Commands tagged perl sorted by votes

Commands tagged perl (190)

sorted by

Look up a unicode character by name

No need for further filedes or substitution for splitting. Simply use read a b
This is sample output - yours may be different.
1

grep -i "$*" /usr/lib/perl5/Unicode/CharName.pm | while read a b; do /usr/bin/printf "\u$a\tU+%s\t%s\n" "$b"; done

ioggstream · 2011-01-04 11:30:16 6
Syntax Highlight your Perl code

This uses Text::Highlight to output the specified Perl file with syntax highlighting. A better alternative is my App::perlhl - find it on the CPAN: http://p3rl.org/App::perlhl
This is sample output - yours may be different.
1

perl -MText::Highlight -E '$h=Text::Highlight->new(ansi=>1); my $text=do{local $/; open my $fh, "<", $ARGV[0]; <$fh>}; say $h->highlight("Perl", $text);' path/to/perl-file.pl

doherty · 2011-01-31 05:52:43 7
Are the two lines anagrams?

This works by reading in two lines of input, turning each into a list of one-character matches that are sorted and compared.
This is sample output - yours may be different.
1

(echo foobar; echo farboo) | perl -E 'say[sort<>=~/./g]~~[sort<>=~/./g]?"anagram":"not anagram"'

doherty · 2011-02-17 02:15:46 119
Pick a random line from a file

This is from perldoc -q random.*line, which says: This has a significant advantage in space over reading the whole file in. You can find a proof of this method in The Art of Computer Programming, Volume 2, Section 3.4.2, by Donald E. Knuth. Who am I to argue with Don Knuth?
This is sample output - yours may be different.
1

perl -e 'rand($.) < 1 && ($line = $_) while <>;'

unixmonkey20842 · 2011-04-25 21:28:26 3
Delete empty directories

Recursively delete empty directories. Use with care.
This is sample output - yours may be different.
1

perl -MFile::Find -e"finddepth(sub{rmdir},'.')"

igorfu · 2011-05-23 08:45:34 7
Syntax Highlight your Perl code
This is sample output - yours may be different.
1

perl -mText::Highlight -E 'say Text::Highlight->new(ansi => 1)->highlight(Perl => do { local (@ARGV,$/) = shift; <> }) ' path/to/perl-file.pl

dbr · 2011-07-12 04:55:12 5
change microdvd subtitles framerate

this command example converts to 25 fps subtitles that were originally created for 24 fps movie
This is sample output - yours may be different.
1

cat subtitles.txt | perl -pe 's/} /}/g; s/{(\d+)}/=1=/; $f1=(24/25*$1); s/{(\d+)}/=2=/; $f2=(24/25*$1); $f1=~s/\..*//; $f2=~s/\..*//; s/=1=/{$f1}/; s/=2=/{$f2}/; ' > subtitles_newfps.txt

ciekawy · 2011-07-30 15:34:43 18
Use Perl like grep

Much better alternatives - grep-alikes using perl regexps. With more options, and nicer outputs.
This is sample output - yours may be different.
1

ack; pcregrep

depesz · 2011-08-14 18:01:36 3
Multiline Search/Replace with Perl

from http://stackoverflow.com/questions/1030787/multiline-search-replace-with-perl added greedy trick in wildcard match (.*?) from http://www.troubleshooters.com/codecorn/littperl/perlreg.htm#Greedy Show Sample Output
This is sample output - yours may be different.
```
$ cat file_to_change
aaa

START
bbb
STOP

START
ccc
STOP

ddd


$ perl -i -pe 'BEGIN{undef $/;} s/START.*?STOP/replace_string/smg' file_to_change

$ cat file_to_change
aaa

replace_string

replace_string

ddd
```
1

perl -i -pe 'BEGIN{undef $/;} s/START.*?STOP/replace_string/smg' file_to_change

hute37 · 2011-10-05 11:22:36 10
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
This is sample output - yours may be different.
```
r14341 | bob | 2011-10-14 15:57:17 +0100 (Fri, 14 Oct 2011) | 1 line jack leave that alone
r14316 | jack | 2011-10-13 21:54:52 +0100 (Thu, 13 Oct 2011) | 1 line thing still broken
r14315 | jack | 2011-10-13 18:03:41 +0100 (Thu, 13 Oct 2011) | 1 line fixed the thing
r14307 | bob | 2011-10-13 15:49:29 +0100 (Thu, 13 Oct 2011) | 1 line made a thing
```
1

svn log | perl -l40pe 's/^-+/\n/'

bazzargh · 2011-10-14 16:02:22 6
wc in perl
This is sample output - yours may be different.
1

perl -ane 'END{printf(" %d %d %d\n", $x, $y, $z)} $x+=1; $y+=@F; $z+=length' file.txt

kev · 2011-10-24 06:14:02 10

Show git branches by date - useful for showing active branches

This fixes a bug found in the other scripts which fail when a branch has the same name as a file or directory in the current directory. Show Sample Output

for k in `git branch|sed s/^..//`;do echo -e `git log -1 --pretty=format:"%Cgreen%ci %Cblue%cr%Creset" "$k" --`\\t"$k";done|sort

ryan · 2011-11-02 06:16:22 7

Creates a 'path' command that always prints the full path to any file

The command creates an alias called 'path', so it's useful to add it to your .profile or .bash_profile. The path command then prints the full path of any file, directory, or list of files given. Soft links will be resolved to their true location. This is especially useful if you use scp often to copy files across systems. Now rather then using pwd to get a directory, and then doing a separate cut and paste to get a file's name, you can just type 'path file' and get the full path in one operation. Show Sample Output
This is sample output - yours may be different.
```
path some_file.txt

/home/espider/some_directory/some_file.txt
```
1

alias path="/usr/bin/perl -e 'use Cwd; foreach my \$file (@ARGV) {print Cwd::abs_path(\$file) .\"\n\" if(-e \$file);}'"

espider1 · 2012-01-18 01:40:05 10
Perl One Liner to Generate a Random IP Address
This is sample output - yours may be different.
1

perl -e 'printf "00:16:3E:%02X:%02X:%02X\n", rand 0xFF, rand 0xFF, rand 0xFF'

Gular · 2012-07-02 09:59:43 5
Update a namecheap @ A record to point to your current internet-facing IP address

Sets the @ A record for your domain hosted by namecheap to your current internet-facing IP address, logs success or failure with syslog, and logs the data returned to /root/dnsupdate. Change the XXX's as appropriate. More info at: http://www.namecheap.com/support/knowledgebase/article.aspx/29/ Show Sample Output
This is sample output - yours may be different.
```
Aug 11 12:05:22 sync dnsupdate: Update Sucessful
```
1

logger -tdnsupdate $(curl -s 'https://dynamicdns.park-your-domain.com/update?host=@&domain=xxx&password=xxx'|tee -a /root/dnsupdate|perl -pe'/Count>(\d+)<\/Err/;$_=$1eq"0"?"Update Sucessful":"Update failed"'&&date>>/root/dnsupdate)

MagisterQuis · 2013-08-11 16:27:39 7
Convert control codes to visible Unicode Control Pictures

Converts control codes and spaces (ASCII code ≤ 32) to visible Unicode Control Pictures, U+2400 ? U+2420. Skips \n characters, which is probably a good thing. Show Sample Output
This is sample output - yours may be different.
```
&#9218;Hello,&#9248;&#9248;Folks&#9225;!&#9229;
```
1

/bin/echo -e '\002Hello, Folks\t!\r' | perl -pwle 'use v5.14; s/([\N{U+0000}-\N{U+0020}])/chr(9216+ord($1))/ge;'

scruss · 2014-06-30 01:45:40 11
Convert JSON to YAML

This is based on __unixmonkey73469__ answer. You will need to supply `--multiline 1` option to JSON importer if your .json is multiline (i.e. it was prettyfied) And you still need catmandu installed via `cpanm Catmandu`
This is sample output - yours may be different.
1

catmandu convert JSON --multiline 1 to YAML < file.json > file.yaml

pavelkaroukin · 2014-09-29 16:45:24 11
drop first column of output by piping to this

An advantage is that this doesn't modify remained string at all. One can change {0,1} with {0,n} to drop several columns
This is sample output - yours may be different.
1

perl -pE's/(\S+\s*){0,1}//'

pung96 · 2015-05-09 15:14:58 12
Calculate the mean or average of a single column of numbers in a text file

single-column-numbers.txt is a text file with 22658 rows (numbers) in a single column. Each number can range from 0 to 134298679.533591 and the dot is for the decimals. This is done with perl because awk can't sum such high numbers. Show Sample Output
This is sample output - yours may be different.
```
87553740.0874476
```
1

perl -lane '$total += $F[0]; END{print $total/$.}' single-column-numbers.txt

bugmenot · 2021-06-30 07:45:56 168
dos2unix

Converts windows lined-style file to unix. see http://en.wikipedia.org/wiki/Newline Can be used to convert from linux2dos : just invert \r\n and \n.
This is sample output - yours may be different.
0

$ perl -pi -e 's/\r\n/\n/g' <finelame>

unixmonkey4200 · 2009-04-10 22:22:31 8
Test if the given argument is a valid ip address.

This command will output 1 if the given argument is a valid ip address and 0 if it is not. Show Sample Output
This is sample output - yours may be different.
```
1
```
0

perl -e '$p=qr!(?:0|1\d{0,2}|2(?:[0-4]\d?|5[0-5]?|[6-9])?|[3-9]\d?)!;print((shift=~m/^$p\.$p\.$p\.$p$/)?1:0);' 123.123.123.123

speaker · 2009-07-12 00:24:29 3
get events from google calendar for a given dates range

substitute the URL with your private/public XML url from calendar sharing settings substitute the dates YYYY-mm-dd adjust the perl parsing part for your needs Show Sample Output
This is sample output - yours may be different.
```
Claudio,2009-07-30
Claudio,2009-07-23
Claudio,2009-07-17
Claudio,2009-07-16
Claudio,2009-07-10
Claudio,2009-07-03
Claudio,2009-07-02
Claudio,2009-06-26
Claudio,2009-06-25
Failure,2009-06-20
Glconsulting,2009-06-18
Failure,2009-06-15
production migration,2009-06-08
```
0

wget -q -O - 'URL/full?orderby=starttime&singleevents=true&start-min=2009-06-01&start-max=2009-07-31' | perl -lane '@m=$_=~m/<title type=.text.>(.+?)</g;@a=$_=~m/startTime=.(2009.+?)T/g;shift @m;for ($i=0;$i<@m;$i++){ print $m[$i].",".$a[$i];}';

unixmonkey4704 · 2009-07-23 14:48:54 4
Get all IPs via ifconfig
This is sample output - yours may be different.
0

ipconfig getpacket en0 | grep yi| sed s."yiaddr = "."en0: ". ipconfig getpacket en1 | grep yi| sed s."yiaddr = "."en1: ".

swormley · 2009-07-29 12:10:32 4
Find all PowerPC applications on OS X

This finds all the PowerPC apps recognized by OS X. A better version is: system_profiler SPApplicationsDataType 2> /dev/null | perl - wnl -e '$i=$j=$k=$p=0; @al=; $c=@al; while($j s[$i].=$al[$j]; $i++ if ($al[$j]) =~ /^\s\s\s\s\S.*:$/; $j++} while($k apps[$k++]; if (/Kind: PowerPC/s) {print; $p++;}} print "$i applications, $p P owerPC applications\n\n"' but that is more than 255 characters...
This is sample output - yours may be different.
0

system_profiler SPApplicationsDataType | perl -nl -e '@al=<>; $c=@al; while($j<$c){ $apps[$i].=$al[$j]; $i++ if ($al[$j] ) =~ /^\s\s\s\s\S.*:$/; $j++} while($k<$i){ $_=$apps[$k++]; if (/Kind: PowerPC/s) {print;}}'

drewk · 2009-09-06 20:56:48 8
print scalar gmtime

print scalar gmtime
This is sample output - yours may be different.
0

perl -e "print scalar(gmtime(1247848584))"

opexxx · 2009-09-11 06:19:09 17
‹ First < 2 3 4 5 6 > Last ›

What's this?

commandlinefu.com is the place to record those command-line gems that you return to again and again. 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.

Share Your Commands

Check These Out

Remove job from crontab by commandline

The "-u USER" is optional if root user is used

Convert CSV to JSON

Replace 'csv_file.csv' with your filename.

Change timestamp on a file

-a for access time, -m for modification time, -c do not create any files, -t timestamp

Convert CSV to JSON

Replace 'csv_file.csv' with your filename.

list files recursively by size

Remove all but one specific file

Solaris get PID socket

Command line to get which PID is opening a socket on IP and PORT. Only useful under Solaris.

Use top to monitor only all processes with the same name fragment 'foo'

top accecpts a comma separated list of PIDs.

Set gnome wallpaper to a random jpg from the specified directory

Every time this is run it will change your background picture. For added fun Add some DBUS magic: . $HOME/.dbus/session-bus/`cat /var/lib/dbus/machine-id`-0 export DBUS_SESSION_BUS_ADDRESS and a crontab entry: */5 * * * * above_command_in_script.sh >/dev/null 2>/dev/null now wallpaper changes every 5 mins

Function to create an alias on the fly

Is used like this: mkalias rmcache "rm -rfv app/cache/*"

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:

» all commands
» commands with 3 up-votes (commandlinefu3)
» commands with 10 up-votes (commandlinefu10)
» commands tagged perl

Commands tagged perl (190) the last day the last week the last month all time sorted by date votes

What's this?

Check These Out

Stay in the loop…

Commands tagged perl (190)

sorted by