Hide

What's this?

commandlinefu.com is the place to record those command-line gems that you return to again and again.

Delete that bloated snippets file you've been using and share your personal repository with the world. 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.


Get involved!

You can sign-in using OpenID credentials, or register a traditional username and password.

First-time OpenID users will be automatically assigned a username which can be changed after signing in.

UpGuard checks and validates configurations for every major OS, network device, and cloud provider.
Hide

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:

Hide

News

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!
Hide

Top Tags

Hide

Functions

Commands using tr from sorted by
Terminal - Commands using tr - 288 results
find / -type d | while read i; do ls $i | wc -l | tr -d \\n; echo " -> $i"; done | sort -n
2017-05-12 00:02:43
User: Zort
Functions: echo find ls read sort tr wc
0

Show file count into directories.

Usefull when you try to find hugh directories that elevate system CPU (vmstat -> sy)

tr -d '\r' < vmargs.txt | tr '\n' ' '
2016-12-31 18:20:03
User: wytten12
Functions: tr
1

Read vmargs.txt, which is a text file that could either be DOS-style (\r\n) or UNIX-style (\n) line endings and join the lines with a space separator. Can this be shortened/made more elegant?

host -t srv _ldap._tcp | sed "s/.*[ ]\([^ ]*\)[.]$/\1/g" | xargs -i ping -c 1 {} | grep -E "(statistics|avg)" | sed "s/^--- \([^ ]*\).*/,\1:/g"|tr -d "\n" | tr "," "\n" | sed "1d;s|^\([^:]*\).*=[^/]*/\([^/]*\).*|\2\t\1|g" |sort -n
2016-09-02 03:26:29
User: glaudiston
Functions: grep host ping sed sort tr xargs
Tags: ldap
2

This command line detect ldap hosts, by mandatory dns entry, then ping them to detect response average. based on ping response average it sorts and print the faster server in first output line

tree -isafF /var|grep -v "/$"|tr '[]' ' '|sort -k1nr|head
docker inspect --format "{{ .Name }} # {{ .NetworkSettings.IPAddress }} # {{ .NetworkSettings.Ports }}" $(docker ps -q) | tr -s '#' '\t'
tr '\0' ' ' </proc/21679/cmdline ; echo
tr -d "\"" < infile.csv > noquotes.csv
2015-09-11 23:41:48
User: UnklAdM
Functions: tr
Tags: CSV quotes
0

I always forget this one and find all kinds of complex solutions on google. Also works great while piping data. ex. 'cat data | process-data | tr -d "\"" > processed-data-without-quotes'

head -1 file.csv | tr ',' '\n' | tr -d " " | awk '{print NR,$0}'
2015-08-26 05:46:15
User: neomefistox
Functions: awk head tr
0

Useful to identify the field number in big CSV files with large number of fields. The index is the reference to use in processing with commands like 'cut' or 'awk' involved.

pyt() { id=$(curl -s 'https://www.youtube.com/results?search_query='$(tr ' ' + <<<"$1") | grep -om3 '"[[:alnum:]]\{11\}"' | awk NR==3 | tr -d \"); youtube-dl -q 'https://www.youtube.com/watch?v='"$id" -o - | mplayer -vo null /dev/fd/3 3<&0 </dev/tty; }
2015-07-20 05:30:27
User: snipertyler
Functions: awk grep tr
4

pyt 'Stairway to heaven - Led Zeppelin'

pyt 'brain damage - Pink Floyd'

No web browser or even X needed. Just a cli and internet connection!

mplayer is pauseable and can skip ahead

This may break if youtube changes their search html.

git diff $(git log --pretty=format:%h -2 --reverse | tr "\n" " ")
2015-07-07 17:50:50
Functions: diff tr
Tags: git
1

A great command to assign to an alias, allowing you to git diff the last two commits in git.

tr -s ' ' | cut -d' ' -f2-
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 '-' ' '
echo {1..9} '* 0 #' | tr ' ' '\n' |paste - - -
nmap -sP 10.0.0.0/8 | 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
0

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

strings /dev/urandom | tr -cd '[:alnum:]' | fold -w 30 | head -n 1
2014-12-11 06:21:51
User: atoponce
Functions: fold head strings tr
2

This command is similar to the alternate, except with head(1), you can pick as many passwords as you wish to generate by changing the number of lines you wish to preview.

ls | tr '[[:punct:][:space:]]' '\n' | grep -v "^\s*$" | sort | uniq -c | sort -bn
2014-10-14 09:52:28
User: qdrizh
Functions: grep ls sort tr uniq
Tags: sort uniq ls grep tr
3

I'm sure there's a more elegant sed version for the tr + grep section.

echo $PATH | tr -s ':' '\n'
ifconfig | egrep -A2 "eth|wlan" | tr -d "\n"| sed 's/\-\-/\n/g'|awk '{print "mac: "$5 " " $7}' | sed 's/addr:/addr: /g'
ifconfig | head -n 2 | tr -d '\n' | sed -n 's/.*\(00:[^ ]*\).*\(adr:[^ ]*\).*/mac:\1 - \2/p'
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
0

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'.

Example:

grep -v OP_GET <raw-records>.trace | tr '|' '\n'
tr -dc '\x15-\x7e' < /dev/urandom| head -c 16 | paste
postqueue -p | grep -A 1 "over quota" | grep @ | sort | uniq | tr --delete ' '
grep "btrfs: checksum error at logical" /var/log/messages | egrep -o "[^ ]+$" | tr -d ')' | sort | uniq
2014-07-01 08:15:26
User: jcoll
Functions: egrep grep sort tr
0

Filter entries in OpenSuse /var/log/messages like:

timestamp servername kernel: [83242.108090] btrfs: checksum error at logical 1592344576 on dev /dev/sda5, sector 5223584, root 5, inode 2652, offset 282624, length 4096, links 1 (path: log/warn)

docker ps | sed -e 's/ /\+/g' -e 's/CONTAINER ID/CONTAINER_ID/' | tr -s '+' '\t' | q -t 'select c1,substr(c7, 0, 40),c2,c6 from -' | column -t
2014-06-06 07:20:36
User: akaivola
Functions: column ps sed tr
0

When you run a lot of containers the built in docker ps output becomes unreadable. This command formats the output to be easier on the eyes.

Requires q (https://github.com/harelba/q) text as data.

git status --porcelain | sed -ne 's/^ M //p' | tr '\n' '\0' | tr -d '"' | xargs -0 vim
2014-05-08 08:36:27
User: uschrisf
Functions: sed tr xargs
Tags: vim git
0

Works even with spaces in filenames.

As an alias in .gitconfig:

[alias]

editchanged = "!git status --porcelain | sed -ne 's/^ M //p' | tr '\\n' '\\0' | tr -d '\"' | xargs -0 vim"