Commands using perl sorted by votes

Commands using perl (369)

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modify a file in place with perl

changes THIS to THAT in all files matching fileglob* without using secondary files
This is sample output - yours may be different.
2

perl -pi -e 's/THIS/THAT/g' fileglob*

elofland · 2009-02-05 19:19:52 60
The top ten commands you use

Show Sample Output
This is sample output - yours may be different.
```
3940 ls
1427 sudo emerge -vpuDN world
1084 top
 684 tail /var/log/samba/log.smbd -n 50
 601 sudo emerge --sync
 573 sudo emerge --depclean
 566 ls -alh
 561 df -ah
 523 cd
 430 sudo revdep-rebuild
```
2

perl -pe 's/.+;//' ~/.zsh_history | sort | uniq -c | sort -r|head -10

aoiaoi · 2009-02-06 15:24:32 168
re-assign line numbers

Show Sample Output
This is sample output - yours may be different.
```
(1) aaa
(2) new line
(3) ccc
(4) aaa
```
2

perl -pe 's/\d+/++$n/e' file.txt

mikeda · 2009-02-17 14:51:31 6
Comma insertions

Insert a comma where necessary when counting large numbers. I needed to separate huge amounts of packets and after 12+ hours of looking in a terminal, I wanted it in readable form. Show Sample Output
This is sample output - yours may be different.
```
more numberfile
34234324324234
9438752687324713254275341234
32476
325379846846524395732

perl -pe '$_=reverse;s/\d{3}(?=\d)(?!.*?\.)/$&,/g;$_=reverse' numberfile
34,234,324,324,234
9,438,752,687,324,713,254,275,341,234
32,476
325,379,846,846,524,395,732
```
2

perl -pe '$_=reverse;s/\d{3}(?=\d)(?!.*?\.)/$&,/g;$_=reverse'

sil · 2009-02-18 16:34:18 15
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.
This is sample output - yours may be different.
2

perl -pi -e's/<what to find>/<what to replace it with>/g' `grep -Rl <what to find> /<dir>/*`

adampbell · 2009-02-26 19:14:39 8
make a list of movies(.m3u).
This is sample output - yours may be different.
2

find $HOME -type f -print | perl -wnlaF'/' -e 'BEGIN{ print "#EXTM3U"; } /.+\.wmv$|.+\.mpg$|.+\.vob$/i and print "#EXTINF:$F[-1]\nfile://$&";' > movies.m3u

ishiduca · 2009-02-28 12:17:41 4
Prints any IP out of a file
This is sample output - yours may be different.
2

perl -ne 'while (/([0-9]+\.){3}[0-9]+/g) {print "$&\n"};' file.txt

P17 · 2009-04-01 13:49:46 6
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.
This is sample output - yours may be different.
2

for i in `screen -ls | perl -ne'if(/^\s+\d+\.([^\s]+)/){print $1, " "}'`; do gnome-terminal -e "screen -x $i"; done

hank · 2009-04-25 22:39:24 7
Replace Every occurrence of a word in a file

Replace 'this' with 'that'
This is sample output - yours may be different.
2

perl -p -i -e 's/this/that/g' filename

rader5 · 2009-08-09 20:53:50 8
show the real times iso of epochs for a given column

When you have one of those (log)files that only has epoch for time (since no one will ever look at them as a date) this is a way to get the human readable date/time and do further inspection. Mostly perl-fu :-/
This is sample output - yours may be different.
2

perl -F' ' -MDate::Format -pale 'substr($_, index($_, $F[1]), length($F[1]), time2str("%C", $F[1]))' file.log

coffeeaddict_nl · 2009-08-13 13:57:33 4
convert unixtime to human-readable
This is sample output - yours may be different.
2

perl -e 'print scalar(gmtime(1234567890)), "\n"'

andrew112358 · 2009-08-25 15:00:52 4
Go get those photos from a Picasa album
This is sample output - yours may be different.
2

wget 'link of a Picasa WebAlbum' -O - |perl -e'while(<>){while(s/"media":{"content":\[{"url":"(.+?\.JPG)//){print "$1\n"}}' |wget -w1 -i -

aciancone · 2009-09-27 14:36:27 7
A command line calculator in Perl

Once I wrote a command line calculator program in C, then I found this... and added to it a bit. For ease of use I normally use this in a tiny Perl program (which I call pc for 'Perl Calculator') #!/usr/bin/perl -w die "Usage: $0 MATHS\n" unless(@ARGV);for(@ARGV){s/x/*/g;s/v/sqrt /g;s/\^/**/g}; print eval(join('',@ARGV)),$/; It handles square roots, power, modulus: pc 1+2 (1 plus 2) 3 pc 3x4 (3 times 4) 12 pc 5^6 (5 to the power of 6) 15625 pc v 49 ( square root of 49 ) 7 pc 12/3 (12 divided by 3) 4 pc 19%4 (19 modulus 4) 3 (you can string maths together too) pc 10 x 10 x 10 1000 pc 10 + 10 + 10 / 2 25 pc 7 x v49 49 Show Sample Output
This is sample output - yours may be different.
```
$ perl -e 'for(@ARGV){s/x/*/g;s/v/sqrt /g;s/\^/**/g};print eval(join("",@ARGV)),$/;' 1+2
3
$ perl -e 'for(@ARGV){s/x/*/g;s/v/sqrt /g;s/\^/**/g};print eval(join("",@ARGV)),$/;' 3x4
12
$ perl -e 'for(@ARGV){s/x/*/g;s/v/sqrt /g;s/\^/**/g};print eval(join("",@ARGV)),$/;' 5^6
9
$ perl -e 'for(@ARGV){s/x/*/g;s/v/sqrt /g;s/\^/**/g};print eval(join("",@ARGV)),$/;' v9
3
$ perl -e 'for(@ARGV){s/x/*/g;s/v/sqrt /g;s/\^/**/g};print eval(join("",@ARGV)),$/;' 9/4
2.25
$ perl -e 'for(@ARGV){s/x/*/g;s/v/sqrt /g;s/\^/**/g};print eval(join("",@ARGV)),$/;' 19%4
3
```
2

perl -e 'for(@ARGV){s/x/*/g;s/v/sqrt /g;s/\^/**/g};print eval(join("",@ARGV)),$/;'

JohnGH · 2009-12-21 21:03:27 9
Recursively grep for string and format output for vi(m)

This is a big time saver for me. I often grep source code and need to edit the findings. A single highlight of the mouse and middle mouse click (in gnome terminal) and I'm editing the exact line I just found. The color highlighting helps interpret the data.
This is sample output - yours may be different.
2

mgc() { grep --exclude=cscope* --color=always -rni $1 . |perl -pi -e 's/:/ +/' |perl -pi -e 's/^(.+)$/vi $1/g' |perl -pi -e 's/:/ /'; }

stinkerweed999 · 2010-01-26 17:00:01 4
Get your commandlinefu points (upvotes - downvotes)

Like command #4845, prints score, number of entries, and average score.
This is sample output - yours may be different.
2

username=bartonski;curl -s http://www.commandlinefu.com/commands/by/$username/json|perl -e 'BEGIN{$s=0;$n=0};END{print "Score: $s\nEntries: $n\nMean: ";printf "%3.2f\n",$s/$n}' -0173 -nae 'foreach $f (@F){if($f =~ /"votes":"(-*\d+)"/){$s += $1; $n++;}}'

bartonski · 2010-02-16 01:03:29 4
Update twitter with Perl

Requires Net::Twitter. Just replace the double quoted strings with the appropriate info.
This is sample output - yours may be different.
2

perl -MNet::Twitter -e '$nt = Net::Twitter->new(traits => [qw/API::REST/], username => "YOUR USERNAME", password => "YOUR PASSWORD"); $ud = $nt->update("YOUR TWEET");'

dbbolton · 2010-06-16 19:46:05 4
diff files while disregarding indentation and trailing white space

**NOTE** Tekhne's alternative is much more succinct and its output conforms to the files actual contents rather than with white space removed My command on the other hand uses bash process substitution (and "Minimal" Perl), instead of files, to first remove leading and trailing white space from lines, before diff'ing the streams. Very useful when differences in indentation, such as in programming source code files, may be irrelevant Show Sample Output
This is sample output - yours may be different.
```
gjempty$ diff <(perl -wpl -e '$_ =~ s/^\s+|\s+$//g ;' file1) <(perl -wpl -e '$_ =~ s/^\s+|\s+$//g ;' file2)
247a248,250
> for ($i = 0; $i < 7; $i++) {
> if (!isset($tabData[$i])) $tabData[$i] = '';
> }

gjempty$ diff -b file1 file2
247a248,250
>                         for ($i = 0; $i < 7; $i++) {
>                             if (!isset($tabData[$i])) $tabData[$i] = '';
>                         }
```
2

diff <(perl -wpl -e '$_ =~ s/^\s+|\s+$//g ;' file1) <(perl -wpl -e '$_ =~ s/^\s+|\s+$//g ;' file2)

jemptymethod · 2010-10-06 19:14:42 5
Decode base64-encoded file in one line of Perl

If you are in an environment where you don't have the base64 executable or MIME tools available, this can be very handy for salvaging email attachments when the headers are mangled but the encoded document itself is intact.
This is sample output - yours may be different.
2

perl -MMIME::Base64 -ne 'print decode_base64($_)' < file.txt > out

dmmst19 · 2010-12-13 23:35:20 3
Find C/C++ source code comments

This is a naive way of finding source code comments in source code files that use C-like comments: // and /*...*/
This is sample output - yours may be different.
2

perl -e 'my $in_comment = 0; while (<>) { $in_comment = 1 if m{\Q/*\E}; print if $in_comment; $in_comment = 0 if m{\Q*/\E}; }' *.cpp

doherty · 2011-07-08 00:17:27 4
Find default gateway (proper at ppp connections too)
This is sample output - yours may be different.
2

route -n | perl -ne '$ANY="0.0.0.0"; /^$ANY/ and split /\s+/ and print "Gateway to the World: ",($_[1]!=$ANY)?$_[1]:(`ip address show $_[$#_]`=~/peer ([0-9\.]+)/ and $1),", via $_[$#_].\n"'

bandie91 · 2011-09-13 08:05:58 5
FizzBuzz One-liner
This is sample output - yours may be different.
2

perl -le 'print$_%3?$_%5?$_:"Buzz":$_%5?"Fizz":"FizzBuzz"for 1..100'

depesz · 2012-01-10 13:10:30 5
Remove a range of lines from a file

Show Sample Output
This is sample output - yours may be different.
```
> echo -e "1\n2\n3\n4\n5\n6\n" > aaa
> perl -i -ne 'print if $. == 3..5' aaa
> cat aaa 
3
4
5
```
2

perl -i -ne 'print if $. == 3..5' <filename>

bashrc · 2012-01-27 23:15:10 4

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

#(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

hute37 · 2012-02-10 16:58:50 3

Text graphing ping output filter

Nasty perl one-liner that provides a sparkline of ping times. If you want a different history than the last 30, just put that value in. It (ab)uses unicode to draw the bars, inspired by https://github.com/joemiller/spark-ping . It's not the most bug-free piece of code, but what it lacks in robustness it makes up for in capability. :) If anyone has any ideas on how to make it more compact or better, I'd love to hear them. I included a ping to google in the command just as an example (and burned up 10 chars doing it!). You should use it with: $ ping example.com | $SPARKLINE_PING_COMMAND Show Sample Output
This is sample output - yours may be different.
```
bgrantham$ ping g.co|perl -ne'$|=/e=(\S+)/||next;(push@_,$1)>30&&shift@_;print"\r",(map{"\xe2\x96".chr(128+7*$_/(sort{$b<=>$a}@_)[0])." "}@_),"$1ms"'
&#9604; &#9606; &#9605; &#9606; &#9605; &#9606; &#9605; &#9605; &#9605; &#9605; &#9605; &#9605; &#9605; &#9605; &#9605; &#9605; &#9604; &#9605; &#9605; &#9605; &#9606; &#9605; &#9604; &#9604; &#9606; &#9605; &#9607; &#9605; &#9605; &#9605; 87.458ms^C
bgrantham$
```
2

ping g.co|perl -ne'$|=/e=(\S+)/||next;(push@_,$1)>30&&shift@_;print"\r",(map{"\xe2\x96".chr(128+7*$_/(sort{$b<=>$a}@_)[0])." "}@_),"$1ms"'

bartgrantham · 2012-07-06 22:42:06 3
MPD + Digitally Imported

1.- Enter into the playlist path. 2.- Run the command. 3.- Playlists created!
This is sample output - yours may be different.
2

wget -q -O - http://listen.di.fm/public2 | sed 's/},{/\n/g' | perl -n -e '/"key":"([^"]*)".*"playlist":"([^"]*)"/; print "$1\n"; system("wget -q -O - $2 | grep -E '^File' | cut -d= -f2 > di_$1.m3u")'

Zort · 2013-02-20 03:37:41 9
‹ First < 2 3 4 5 6 > Last ›

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print java packages by using unix tree and sed

if you need a quick way of printing out all the packages that contain classes this command will print the directory structure and replace '/' with '.' It will also ignore CVS directories (we use CVS here)

Print all open regular files sorted by the number of file handles open to each.

List all open files of all processes. . $ find /proc/*/fd Look through the /proc file descriptors . $ -xtype f list only symlinks to file . $ -printf "%l\n" print the symlink target . $ grep -P '^/(?!dev|proc|sys)' ignore files from /dev /proc or /sys . $ sort | uniq -c | sort -n count the results . Many processes will create and immediately delete temporary files. These can the filtered out by adding: $ ... | grep -v " (deleted)$" | ...

Recursively grep for string and format output for vi(m)

This is a big time saver for me. I often grep source code and need to edit the findings. A single highlight of the mouse and middle mouse click (in gnome terminal) and I'm editing the exact line I just found. The color highlighting helps interpret the data.

Find all folder in /var that contains log in their path and have more than 10 files inside them, print the folder and the count

-L is for following symbolic links, it can be omitted and then you can find in your whole / dir

Convert YAML to JSON

* Output is jq compatible * Output is single lines - unix compatible * Multiple files supported

Create md5sum of files under the current dir excluding some directories

Useful if you want get all the md5sum of files but you want exclude some directories. If your list of files is short you can make in one command as follow: $ find . -type d $ -name DIR1 -o -name DIR2 $ -prune -o -type f -exec md5sum {} \; Alternatively you can specify a different command to be executed on the resulting files.

Block all IP addresses and domains that have attempted brute force SSH login to computer

Searches all log files (including archived bzip2 files) for invalid user and PAM authentication errors, both of which are indicative of brute force attempts at logging into computer. A list of all unique IP addresses and domain names is appended to hosts.deny. The command (and grep error messages) will work on Mac OS X 10.6, small adjustments may be needed for other OSs.

shutdown if wget exit

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"

Check if a machine is online with better UI

I have used single packet, and in a silent mode with no display of ping stats. This is with color and UI improvement to the http://www.commandlinefu.com/commands/view/10220/check-if-a-machine-is-online. It is as per the enhancements suggested.

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Commands using perl (369)

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