Commands using perl sorted by votes

Commands using perl (369)

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Replace DOS character ^M with newline using perl inline replace.

Replace DOS character ^M with newline using perl inline replace.
This is sample output - yours may be different.
-1

perl -pi -e "s/\r/\n/g" <file>

din7 · 2010-07-29 16:07:36 4
calculate in commandline with perl
This is sample output - yours may be different.
-1

perl -e 'print 1+1 ."\n";'

stubby · 2010-08-08 23:19:10 3
Perl One Liner to Generate a Random IP Address

Show Sample Output
This is sample output - yours may be different.
```
108.134.80.236
```
-1

perl -e 'printf "%vd\n",pack "N",rand 256**4'

seungwon · 2011-01-18 06:10:18 3
Print just line 4 from a textfile

Perl version - just for completeness sake ;)
This is sample output - yours may be different.
-1

perl -ne '$. == 4 && print && exit'

bashrc · 2011-09-05 21:52:16 3
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]).
This is sample output - yours may be different.
-1

perl -ne 's/\^.{1,7}?m//g;print'

Tracerneo · 2012-01-02 01:32:33 6
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
This is sample output - yours may be different.
-1

perl -p -i -e 's/.*\n//g if $.==2' ~/.ssh/known_hosts

meappy · 2012-01-17 14:11:03 3
Generate Random Text based on Length

If you don't have seq, you can use perl.
This is sample output - yours may be different.
-1

genRandomText() { perl -e '$n=shift; print chr(int(rand(26)) + 97) for 1..$n; print "\n"' $1;}

putnamhill · 2012-01-21 00:21:20 3
Per country GET report, based on access log. Easy to transform to unique IP

Per country GET report, based on access log. Easy to transform to unique IP Show Sample Output
This is sample output - yours may be different.
```
     71 , Poland
    116 , France
    300 , United States
   2426 , Spain
```
-1

cat /var/log/nginx/access.log | grep -oe '^[0-9.]\+' | perl -ne 'system("geoiplookup $_")' | grep -v found | grep -oe ', [A-Za-z ]\+$' | sort | uniq -c | sort -n

theist · 2012-05-08 13:28:25 3
Print environment information.

Show Sample Output
This is sample output - yours may be different.
```
user@server:~$ perl -e 'print "$_=$ENV{$_}\n" for keys %ENV'
HOME=/home/user
LESS=-R
LC_ALL=de_DE.utf8
EDITOR=/usr/bin/vim
...
```
-1

perl -e 'print "$_=$ENV{$_}\n" for keys %ENV'

sgikas · 2012-11-12 13:14:28 4
Find out if a module is installed in perl

Will check if the given module is installed in the @INC. It will print the path and return 0 if found, or 1 otherwise. Based on script from SharpyWarpy in http://www.linuxquestions.org/questions/linux-general-1/how-to-list-all-installed-perl-modules-216603/ Show Sample Output
This is sample output - yours may be different.
```
/usr/local/share/perl5/Collectd/Plugins/Graphite.pm
```
-1

perl -MFile::Find=find -MFile::Spec::Functions -Tlwe '$found=1; find { wanted => sub { if (/$ARGV[0]\.pm\z/) { print canonpath $_; $found=0; } }, no_chdir => 1 }, @INC; exit $found;' Collectd/Plugins/Graphite

keymon · 2013-01-11 11:01:46 5

Find out if a module is installed in perl (and what version)

This attempts to load a Perl Module (-M flag) and use version 9999, since no module has a version this high, Perl exits either a) telling you the version of the module installed or b) tells you it can't find the module. Show Sample Output

-1

perl -MModule::Name\ 9999 -e 1

three18ti · 2013-01-15 22:51:39 4

Display Spinner while waiting for some process to finish

Replace 'sleep 10' with the command to wait for Show Sample Output
This is sample output - yours may be different.
```
\oOooo
```
-1

sleep 10 & perl -e '$|=@s=qw(-Ooooo \oOooo |ooOoo /oooOo -ooooO \oooOo |ooOoo /oOooo);while(kill 0,'$!'){ print "\r",$s[$t++%($#s+1)];select(undef,undef,undef,0.2);}'

unixmonkey74668 · 2015-05-09 10:00:35 9
shell function to create an 'invisible regex' that won't show up when grepping the output from 'ps'

Note that `grep "$(ir foo)"` really doesn't save any typing, but wrapping this inside a second shell function will: psg() { grep "$(ir \"$@\")" ;} Show Sample Output
This is sample output - yours may be different.
```
$ ir foo
[f]oo

$ ps aux | grep "$(ir foo)"
[returns nothing]
```
-1

ir() { perl -pne 's/(.)(.*)/\[\1]\2/' <<< "$@" ;}

bartonski · 2015-07-25 14:13:33 12
rename all images in folder with original date time from exif data

for filename multilingual (ex.japanese, chinese, ...etc)
This is sample output - yours may be different.
-1

c=1; for i in *; do identify -verbose $i | perl -ane 'if(/exif:DateTimeOriginal:/){print "@F[1,2] "}'; ls -i $i; done | sort | perl -ane 'print "@F[2]\n"' | while read j; do find -inum $j | xargs -iX cp X NEW_`printf %02d $c`.jpg; cnt=`expr $c + 1`; done

huzioka · 2015-09-22 19:06:43 11
Binary digits Matrix effect
This is sample output - yours may be different.
-1

perl -e 'use Term::ANSIColor;$|++; while (1) { print color("green")," " x (rand(35) + 1), int(rand(2)), color("reset") }'

mvrpl · 2017-04-26 14:05:48 20
Inserting a decimal every third digit

self explanatory see sample output Show Sample Output
This is sample output - yours may be different.
```
# echo "1234435324523443212343241" | perl -lpe'1 while s/^([-+]?\d+)(\d{3})/$1.$2/'
1.234.435.324.523.443.212.343.241
```
-2

perl -lpe'1 while s/^([-+]?\d+)(\d{3})/$1.$2/'

sil · 2009-02-18 21:54:22 6
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
This is sample output - yours may be different.
```
crtonl mymacfile.csv
```
-2

function crtonl { perl -i -ape 's/\r\n?/\n/g;' $* ; }

totoro · 2009-03-25 20:28:32 10
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
This is sample output - yours may be different.
```
4d 23:15:43
```
-2

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]);'\'

penpen · 2009-03-29 19:53:36 8
Read just the IP address of a device

Found this useful for scripts where I needed to work with the machine's IP. If $DEVICE is not specified, this will return all IPs on the machine. If $DEVICE is set to a network adapter, it will return just that adapter's IP.
This is sample output - yours may be different.
-2

ifconfig $DEVICE | perl -lne '/inet addr:([\d.]+)/ and print $1'

jdob · 2009-07-21 13:48:19 6
Make perl crash

It is not easy to make perl give a segfault, but this does it. This is a known issue but apparently not easy to fix. This is completely useless except for showing people that perl is not bullet-proof. Show Sample Output
This is sample output - yours may be different.
```
Segmentation fault
```
-2

perl -e '$x = []; push @$x, eval { $x = 1; return $x = 1; }'

dstahlke · 2009-10-07 22:42:18 8
Transforms a file to all uppercase.

same, except it works on any OS with Perl installed. DOS, Windose, whatever
This is sample output - yours may be different.
-2

perl -pi -e 's/([[:lower:]]+)/uc $1/gsex' file

linuxrawkstar · 2009-10-08 14:18:50 3
Echo several blank lines

Perl variant of echo several blank lines command
This is sample output - yours may be different.
-2

perl -e 'print "\n"x100'

SunX · 2010-09-07 10:11:10 3
Bulk install

I used this to mass install a lot of perl stuff. Threw it together because I was feeling *especially* lazy. The 'perl' and the 'module' can be replaced with whatever you like.
This is sample output - yours may be different.
-2

apt-cache search perl | grep module | awk '{print $1;}' | xargs sudo apt-get install -y

captwheeto · 2010-11-26 14:00:39 3
Get DELL Warranty Information from support.dell.com

The dates in the output are Start Date, End Date, Days Remaining in warranty, respectively. This will only work if you are running it on a dell machine. You can substitute the dmidecode command with a service tag if you are not using a dell. Also, you have to either allow your user to run sudo dmidecode with no password or run this command as root. Show Sample Output
This is sample output - yours may be different.
```
Product Support for Latitude D820

Your Warranty
Next Business Day Support 4/16/2008 4/16/2010 0
```
-2

curl -Ls "http://support.dell.com/support/DPP/Index.aspx?c=us&cs=08W&l=en&s=biz&ServiceTag=$(dmidecode -s system-serial-number)"|egrep -i '>Your Warranty<|>Product Support for'|html2text -style pretty|egrep -v 'Request|View'|perl -pane 's/^(\s+|\})//g;'

din7 · 2011-02-18 22:29:05 3
Print sorted list of all installed packages (Debian)

A space-padded version: perl -m'AptPkg::Cache' -e '$c=AptPkg::Cache->new; for (keys %$c){ push @a, $_ if $c->{$_}->{'CurrentState'} eq 'Installed';} print "$_ " for sort @a;'
This is sample output - yours may be different.
-2

perl -m'AptPkg::Cache' -le '$c=AptPkg::Cache->new; for (keys %$c){ push @a, $_ if $c->{$_}->{'CurrentState'} eq 'Installed';} print for sort @a;'

dbbolton · 2011-03-14 23:56:43 3
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Grab just the title of a youtube video

There's another version on here that uses GET but some people don't have lwp-request, so here's an alternative. It's also a little shorter and should work with most youtube URLs since it truncates at the first &

sort the output of the 'du' command by largest first, using human readable output.

In this case I'm just grabbing the next level of subdirectories (and same level regular files) with the --max-depth=1 flag. leaving out that flag will just give you finer resolution. Note that you have to use the -h switch with both 'du' and with 'sort.'

Fill a hard drive with ones - like zero-fill, but the opposite :)

Note: Replace 200000 with drive bytes/512, and /dev/sdx with the destination drive/partition. ;) Note: You may need to install pipebench, this is easy with "sudo apt-get install pipebench" on Ubuntu. The reason I hunted around for the pieces to make up this command is that I wanted to specifically flip all of the bits on a new HDD, before running an Extended SMART Self-Test (actually, the second pass, as I've already done one while factory-zeroed) to ensure there are no physical faults waiting to compromise my valuable data. There were several sites that came up in a Google search which had a zero-fill command with progress indicator, and one or two with a fill-with-ones command, but none that I could find with these two things combined (I had to shuffle around the dd command(s) to get this to happen without wasting speed on an md5sum as well). For reference, these are the other useful-looking commands I found in my search: Zero-fill drive "/dev/sdx", with progress indicator and md5 verification (run sudo fdisk -l to get total disk bytes, then divide by 512 and enter the resulting value into this command for a full wipe) $ dd if=/dev/zero bs=512 count= | pipebench | sudo tee /dev/sdx | md5sum And this command for creating a file filled with ones is my other main source (besides the above command and man pages, that is - I may be a Linux newbie but I do read!): $ tr '\000' '\377' < /dev/zero | dd of=allones bs=1024 count=2k Hope someone finds this useful! :) Cheers, - Gliktch

Word-based diff on reformatted text files

It can be hard to spot differences in reformatted files, because of all the diff noise created by word wrapped lines. This command removes all the noise and performs a word-by-word diff. To ignore empty lines, add -B to the diff command. Also, if this is something you do often, you might want to check out the wdiff(1) program.

resolve short urls

since the most url shorteners respond with a header containing the Location: ... this works with most common shorteners

let the cow suggest some commit messages for you

check open ports without netstat or lsof

check the status of 'dd' in progress (OS X)

Sends SIGINFO to the process. This is a BSD feature OS X inherited. You must have the terminal window executing dd selected when entering CTRL + T for this to work.

Restart X11 with HUP signal

Rename files in batch

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Commands using perl (369)

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