) ; tar cvf - $tobk | tee >(sha512sum > $bkname.sha512) >(tar -tv > $bkname.lst) | mbuffer -m 4G -P 100% | pv -s $totalsize -w 100 | dd of=/dev/nst0 bs=256k
2014-07-22 15:47:50
User: johnr
Functions: cut dd du tail tar tee

This will write to TAPE (LTO3-4 in my case) a backup of files/folders. Could be changed to write to DVD/Blueray.

Go to the directory where you want to write the output files : cd /bklogs

Enter a name in bkname="Backup1", enter folders/files in tobk="/home /var/www".

It will create a tar and write it to the tape drive on /dev/nst0.

In the process, it will

1) generate a sha512 sum of the tar to $bkname.sha512; so you can validate that your data is intact

2) generate a filelist of the content of the tar with filesize to $bkname.lst

3) buffer the tar file to prevent shoe-shining the tape (I use 4GB for lto3(80mb/sec), 8gb for lto4 (120mb/sec), 3Tb usb3 disks support those speed, else I use 3x2tb raidz.

4) show buffer in/out speed and used space in the buffer

5) show progress bar with time approximation using pv


To eject the tape :

; sleep 75; mt-st -f /dev/nst0 rewoffl


1) When using old tapes, if the buffer is full and the drive slows down, it means the tape is old and would need to be replaced instead of wiping it and recycling it for an other backup. Logging where and when it slows down could provide good information on the wear of the tape. I don't know how to get that information from the mbuffer output and to trigger a "This tape slowed down X times at Y1gb, Y2gb, Y3gb down to Zmb/s for a total of 30sec. It would be wise to replace this tape next time you want to write to it."

2) Fix filesize approximation

3) Save all the output to $bkname.log with progress update being new lines. (any one have an idea?)

4) Support spanning on multiple tape.

5) Replace tar format with something else (dar?); looking at xar right now (https://code.google.com/p/xar/), xml metadata could contain per file checksum, compression algorithm (bzip2, xv, gzip), gnupg encryption, thumbnail, videopreview, image EXIF... But that's an other project.


1) You can specify the width of the progressbar of pv. If its longer than the terminal, line refresh will be written to new lines. That way you can see if there was speed slowdown during writing.

2) Remove the v in tar argument cvf to prevent listing all files added to the archive.

3) You can get tarsum (http://www.guyrutenberg.com/2009/04/29/tarsum-02-a-read-only-version-of-tarsum/)

and add >(tarsum --checksum sha256 > $bkname_list.sha256) after the tee to generate checksums of individual files !

tail -f *.log | grep --color=always '|==>.+<=='
2014-07-11 07:47:27
User: danimath
Functions: grep tail
Tags: grep tail -f

This shows the the filenames of tail output in color. Helpful if you have many log files to tail

echo $(ifconfig) | egrep -o "en.*?inet [^ ]* " | sed 's/.*inet \(.*\)$/\1/' | tail -n +2
find -type f -iregex '.*\.\(mkv\|mp4\|wmv\|flv\|webm\|mov\|dat\|flv\)' -print0 | xargs -0 mplayer -vo dummy -ao dummy -identify 2>/dev/null | perl -nle '/ID_LENGTH=([0-9\.]+)/ && ($t +=$1) && printf "%02d:%02d:%02d\n",$t/3600,$t/60%60,$t%60' | tail -n 1
2014-06-07 15:50:41
User: powerinside
Functions: find perl printf tail xargs

Use case insensitive regex to match files ending in popular video format extensions and calculate their total time. (traverses all files recursively starting from the current directory)

getlunid() { lv=$(df -P $1|grep "^/dev/"|awk '{print $1}'|awk -F/ '{print $3}'); hd=$(lslv -l $lv|tail -1|awk '{print $1}');id=$(odmget -q "name like $hd AND attribute=unique_id" CuAt|grep "value ="|awk -F= '{print $2}'|tr -d '"');echo $id;}
2014-04-20 18:43:21
User: bigstupid
Functions: awk df echo grep tail tr
Tags: aix lvm SAN odm

For a given filesystem return the LUN ID. Command assumes 1:1 relationship between fs:lv:hdisk:lun which may not be the case in all environments.

echo $(sudo lshw -businfo | grep -B 1 -m 1 $(df "/path/to/file" | tail -1 | awk '{print $1}' | cut -c 6-8) | head -n 1 | awk '{print $1}' | cut -c 5- | tr ":" "-") | sudo tee /sys/bus/usb/drivers/usb/unbind
2014-04-06 12:06:29
User: tweet78
Functions: awk cut df echo grep head sudo tail tee tr

You have an external USB drive or key.

Apply this command (using the file path of anything on your device) and it will simulate the unplug of this device.

If you just want the port, just type :

echo $(sudo lshw -businfo | grep -B 1 -m 1 $(df "/path/to/file" | tail -1 | awk '{print $1}' | cut -c 6-8) | head -n 1 | awk '{print $1}' | cut -c 5- | tr ":" "-")

eval $(history | cut -c 8- | grep "adb connect [0-9]" | tail -1)
2014-02-27 14:44:27
User: CanOrhan
Functions: cut eval grep tail

Connects to the last adb connection in history.

find . -name "pattern" -type f -exec du -ch {} + | tail -n1
convert image.jpg -resize 1x1 txt: | tail -1 | awk '{gsub(/[,\)]/," "); print $3+$4+$5}'
2013-12-11 09:13:00
User: sucotronic
Functions: awk tail

You can get the mean value for the colours in an image. Then you can determine, in general, how dark or bright is the image and run some other actions based on that. I'll recommend to readjust the brightness of the images using +sigmoidal-contrast option of imagemagick convert command.

export KEEP_KERNEL=2; dpkg -l 'linux-image*' | awk '/^ii/ { print $2 }' | grep "[0-9]" | awk 'BEGIN{i=1}{print i++, $0}' | grep `uname -r` -B99 | sort -r | tail -n+$(($KEEP_KERNEL+2)) | awk '{print $2}'| xargs apt-get -y purge
telnet towel.blinkenlights.nl 666 2>/dev/null |tail -2
2013-11-08 01:56:15
User: snaguber
Functions: tail telnet
Tags: telnet BOFH

Almost same output with fewer typing... OP had a great idea : BOFH !!!

for ff in directory; do numLines=`wc -l $ff`; numLines=$(echo $numLines | sed 's/ .*//g'); min=$(sort -nrk 1 $ff | tail -1); if [ $numLines -gt 100 ]; then echo $min >> minValues; fi;done;
pbpaste | coffee -bcsp | tail -n +2
2013-09-13 04:50:27
User: roryokane
Functions: tail

This particular combination of flags mimics Try CoffeeScript (on http://coffeescript.org/#try:) as closely as possible. And the `tail` call removes the comment `// Generated by CoffeeScript 1.6.3`.

See `coffee -h` for explanation of `coffee`'s flags.

function garg () { tail -n 1 ${HISTFILE} | awk "{ print \$$1 }" }
2013-09-10 04:07:46
User: plasticphyte
Functions: awk tail

This gets the Nth argument in the last line of your history file. This is useful where history is being written after each command, and you want to use arguments from the previous command in the current command, such as when doing copies/moving directories etc.

I wrote this after getting irritated with having to continually type in long paths/arguments.

You could also use $_ if all you want is the last argument.

nslookup www.example.com | tail -2 | head -1 | awk '{print $2}'
2013-09-05 20:26:45
User: wsams
Functions: awk head nslookup tail

I'm not sure how reliable this command is, but it works for my needs. Here's also a variant using grep.

nslookup www.example.com | grep "^Address: " | awk '{print $2}'

tail -n 1000 access.log | grep "200 POST" | awk '{print substr($3,0,9)}' | awk '{data[$0]++}END{for(item in data){print item, data[item]}}'
nl FILE_NAME | tail -n 1
2013-07-04 21:54:59
User: P3ter
Functions: nl tail

This command print the last line of a file with in first position the total lines number.