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.

Universal configuration monitoring and system of record for IT.
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

Hide

Credits

Maintained by Jon H.

Site originally by David Winterbottom (user root).

Psst. Open beta.

Wow, didn't really expect you to read this far down. The latest iteration of the site is in open beta. It's a gentle open beta-- not in prime-time just yet. It's being hosted over at UpGuard (link) and you are more than welcome to give it a shot. Couple things:

  • » The open beta is running a copy of the database that will not carry over to the final version. Don't post anything you don't mind losing.
  • » If you wish to use your user account, you will probably need to reset your password.
Your feedback is appreciated via the form on the beta page. Thanks! -Jon & CLFU Team

Commands using perl from sorted by
Terminal - Commands using perl - 345 results
#(see sample) $ cat x | perl -pe 'BEGIN{ print "TIME;...\n"; } s!(\S+) - (\S+) - \[(\d\d)/(\S\S\S)/(\S+):(\d\d):(\d\d:\d\d) \S+\] "(\S+) (.*/)(\S+)(?:\.([^?]*)(\?\S*)?) HTTP/\S+" (\d+) (\S+)!$3-$4-$5 $6:$7;$6;$2;$1;$8;$13;1;$14;$11;$10;$9;$12;!' > x.csv
2012-02-10 16:58:50
User: hute37
Functions: cat perl
2
Up
Down
Apache CLF access log format to CSV converter

- excel date compatible with a separate hour field

- added a fixed 1 for easier request counter aggregation

- split URL in directory, filename, fileext, query

- used with tomcat valve with response bytes replaced by elapsed time

Show sample output | Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
du -k | sort -n | perl -ne 'if ( /^(\d+)\s+(.*$)/){$l=log($1+.1);$m=int($l/log(1024)); printf ("%6.1f\t%s\t%25s %s\n",($1/(2**(10*$m))),(("K","M","G","T","P")[$m]),"*"x (1.5*$l),$2);}' | more
2012-02-07 15:49:19
User: Q_Element
Functions: du perl printf sort
Tags: perl, file sizes one line
1
Up
Down
One line Perl Script to determine the largest file sizes on a Linux Server

This one line Perl script will display the smallest to the largest files sizes in all directories on a server.

Show sample output | Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
useradd -m -p $(perl -e'print crypt("passwordscelta", "stigghiola")') user
2012-02-06 19:53:01
User: 0disse0
Functions: perl useradd
1
Up
Down
Create new user with home dir and given password

The crypt function takes a password, key, as a string, and a salt character array which is described below, and returns a printable ASCII string which starts with another salt. It is believed that, given the output of the function, the best way to find a key that will produce that output is to guess values of key until the original value of key is found.

from http://en.wikipedia.org/wiki/Crypt_(Unix)

Comments (14) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
perl -i -ne 'print if $. == 3..5' <filename>
2012-01-27 23:15:10
User: bashrc
Functions: perl
Tags: bash vi
3
Up
Down
Remove a range of lines from a file
Show sample output | Comments (4) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
genRandomText() { perl -e '$n=shift; print chr(int(rand(26)) + 97) for 1..$n; print "\n"' $1;}
2012-01-21 00:21:20
User: putnamhill
Functions: perl
Tags: perl random for loop
-1
Up
Down
Generate Random Text based on Length

If you don't have seq, you can use perl.

Comments (2) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
perl -p -i -e 's/.*\n//g if $.==2' ~/.ssh/known_hosts
2012-01-17 14:11:03
User: meappy
Functions: perl
Tags: ssh perl known_hosts
-1
Up
Down
Remove a line from a file using sed (useful for updating known SSH server keys when they change)

Easily removes line #2 in ~/.ssh/known_hosts.

Show sample output | Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
perl -le 'print$_%3?$_%5?$_:"Buzz":$_%5?"Fizz":"FizzBuzz"for 1..100'
2012-01-10 13:10:30
User: depesz
Functions: perl
Tags: perl fizzbuzz
2
Up
Down
FizzBuzz One-liner
Comments (3) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
comm -13 <(od -vw1 -tu1 dummy.txt|cut -c9-|sort -u) <(seq 0 127|sort)|perl -pe '$_=chr($_)'|od -c
2012-01-09 01:32:20
User: bazzargh
Functions: comm cut od perl seq sort
Tags: bash
0
Up
Down
Delimiter Hunting

Search in decimal rather than hex. od dumps the character list, cut to remove offsets, sort -u gives the used characters. seq gives the comparison list, but we need this sorted alphabetically for comm, which does the filtering. I drop to perl to convert back to characters (is there a better way?) and then use od to dump them in a print-safe format.

Show sample output | Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
find . -type f|perl -lne [email protected]=sort {$b->[0]<=>$a->[0]}[(stat($_))[7],$_],@x;splice(@x,11);print "@{$x[0]}";END{for(@x){print "@$_"}'
2012-01-08 14:43:43
User: bazzargh
Functions: find perl
Tags: sort perl find
-2
Up
Down
find the biggest files recursively, no matter how many

A different approach to the problem - maintain a small sorted list, print the largest as we go, then the top 10 at the end. I often find that the find and sort take a long time, and the large file might appear near the start of the find. By printing as we go, I get better feedback. The sort used in this will be much slower on perls older than 5.8.

Show sample output | Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
perl -e '$f = join("", <>); for (0..127) {$_ = chr($_); if (/[[:print:]]/) {print if index($f, $_) < 0}} print "\n"'
2012-01-05 23:38:06
User: putnamhill
Functions: perl
Tags: perl slurp
0
Up
Down
Delimiter Hunting

Here's a perl version that only considers printable characters. Change the regex /[[:print:]]/ to look for different sets of delimiter characters.

Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
perl -e "binmode(STDOUT, ':utf8'); print \"$@\""; echo # newline
2012-01-02 10:34:51
User: mathias
Functions: echo perl
Tags: perl ascii escape unicode escape sequence characters
0
Up
Down
Decode \x{ABCD}-style Unicode escape sequences

This is especially useful to get crazy stuff like space characters copied to your pasteboard correctly.

Source: https://github.com/mathiasbynens/dotfiles/blob/master/.functions

Show sample output | Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
perl -ne 's/\^.{1,7}?m//g;print'
2012-01-02 01:32:33
User: Tracerneo
Functions: perl
Tags: perl regex colors
-1
Up
Down
Remove color codes (special characters) with perl

Removes special characters (colors) in '^]]Xm' and '^]]X;Ym' format from file.

Use pipe ('input | perl [...]') or stream ('perl [...]

You can use 'cat -v infile' as 'input' to show special characters instead of interpreting (there is problem with non-ASCII chars, they are replaced by M-[char]).

Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
cvs -Q status | perl -ne 'print if m/^File.+Status: (?!Up-to-date)/ .. m/^=/;'
2011-12-07 00:33:49
User: dexterp
Functions: cvs perl
0
Up
Down
List only locally modified files with CVS

This will also print the path to file which is not included in the other examples.

Show sample output | Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
find . -iregex ".+\.\(c\|cpp\|h\)" | xargs -I{} perl -e "system(\"iconv -f SHIFT_JIS -t UTF-8 {} > temp; mv temp {} \");" ;
2011-12-02 18:03:27
User: inomas
Functions: find perl xargs
0
Up
Down
Converts Character Set of Files in a Folder
Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
lsmod | perl -e 'print "digraph \"lsmod\" {";<>;while(<>){@_=split/\s+/; print "\"$_[0]\" -> \"$_\"\n" for split/,/,$_[3]}print "}"' | dot -Tpng | display -
2011-11-27 14:02:35
User: bandie91
Functions: dot lsmod perl
Tags: perl lsmod dot modules
35
Up
Down
Draw kernel module dependancy graph.

parse `lsmod' output and pass to `dot' drawing utility then finally pass it to an image viewer

Comments (14) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
perl -MO=Deparse filename.pl | perltidy > new.pl
2011-11-16 18:54:30
User: kimmel
Functions: perl
Tags: perl oneliner beautify
0
Up
Down
clean up syntax and de-obfuscate perl script

This will create a new file with proper code formatting and all comments removed.

Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
perl -le 'print scalar gmtime shift' 1234567890
2011-11-16 18:37:11
User: kimmel
Functions: perl
Tags: Date manipulation perl oneliner epoch
0
Up
Down
convert unixtime to human-readable

convert a unix timestamp to a human readable format.

Show sample output | Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
perl -MExtUtils::Installed -E 'say for ExtUtils::Installed->new()->modules()'
2011-11-16 17:26:47
User: kimmel
Functions: perl
Tags: perl oneliner
0
Up
Down
Print a list of installed Perl modules

Lists all the modules that were installed the "proper way". It also uses Perl 5.10(or higher)'s say command for less typing.

Show sample output | Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
for f in $(ls -A ./dir); do echo -n $f && diff original.txt ./dir/$f | wc -l ; done | perl -ne 'my $h={}; while (<>) { chomp; if (/^(\S+?)\s*(\d+?)$/){$h->{$1}=$2;} }; for my $k (sort { $h->{$a} $h->{$b} } keys %$h ){ print "$k\t$h->{$k}\n"}'
2011-11-15 06:02:12
User: 1vq9
Functions: diff echo ls perl sort wc
0
Up
Down
display list of files in a directory sorted by amount of lines different with original.txt.
Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
perl -ane 'END{printf(" %d %d %d\n", $x, $y, $z)} $x+=1; [email protected]; $z+=length' file.txt
2011-10-24 06:14:02
User: kev
Functions: perl
Tags: perl
1
Up
Down
wc in perl
Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
perl -C -e 'print for sort { length $a <=> length $b or $a cmp $b } <>' < /usr/share/dict/words | tail
2011-10-20 01:43:25
User: dbr
Functions: cmp perl sort
3
Up
Down
sort lines by length

making it "sound" more "natural" language like -- additionally sorting the longest words alphabetically:

this approach is using:

* to get at all lines of input

* post-"for" structure

* short-circuit-or in sort: if the lengths are the same, then sort alphabetically otherwise don't even evaluate the right hand side of the or

* -C sets all input and ouput channels to utf8

Comments (3) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
svn log | perl -pe 's/\n//g => s/^-.*/\n/g'
2011-10-20 01:20:52
User: dbr
Functions: perl
Tags: svn perl svn log
0
Up
Down
one-line log format for svn

dirrrty: use -p to chomp automatically, substitute all newlines away and then replace the "---" by a newline ? bingo!

s/// => s/// is just a cooler way to write s///, s/// which is just the small brother of s///; s/// (comma is an operator!)

have fun!

Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
svn log | perl -l40pe 's/^-+/\n/'
2011-10-14 16:02:22
User: bazzargh
Functions: perl
Tags: svn perl svn log
1
Up
Down
one-line log format for svn

the output of svn log is annoying to grep, since it spreads the useful info over multiple lines. This compacts the output down to one line so eg you can grep for a comment and see the rev, date & committer straight away.

Updated: MUCH shorter, easier to remember. Now it just replaces newlines with spaces, except on '---' lines.

Show sample output | Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
perl -MAcme::POE::Tree -e 'Acme::POE::Tree->new()->run()'
2011-10-13 10:33:31
User: anhpht
Functions: perl
0
Up
Down
Create a Christmas tree with perl

Require: perl -MCPAN -e 'install Acme::POE::Tree'

From: http://www.catonmat.net/blog/christmas-tree-in-the-shell/

Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
cat table-mv.txt | perl -pe 's{([^;]+);([^;]+)}{tbl$1/tbl$2}' | perl -pe 's{(\S+)}{perl -i -pe #s/$1/g# xxx.sql}' | tr "#" "\'" | bash
2011-10-05 15:55:34
User: hute37
Functions: cat perl tr
0
Up
Down
Multiple Perl Search/Replace from a file

with a semicolon text file map, apply multiple replace to a single file

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