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.

OpenID
or
Sign in Register

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


awk, bash, curl, find, grep, Linux, sed
Hide

Functions

Commands using perl from sorted by
Terminal - Commands using perl - 346 results
wget -q -O- http://www.gutenberg.org/dirs/etext96/cprfd10.txt | sed '1,419d' | tr "\n" " " | tr " " "\n" | perl -lpe 's/\W//g;$_=lc($_)' | grep "^[a-z]" | awk 'length > 1' | sort | uniq -c | awk '{print $2"\t"$1}'
2009-05-04 16:00:39
User: alperyilmaz
Functions: awk grep perl sed sort tr uniq wget
Tags: sort perl sed awk uniq wget tr
-4
Up
Down
count occurences of each word in novel David Copperfield

This command might not be useful for most of us, I just wanted to share it to show power of command line.

Download simple text version of novel David Copperfield from Poject Gutenberg and then generate a single column of words after which occurences of each word is counted by sort | uniq -c combination.

This command removes numbers and single characters from count. I'm sure you can write a shorter version.

Show sample output | Comments (10) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
for i in `screen -ls | perl -ne'if(/^\s+\d+\.([^\s]+)/){print $1, " "}'`; do gnome-terminal -e "screen -x $i"; done
2009-04-25 22:39:24
User: hank
Functions: perl
Tags: screen Linux perl
2
Up
Down
Connect to all running screen instances

There was another line that was dependent on having un-named screen sessions. This just wouldn't do. This one works no matter what the name is. A possible improvement would be removing the perl dependence, but that doesn't effect me.

Comments (1) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
ldapsearch -v -H ldap://<server> -x -D cn=<johndoe>,cn=<users>,dc=<ourdomain>,dc=<tld> -w<secret> -b ou=<lazystaff>,dc=<ourdomain>,dc=<tld> -s sub sAMAccountName=* '*' | perl -pne 's/(\d{11})\d{7}/"DATE-AD(".scalar(localtime($1-11644473600)).")"/e'
2009-04-22 00:57:34
User: flux
Functions: perl
Tags: Date manipulation perl ldap
4
Up
Down
decoding Active Directory date format

When Ldapsearch queries an Active directory server, all the dates are shown using a timestamp of 18 digits. This perl regexp decodes them in a more human friendly notation. 11644473600 corresponds to some microsoft epoch.

Show sample output | Comments (58) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
cat <filename> | perl -e '$/ = ""; $_ = <>; s/<!--.*?-->//gs; print;'
2009-04-15 20:29:11
User: unixx
Functions: cat perl
0
Up
Down
remove comments from xml

xml with verbose commenting can be difficult to read. remove comments from xml.

Comments (9) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
$ perl -pi -e 's/\r\n/\n/g' <finelame>
2009-04-10 22:22:31
User: unixmonkey4200
Functions: perl
Tags: perl dos2unix
0
Up
Down
dos2unix

Converts windows lined-style file to unix.

see http://en.wikipedia.org/wiki/Newline

Can be used to convert from linux2dos : just invert \r\n and \n.

Comments (5) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
u=`curl -d 'dl.start=Free' $(curl $1|perl -wpi -e 's/^.*"(http:\/\/rs.*)" method.*$/$1/'|egrep '^http'|head -n1)|grep "Level(3) \#2"|perl -wpi -e 's/^.*(http:\/\/rs[^\\\\]*).*$/$1/'`;sleep 60;wget $u
2009-04-01 20:14:41
User: fel1x
Functions: egrep grep head perl
5
Up
Down
rapidshare download script in 200 characters
Comments (1) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
perl -ne 'while (/([0-9]+\.){3}[0-9]+/g) {print "$&\n"};' file.txt
2009-04-01 13:49:46
User: P17
Functions: perl
2
Up
Down
Prints any IP out of a file
Comments (2) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
watch -tn1 'bc<<<"`date -d'\''friday 21:00'\'' +%s`-`date +%s`"|perl -ne'\''@p=gmtime($_);printf("%dd %02d:%02d:%02d\n",@p[7,2,1,0]);'\'
2009-03-29 19:53:36
User: penpen
Functions: perl watch
Tags: Linux unix date
-2
Up
Down
Not so simple countdown from a given date

An improved version of http://www.commandlinefu.com/commands/view/1772/simple-countdown-from-a-given-date that uses Perl to pretty-print the output. Note that the GNU-style '--no-title' option has been replaced by its one-letter counterpart '-t'.

Show sample output | Comments (3) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
perl -pi -e 's/foo/bar/g' $(grep -rl foo ./*)
2009-03-27 17:21:35
User: dopeman
Functions: grep perl
Tags: perl
-1
Up
Down
Change all instances of a word in all files in the current directory and it's sub-directories

This command will replace all instances of 'foo' with 'bar' in all files in the current working directory and any sub-directories.

Comments (2) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
perl -pi -e 's/foo/bar/g' $(grep -l foo ./*)
2009-03-27 17:18:08
User: dopeman
Functions: grep perl
-1
Up
Down
Change all instances of a word in all files in the current directory

This command will replace all instances of 'foo' with 'bar' in all files in the current working directory.

Comments (1) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
function crtonl { perl -i -ape 's/\r\n?/\n/g;' $* ; }
2009-03-25 20:28:32
User: totoro
Functions: perl
Tags: files
-2
Up
Down
Convert files with CR-terminated lines (as created by Mac OS X programs) into NL-terminated lines suitable for Unix programs

Many Mac OS X programs, especially those in Microsoft:Office, create ASCII files with lines terminated by CRs (carriage returns). Most Unix programs expect lines separated by NLs (newlines). This little command makes it trivial to convert them.

Show sample output | Comments (5) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
perl -e 'print scalar localtime $ARGV[0],"\n" ' epoch
2009-03-25 18:40:21
User: hypnojazz
Functions: perl
-1
Up
Down
print the date of the unix epoch in a human readable form using perl.
Comments (5) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
du -hS / | perl -ne '(m/\d{3,}M\s+\S/ || m/G\s+\S/) && print'
2009-03-25 18:06:53
User: Alioth
Functions: du perl
Tags: Filesystem perl du
6
Up
Down
Find all directories on filesystem containing more than 99MB

Finds all directories containing more than 99MB of files, and prints them in human readable format. The directories sizes do not include their subdirectories, so it is very useful for finding any single directory with a lot of large files.

Show sample output | Comments (71) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
perl -e 'print "Hello World!", "\n";'
2009-03-24 14:58:01
User: netp
Functions: perl
-27
Up
Down
hello Command-line-fu

hello

Comments (2) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
history | perl -lane '$lsize{$_} = scalar(@F); if($longest<$lsize{$_}) { $longest = $lsize{$_}; print "$_"; };' | tail -n1
2009-03-19 02:52:30
User: salparadise
Functions: perl tail
Tags: history perl
3
Up
Down
find the longest command in your history
Comments (1) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
perl -e 'print map { $_ . "\n" } @INC;'
2009-03-12 15:11:27
User: unixmonkey2244
Functions: perl
1
Up
Down
print lib path of perl
Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
perl -0777 -ne 'print "$1\n" while /word-a(.*?)word-b/gs' filename.txt
2009-03-08 11:47:18
User: eleffie
Functions: perl
3
Up
Down
How to pull out lines between two patterns

This command will display all lines between 2 patterns: word-a and word-b

useful for grepping command outputs from file

Comments (2) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
find $HOME -type f -print | perl -wnlaF'/' -e 'BEGIN{ print "#EXTM3U"; } /.+\.wmv$|.+\.mpg$|.+\.vob$/i and print "#EXTINF:$F[-1]\nfile://$&";' > movies.m3u
2009-02-28 12:17:41
User: ishiduca
Functions: find perl
2
Up
Down
make a list of movies(.m3u).
Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
perl -pi -e's/<what to find>/<what to replace it with>/g' `grep -Rl <what to find> /<dir>/*`
2009-02-26 19:14:39
User: adampbell
Functions: perl
2
Up
Down
Recursive Search and Replace

Finds the string in every file in an entire directory and all its subdirectories and replaces it with a new string. Especially useful when changing a machine's IP address or hostname - run it on /etc.

Comments (2) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
find . -type d | perl -nle 'print s,/,/,g," $_"' | sort -n | tail
2009-02-23 22:52:07
User: sirhc
Functions: find perl sort
4
Up
Down
Print the 10 deepest directory paths
Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
du -b --max-depth 1 | sort -nr | perl -pe 's{([0-9]+)}{sprintf "%.1f%s", $1>=2**30? ($1/2**30, "G"): $1>=2**20? ($1/2**20, "M"): $1>=2**10? ($1/2**10, "K"): ($1, "")}e'
2009-02-20 06:11:31
User: mrtheplague
Functions: du perl sort
36
Up
Down
Sort the size usage of a directory tree by gigabytes, kilobytes, megabytes, then bytes.

Probably only works with GNU du and modern perls.

Show sample output | Comments (4) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
nmap -sS -O -oX /tmp/nmap.xml 10.1.1.0/24 -v -v && perl nmap2nagios.pl -v -r /tmp/10net.xml -o /etc/nagios/10net.cfg
2009-02-19 18:42:37
User: scubacuda
Functions: perl
6
Up
Down
nmap IP block and autogenerate comprehensive Nagios service checks

More info here:

http://nagioswiki.com/wiki/index.php/Autocreating_Nagios_Configuration_with_Nmap_and_Nmap2Nagios.pl

Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
perl -e 'print 1, 2, 3' > /dev/full
2009-02-19 17:08:13
User: mkc
Functions: perl
8
Up
Down
Use /dev/full to test language I/O-failsafety

The Linux /dev/full file simulates a "disk full" condition, and can be used to verify how a program handles this situation.

In particular, several programming language implementations do not print error diagnostics (nor exit with error status) when I/O errors like this occur, unless the programmer has taken additional steps. That is, simple code in these languages does not fail safely. In addition to Perl, C, C++, Tcl, and Lua (for some functions) also appear not to fail safely.

Show sample output | Comments (2) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
perl -e 'use MIME::Base64; print encode_base64("encode me plz");'
2009-02-18 22:49:18
User: therek
Functions: perl
1
Up
Down
Encode text in Base64 using Perl

MIME::Base64 is a part of Perl5 distribution. You can also use decode_base64 for oposite result.

Show sample output | Comments (2) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
perl -lpe'1 while s/^([-+]?\d+)(\d{3})/$1.$2/'
2009-02-18 21:54:22
User: sil
Functions: perl
-2
Up
Down
Inserting a decimal every third digit

self explanatory see sample output

Show sample output | Comments (1) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate