JDT |
John Dixon |
Introduction to Perl |
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Perl is a programming language created by Larry Wall and was first released in 1987. Perl borrows features from a variety of other languages including C, shell scripting (sh), AWK, sed and Lisp. Structurally, Perl is based on the brace-delimited block style of AWK and C, and was widely adopted for its strengths in string processing, and lack of the arbitrary limitations of many scripting languages at the time. Sample Perl Script Here is the classic "Hello World" program written in Perl. #!/usr/bin/perl -w HistoryLarry Wall began work on Perl in 1987, while working as a programmer at Unisys, and released version 1.0 to the comp.sources.misc newsgroup on December 18, 1987. The language expanded rapidly over the next few years. Perl 2, released in 1988, featured a better regular expression engine. Perl 3, released in 1989, added support for binary data. Until 1991, the only documentation for Perl was a single (increasingly lengthy) man page. In 1991, Programming Perl (the Camel Book) was published, and became the de facto reference for the language. 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 documented by the book. Perl 4 went through a series of maintenance releases, culminating in Perl 4.036 in 1993. At that point, Larry Wall abandoned Perl 4 to begin work on Perl 5. Perl 4 remains at version 4.036 to this day. Development 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. Perl 5 was released on October 17, 1994. It was a nearly complete rewrite of the interpreter, and added many new features to the language, including objects, references, packages, 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. On October 26, 1995, the Comprehensive Perl Archive Network (CPAN) was established. The CPAN is a collection of web sites that archive and distribute Perl sources, binary distributions, documentation, scripts, and modules. As of June 2008, Perl is at version 5.10.0. NamePerl was originally named "Pearl", after the Parable of the Pearl. Larry Wall wanted to give the language a short name with positive connotations; he claims that he looked at (and rejected) every three- and four-letter word in the dictionary. He also considered naming it after his wife Gloria. Wall discovered the existing PEARL programming language before Perl's official release and changed the spelling of the name. The name is normally capitalized (Perl) when referring to the language and uncapitalized (perl) when referring to the interpreter program itself since Unix-like file systems are case sensitive. Before the release of the first edition of Programming Perl it was common to refer to the language as perl; Randal L. Schwartz, however, capitalised the language's name in the book to make it stand out better when typeset. The case distinction was subsequently adopted by the community. The name is occasionally given as "PERL" (for Practical Extraction and Report Language). Although the expansion has prevailed in many of today's manuals, including the official Perl man page, it is a backronym and officially the name stands for nothing. The spelling of PERL in all caps is therefore used as a shibboleth for detecting community outsiders. Several other backronyms have been suggested, including the humorous Pathologically Eclectic Rubbish Lister. The camel symbolPerl is generally symbolized by a camel, which was a result of the picture chosen by publisher O'Reilly Media for the cover of Programming Perl, which consequently acquired the name The Camel Book. O'Reilly owns the symbol as a trademark, but claims to use their legal rights only to protect the "integrity and impact of that symbol". O'Reilly allows non-commercial use of the symbol, and provides Programming Republic of Perl logos and Powered by Perl buttons. Article source: http://www.computernostalgia.net/articles/Perl.htm and http://en.wikipedia.org/wiki/PERL Go back to Programming and Web Development Articles home page
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