Commands using perl sorted by votes

Commands using perl (369)

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Run an interactive program with perl code expansion

Start an interactive program with perl code expansion. Everything between #[ ] is evaluated as perl code. #[ ] tags must not be nested (it wouldn't make sense anyway). Show Sample Output
This is sample output - yours may be different.
```
plexpand sed -s 's/a/x/g'
banana
bxnxnx
b#["an"x2]a
bxnxnx
```
0

plexpand() { mkfifo /tmp/plxpnd; $@ </tmp/plxpnd & perl -p -e '$|=1; s/#\[(.*)\]/eval($1)/ge' >/tmp/plxpnd; rm /tmp/plxpnd; }

hellcode · 2016-05-10 04:49:35 9

perl http get one-liner

HTTP Get, without LWP::Simple Show Sample Output

perl -MLWP::UserAgent -le 'print LWP::UserAgent->new(requests_redirectable => [])->get(shift)->decoded_content()' "http://dazzlepod.com/ip/me.json"

dbiesecke · 2016-06-23 21:12:26 13

Optimal way of deleting huge numbers of files

cd $target_dir then run the command for fast removal of millions of files
This is sample output - yours may be different.
0

perl -e 'for(<*>){((stat)[9]<(unlink))}'

neocruiser · 2016-07-14 04:05:53 13
Pretty print docker ps command

If you have many port mappings, docker ps output becomes pretty illegible. The ~120 char one-liner changes the output into a more readable list of container! Show Sample Output
This is sample output - yours may be different.
```
$ docker ps [...]

70f949a68c3f               # bold
image:latest
"/start.sh"
8 hours ago
Up 8 hours                 # colorful if up or down
127.0.0.1:9002->9000/tcp
zauberstuhl                # underlined

[...]
```
0

docker ps | perl -ple "s/\$/\n\n/g;s/\s{2,}/\n/g;s/(Up)/\\e\[32m\$1\\e\[0m/g;s/(Down)/\\e\[31m\\e\[5m\$1\\e\[25m\\e\[0m/g;s/^([^\n]+)/\\e\[1m\$1\\e\[0m/g;s/(\w+?)$/\\e\[4m\$1\\e\[24m/g" | more

zauberstuhl · 2017-01-05 02:46:15 14
Parsing URL
This is sample output - yours may be different.
0

perl -MURI::Split=uri_split,uri_join -nle '($s,$a,$p,$q,$f)=uri_split($_);print "$s\t$a\t$p\t$q\t$f"'

akanehara · 2017-02-10 06:05:37 20
Visual system load display

It takes the first value of /prov/loadavg to print that many stars followed by the value. Show Sample Output
This is sample output - yours may be different.
```
******************** 20.98
********************* 21.30
******************* 19.92
**************** 16.85
*************** 15.50
************** 14.90
```
0

while [ true ]; do cat /proc/loadavg | perl -ne 'm/(^[^ ]+)/; $L = $1; print "*" x $L; print " $L\n";' ; sleep 6; done

t3o · 2017-10-13 06:47:06 22
Remove multiple entries of the same command in .bash_history with preserving the chronological order

Only the first appearance of a repeated command in the history will be kept. Otherwise, if you prefer to keep last occurrence of a repeated command then maybe you can achieve that by including reverse input/output i.e with 'tac' command in expression above. To see statistics of removed repeated commands: diff --suppress-common-lines -y ~/.bash_history.bak ~/.bash_history|uniq -c|sort -n|tr -s " "|sed '/^ 1/d'|grep '<'
This is sample output - yours may be different.
0

cp -a ~/.bash_history ~/.bash_history.bak && perl -ne 'print unless $seen{$_}++' ~/.bash_history.bak >~/.bash_history

knoppix5 · 2019-04-15 12:39:09 71
shuffle lines via perl
This is sample output - yours may be different.
0

seq 1 9 | perl -MList::Util=shuffle -e 'print shuffle <>;'

emphazer · 2019-07-03 09:39:08 38
From all PDF files in all subdirectories, extract two metadata fields (here: Creator and Producer) into a CSV table
This is sample output - yours may be different.
0

echo "File;Creator;Producer";find . -name '*.pdf' -print0 | while IFS= read -d $'\0' line;do echo -n "$line;";pdfinfo "$line"|perl -ne 'if(/^(Creator|Producer):\s*(.*)$/){print"$2";if ($1 eq "Producer"){exit}else{print";"}}';echo;done 2>/dev/null

langec · 2020-12-17 21:08:55 1264
change the all files which contains xxxxx to yyyyyy

This script first find all files which contains word xxxxx recursively. Then replace the word xxxxx to yyyyy of the files. Use case: - Web site domain change - Function name change of the program
This is sample output - yours may be different.
-1

grep -r -l xxxxx . | xargs perl -i -pe "s/xxxxx/yyyyy/g"

hassylin · 2009-02-06 08:18:50 18
rows2columns

joins multiple lines to create single line with comma separated values. for example if we have an email addresses one per line (copy&paste from spreadsheet) it will oputput one line with comman separated addresses to put it to email client. Show Sample Output
This is sample output - yours may be different.
```
email@number.one, email@number.one, email@number.one, ...
```
-1

perl -le 'print join ", ", map { chomp; $_ } <>'

jozef · 2009-02-06 12:50:43 14
Renaming jpg extension files at bunch
This is sample output - yours may be different.
-1

find . -name "*.jpg" | perl -ne'chomp; $name = $_; $quote = chr(39); s/[$quote\\!]/_/ ; print "mv \"$name\" \"$_\"\n"'

mnikhil · 2009-02-07 18:44:54 11
print the date of the unix epoch in a human readable form using perl.
This is sample output - yours may be different.
-1

perl -e 'print scalar localtime $ARGV[0],"\n" ' epoch

hypnojazz · 2009-03-25 18:40:21 10
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.
This is sample output - yours may be different.
-1

perl -pi -e 's/foo/bar/g' $(grep -l foo ./*)

dopeman · 2009-03-27 17:18:08 6
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.
This is sample output - yours may be different.
-1

perl -pi -e 's/foo/bar/g' $(grep -rl foo ./*)

dopeman · 2009-03-27 17:21:35 10
regex to match an ip

if you want to only print the IP address from a file. In this case the file will be called "iplist" with a line like "ip address 1.1.1.1" it will only print the "1.1.1.1" portion
This is sample output - yours may be different.
-1

perl -wlne 'print $1 if /(([01]?\d\d?|2[0-4]\d|25[0-5])\.([01]?\d\d?|2[0-4]\d|25[0-5])\.([01]?\d\d?|2[0-4]\d|25[0-5])\.([01]?\d\d?|2[0-4]\d|25[0-5]))/' iplist

salparadise · 2009-09-17 16:14:52 3
Print all members of US House of Representatives

Uses curl to download page of membership of US Congress. Use sed to strip HTML then perl to print a line starting with two tabs (a line with a representative) Show Sample Output
This is sample output - yours may be different.
```
curl "http://www.house.gov/house/MemberWWW.shtml" 2>/dev/null | sed -e :a -e 
  's/<[^>]*>//g;/</N;//ba' | perl -nle 's/^\t\t(.*$)/ $1/ and 
  print;' > DefeatedIn2010.txt

#Fills a file called "DefeatedIn2010.txt" with the name of every member of congress.
```
-1

curl "http://www.house.gov/house/MemberWWW.shtml" 2>/dev/null | sed -e :a -e 's/<[^>]*>//g;/</N;//ba' | perl -nle 's/^\t\t(.*$)/ $1/ and print;'

drewk · 2009-09-24 23:37:36 15
Transforms a file to all uppercase.
This is sample output - yours may be different.
-1

perl -i -ne 'print uc $_' $1

rbs · 2009-10-15 16:59:38 4
search for a pattern (regex) in all text files (ignoring binary files) in a directory tree
This is sample output - yours may be different.
-1

find . -type f | perl -lne 'print if -T;' | xargs egrep "somepattern"

unixmonkey7263 · 2009-12-01 19:12:03 6
prints line numbers

This command prints all lines of a file together with is line number. Show Sample Output
This is sample output - yours may be different.
```
1 - #include <vector>
2 - #include <iostream>
3 - #include <sstream>
4 - #include <algorithm>
5 - 
6 - class Ponto{
```
-1

perl -ne 'print "$. - $_"' infile.txt

netp · 2009-12-08 15:27:39 3
perl find and replace
This is sample output - yours may be different.
-1

find -name ".php" -exec perl -pi -e 's/search/replace/g/' {} \;

unixmonkey8504 · 2010-03-02 14:18:44 3
Length of longest line of code

Find the length of the longest line of code in your files. Show Sample Output
This is sample output - yours may be different.
```
96
```
-1

perl -ne 'push(@w, length); END {printf "%0d\n" , (sort({$b <=> $a} @w))[0]}' *.cpp

asolkar · 2010-05-11 19:46:37 4
Check a nfs mountpoint and force a remount if it does not reply after a given timeout.

Based on the execute with timeout command in this site. A more complex script: #!/bin/sh # This script will check the avaliability of a list of NFS mount point, # forcing a remount of those that do not respond in 5 seconds. # # It basically does this: # NFSPATH=/mountpoint TIMEOUT=5; perl -e "alarm $TIMEOUT; exec @ARGV" "test -d $NFSPATH" || (umount -fl $NFSPATH; mount $NFSPATH) # TIMEOUT=5 SCRIPT_NAME=$(basename $0) for i in $@; do echo "Checking $i..." if ! perl -e "alarm $TIMEOUT; exec @ARGV" "test -d $i" > /dev/null 2>&1; then echo "$SCRIPT_NAME: $i is failing with retcode $?."1>&2 echo "$SCRIPT_NAME: Submmiting umount -fl $i" 1>&2 umount -fl $i; echo "$SCRIPT_NAME: Submmiting mount $i" 1>&2 mount $i; fi done
This is sample output - yours may be different.
-1

NFSPATH=/mountpoint TIMEOUT=5; perl -e "alarm $TIMEOUT; exec @ARGV" "test -d $NFSPATH" || (umount -fl $NFSPATH; mount $NFSPATH)

keymon · 2010-06-04 07:58:53 3
Get IPv4 of eth0 for use with scripts
This is sample output - yours may be different.
-1

ifconfig eth0 | perl -ne 'print $1 if m/addr:((?:\d+\.){3}\d+)/'

mensa13 · 2010-06-26 10:41:09 4
Find all symlinks that link to directories

This will list all symlinks that are directories under the current directory. This will help you distinguish them from regular files.
This is sample output - yours may be different.
-1

ls -l $(find ./ -type l | perl -ne 'chomp; if (-d) { print "$_\n" }')

rwadkins · 2010-07-16 19:31:28 3
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Generate a random password 30 characters long

connect via ssh using mac address

Instead of looking for the right ip address, just pick whatever address you like and set a static ip mapping.

Execute a command with a timeout

A timeout is great, but what if the command is taking longer than expected because it's hung up or ran into some other problem? That's where the -k option comes in. Run "some_command" and timeout after 30s. If the command is still running after 1 minute, it will receive a kill signal.

Check whether IPv6 is enabled

Checks whether IPv6 is enabled system-wide by reading from procfs.

Deleting / Ignoring lines from the top of a file

Undo several commits by committing an inverse patch.

Use this to make a new commit that "softly" reverts a branch to some commit (i.e. squashes the history into an inverse patch). You can review the changes first by doing the diff alone.

Go up multiple levels of directories quickly and easily.

Print all git repos from a user (only curl and grep)

Interactively build regular expressions

txt2regex can be interactive or noninteractive and generates regular expressions for a variety of dialects based on user input. In interactive mode, the regex string builds as you select menu options. The sample output here is from noninteractive mode, try running it standalone and see for yourself. It's written in bash and is available as the 'txt2regex' package at least under debian/ubuntu.

Ensure that each machine that you log in to has its own history file

On systems where your home directory is shared across different machines, your bash history will be global, rather than being a separate history per machine. This setting in your .bashrc file will ensure that each machine has its own history file.

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Commands using perl (369)

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