Perl experts advice live, Perl live experts, Perl online experts, Perl online help

In computer programming, Perl is a high-level, general-purpose, interpreted, dynamic programming language. Perl was originally developed by Larry Wall, a linguist working as a systems administrator for NASA, in 1987, as a general purpose Unix scripting language to make report processing easier. Since then, it has undergone many changes and revisions and became widely popular among programmers. Larry Wall continues to oversee development of the core language, and its newest version, Perl 6.

Perl borrows features from other programming languages including C, shell scripting , AWK, sed and Lisp. The language provides powerful text processing facilities without the arbitrary data length limits of many contemporary Unix tools, [4] making it the ideal language for manipulating text files. It is also used for graphics programming, system administration, network programming, applications that require database access and CGI programming on the Web. Perl is nicknamed "the Swiss Army chainsaw of programming languages" due to its flexibility and adapta

Features

The overall structure of Perl derives broadly from C. Perl is procedural in nature, with variables, expressions, assignment statements, brace-delimited code blocks, control structures, and subroutines. Perl also takes features from shell programming. All variables are marked with leading sigils, which unambiguously identify the data type of the variable in context. Importantly, sigils allow variables to be interpolated directly into strings. Perl has many built-in functions which provide tools often used in shell programming like sorting, and calling on system facilities. Perl takes lists from Lisp, associative arrays (hashes) from AWK, and regular expressions from sed. These simplify and facilitate many parsing, text handling, and data management tasks.

In Perl 5, features were added that support complex data structures, first-class functions, and an object-oriented programming model. These include references, packages, class-based method dispatch, and lexically scoped variables, along with compiler directives. A major additional feature introduced with Perl 5 was the ability to package code as reusable modules. Larry 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."

 All versions of Perl do automatic data typing and memory management. The interpreter knows the type and storage requirements of every data object in the program; it allocates and frees storage for them as necessary using reference counting. Legal type conversions—for example, conversions from number to string—are done automatically at run time; illegal type conversions are fatal errors

Perl experts advice live, Perl live experts, Perl online experts, Perl online help