Perl Study Notes

Building a Log Parser in Perl

A hands-on walkthrough of building a robust Perl log parser that reads, matches, aggregates, and reports on structured log data using core Perl idioms.

Closures in Perl

Understand how Perl closures capture lexical variables to create private state, counters, and callback generators using anonymous subroutines.

Conditionals in Perl

Learn how Perl evaluates truth and branches control flow using if, unless, elsif, and postfix conditional modifiers.

Context in Perl (Scalar vs List)

Learn how Perl's scalar and list context changes the meaning of operators and function calls, and how to control context explicitly.

Exception Handling in Perl

Learn how Perl handles errors through die/eval, the modern try/catch feature, and object-based exceptions using Try::Tiny or custom exception classes.

File I/O in Perl

Learn how to open, read, write, and safely close files in Perl using lexical filehandles, three-argument open, and proper error checking.

Hashes of Arrays and Nested Structures

Learn how to build and traverse complex nested data structures in Perl using references, including hashes of arrays, arrays of hashes, and hashes of hashes.

Installing and Running Perl

How to check for an existing Perl installation, install Perl on Windows, macOS, and Linux, and run your first scripts safely.

Loops in Perl

Master Perl's loop constructs — while, until, for, foreach — along with loop control statements like next, last, and redo.

Modern Perl Best Practices

A guide to writing clean, safe, and maintainable Perl using strict, warnings, modern object systems, and idiomatic patterns favored in current Perl codebases.

Object-Oriented Perl

Learn how Perl implements classes, objects, and inheritance using packages, blessed references, and the arrow operator, plus the modern Moose/Moo/class approac…

Packages and Namespaces

Understand how Perl's 'package' keyword partitions global symbol tables to avoid naming collisions and how namespaces underpin every module and class.

Perl and Databases (DBI)

Learn how Perl's DBI module provides a uniform interface for connecting to databases, running parameterized queries, and managing transactions safely.

Perl for System Administration

Use Perl's file, process, and text-processing tools to automate sysadmin tasks like file management, process control, and log analysis.

Perl Interview Questions

A curated set of commonly asked Perl interview questions covering context, references, object orientation, and idiomatic patterns, with explanations suitable f…

Perl Modules and CPAN

Learn how Perl organizes reusable code into modules and how CPAN gives you instant access to over 200,000 community-tested packages.

Perl One-Liners

Master Perl's command-line switches like -e, -n, -p, -a, and -i to write powerful text-processing one-liners without writing a script file.

Perl Operators

A tour of Perl's arithmetic, string, comparison, logical, and assignment operators, and the pitfalls of mixing numeric and string comparisons.

Perl Quick Reference

A condensed reference covering Perl's core syntax, data structures, regular expressions, and common idioms for fast lookup while coding.

Perl vs Python

A practical comparison of Perl and Python covering syntax philosophy, text processing, and ecosystem tooling to help you choose the right tool for a scripting…

References in Perl

Understand Perl references — pointers to scalars, arrays, hashes, and subs — and how to build complex, nested data structures.

Regular Expressions in Perl

Learn how Perl's built-in regex engine lets you match, capture, and substitute text patterns using operators like m//, s///, and tr///.

Scalars, Arrays, and Hashes

A guide to Perl's three core data types, how their sigils work, and the everyday operations for each one.

split, join, and map

Learn Perl's core list-transformation trio: split to break strings into lists, join to reassemble them, and map to transform every element.