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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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"

Double your disk read performance in a single command

(WARN) This will absolutely not work on all systems, unless you're running large, high speed, hardware RAID arrays. For example, systems using Dell PERC 5/i SAS/SATA arrays. If you have a hardware RAID array, try it. It certainly wont hurt. You may be can test the speed disk with some large file in your system, before and after using this: $ time dd if=/tmp/disk.iso of=/dev/null bs=256k To know the value of block device parameter known as readahead. $ blockdev --getra /dev/sdb And set the a value 1024, 2048, 4096, 8192, and maybe 16384... it really depends on the number of hard disks, their speed, your RAID controller, etc. (see sample)

Simultaneously running different Firefox profiles

After running $ firefox -ProfileManager and creating several different profiles, use this command to run multiple Firefox profiles simultaneously.

creating you're logging function for your script

You could also pipe to logger.

Run bash on top of a vi session (saved or not saved), run multiple commands, instead of one at a time with :!(bashcommand), type exit and [enter] to get back to where you left off in vi.

Helps when I'm editing a script and want to double check some commands without having to exit out of vi multiple times or having to use another terminal session.

List your MACs address

No need for the ls -r and a sort is also not really needed.

Prepend a text to a file.

Syntax: $ prepend content to add [filename] Uses ed, so no temp files created.

Parse m3u playlist file for total time

Parse an m3u file with seconds for each item and output the length of the entire playlist

Create a html of information about you harddisk

www.fir3net.com

Print a single route to a destination and its contents exactly as the kernel sees it

Useful to determine the source_ip of outgoing packages to a certain destination

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Commands using perl (369)

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