Perl
Developer Larry Wall | | |
First appeared | December 18, 1987[1] | |
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Stable release | ||
Preview release | 5.41.3[4] / 29 August 2024
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Perl is a high-level, general-purpose, interpreted, dynamic programming language. Though Perl is not officially an acronym,[9] there are various backronyms in use, including "Practical Extraction and Reporting Language".[10]
Perl was developed by Larry Wall in 1987[11] as a general-purpose Unix scripting language to make report processing easier.[12][11][13] Since then, it has undergone many changes and revisions. Perl originally was not capitalized and the name was changed to being capitalized by the time Perl 4 was released.[13] The latest release is Perl 5, first released in 1994. From 2000 to October 2019 a sixth version of Perl was in development; the sixth version's name was changed to Raku.[14][15] Both languages continue to be developed independently by different development teams which liberally borrow ideas from each other.
Perl borrows features from other programming languages including
Perl gained widespread popularity in the mid-1990s as a
Name and logos
Perl was originally named "Pearl". Wall wanted to give the language a short name with positive connotations. It is also a Christian reference to the Parable of the Pearl from the Gospel of Matthew.[11][25] However, Wall discovered the existing PEARL language before Perl's official release and dropped the "a" from the name.[26][11]
The name is occasionally expanded as a backronym: Practical Extraction and Report Language[27] and Wall's own Pathologically Eclectic Rubbish Lister, which is in the manual page for perl.[28]
Programming Perl, published by
History
Early versions
Larry Wall began work on Perl in 1987, while employed as a programmer at Unisys;[16] he released version 1.0 on December 18, 1987.[1][11] Wall based early Perl on some methods existing languages used for text manipulation.[11]
Perl 2, released in June 1988,[33][34] featured a better regular expression engine. Perl 3, released in October 1989,[33] added support for binary data streams.[35]
1990s
Originally, the only documentation for Perl was a single lengthy man page. In 1991, Programming Perl, known to many Perl programmers as the "Camel Book" because of its cover, was published and became the de facto reference for the language.[36] At the same time, the Perl version number was bumped to 4, not to mark a major change in the language but to identify the version that was well documented by the book.[37] Perl 4 was released in March 1991.[33]
Perl 4 went through a series of maintenance releases, culminating in Perl 4.036 in 1993, whereupon Wall abandoned Perl 4 to begin work on Perl 5. Initial design of Perl 5 continued into 1994. The perl5-porters mailing list was established in May 1994 to coordinate work on porting Perl 5 to different platforms. It remains the primary forum for development, maintenance, and porting of Perl 5.[38]
Perl 5.000 was released on October 17, 1994.[39] It was a nearly complete rewrite of the interpreter, and it added many new features to the language, including objects, references, lexical (my) variables, and modules. Importantly, modules provided a mechanism for extending the language without modifying the interpreter. This allowed the core interpreter to stabilize, even as it enabled ordinary Perl programmers to add new language features. Perl 5 has been in active development since then.
Perl 5.001 was released on March 13, 1995. Perl 5.002 was released on February 29, 1996 with the new prototypes feature. This allowed module authors to make
One of the most important events in Perl 5 history took place outside of the language proper and was a consequence of its module support. On October 26, 1995, the Comprehensive Perl Archive Network (CPAN) was established as a repository for the Perl language and Perl modules; as of December 2022[update], it carries over 211,850 modules in 43,865 distributions, written by more than 14,324 authors, and is mirrored worldwide at more than 245 locations.[41]
Perl 5.004 was released on May 15, 1997, and included, among other things, the UNIVERSAL package, giving Perl a base object from which all classes were automatically derived and the ability to require versions of modules. Another significant development was the inclusion of the CGI.pm module,[42] which contributed to Perl's popularity as a CGI scripting language.[43]
Perl 5.004 added support for Microsoft Windows, Plan 9, QNX, and AmigaOS.[42]
Perl 5.005 was released on July 22, 1998. This release included several enhancements to the regex engine, new hooks into the backend through the B::*
modules, the qr//
regex quote operator, a large selection of other new core modules, and added support for several more operating systems, including BeOS.[44]
2000–2020
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5.4 | 1999-04-29 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5.5 | 2004-02-23 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5.6 | 2003-11-15 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5.8 | 2008-12-14 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5.10 | 2009-08-22 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5.12 | 2012-11-10 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5.14 | 2013-03-10 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5.16 | 2013-03-11 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5.18 | 2014-10-01 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5.20 | 2015-09-12 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5.22 | 2017-07-15 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5.24 | 2018-04-14 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5.26 | 2018-11-29 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5.28 | 2020-06-01 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5.30 | 2020-06-01 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5.32 | 2021-01-23 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5.34 | 2023-11-29 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5.36 | 2023-11-29 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5.38 | 2023-11-29 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5.40 | 2024-06-09 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Old version
Old version, still maintained Current stable version Latest preview version Future release |
Perl 5.6 was released on March 22, 2000. Major changes included 64-bit support, Unicode string representation, support for files over 2 GiB, and the "our" keyword.[46][47] When developing Perl 5.6, the decision was made to switch the versioning scheme to one more similar to other open source projects; after 5.005_63, the next version became 5.5.640, with plans for development versions to have odd numbers and stable versions to have even numbers.[48]
In 2000, Wall put forth a call for suggestions for a new version of Perl from the community. The process resulted in 361 RFC (Request for Comments) documents that were to be used in guiding development of Perl 6. In 2001,[49] work began on the "Apocalypses" for Perl 6, a series of documents meant to summarize the change requests and present the design of the next generation of Perl. They were presented as a digest of the RFCs, rather than a formal document. At this time, Perl 6 existed only as a description of a language.[citation needed]
Perl 5.8 was first released on July 18, 2002, and further 5.X versions have been released approximately yearly since then. Perl 5.8 improved Unicode support, added a new I/O implementation, added a new thread implementation, improved numeric accuracy, and added several new modules. 5.
In 2004, work began on the "Synopses" – documents that originally summarized the Apocalypses, but which became the specification for the Perl 6 language. In February 2005, Audrey Tang began work on Pugs, a Perl 6 interpreter written in Haskell.[51] This was the first concerted effort toward making Perl 6 a reality. This effort stalled in 2006.[52]
The Perl On New Internal Engine (PONIE) project existed from 2003 until 2006. It was to be a bridge between Perl 5 and 6, and an effort to rewrite the Perl 5 interpreter to run on the Perl 6 Parrot virtual machine. The goal was to ensure the future of the millions of lines of Perl 5 code at thousands of companies around the world.[53] The PONIE project ended in 2006 and is no longer being actively developed. Some of the improvements made to the Perl 5 interpreter as part of PONIE were folded into that project.[54]
On December 18, 2007, the 20th anniversary of Perl 1.0, Perl 5.10.0 was released. Perl 5.10.0 included notable new features, which brought it closer to Perl 6. These included a switch statement (called "given"/"when"), regular expressions updates, and the smart match operator (~~).[55][56] Around this same time, development began in earnest on another implementation of Perl 6 known as Rakudo Perl, developed in tandem with the Parrot virtual machine. As of November 2009, Rakudo Perl has had regular monthly releases and now is the most complete implementation of Perl 6.
A major change in the development process of Perl 5 occurred with Perl 5.11; the development community has switched to a monthly release cycle of development releases, with a yearly schedule of stable releases. By that plan, bugfix point releases will follow the stable releases every three months.[citation needed]
On April 12, 2010, Perl 5.12.0 was released. Notable core enhancements include new package NAME VERSION
syntax, the
On May 14, 2011, Perl 5.14 was released with JSON support built-in.[58]
On May 20, 2012, Perl 5.16 was released. Notable new features include the ability to specify a given version of Perl that one wishes to emulate, allowing users to upgrade their version of Perl, but still run old scripts that would normally be incompatible.[59][failed verification] Perl 5.16 also updates the core to support Unicode 6.1.[59]
On May 18, 2013, Perl 5.18 was released. Notable new features include the new dtrace hooks, lexical subs, more CORE:: subs, overhaul of the hash for security reasons, support for Unicode 6.2.[60]
On May 27, 2014, Perl 5.20 was released. Notable new features include subroutine signatures, hash slices/new slice syntax, postfix dereferencing (experimental), Unicode 6.3, and a rand() function using a consistent random number generator.[61]
Some observers credit the release of Perl 5.10 with the start of the Modern Perl movement.[62] In particular, this phrase describes a style of development that embraces the use of the CPAN, takes advantage of recent developments in the language, and is rigorous about creating high quality code.[63] While the book Modern Perl[64] may be the most visible standard-bearer of this idea, other groups such as the Enlightened Perl Organization[65] have taken up the cause.
In late 2012 and 2013, several projects for alternative implementations for Perl 5 started: Perl5 in Perl6 by the Rakudo Perl team,[66] moe by Stevan Little and friends,[67] p2[68] by the Perl11 team under Reini Urban, gperl by goccy,[69] and rperl, a Kickstarter project led by Will Braswell and affiliated with the Perl11 project.[70]
Perl 6 and Raku
At the 2000 Perl Conference, Jon Orwant made a case for a major new language initiative.[72] This led to a decision to begin work on a redesign of the language, to be called Perl 6. Proposals for new language features were solicited from the Perl community at large, which submitted more than 300 RFCs.[73]
Wall spent the next few years digesting the RFCs and synthesizing them into a coherent framework for Perl 6. He presented his design for Perl 6 in a series of documents called "apocalypses" – numbered to correspond to chapters in Programming Perl. As of January 2011[update], the developing specification of Perl 6 was encapsulated in design documents called Synopses – numbered to correspond to Apocalypses.[74]
Thesis work by Bradley M. Kuhn, overseen by Wall, considered the possible use of the Java virtual machine as a runtime for Perl.[75] Kuhn's thesis showed this approach to be problematic. In 2001, it was decided that Perl 6 would run on a cross-language virtual machine called Parrot.
In 2005, Audrey Tang created the Pugs project, an implementation of Perl 6 in Haskell. This acted as, and continues to act as, a test platform for the Perl 6 language (separate from the development of the actual implementation), allowing the language designers to explore. The Pugs project spawned an active Perl/Haskell cross-language community centered around the Libera Chat #raku IRC channel. Many functional programming influences were absorbed by the Perl 6 design team.[76]
In 2012, Perl 6 development was centered primarily on two compilers:[77]
- Rakudo, an implementation running on the Parrot virtual machine and the Java virtual machine.[78]
- Niecza, which targets the Common Language Runtime.
In 2013, MoarVM ("Metamodel On A Runtime"), a C language-based virtual machine designed primarily for Rakudo was announced.[79]
In October 2019, Perl 6 was renamed to Raku.[80]
As of 2017[update] only the Rakudo implementation and MoarVM are under active development, and other virtual machines, such as the Java Virtual Machine and JavaScript, are supported.[81]
Perl 7
In June 2020, Perl 7 was announced as the successor to Perl 5.[82] Perl 7 was to initially be based on Perl 5.32 with a release expected in first half of 2021, and release candidates sooner.[83]
This plan was revised in May 2021, without any release timeframe or version of Perl 5 for use as a baseline specified.[84] When Perl 7 would be released, Perl 5 would have gone into long term maintenance. Supported Perl 5 versions however would continue to get important security and bug fixes.[85]
Perl 7 was announced on 24 June 2020 at "The Perl Conference in the Cloud" as the successor to Perl 5.[83][82] Based on Perl 5.32, Perl 7 was planned to be backward compatible with modern Perl 5 code; Perl 5 code, without boilerplate (pragma) header needs adding use compat::perl5;
to stay compatible, but modern code can drop some of the boilerplate.
The plan to go to Perl 7 brought up more discussion, however, and the Perl Steering Committee canceled it to avoid issues with backward compatibility for scripts that were not written to the pragmas and modules that would become the default in Perl 7. Perl 7 will only come out when the developers add enough features to warrant a major release upgrade.[86]
Design
Philosophy
According to Wall, Perl has two slogans. The first is "There's more than one way to do it," commonly known as TMTOWTDI, (pronounced Tim Toady). As proponents of this motto argue, this philosophy makes it easy to write concise statements.[87][88][89]
The second slogan is "Easy things should be easy and hard things should be possible".[16]
The design of Perl can be understood as a response to three broad trends in the computer industry: falling hardware costs, rising labor costs, and improvements in compiler technology. Many earlier computer languages, such as Fortran and C, aimed to make efficient use of expensive computer hardware. In contrast, Perl was designed so that computer programmers could write programs more quickly and easily.[90]
Perl has many features that ease the task of the programmer at the expense of greater
Wall was trained as a linguist, and the design of Perl is very much informed by
Perl's syntax reflects the idea that "things that are different should look different."[92] For example, scalars, arrays, and hashes have different leading sigils. Array indices and hash keys use different kinds of braces. Strings and regular expressions have different standard delimiters.
There is a broad practical bent to both the Perl language and the community and culture that surround it. The preface to Programming Perl begins: "Perl is a language for getting your job done."
Features
The overall structure of Perl derives broadly from C. Perl is
Perl also takes features from shell programming. All variables are marked with leading
Perl takes hashes ("associative arrays") from AWK and regular expressions from sed. These simplify many parsing, text-handling, and data-management tasks. Shared with Lisp is the implicit return of the last value in a block, and all statements are also expressions which can be used in larger expressions themselves.[citation needed]
Perl 5 added features that support complex
strict
pragma). A major additional feature introduced with Perl 5 was the ability to package code as reusable modules. Wall later stated that "The whole intent of Perl 5's module system was to encourage the growth of Perl culture rather than the Perl core."[95]All versions of Perl do automatic
Syntax
Perl has been referred to as "line noise" and a "write-only language" by its critics. Randal L. Schwartz in the first edition of the book Learning Perl,[96] in the first chapter states: "Yes, sometimes Perl looks like line noise to the uninitiated, but to the seasoned Perl programmer, it looks like checksummed line noise with a mission in life."[97] He also stated that the accusation that Perl is a write-only language could be avoided by coding with "proper care".[97] The Perl overview document perlintro states that the names of built-in "magic" scalar variables "look like punctuation or line noise".[98] However, the English module provides both long and short English alternatives. perlstyle document states that line noise in regular expressions could be mitigated using the /x
modifier to add whitespace.[99]
According to the Perl 6 FAQ, Perl 6 was designed to mitigate "the usual suspects" that elicit the "line noise" claim from Perl 5 critics, including the removal of "the majority of the punctuation variables" and the sanitization of the regex syntax.
In Perl, one could write the "Hello, World!" program as:
print "Hello, World!\n";
Here is a more complex Perl program, that counts down seconds from a given starting value:
#!/usr/bin/perl
use strict;
use warnings;
my ( $remaining, $total );
$remaining=$total=shift(@ARGV);
STDOUT->autoflush(1);
while ( $remaining ) {
printf ( "Remaining %s/%s \r", $remaining--, $total );
sleep 1;
}
print "\n";
The Perl interpreter can also be used for one-off scripts on the command line. The following example (as invoked from an sh-compatible shell, such as Bash) translates the string "Bob" in all files ending with .txt in the current directory to "Robert":
$ perl -i.bak -lp -e 's/Bob/Robert/g' *.txt
Implementation
No written specification or standard for the Perl language exists for Perl versions through Perl 5, and there are no plans to create one for the current version of Perl. There has been only one implementation of the interpreter, and the language has evolved along with it. That interpreter, together with its functional tests, stands as a de facto specification of the language. Perl 6, however, started with a specification,[102] and several projects[103] aim to implement some or all of the specification.[citation needed]
Perl is implemented as a core interpreter, written in C, together with a large collection of modules, written in Perl and C. As of 2010[update], the interpreter is 150,000 lines of C code and compiles to a 1 MB executable on typical machine architectures. Alternatively, the interpreter can be compiled to a link library and embedded in other programs. There are nearly 500 modules in the distribution, comprising 200,000 lines of Perl and an additional 350,000 lines of C code (much of the C code in the modules consists of character encoding tables).[citation needed]
The interpreter has an object-oriented architecture. All of the elements of the Perl language—scalars, arrays, hashes, coderefs,
The life of a Perl interpreter divides broadly into a compile phase and a run phase.[104] In Perl, the phases are the major stages in the interpreter's life-cycle. Each interpreter goes through each phase only once, and the phases follow in a fixed sequence.[citation needed]
Most of what happens in Perl's compile phase is compilation, and most of what happens in Perl's run phase is execution, but there are significant exceptions. Perl makes important use of its capability to execute Perl code during the compile phase. Perl will also delay compilation into the run phase. The terms that indicate the kind of processing that is actually occurring at any moment are compile time and run time. Perl is in compile time at most points during the compile phase, but compile time may also be entered during the run phase. The compile time for code in a string argument passed to the eval
built-in occurs during the run phase. Perl is often in run time during the compile phase and spends most of the run phase in run time. Code in BEGIN
blocks executes at run time but in the compile phase.
At compile time, the interpreter parses Perl code into a syntax tree. At run time, it executes the program by walking the tree. Text is parsed only once, and the syntax tree is subject to optimization before it is executed, so that execution is relatively efficient. Compile-time optimizations on the syntax tree include constant folding and context propagation, but peephole optimization is also performed.[105]
Perl has a
It is often said that "Only perl can parse Perl",[107] meaning that only the Perl interpreter (perl
) can parse the Perl language (Perl), but even this is not, in general, true. Because the Perl interpreter can simulate a Turing machine during its compile phase, it would need to decide the halting problem in order to complete parsing in every case. It is a longstanding result that the halting problem is undecidable, and therefore not even Perl can always parse Perl. Perl makes the unusual choice of giving the user access to its full programming power in its own compile phase. The cost in terms of theoretical purity is high, but practical inconvenience seems to be rare.[108]
Other programs that undertake to parse Perl, such as
Perl is distributed with over 250,000 functional tests for core Perl language and over 250,000 functional tests for core modules. These run as part of the normal build process and extensively exercise the interpreter and its core modules. Perl developers rely on the functional tests to ensure that changes to the interpreter do not introduce software bugs; further, Perl users who see that the interpreter passes its functional tests on their system can have a high degree of confidence that it is working properly.[citation needed]
Ports
Perl is
Because of unusual changes required for the classic Mac OS environment, a special port called MacPerl was shipped independently.[112]
The Comprehensive Perl Archive Network carries a complete list of supported platforms with links to the distributions available on each.[113] CPAN is also the source for publicly available Perl modules that are not part of the core Perl distribution.[citation needed]
ActivePerl is a closed-source distribution from
Performance
The Computer Language Benchmarks Game compares the performance of implementations of typical programming problems in several programming languages.[118] The submitted Perl implementations typically perform toward the high end of the memory-usage spectrum and give varied speed results. Perl's performance in the benchmarks game is typical for interpreted languages.[119]
Large Perl programs start more slowly than similar programs in compiled languages because Perl has to compile the source every time it runs. In a talk at the
A number of tools have been introduced to improve this situation. The first such tool was Apache's
Once Perl code is compiled, there is additional overhead during the execution phase that typically isn't present for programs written in compiled languages such as C or C++. Examples of such overhead include bytecode interpretation, reference-counting memory management, and dynamic type-checking.[124]
The most critical routines can be written in other languages (such as C), which can be connected to Perl via simple Inline modules or the more complex, but flexible, XS mechanism.[125]
Applications
Perl has many and varied applications, compounded by the availability of many standard and third-party modules.
Perl has chiefly been used to write
. It is also an optional component of the popular LAMP technology stack for Web development, in lieu of PHP or Python. Perl is used extensively as a system programming language in the Debian Linux distribution.[130]Perl is often used as a
Perl code can be made portable across Windows and Unix; such code is often used by suppliers of software (both commercial off-the-shelf (COTS) and bespoke) to simplify packaging and maintenance of software build- and deployment-scripts.[citation needed]
Perl's text-handling capabilities can be used for generating
perl
executable to using just one database interface at a time.[133]In Perl 5, database interfaces are implemented by Perl DBI modules. The DBI (Database Interface) module presents a single, database-independent interface to Perl applications, while the DBD (Database Driver) modules handle the details of accessing some 50 different databases; there are DBD drivers for most ANSI SQL databases.[134]
DBI provides caching for database handles and queries, which can greatly improve performance in long-lived execution environments such as mod_perl,[135] helping high-volume systems avert load spikes as in the Slashdot effect.[136]
In modern Perl applications, especially those written using
Community
Perl's culture and community has developed alongside the language itself. Usenet was the first public venue in which Perl was introduced, but over the course of its evolution, Perl's community was shaped by the growth of broadening Internet-based services including the introduction of the World Wide Web. The community that surrounds Perl was, in fact, the topic of Wall's first "State of the Onion" talk.[140]
State of the Onion is the name for Wall's yearly keynote-style summaries on the progress of Perl and its community. They are characterized by his hallmark humor, employing references to Perl's culture, the wider hacker culture, Wall's linguistic background, sometimes his family life, and occasionally even his Christian background.[141] Each talk is first given at various Perl conferences and is eventually also published online.
In email, Usenet, and message board postings, "Just another Perl hacker" (JAPH) programs are a common trend, originated by Randal L. Schwartz, one of the earliest professional Perl trainers.[142] In the parlance of Perl culture, Perl programmers are known as Perl hackers, and from this derives the practice of writing short programs to print out the phrase "Just another Perl hacker". In the spirit of the original concept, these programs are moderately obfuscated and short enough to fit into the signature of an email or Usenet message. The "canonical" JAPH as developed by Schwartz includes the comma at the end, although this is often omitted.[143]
Perl "golf" is the pastime of reducing the number of characters (key "strokes") used in a Perl program to the bare minimum, much in the same way that
As with C,
Perl poetry is the practice of writing poems that can be compiled as legal Perl code, for example the piece known as "Black Perl". Perl poetry is made possible by the large number of English words that are used in the Perl language. New poems are regularly submitted to the community at PerlMonks.[148]
See also
References
- ^ a b c Ashton, Elaine (1999). "The Timeline of Perl and its Culture (v3.0_0505)". Archived from the original on January 11, 2013. Retrieved March 12, 2004.
- ^ "Perl v5.40.0 is now available". www.nntp.perl.org. Retrieved June 11, 2024.
- ^ "Perl 5.34.3, Perl 5.36.3 and Perl 5.38.2 are now available". www.nntp.perl.org. Retrieved December 5, 2023.
- ^ "Release announcement for perl v5.41.3". www.nntp.perl.org. Retrieved August 29, 2024.
- ^ a b "The "Artistic License" - dev.perl.org". dev.perl.org. Archived from the original on July 24, 2018. Retrieved June 24, 2016.
- ^ a b Artistic Archived July 25, 2018, at the Wayback Machine - file on the Perl 5 git repository
- ^ a b "Perl Licensing". dev.perl.org. Archived from the original on January 22, 2011. Retrieved January 8, 2011.
- ^ Wall, Larry (December 12, 2007). "Programming is Hard, Let's Go Scripting..." Archived from the original on July 28, 2017. Retrieved April 14, 2019.
All language designers have their occasional idiosyncracies. I'm just better at it than most.
- ^ Lapworth, Leo. "General Questions About Perl". Perl FAQ. Perl.org. Archived from the original on May 28, 2013. Retrieved February 24, 2012.
- ^ "perl(1): Practical Extraction/Report Language - Linux man page". Linux.die.net. Archived from the original on June 3, 2013. Retrieved July 23, 2013.
- ^ ISSN 1059-1028. Retrieved February 14, 2023.
- ^ Sheppard, Doug (October 16, 2000). "Beginner's Introduction to Perl". dev.perl.org. Archived from the original on June 5, 2011. Retrieved January 8, 2011.
- ^ a b "Larry Wall, the Guru of Perl". Linux Journal. Retrieved August 30, 2023.
- ^ "About Perl". perl.org. Archived from the original on November 6, 2015. Retrieved April 20, 2013.
"Perl" is a family of languages, "Perl 6" is part of the family, but it is a separate language that has its own development team. Its existence has no significant impact on the continuing development of "Perl 5".
- ^ "Path to Raku". GitHub. Archived from the original on November 12, 2020. Retrieved January 14, 2021.
This document describes the steps to be taken to effectuate a rename of Perl 6 to Raku
- ^ ISBN 978-0-596-00027-1.
- ^ "How programs are measured". Computer Language Benchmarks Game, Debian.net. Archived from the original on July 12, 2020. Retrieved October 5, 2020.
- ^ "RSA in 3 lines of perl - Everything2.com". everything2.com. Archived from the original on October 8, 2020. Retrieved October 5, 2020.
- ^ "Language Evaluations". Archived from the original on March 10, 2015. Retrieved January 30, 2015.
Perl's strongest point is its extremely powerful built-in facilities for pattern-directed processing of textual, line-oriented data formats; it is unsurpassed at this.
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Further reading
- Learning Perl 6th Edition (2011), O'Reilly. Beginner-level introduction to Perl.
- Beginning Perl 1st Edition (2012), Wrox. A beginner's tutorial for those new to programming or just new to Perl.
- Modern Perl Archived December 22, 2011, at the Wayback Machine 2nd Edition (2012), Onyx Neon. Describes Modern Perl programming techniques.
- Programming Perl 4th Edition (2012), O'Reilly. The definitive Perl reference.
- Effective Perl Programming 2nd Edition (2010), Addison-Wesley. Intermediate- to advanced-level guide to writing idiomatic Perl.
- ISBN 0-596-00313-7. Practical Perl programming examples.
- Dominus, Mark Jason (2005). Higher Order Perl. Morgan Kaufmann. ISBN 978-1-55860-701-9. Functional programming techniques in Perl.