Perl 5 added features that support complex data structures, first-class functions (that is, closures as values), and an object-oriented programming model. Also shared with Lisp are the implicit return of the last value in a block, and the fact that all statements have a value, and thus are also expressions and can be used in larger expressions themselves. These simplify and facilitate many parsing, text-handling, and data-management tasks. Perl takes lists from Lisp, hashes (“associative arrays”) from AWK, and regular expressions from sed. Perl also has many built-in functions that provide tools often used in shell programming (although many of these tools are implemented by programs external to the shell) such as sorting, and calling operating system facilities. So for example, to access a list of values in a hash, the sigil for an array is used, not the sigil for a hash (“%”). However, unlike the shell, Perl uses sigils on all accesses to variables, and unlike most other programming languages that use sigils, the sigil doesn’t denote the type of the variable but the type of the expression. All variables are marked with leading sigils, which allow variables to be interpolated directly into strings. Perl also takes features from shell programming. Perl is procedural in nature, with variables, expressions, assignment statements, brace-delimited blocks, control structures, and subroutines.
The overall structure of Perl derives broadly from C. Its major features are that it’s easy to use, supports both procedural and object-oriented (OO) programming, has powerful built-in support for text processing, and has one of the world’s most impressive collections of third-party modules. The language is intended to be practical (easy to use, efficient, complete) rather than beautiful (tiny, elegant, minimal). Perl is a general-purpose programming language originally developed for text manipulation and now used for a wide range of tasks including system administration, web development, network programming, GUI development, and more. $ – requires given linux commands to be executed as a regular non-privileged user # – requires given linux commands to be executed with root privileges either directly as a root user or by use of sudo command Privileged access to your Linux system as root or via the sudo command.
PERL DOWNLOAD SOFTWARE
Requirements, Conventions or Software Version Used Software Requirements and Conventions Used Software Requirements and Linux Command Line Conventions Category
0 kommentar(er)
