All commands sorted by votes

All commands (14,187)

sorted by

add random color and external ip address to prompt (PS1)

this adds a random color to your prompt and the external ip. useful if you are using multiple mashines with the same hostname. Show Sample Output
This is sample output - yours may be different.
```
user@host^192.168.0.1:~$ 
```
0

IP=$(nslookup `hostname` | grep -i address | awk -F" " '{print $2}' | awk -F# '{print $1}' | tail -n 1 ); R=3$((RANDOM%6 + 1)); PS1="\n\[\033[1;37m\]\u@\[\033[1;$R""m\]\h^$IP:\[\033[1;37m\]\w\$\[\033[0m\] "

rubo77 · 2010-10-20 07:29:14 7
Reorder file with max 100 file per folder

Smaller Code Better Runtime
This is sample output - yours may be different.
0

find files/ -type f | while read line; do if [ $((i++%100)) -eq 0 ]; then mkdir $((++folder)); fi; cp $line $folder/; done

sraeder · 2011-02-13 00:25:48 3
xpath function

This function uses xmllint to evaluate xpaths. Usage: xpath /some/xpath XMLfile Show Sample Output
This is sample output - yours may be different.
```
$ xpath "//head/title" index.html
<title>All commands | commandlinefu.com</title>
```
0

xpath () { xmllint --format --shell "$2" <<< "cat $1" | sed '/^\/ >/d' }

sharfah · 2011-10-05 07:45:16 14
save login cookie
This is sample output - yours may be different.
0

curl -c cookie.txt -d username=hello -d password=w0r1d http://www.site.com/login

kev · 2011-11-09 02:57:39 3
Get tagged flashcards from Anki databases

Produces a CSV file containing fronts/backs of cards with specified tag ("mytag" above). This command pulls these cards from different card databases, and allows them to be merged into one (by importing the resulting CSV file). The CSV file is not directly produced; instead of commas, "||" are inserted. In your editor of choice, modify the resulting file to put quotes around the text before || and after ||, then change || to a comma (for every line).
This is sample output - yours may be different.
0

for i in `ls *.anki`; do sqlite3 $i "select (cards.question || '||' || cards.answer) from cards, facts where cards.factid=facts.id and facts.tags like '%mytag%';" >> mytag.csv; done

joshuaeckroth · 2012-03-13 19:03:20 3
don't have video stop at EOF while it is downloading

It will just start playing and will not stop at the point that it has downloaded up to when the video starts
This is sample output - yours may be different.
0

mplayer <(tail -fc +0 <filename>)

gtmanfred · 2012-04-30 07:28:42 3
top ten shell command in bash shell
This is sample output - yours may be different.
0

cat ~/.bash_history | perl -lane 'if($F[0] eq "sudo"){$hash{$F[1]}++}else{$hash{$F[0]}++};$all++;END {@top = map {[$_, $hash{$_}]} sort {$hash{$b}<=>$hash{$a}} keys %hash;printf("%10s%10d%10.2f%%\n", $_->[0],$_->[1],$_->[1]/$all*100) for @top[0..9]}'

vinian · 2012-07-02 09:38:06 7
List MP3 albums (e.g. on iPod etc.)
This is sample output - yours may be different.
0

MP3TAG_DECODE_UTF8=0 mp3info2 -p "%a - %l\n" -R . | sort | uniq

infojunkie · 2012-10-31 01:08:09 4
Show reason of revocation for 0xDEADBEEF with gpg.

Shows a sigclass 0x20 (Key revocation) signature packet on a key, including all subpackets. Subpacket 2 is the date of revocation, subpacket 26 the relevant policy, subpacket 29 the reason of revocation (cf. http://rfc.askapache.com/rfc4880/rfc4880.html#section-5.2.3.23 ) and subpacket 16 the issuer of the revocation certificate (usually should be the same as the revoked key). Show Sample Output
This is sample output - yours may be different.
```
:signature packet: algo 1, keyid DEADBEEFDEADBEEF
	version 4, created 1361391004, md5len 0, sigclass 0x20
	digest algo 8, begin of digest ef ce
	hashed subpkt 2 len 4 (sig created 2013-02-20)
	hashed subpkt 26 len 21 (policy: http://example.net/policy)
	hashed subpkt 29 len 23 (revocation reason 0x01 (I felt funny and wanted to revoke this key))
	subpkt 16 len 8 (issuer key ID DEADBEEFDEADBEEF)
	data: [4093 bits]
```
0

gpg --export 0xDEADBEEF | gpg --list-packets | grep -Pzao ':signature packet:.*\n\t.*sigclass 0x20(\n\t.*)*'

claudius · 2013-03-05 14:11:11 5
Encrypt/decrypt a string from the command line

Need to encrypt something from the command line? I've used this before to encrypt passwords with a master password that was shared amongst a team. To decrypt: ~$ echo -n 'jA0EAwMCPdknsznAww5gySL1/quqhXg6QgQkIz5abzGP5EZgTbXCFU+y6dP8ySWovytc' | base64 --decode | gpg --decrypt gpg: CAST5 encrypted data Enter passphrase: secret gpg: encrypted with 1 passphrase HelloWorld! Show Sample Output
This is sample output - yours may be different.
```
Enter passphrase: secret
Repeat passphrase: secret
jA0EAwMCPdknsznAww5gySL1/quqhXg6QgQkIz5abzGP5EZgTbXCFU+y6dP8ySWovytc
```
0

echo 'HelloWorld!' | gpg --symmetric | base64

ryanchapman · 2013-07-06 08:30:35 46
IBM AIX: Calculate the SHA256 hashes of a directory without sha256sum

This command is for producing GNU sha256sum-compatible hashes on UNIX systems that don't have sha256sum but do have OpenSSL, such as stock IBM AIX. 1.- Saves a wrapper script for UNIX find that does the following: A.- Feeds a file to openssl on SHA256 hash calculation mode B.- Echoes the output followed by the filename 2.- Makes the file executable 3.- Runs find on a directory, only processing files, and running on each one the wrapper script that calculates SHA256 hashes Pending is figuring out how to verify a sha256sum file on a similar environment. Show Sample Output
This is sample output - yours may be different.
```
6e94b0b7fc2805ad558f8039ed038a6272f61846eaa5f4931abd826193c78b83 cognos-installers/TM1-952-AIX/952_FP2_aix.tar.gz
c9d0f04ad6f86482bf4c41ba7a303e0d8a0e8c96c9c9492bc518d2a2bc0166c7 cognos-installers/TM1-952-AIX/952_FP2_HF6_aix.tar.gz
46ede3255abff4e356b002a9cd12df259275a15910768997bfbbae3c637b7f32 cognos-installers/TM1-952-windows/TM1_9.5.2_Windows_x64.7z
92faf20dd3ff25d2c8d94308f03fd8477d0980d6b740baa96a8e79b30b49456f cognos-installers/TM1-952-windows/TM1_Workflow_9.5.2_Windows_x64.7z
630a66a1f7cc3044f370cec730820d73d66cb284a2a09e197c00f82d6900d932 cognos-installers/cognos-BI-102/cognos-FM/fm_10.2_win_ml.tar.xz
```
0

echo '#! /usr/bin/ksh\necho `cat $1 | openssl dgst -sha256` $1' > sslsha256; chmod +x sslsha256; find directory -type f -exec ./sslsha256 \{\} \;

RAKK · 2013-09-18 17:37:50 8
postgresql : drop all sequences from the public schema

This command drops all the sequences of the 'public' schema from the database. First, it constructs a 'drop sequence' instruction for each table found in the schema, then it pipes the result to the psql interactive command. See it scripted here : https://gist.github.com/cuberri/6868774#file-postgresql-drop-create-sh
This is sample output - yours may be different.
0

psql -h <ph_host> -p <pg_port> -U <pg_user> <pg_db> -t -c "select 'drop sequence \"' || relname || '\" cascade;' from pg_class where relkind='S'" | psql -h <ph_host> -p <pg_port> -U <pg_user> <pg_db>

cuberri · 2013-12-11 15:42:34 6

xcowsay "$(cowsay smile)"

brownman · 2014-06-24 05:17:04 7

Set APM_level for HDD to prevent frequent parking
This is sample output - yours may be different.
0

sudo hdparm -B 200 /dev/sda

13_rom · 2014-10-16 13:01:13 8
Find which fibre HBA a disk is connected to

Useful for big systems with lots of cards. (Update: does not work with USB disks)
This is sample output - yours may be different.
0

udevadm info -q all -n /dev/sdc | grep ID_PATH | cut -d'-' -f 2 | xargs -n 1 lspci -s

mhs · 2015-01-27 15:34:02 9
get a random regex match from a file

seed the random number generator, find all matches in a file put all matches from the capture group into an array return a random element from the array Show Sample Output
This is sample output - yours may be different.
```
25
```
0

awk 'BEGIN{srand()} match($0, /DELTA=([0-9]+);/, a) {w[i++]=a[1]} END {print w[int(rand()*i)]}' file.name

jkirchartz · 2015-11-13 17:56:34 11
Convert audio to video [m4a 2 mp4]

http://www.labnol.org/internet/useful-ffmpeg-commands/28490/
This is sample output - yours may be different.
0

ffmpeg -loop 1 -i image.jpg -i audio.m4a -c:v libx264 -c:a aac -strict experimental -b:a 192k -vf scale=720:-1 -shortest video-output.mp4

andresaquino · 2016-01-02 18:01:17 11
Amount of physical memory in HP-UX
This is sample output - yours may be different.
0

/opt/ignite/bin/print_manifest

mezgani · 2017-07-05 06:32:32 20
Create a role on the Chef server with a description
This is sample output - yours may be different.
0

knife role create role-name --description "this is a role that does cool stuff"

niko47 · 2018-10-05 16:00:41 408
Clear Cached Memory on Ubuntu

Clear Cached Memory on Ubuntu based distributions, and also display memory status. Please do not use this on a production machine unless you really really know what you are doing. Echo 3 is a kinder way of purging the memory, you can also use 'echo 2' or 'echo 1' if #1 You know what you are doing, and #2 refer to number 1 :-)
This is sample output - yours may be different.
0

sudo free && sync && sudo echo 3 | sudo tee /proc/sys/vm/drop_caches

tg0000 · 2021-09-13 16:45:20 584
Install a library to a remote repository
This is sample output - yours may be different.
0

mvn deploy:deploy-file -DgroupId=groupId -DartifactId=artifactId -Dversion=1.0 -Dpackaging=jar -Dfile=pathtolib -DrepositoryId=repository -Durl=url

agasea · 2009-04-23 18:13:08 4
get the list of temps for your hard-drives

get a list of temps of your hard-drives. Show Sample Output
This is sample output - yours may be different.
```
31 31 31 29
```
0

hddtemp /dev/sda /dev/sdb /dev/hda /dev/hdb | gawk '{print $NF}' | perl -n -e '$_ =~ s/(\d+)/print "$1 "/eg }{ print "\n"'

microft · 2009-05-20 16:01:58 4
Get your public ip using dyndns
This is sample output - yours may be different.
0

curl -s 'http://www.loopware.com/ip.php'

incognitus · 2009-12-09 11:27:48 3
Ramp the system volume up 5%

Or, aumix -v -5 Map these to key combinations in your window manager and who needs special buttons?
This is sample output - yours may be different.
0

aumix -v +5

h3xx · 2011-07-24 07:41:40 3
send cookie
This is sample output - yours may be different.
0

curl -b cookie.txt http://www.site.com/download/file.txt

kev · 2011-11-09 03:00:49 4
‹ First < 416 417 418 419 420 > 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

Port Knocking!

Knock on ports to open a port to a service (ssh for example) and knock again to close the port. You have to install knockd. See example config file below. [options] logfile = /var/log/knockd.log [openSSH] sequence = 3000,4000,5000 seq_timeout = 5 command = /sbin/iptables -A INPUT -i eth0 -s %IP% -p tcp --dport 22 -j ACCEPT tcpflags = syn [closeSSH] sequence = 5000,4000,3000 seq_timeout = 5 command = /sbin/iptables -D INPUT -i eth0 -s %IP% -p tcp --dport 22 -j ACCEPT tcpflags = syn

List the largest directories & subdirectoties in the current directory sorted from largest to smallest.

Find wich ports you probably want to open in your firewall on a fresh installed machine

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"

Recursively search and replace old with new string, inside every instance of filename.ext

This is a slightly modified version of http://www.commandlinefu.com/commands/view/4283/recursive-search-and-replace-old-with-new-string-inside-files (which did not work due to incorrect syntax) with the added option to sed inside only files named filename.ext

convert single digit to double digits

each number in a file name gets expanded to the number of digets provided as arg_1 of the arguments in rjust_file_nums. Put the funciton in the .bashrc file. Be sure to $ source ~/.bashrc so that the function will be accessible from bash.

Convert seconds to [DD:][HH:]MM:SS

Converts any number of seconds into days, hours, minutes and seconds. sec2dhms() { declare -i SS="$1" D=$(( SS / 86400 )) H=$(( SS % 86400 / 3600 )) M=$(( SS % 3600 / 60 )) S=$(( SS % 60 )) [ "$D" -gt 0 ] && echo -n "${D}:" [ "$H" -gt 0 ] && printf "%02g:" "$H" printf "%02g:%02g\n" "$M" "$S" }

list block devices

Shows all block devices in a tree with descruptions of what they are.

ffmpeg command that transcodes a MythTV recording for Google Nexus One mobile phone

This command will transcode a MythTV recording. The target device is a Google Nexus One mobile phone. My recordings are from a HDHomerun with Over The Air content. Plays back nicely on the N1.

Show available conversions

aliases on each line. i.e. txt2html: $recode ..HTML file.html txt to Base64: $recode ../b64 file.b64 and so on.

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:

» all commands
» commands with 3 up-votes (commandlinefu3)
» commands with 10 up-votes (commandlinefu10)

All commands (14,187) the last day the last week the last month all time sorted by date votes

What's this?

Check These Out

Stay in the loop…

All commands (14,187)

sorted by