Image:Programming-republic-of-perl.gif|right|framed|Programming Republic of Perl logo]]Perl, also Practical Extraction and Report Language (a backronym, see below ), is a programming language released by Larry Wall on December 18, 1987 that borrows features from C, sed, awk, shell scripting ( sh), and (to a lesser extent) from many other programming languages.
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Perl was designed to be a practical language to extract information from text files and to generate reports from that information. One of its mottoes is "There's more than one way to do it" (TMTOWTDI - pronounced 'Tim Toady'). Another is Perl: the Swiss Army Chainsaw of Programming Languages. One stated design goal is to make easy tasks easy and difficult tasks possible. Its versatility permits versions of many programming paradigms: procedural, functional, and object-oriented (though some claim that Perl is not a cleanly designed language because of its multiple paradigms). Perl has a powerful regular expression engine built directly into its syntax. Perl is often considered the archetypal scripting language and has been called the "glue that holds the web together", as it is one of the most popular CGI languages. Its function as a "glue language" can be described broadly as its ability to tie together different systems and interfaces that were not designed to interoperate.
Perl is one of the programming language components of the popular LAMPNote: this article is about "LAMP" as an acronym; for the word lamp, see lighting. LAMP is an acronym for a set of free software programs commonly used together to run dynamic Web sites: L inux, the operating system; A pache, the Web server; M ySQL, the d free software platform for web development.
Perl is free softwareThe free-software movement began in 1983 when Richard Stallman announced the GNU project. The goal of the movement is to give freedom to computer users by replacing software which has restrictive licensing terms with free software ( free as in freedom)., available under a combination of the Artistic LicenseThe Artistic License is a software license used for certain free software packages, most notably the standard Perl implementation, most of CPAN modules and Parrot, which are dual-licensed under the Artistic License and the GNU General Public License. and the GPL. It is available for most operating systemsIn computing, an operating system OS is the system software responsible for the direct control and management of hardware and basic system operations, as well as running application software such as word processing programs and web browsers. In general, t but is particularly prevalent on UnixUNIX (or Unix is a portable, multi-task and multi-user computer operating system originally developed by a group of AT&T Bell Labs employees including Ken Thompson, Dennis Ritchie and Douglas McIlroy. Unices The term Unices includes Unix and Unix-like ope and Unix-likeA Unix-like operating system is one that behaves in a manner similar to the UNIX system, while not necessarily conforming to or being certified to any version of the Single UNIX Specification. The term is now most often used to refer to the Unix-like open systems (such as Linux and FreeBSD), and is growing in popularity on Microsoft Windows systems. As an example of Perl in action, Wikipedia itself was a CGI script written in Perl until January 2002. Another example is Slashdot, which runs on the Perl-based Slashcode software. When used on the web, Perl is often used in conjunction with the Apache web server and its mod_perl module.
Perl is regarded by both its proponents and detractors as something of a grab bag of features and syntax. The difference between the two camps lies in whether this is seen as a virtue or a vice. Perl votaries maintain that this varied heritage is what makes the language so useful. Reference is often made to natural languages such as English and to evolution. For example, Larry Wall has argued that:
- ... we often joke that a camel is a horse designed by a committee, but if you think about it, the camel is pretty well adapted for life in the desert. The camel has evolved to be relatively self-sufficient. On the other hand, the camel has not evolved to smell good. Neither has Perl.
In recognition of its ugly-but-useful nature, Perl has adopted the camel as its mascot; and the O'Reilly manual on Perl, Programming Perl, is known as the camel book: so named because of the camel that graces its cover.
