Perl Tutorial

• Introduction to Perl
• Installation and Environment Setup
• Syntax of a Perl Program
• Hello World Program in Perl
• Perl vs C/C++
• Perl vs Java
• Perl vs Python

Fundamentals

• Modes of Writing a Perl Code
• Boolean Values
• Operators
• Variables
• Variables and its Types
• Scope of Variables
• Modules in Perl
• Packages in Perl
• Number and its Types
• Directories with CRUD operations

Input and Output

• Use of print() and say() in Perl
• Perl | print operator
• Use of STDIN for Input

Control Flow

• Decision Making
• Loops
• Perl given-when Statement
• Perl goto operator
• next operator
• redo operator
• last in loop

Arrays and Lists

• Arrays
• Array Slices
• Getting the Number of Elements of an Array
• Reverse an array
• Sorting of Arrays
• Useful Array functions
• Arrays (push, pop, shift, unshift)
• Implementing a Stack
• List and its Types
• List Functions

Hash

• Introduction to Hash
• Working of a Hash
• Hash Operations
• Sorting a Hash
• Multidimensional Hashes
• Hash in Scalar and List Context
• Useful Hash functions

Scalars

• Scalars
• Comparing Scalars
• scalar keyword

Strings

• Quoted, Interpolated and Escaped Strings
• Multi-line Strings | Here Document
• Sorting mixed Strings in Perl
• String Operators
• Useful String Operators
• String functions (length, lc, uc, index, rindex)
• Useful String functions
• Automatic String to Number Conversion or Casting
• Count the frequency of words in text
• Removing leading and trailing white spaces (trim)

Object Oriented Programming in Perl

• Introduction to OOPs
• Classes
• Objects
• Methods
• Constructors and Destructors
• Method Overriding
• Inheritance
• Polymorphism
• Encapsulation

Subroutines

• Subroutines or Functions
• Function Signature in Perl
• Passing Complex Parameters to a Subroutine
• Mutable and Immutable parameters
• Multiple Subroutines
• Use of return() Function
• References
• Pass By Reference
• Recursion in Perl

Regular Expressions

• Regular Expressions
• Operators in Regular Expression
• Regex Character Classes
• Special Character Classes in Regular Expressions
• Quantifiers in Regular Expression
• Backtracking in Regular Expression
• ‘e’ modifier in Regex
• ‘ee’ Modifier in Regex
• pos() function in Regex
• Regex Cheat Sheet
• Searching in a File using regex

File Handling

• File Handling Introduction
• Opening and Reading a File
• Writing to a File
• Appending to a File
• Reading a CSV File
• File Test Operators
• File Locking
• Use of Slurp Module
• Useful File-handling functions

Context Sensitivity

• Scalar Context Sensitivity
• List Context Sensitivity
• STDIN in Scalar and List Context

CGI Programming

• CGI Programming
• File Upload in CGI
• GET vs POST in CGI

Misc

• Breakpoints of a Debugger
• Exiting from a Script
• Creating Excel Files
• Reading Excel Files
• Number Guessing Game using Perl
• Database management using DBI
• Accessing a Directory using File Globbing
• Use of Hash bang or Shebang line
• Useful Math functions

Perl vs Java

Perl and Java are both powerful languages, but they have distinct characteristics, histories, and use cases. Here's a comparison between the two:

1. Origin and Design Philosophy:

• Perl: Created by Larry Wall in 1987, Perl was designed for text processing and later grew into a general-purpose programming language. Its motto, "There's more than one way to do it," reflects its flexible and expressive nature.

• Java: Developed by Sun Microsystems in the 1990s, Java was designed with the philosophy "Write Once, Run Anywhere" (WORA), emphasizing portability across platforms. Java introduced the concept of bytecode, which can be run on any machine with a Java Virtual Machine (JVM).

2. Use Cases:

• Perl:

  • Text processing and report generation.
  • System administration scripts.
  • Web development (CGI scripts, though this is old-fashioned now).
  • Bioinformatics.

• Java:

  • Web applications (Servlets, JSP, Spring).
  • Android app development.
  • Enterprise software (large-scale backend systems).
  • Embedded systems.

3. Performance:

• Perl: As an interpreted language, Perl might not be as fast as compiled languages, but it's suitable for its typical tasks like text processing.

• Java: Java code is compiled to bytecode, which is then interpreted or JIT-compiled by the JVM. This makes Java generally faster than traditional interpreted languages but typically slower than fully compiled languages like C++.

4. Syntax and Ease of Use:

• Perl: Known for its TMTOWTDI (There's More Than One Way To Do It) philosophy. While this offers flexibility, it can make Perl code harder to read for those unfamiliar with the language's idioms.

• Java: Java has a more rigid and structured syntax, emphasizing object-oriented programming. It can be verbose but is consistent and relatively easy to read.

5. Memory Management:

• Perl: Uses automatic garbage collection, with memory allocation and deallocation handled by the interpreter.

• Java: Features a robust garbage collector, but developers might still need to be cautious about object lifecycle to avoid memory leaks.

6. Portability:

• Perl: Scripts can be cross-platform, given that the appropriate Perl interpreter is installed on the machine.

• Java: Embodies the "Write Once, Run Anywhere" philosophy. A compiled Java program can run on any device with a JVM, making it highly portable.

7. Community and Libraries:

• Perl: Has CPAN (Comprehensive Perl Archive Network), a large repository of Perl modules and libraries.

• Java: Boasts a vast ecosystem, with the Java Standard Library and frameworks like Spring, Hibernate, and many others. The Maven Central Repository is a massive collection of Java libraries and modules.

8. Modern Development:

• Perl: Its popularity has decreased in recent years in favor of other scripting languages, though Perl 6 (renamed Raku) represents a significant evolution.

• Java: Continues to be widely used, especially in enterprise environments. Java has seen regular updates, with new features added to modernize the language and platform.

9. Tooling:

• Perl: Features tools like perlcritic for static code analysis and Devel::Cover for code coverage.

• Java: Offers a wealth of tooling, including sophisticated Integrated Development Environments (IDEs) like IntelliJ IDEA and Eclipse, build tools like Maven and Gradle, and profiling tools.

10. Concurrency:

• Perl: Supports multi-threading, but the model is not as advanced or integrated as Java's.

• Java: Has built-in support for multi-threading and concurrency, with a rich set of primitives and high-level utilities in the java.util.concurrent package.

Summary:

Perl and Java cater to different audiences and needs. While Perl is flexible and powerful, especially for text manipulation and scripting tasks, Java is a versatile language suitable for large-scale applications, web systems, and portable solutions. The choice between them depends on the specific requirements of a project.