Questions tagged [perl]

Perl is a procedural, high-level, general-purpose, dynamic programming language, known for its native support of regular expressions and string parsing capabilities. Please use this tag for questions about Perl in general. For things related to the new (but related) language Raku (formerly "Perl 6"), please use the raku tag. For Perl-style regular expressions in other languages, use the regex tag, or, if they are based on the PCRE library, the pcre tag.

Perl is a highly capable, feature-rich programming language with over 25 years of development. Perl runs on over 100 platforms from portables to mainframes and is suitable for both rapid prototyping and large-scale development projects.

Perl can also refer to a family of high-level, general-purpose, interpreted, dynamic programming languages. The languages in this family include Perl and Raku (formerly known as Perl 6). For Raku-related questions, please use the tag raku. For "Perl-style" regular expressions in other languages, often based on the PCRE library, do not use tag perl, but tag regex or a more specific tag such as tag pcre.

Related Resources

Official Perl documentation
PerlMonks (aka "The Monastery") - Perl community website with discussion topics, tutorials, reviews, and code snippets.
/r/perl - A subreddit for Perl discussion
jobs.perl.org - Perl jobs
Perl Weekly - Weekly curated news round-up in e-mail and RSS
Perl Mongers - Perl user groups
perl-tutorial.org - collects up-to-date Perl tutorials and warns about outdated ones
Comprehensive Perl Archive Network - The canonical location for Perl code and modules
MetaCPAN - A modern CPAN search site, with an open source backend.
Perl Iron Man - An aggregator of Perl blog posts from all over the world
Learn Perl in about 2 hours 30 minutes
Freenode#perl - Freenode IRC channel for Perl help and discussion
irc.perl.org - Perl IRC network

Perl-related Blogs and Bloggers

blogs.perl.org - Hosted site for Perl-related blogging
$perl->buzz - Perl-related news roundup
Perl Maven - Articles, tutorials, screencasts about Perl
The Effective Perler - A blog by brian d foy
ν42 - Sinan Ünür's blog
Perl Is My Cocaine - Tudor Constantin's blog

Free Perl Programming Books

Perl Programming Books

Related tags

cpan The Comprehensive Perl Archive Network
dbi Database-independent interface for Perl
dbix-class An object-relational mapper (ORM) for accessing DB rows as OO style objects
mod-perl Integrate Perl and the Apache web server
moose A post-modern object system for Perl 5
catalyst An elegant web application framework
mojolicious Perl real-time web framework
dancer A micro web application framework, originally inspired by the Sinatra framework in Ruby.
raku A new language in the Perl family
rakudo Raku implementation that targets MoarVM, the JVM, and the Parrot virtual machine
pugs Raku implemented in Haskell
perl-module Extensions to Perl
tkx, perltk Perl interfaces to Tk.
dist-zilla An increasingly popular Module Authoring and Release tool-kit.
pcre Perl-Compatible Regular Expressions (PCRE)
perlbrew A tool to manage multiple Perl installations in your $HOME directory.
perl-data-structures Data structures in Perl.
pdl Perl Data Language.
strawberry-perl Perl environment for Microsoft Windows.
perl-pod, perldoc Perl documentation
perl-tidy, perl-critic Perl utilities
devel-cover Code coverage metrics for Perl

Date & Time

Libraries for working with dates and times

Devices

Libraries to talk to physical devices

Device::Modem - Talk to modem devices connected via a serial port
Device::Onkyo - Control Onkyo/Integra AV equipment via LAN or serial https://metacpan.org/pod/Device::Modem https://metacpan.org/pod/Device::Onkyo

DevOps Tools

Libraries that help when you want to deploy software across networks on several hosts that are working across computer networks

Rex - Remote Execution

FAQs

Frequently ask questions

Why doesn't my Perl one-liner work on Windows?

More information

Perl Wikipedia Article

67820 questions

103

votes

3 answers

How should I use the "my" keyword in Perl?

I keep seeing the my keyword in front of variable names in example Perl scripts online, but I have no idea what it means. I tried reading the manual pages and other sites online, but I'm having difficulty discerning what it is for, given the…

perl scope declaration

asked Jan 02 '14 at 18:43

FistOfFury

6,735
7
49
57

103

votes

8 answers

Turning multiple lines into one comma separated line

I have the following data in multiple lines: foo bar qux zuu sdf sdfasdf What I want to do is to convert them to one comma separated line: foo,bar,qux,zuu,sdf,sdfasdf What's the best unix one-liner to do that?

linux perl unix sed awk

asked Apr 02 '13 at 07:48

neversaint

60,904
137
310
477

100

votes

2 answers

In Perl, what is the difference between a .pm (Perl module) and .pl (Perl script) file?

What is the Difference between .pm (Perl module) and .pl (Perl script) file? Please also tell me why we return 1 from file. If return 2 or anything else, it's not generating any error, so why do we return 1 from Perl module?

perl perl-module

asked Aug 04 '10 at 05:20

user380979

1,387
5
16
20

votes

9 answers

How can I convert a string to a number in Perl?

I have a string which holds a decimal value in it and I need to convert that string into a floating point variable. So an example of the string I have is "5.45" and I want a floating point equivalent so I can add .1 to it. I have searched around the…

string perl floating-point

asked Nov 14 '08 at 00:39

Anton

12,285
20
64
84

votes

14 answers

How do I tell if a variable has a numeric value in Perl?

Is there a simple way in Perl that will allow me to determine if a given variable is numeric? Something along the lines of: if (is_number($x)) { ... } would be ideal. A technique that won't throw warnings when the -w switch is being used is…

perl numbers

asked Aug 15 '08 at 19:43

Derek Park

45,824
15
58
76

votes

8 answers

What are the Python equivalents to Ruby's bundler / Perl's carton?

I know about virtualenv and pip. But these are a bit different from bundler/carton. For instance: pip writes the absolute path to shebang or activate script pip doesn't have the exec sub command (bundle exec bar) virtualenv copies the Python…

python ruby perl virtualenv pip

asked Jan 04 '12 at 11:37

riywo

1,378
1
11
14

votes

13 answers

How do I daemonize an arbitrary script in unix?

I'd like a daemonizer that can turn an arbitrary, generic script or command into a daemon. There are two common cases I'd like to deal with: I have a script that should run forever. If it ever dies (or on reboot), restart it. Don't let there ever…

perl unix scripting system-administration daemon

asked Feb 08 '09 at 06:11

dreeves

26,430
45
154
229

votes

9 answers

How to print lines between two patterns, inclusive or exclusive (in sed, AWK or Perl)?

I have a file like the following and I would like to print the lines between two given patterns PAT1 and PAT2. 1 2 PAT1 3 - first block 4 PAT2 5 6 PAT1 7 - second block PAT2 8 9 PAT1 10 - third block I have read How to select lines between…

shell perl awk sed pattern-matching

asked Aug 16 '16 at 10:40

fedorqui

275,237
103
548
598

votes

9 answers

In Perl, how can I concisely check if a $variable is defined and contains a non zero length string?

I currently use the following Perl to check if a variable is defined and contains text. I have to check defined first to avoid an 'uninitialized value' warning: if (defined $name && length $name > 0) { # do something with $name } Is there a…

perl string

asked Sep 26 '09 at 00:23

Jessica

1,421
5
15
10

votes

6 answers

Use of 'use utf8;' gives me 'Wide character in print'

If I run the following Perl program: perl -e 'use utf8; print "鸡\n";' I get this warning: Wide character in print at -e line 1. If I run this Perl program: perl -e 'print "鸡\n";' I do not get a warning. I thought use utf8 was required to use…

perl unicode utf-8

asked Mar 04 '13 at 20:29

Eric Johnson

17,502
10
52
59

votes

5 answers

Perl build, unit testing, code coverage: A complete working example

Most Stackoverflow answers that I have found in regards to the Perl build process and unit testing and code coverage simply point me to CPAN for the documentation there. There's absolutely nothing wrong with pointing to CPAN modules because that's…

perl unit-testing build-process build-automation code-coverage

asked Feb 10 '09 at 18:32

Kurt W. Leucht

4,725
8
33
45

votes

10 answers

Perl: function to trim string leading and trailing whitespace

Is there a built-in function to trim leading and trailing whitespace such that trim(" hello world ") eq "hello world"?

perl

asked Jan 04 '11 at 20:10

Landon Kuhn

76,451
45
104
130

votes

6 answers

How can I de-install a Perl module installed via `cpan`?

I am using Perl running in user space (not installed via root) and installing modules via the command-line cpan. I would like to know if there is a simple way to remove a module without having to do a lot of work deleting individual files. I…

perl module cpan

asked Apr 13 '10 at 01:33

user181548

votes

15 answers

What is the best way to delete a value from an array in Perl?

The array has lots of data and I need to delete two elements. Below is the code snippet I am using, my @array = (1,2,3,4,5,5,6,5,4,9); my $element_omitted = 5; @array = grep { $_ != $element_omitted } @array;

arrays perl

asked Oct 06 '08 at 13:29

user21246

1,774
3
15
15

votes

4 answers

How to replace a string in an existing file in Perl

I want to replace the word "blue" with "red" in all text files named as 1_classification.dat, 2_classification.dat and so on. I want to edit the same file so I tried the following code, but it does not work. Where am I going wrong? @files =…

regex perl

asked Aug 09 '11 at 10:45

user831579

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