Larry Wall

Creator of the Perl programming language

• Born: September 27, 1954
• Place of Birth: Los Angeles, California

Primary Company/Organization: Unisys

Introduction

Larry Wall created the scripting language Perl and, as of 2024, remained its "Benevolent Dictator for Life," overseeing its continued development.

Early Life

Larry Wall was born on September 27, 1954, in Los Angeles, California. He was the son of a pastor, and both his grandfathers were pastors as well. His family moved to Bremerton, Washington, on the Puget Sound, and he enrolled at Seattle Pacific University in 1976. He shifted majors from chemistry to music to a premedical program, and after taking some time off from school to work in the university's computer center, he earned his bachelor's degree with a self-designed major in natural and artificial languages. His intention when attending graduate school for linguistics at the University of California, Berkeley, was to find an unwritten language and create a writing system for it. Instead, he took a job with the Jet Propulsion Laboratory, part of the National Aeronautics and Space Administration, in Pasadena, California.

Life's Work

Wall later took a programming job at Unisys, where he created the Perl programming language. Unisys was formed in 1986 by the merger of two mainframe manufacturers, Sperry and Burroughs, both of which had been part of the creation of the COBOL programming language in 1960. The new name was formed from a contraction of United Information Systems. The merger made Unisys the second-largest computer company, with about 120,000 employees.

Wall began work on Perl in 1987 and released version 1.0 on December 18, 1987, distributing it through the comp.sources.misc Usenet newsgroup. Perl is a high-level general-pupose dynamic programming language, originally designed as a Unix scripting language. Like many computer terms, the name Perl was originally uncapitalized; when it was capitalized in the first edition of Programming Perl (1991), for the purposes of typesetting, the change was made permanent, and Perl has been capitalized since. (Perl is occasionally written as PERL in all caps, out of the mistaken belief that it is an acronym; "backronyms" such as Practical Extraction and Report Language have even been attributed to it and are sometimes used in literature about it, erroneously reported as the "full name" of the language.)

Programming Perl was the first published documentation for the language; prior to, that documentation had simply been stored at the main page. The book—called the Camel Book by the programming community because of the Camel symbol O'Reilly Media used on the cover and subsequently trademarked for Perl-related uses—covered Perl 4.0. This was substantially similar to Perl 3, released in 1989, but renumbered for association with the book.

Wall continued to develop Perl 4 through 1993, at which point he began to develop Perl 5. It is notable that Perl 5 remained the current version for decades, compared to the four versions released in the four years from 1987 to 1991. Perl 5.000, released on October 17, 1994, was a significantly overhauled version of the language, adding objects, modules, and a completely rewritten interpreter. Because modules allowed extensions of the language without needing to change the interpreter, Perl 5 remained in active development without the need for an overhaul. The Comprehensive Perl Archive Network was established a year later as a repository for modules for the Perl community. It remained active and an integral part of the Perl programming community, with nearly twenty-five thousand modules by 2012, representing the work of about ten thousand authors.

The 5.004 release in 1997 gave Perl more module functionality, including the CGI.pm module, which thenceforth drove Perl's popularity in CGI scripting, which is now one of its most popular uses. As of this release, Perl supported most popular operating systems, no longer just a Unix scripting language. The next major change was 64-bit support, added in Perl 5.6 in 2000. Perl 5.6 also changed the numbering scheme of Perl versions. Wall had in the interim become more deeply involved with and committed to the open source movement, which had developed considerably in the 1990s, and Perl's versioning scheme adopted the scheme in common use through the movement. After 2002, Perl 5 was updated roughly yearly. Perl 5.16 added the ability to emulate older versions of Perl so that older scripts could be run without needing to be rewritten.

Work on Perl 6 actually began in 2000, when Wall asked for suggestions for the new versions. Almost 400 documents in response to this requests for comment (or RFC) formed the first stage of Perl 6 development. Wall spent years preparing a design for Perl 6, and has presented it in a series of what he calls "apocalypses," documents that present Perl 6 specification. Originally intended only to remove the "warts" from Perl, Perl 6 eventually turned into a language distinct from Perl 5, without backward compatibility. The first stable version appeared in late 2015. In 2019 Perl 6 was renamed Raku, and Perl 5 continued as the current release (reaching version 5.30.0 that same year).

Today, Perl is used for CGI, system administration, finance, network programming, and graphics programming, but it is flexible enough to be used in most scripting language applications. It is one of the most commonly used languages on the internet. In some ways it is the opposite of Python, another common scripting language on the web; whereas Python is small and elegant, written by a programmer who had no concerns for practical uses, Perl is inelegant but easy to use and highly practical. Wall often referred to the motto, "Easy things should be easy and hard things should be possible." Perl is influenced by Wall's education as a linguist, which sometimes affects the terminology; he refers to verbs and nouns instead of variables and functions, for instance. Perl's grammar is Turing-complete, meaning that it can simulate any other general-purpose language.

Perl is also associated with the onion logo, owned by the Perl Foundation, a pun on "pearl onion." Wall's annual addresses on Perl matters are called "State of the Onion" addresses.

In addition to his Perl work, Wall wrote the rn Usenet client in 1984 for Unix systems. Even apart from its superiority to most other newsreaders, rn is notable for introducing the KILL file: a user-edited file containing any regular expression, which would mark as read any news article containing that expression. The KILL file thus allowed the user to avoid reading posts on certain specified topics or by certain specified users. The term killfiling has become a synonym in the internet community for blocking a topic or user, whether in newsgroups, in logged-in message boards, in chat rooms, on instant-messenging programs, or in e-mail—it is a key element of the internet's social sphere, and the combination of kill and search forms the main difference between social interaction online and offline.

Wall also wrote the patch program for Unix, which accesses a user-edited text file called the patch file and follows the instructions in that file in order to update other text files. It was released in 1985, and although usable with any text file, it became associated with programmers' need frequently to update, or patch, source code files to newer versions.

Personal Life

Wall and his wife Gloria, a linguist, attended graduate school together. The couple had four children together. Well known for his sense of humor, Wall has been considered one of the best-liked prominent figures in the computer industry.

A devout Christian, Wall often discussed his membership in the New Life Nazarene Church. The terminology he used in his work has at times been influenced by his Christianity; the name Perl is a reference to the "pearl of great price" of the Gospel of Matthew (there was already a language called PEARL, prompting Wall to change the spelling just before release), and Perl includes a function called "bless." Wall was known to speak frankly about his beliefs at conferences.

Bibliography

Burks, Alice Rowe. Who Invented the Computer? New York: Prometheus, 2003. Print.

DiBona, Chris, Sam Ockman, and Mark Stone. Open Source: Voices from the Revolution. Sebastopol: O'Reilly, 1999. Print.

"Larry Wall." Big Think, 2024, bigthink.com/people/larrywall/. Accessed 7 Mar. 2024.

Wall, Larry, Tom Christiansen, and Jon Orwant. Programming Perl. Sebastopol: O'Reilly, 2000. Print.